Document:

[  *  ] = Certain confidential information contained in this document, marked by
brackets, has been omitted and filed separately with the Securities and Exchange
Commission  pursuant  to  Rule  24b-2 of the Securities Exchange Act of 1934, as
amended.

                                                                   Exhibit 10.37

                   STOCK PURCHASE AND STOCK ISSUANCE AGREEMENT

                                     BETWEEN

                         SMITHKLINE BEECHAM CORPORATION
                                       AND

                                 EXELIXIS, INC.

                                   DATED AS OF
                                OCTOBER 28, 2002

<PAGE>
                                  TABLE OF CONTENTS

                                                                     PAGE
ARTICLE I
DEFINITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   1
     Affiliate. . . . . . . . . . . . . . . . . . . . . . . . . . . .   2
     Change of Control. . . . . . . . . . . . . . . . . . . . . . . .   2
     Closing. . . . . . . . . . . . . . . . . . . . . . . . . . . . .   2
     Common Stock . . . . . . . . . . . . . . . . . . . . . . . . . .   2
     Deferral Notice. . . . . . . . . . . . . . . . . . . . . . . . .   2
     Deferral Period. . . . . . . . . . . . . . . . . . . . . . . . .   2
     Development Term . . . . . . . . . . . . . . . . . . . . . . . .   2
     DWAC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   2
     Effective Date . . . . . . . . . . . . . . . . . . . . . . . . .   2
     Exchange Act . . . . . . . . . . . . . . . . . . . . . . . . . .   2
     Exercise Notice. . . . . . . . . . . . . . . . . . . . . . . . .   2
     Expanded Program Option. . . . . . . . . . . . . . . . . . . . .   2
     Expanded Program Option Shares . . . . . . . . . . . . . . . . .   2
     Extension Period . . . . . . . . . . . . . . . . . . . . . . . .   2
     Fair Market Value. . . . . . . . . . . . . . . . . . . . . . . .   3
     Financial Statements . . . . . . . . . . . . . . . . . . . . . .   3
     Form 10-K. . . . . . . . . . . . . . . . . . . . . . . . . . . .   3
     Form 10-Q. . . . . . . . . . . . . . . . . . . . . . . . . . . .   3
     Governmental Authority . . . . . . . . . . . . . . . . . . . . .   3
     HSR Act. . . . . . . . . . . . . . . . . . . . . . . . . . . . .   3
     Initial Closing. . . . . . . . . . . . . . . . . . . . . . . . .   3
     Initial Shares . . . . . . . . . . . . . . . . . . . . . . . . .   3
     Intellectual Property. . . . . . . . . . . . . . . . . . . . . .   3
     Legal Proceeding . . . . . . . . . . . . . . . . . . . . . . . .   3
     Limited Program Option . . . . . . . . . . . . . . . . . . . . .   3
     Limited Program Option Shares. . . . . . . . . . . . . . . . . .   3
     Limited Release Date . . . . . . . . . . . . . . . . . . . . . .   3
     Loan Documents . . . . . . . . . . . . . . . . . . . . . . . . .   3
     Material Adverse Effect. . . . . . . . . . . . . . . . . . . . .   3
     Material Agreement . . . . . . . . . . . . . . . . . . . . . . .   4
     Material Breach. . . . . . . . . . . . . . . . . . . . . . . . .   4
     Material Event . . . . . . . . . . . . . . . . . . . . . . . . .   4
     National Securities Market . . . . . . . . . . . . . . . . . . .   4
     OfficerCertificate . . . . . . . . . . . . . . . . . . . . . . .   4
     Operating Documents. . . . . . . . . . . . . . . . . . . . . . .   4
     Option . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   4
     Option Closing Date. . . . . . . . . . . . . . . . . . . . . . .   4
     Option Exercise Date . . . . . . . . . . . . . . . . . . . . . .   4
     Option Shares. . . . . . . . . . . . . . . . . . . . . . . . . .   4
     Permitted Transferee . . . . . . . . . . . . . . . . . . . . . .   4
     Person . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   4
     Registrable Shares . . . . . . . . . . . . . . . . . . . . . . .   4
     Registration Expenses. . . . . . . . . . . . . . . . . . . . . .   4
     Registration Statement . . . . . . . . . . . . . . . . . . . . .   4
     Registration Trigger Date. . . . . . . . . . . . . . . . . . . .   4
     Restricted Period. . . . . . . . . . . . . . . . . . . . . . . .   4
     Rule 144 . . . . . . . . . . . . . . . . . . . . . . . . . . . .   4
     SEC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   4
     SEC Affiliate. . . . . . . . . . . . . . . . . . . . . . . . . .   4
     SEC Filings. . . . . . . . . . . . . . . . . . . . . . . . . . .   4
     Securities Act . . . . . . . . . . . . . . . . . . . . . . . . .   5
     Selling Expenses . . . . . . . . . . . . . . . . . . . . . . . .   5
     Shares . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   5
     Standstill Period. . . . . . . . . . . . . . . . . . . . . . . .   5
     Stock Repayment. . . . . . . . . . . . . . . . . . . . . . . . .   5
     Stock Repayment Amount . . . . . . . . . . . . . . . . . . . . .   5
     Stock Repayment Closing Date . . . . . . . . . . . . . . . . . .   5
     Stock Repayment Notice . . . . . . . . . . . . . . . . . . . . .   5
     Stock Repayment Shares . . . . . . . . . . . . . . . . . . . . .   5
     Transaction Documents. . . . . . . . . . . . . . . . . . . . . .   5
     Third Party. . . . . . . . . . . . . . . . . . . . . . . . . . .   5
     Trading Day. . . . . . . . . . . . . . . . . . . . . . . . . . .   5
     United States or U.S.. . . . . . . . . . . . . . . . . . . . . .   5
ARTICLE 2
AUTHORIZATION AND ISSUANCE OF THE SHARES. . . . . . . . . . . . . . .   5
     Authorization. . . . . . . . . . . . . . . . . . . . . . . . . .   5
     Issuance and Sale of the Initial Shares. . . . . . . . . . . . .   5
     Issuance, Sale, Pricing and Conditions of the Option Shares. . .   5
       The Expanded Program Option. . . . . . . . . . . . . . . . . .   6
       The Limited Program Option . . . . . . . . . . . . . . . . . .   6
     Issuance of the Stock Repayment Shares . . . . . . . . . . . . .   6
     Conditional Limitation on Ownership. . . . . . . . . . . . . . .   7
ARTICLE 3
CLOSING; DELIVERY; NOTICE . . . . . . . . . . . . . . . . . . . . . .   7
     Initial Closing. . . . . . . . . . . . . . . . . . . . . . . . .   7
     Payment and Delivery of the Initial Shares . . . . . . . . . . .   7
       Payment. . . . . . . . . . . . . . . . . . . . . . . . . . . .   7
       Delivery . . . . . . . . . . . . . . . . . . . . . . . . . . .   7
     Payment and Delivery of the Option Shares. . . . . . . . . . . .   8
       Notice . . . . . . . . . . . . . . . . . . . . . . . . . . . .   8
       Payment. . . . . . . . . . . . . . . . . . . . . . . . . . . .   8
       Delivery . . . . . . . . . . . . . . . . . . . . . . . . . . .   8
     The Stock Repayment Shares . . . . . . . . . . . . . . . . . . .   8
       Notice . . . . . . . . . . . . . . . . . . . . . . . . . . . .   8
       Stock Repayment Closings . . . . . . . . . . . . . . . . . . .   8
     Delivery; Satisfaction of Obligation . . . . . . . . . . . . . .   8
     Location . . . . . . . . . . . . . . . . . . . . . . . . . . . .   9
ARTICLE 4
REPRESENTATIONS AND WARRANTIES OF EXELIXIS. . . . . . . . . . . . . .   9
     Organization, Good Standings and Qualification.  Exelixis. . . .   9
     Authorization; Due Execution . . . . . . . . . . . . . . . . . .   9
     Capital Stock. . . . . . . . . . . . . . . . . . . . . . . . . .  10
     Validity of Shares . . . . . . . . . . . . . . . . . . . . . . .  10
     SEC Filings; Financial Statements. . . . . . . . . . . . . . . .  10
       SEC Filings. . . . . . . . . . . . . . . . . . . . . . . . . .  10
       Financial Statements . . . . . . . . . . . . . . . . . . . . .  11
       No Material Adverse Effect . . . . . . . . . . . . . . . . . .  11
     Litigation . . . . . . . . . . . . . . . . . . . . . . . . . . .  11
     Governmental Consents. . . . . . . . . . . . . . . . . . . . . .  11
     Compliance with Applicable Laws and Other Instruments. . . . . .  12
     Compliance with Environmental Laws . . . . . . . . . . . . . . .  12
     Taxes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  12
     Insurance. . . . . . . . . . . . . . . . . . . . . . . . . . . .  12
     Properties . . . . . . . . . . . . . . . . . . . . . . . . . . .  12
     Intellectual Property. . . . . . . . . . . . . . . . . . . . . .  13
     Effect of Representations and Warranties . . . . . . . . . . . .  13
ARTICLE 5
REPRESENTATIONS AND WARRANTIES OF GSK; RESTRICTIONS ON TRANSFER OF
THE SHARES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  13
     Representations and Warranties . . . . . . . . . . . . . . . . .  13
       Corporate Organization and Authority . . . . . . . . . . . . .  13
       Authorization; Due Execution . . . . . . . . . . . . . . . . .  13
       Investment Only. . . . . . . . . . . . . . . . . . . . . . . .  14
       Experience . . . . . . . . . . . . . . . . . . . . . . . . . .  14
       Accredited Purchaser . . . . . . . . . . . . . . . . . . . . .  14
     No Registration. . . . . . . . . . . . . . . . . . . . . . . . .  14
     Limitations on Transfer. . . . . . . . . . . . . . . . . . . . .  14
     Legend . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  14
ARTICLE 6
CONDITIONS TO CLOSING . . . . . . . . . . . . . . . . . . . . . . . .  15
     Conditions to Obligations of GSK to Consummate each Closing. . .  15
     Conditions to Obligations of Exelixis to Consummate each Closing  17
ARTICLE 7
ADDITIONAL AGREEMENTS; LOCK UP; STANDSTILL. . . . . . . . . . . . . .  17
     Registration of Shares . . . . . . . . . . . . . . . . . . . . .  17
       Registration Requirements. . . . . . . . . . . . . . . . . . .  17
       Incidental Registration. . . . . . . . . . . . . . . . . . . .  18
       Registration Expenses. . . . . . . . . . . . . . . . . . . . .  19
       Registration Suspension. . . . . . . . . . . . . . . . . . . .  19
       Registration Procedures. . . . . . . . . . . . . . . . . . . .  20
       Indemnification. . . . . . . . . . . . . . . . . . . . . . . .  20
     Filings. . . . . . . . . . . . . . . . . . . . . . . . . . . . .  22
     Other Actions. . . . . . . . . . . . . . . . . . . . . . . . . .  22
     Lock Up and Selling Restrictions . . . . . . . . . . . . . . . .  22
     Standstill . . . . . . . . . . . . . . . . . . . . . . . . . . .  23
     Conditions Eliminating Standstill. . . . . . . . . . . . . . . .  24
     Conditions Eliminating Lock Up . . . . . . . . . . . . . . . . .  24
     Use of Proceeds. . . . . . . . . . . . . . . . . . . . . . . . .  25
     Exelixis Repurchase Option . . . . . . . . . . . . . . . . . . .  25
ARTICLE 8
MISCELLANEOUS . . . . . . . . . . . . . . . . . . . . . . . . . . . .  26
     Publicity. . . . . . . . . . . . . . . . . . . . . . . . . . . .  26
     Dispute Resolution . . . . . . . . . . . . . . . . . . . . . . .  26
     Governing Law. . . . . . . . . . . . . . . . . . . . . . . . . .  26
     Assignment . . . . . . . . . . . . . . . . . . . . . . . . . . .  26
     Performance Warranty . . . . . . . . . . . . . . . . . . . . . .  26
     Notices. . . . . . . . . . . . . . . . . . . . . . . . . . . . .  26
     Force Majeure. . . . . . . . . . . . . . . . . . . . . . . . . .  28
     Waiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  28
     Severability . . . . . . . . . . . . . . . . . . . . . . . . . .  28
     Entire Agreement . . . . . . . . . . . . . . . . . . . . . . . .  28
     Headings . . . . . . . . . . . . . . . . . . . . . . . . . . . .  29
     Use of Name. . . . . . . . . . . . . . . . . . . . . . . . . . .  29
     Further Actions. . . . . . . . . . . . . . . . . . . . . . . . .  29
     Survival of Representations and Warranties . . . . . . . . . . .  29
     Parties in Interest. . . . . . . . . . . . . . . . . . . . . . .  29
     Construction of Agreement. . . . . . . . . . . . . . . . . . . .  29
     Counterparts . . . . . . . . . . . . . . . . . . . . . . . . . .  29
     FinderFees . . . . . . . . . . . . . . . . . . . . . . . . . . .  29
     Waiver of Jury Trial . . . . . . . . . . . . . . . . . . . . . .  30

<PAGE>

                                LIST OF SCHEDULES

     SCHEDULE  4.3     SCHEDULE  OF  OUTSTANDING  SECURITIES

     SCHEDULE  4.6     DISCLOSURE  OF  OUTSTANDING  LITIGATION

[  *  ] = Certain confidential information contained in this document, marked by
brackets, has been omitted and filed separately with the Securities and Exchange
Commission  pursuant  to  Rule  24b-2 of the Securities Exchange Act of 1934, as
amended.
<PAGE>

                   STOCK PURCHASE AND STOCK ISSUANCE AGREEMENT

THIS  STOCK  PURCHASE  AND  STOCK  ISSUANCE  AGREEMENT  (the  "Stock  Purchase
Agreement")  is  made  and  entered  into as of October 28, 2002 (the "Effective
Date")  by  and  between  EXELIXIS,  INC.,  a  Delaware  corporation, having its
principal  place  of  business  at  170  Harbor  Way,  P.O.  Box  511, South San
Francisco,  California 94083 ("Exelixis"), and SMITHKLINE BEECHAM CORPORATION, a
Pennsylvania corporation doing business as GlaxoSmithKline ("GSK"). Exelixis and
GSK  are sometimes referred to herein individually as a "Party" and collectively
as  the  "Parties."

                                    RECITALS

     A.  Exelixis  and  GSK  have  entered into that certain Product Development
and  Commercialization  Agreement  of  even  date  herewith  (the  "Development
Agreement") and the Loan and Security Agreement of even date herewith (the "Loan
Agreement")  (this  Stock  Purchase  Agreement,  Development  Agreement and Loan
Agreement,  are  collectively referred to herein as the "Transaction Documents")
and,  in  connection  with,  and as a condition of entering into the Development
Agreement,  the  Parties  desire  to  enter  into  this Stock Purchase Agreement
providing  for  the  purchase  of  capital  stock  of  Exelixis  by  GSK.

     B.  Exelixis  desires  to  sell  to GSK, and GSK desires to make an initial
purchase  from Exelixis of Two Million (2,000,000) shares (the "Initial Shares")
of Exelixis' common stock, par value $0.001 per share (the "Common Stock"), upon
the  Initial  Closing  (as  defined  in  Section  3.1).

     C.  Exelixis  and  GSK  desire to provide for the possibility of additional
     purchases  by GSK of up to [*] shares of Common Stock, at Exelixis' option,
     in  accordance  with  the terms and conditions set forth herein, subject to
     the  reduction  of  the  number  of  shares  as  provided  in  Section 2.2.

     D. Exelixis and GSK desire to provide for the issuance of additional shares
of  Common  Stock  that  may  be  issued, at Exelixis' option, such option to be
dependent on terms and conditions contained in the Loan Agreement and this Stock
Purchase  Agreement, in repayment of any outstanding loan amounts under the Loan
Agreement  (the  "Stock  Repayment  Shares").

     NOW,  THEREFORE,  in consideration of the foregoing recitals and the mutual
covenants  and  agreements  contained  herein,  and  for other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged, the
Parties  hereto,  intending  to  be  legally  bound, do hereby agree as follows:

                                    ARTICLE I
                                   DEFINITIONS

     Unless  otherwise defined in this Stock Purchase Agreement, all capitalized
terms  shall  have  the  meanings given them in the Development Agreement or the
Loan  Agreement.  As  used in this Stock Purchase Agreement, the following terms
shall  have  the  following  respective  meanings:

     1.1  "Affiliate"  shall  mean  any  Person,  whether  de  jure or de facto,
which directly or indirectly through one (1) or more intermediaries controls, is
controlled  by  or  is under common control with, a Party to this Stock Purchase
Agreement.  A Person shall be deemed to "control" another Person if it (i) owns,
directly or indirectly, beneficially or legally, at least fifty percent (50%) of
the  outstanding  voting  securities or capital stock (or such lesser percentage
which  is  the  maximum  allowed  to  be  owned  by  a  Person  in  a particular
jurisdiction)  of  such other Person, or has other comparable ownership interest
with  respect  to  any  Person  other than a corporation; or (ii) has the power,
whether  pursuant  to  contract, ownership of securities or otherwise, to direct
the  management  and  policies  of  the  Person.

     1.2  "Change  of  Control"  shall mean a transaction in which [ * ].

     1.3  "Closing"  shall  have  the  meaning  set  forth  in  Section  3.4.2.

     1.4  "Common  Stock"  shall  have  the  meaning  set  forth  in  Recital B.

     1.5  "Deferral Notice" shall have the meaning set forth in Section 7.1.4(b)

     1.6  "Deferral Period" shall have the meaning set forth in Section 7.1.4(b)

     1.7 "Development Term" shall have the meaning set forth in Section 3.1.1 of
the  Development  Agreement,  as  it  may  be  amended  from  time  to  time.

     1.8  "DWAC"  shall  have  the  meaning  set  forth  in  Section  3.4.3.

     1.9  "Effective  Date" shall have the meaning set forth in the introductory
paragraph.

     1.10  "Exchange  Act" means the Securities Exchange Act of 1934, as amended
from  time  to  time,  and  the  rules  and  regulations promulgated thereunder.

     1.11  "Exercise  Notice"  shall  have  the  meaning  set  forth  in Section
3.3.1.

     1.12  "Expanded Program Option" shall have the meaning set forth in Section
2.3.1.

     1.13  "Expanded  Program Option Shares" shall have the meaning set forth in
Section  2.3.1.

     1.14  "Extension  Period" shall have the meaning set forth in Section 3.1.2
of  the  Development  Agreement,  as  it  may  be  amended  from  time  to time.

     1.15  "Fair  Market Value" shall have the meaning set forth in Section 2.4.

     1.16  "Financial  Statements"  shall  have the meaning set forth in Section
4.5.2.

     1.17 "Form 10-K" shall mean an annual report filed by Exelixis with the SEC
pursuant  to  Section  13  or  15(d)  of  the  Exchange  Act.

     1.18  "Form  10-Q" shall mean a quarterly report filed by Exelixis with the
SEC  pursuant  to  Section  13  or  15(d)  of  the  Exchange  Act.

     1.19  "Governmental Authority" means any nation or government, any state or
other  political  subdivision  thereof, any central bank (or similar monetary or
regulatory  authority)  thereof,  any  entity exercising executive, legislative,
judicial, regulatory or administrative functions of or pertaining to government,
and  any  corporation  or  other  entity  owned  or controlled, through stock or
capital  ownership  or  otherwise,  by  any  of  the  foregoing.

     1.20  "HSR  Act"  means the Hart-Scott-Rodino Antitrust Improvements Act of
1976,  as  amended.

     1.21.  "Initial  Closing"  shall have the meaning set forth in Section 3.1.

     1.22  "Initial  Shares"  shall  have  the  meaning  set forth in Recital B.

     1.23  "Intellectual  Property" shall have the meaning set forth in the Loan
Agreement.

     1.24  "Legal  Proceeding"  shall  mean  any  action,  suit,  litigation,
arbitration,  proceeding  (including  any  civil,  criminal,  administrative,
governmental  or  appellate proceeding), hearing, inquiry, audit, examination or
investigation  commenced, brought, conducted or heard by or before, or otherwise
involving,  any  court  or  other  Governmental  Authority  or any arbitrator or
arbitration  panel.

     1.25  "Limited  Program Option" shall have the meaning set forth in Section
2.3.2.

     1.26  "Limited  Program  Option Shares" shall have the meaning set forth in
Section  2.3.2.

     1.27  "Limited  Release  Date"  shall have the meaning set forth in Section
7.4.2.

     1.28  "Loan  Documents" shall have the meaning set forth in Section 1.45 of
the  Loan  Agreement.

     1.29  "Material Adverse Effect" shall mean any material adverse effect upon
(a)  the  validity  or enforceability of this Stock Purchase Agreement or any of
the  transactions  contemplated  by  this  Stock  Purchase Agreement, (b) on the
business,  operations,  condition  (financial  or  otherwise),  performance  or
properties  of Exelixis taken as a whole, or (c) upon the ability of Exelixis to
fulfill  any  of  its  obligations  under  this  Stock  Purchase  Agreement.

     1.30  "Material  Agreement"  shall  mean  any  agreement  which is filed by
Exelixis  as  part  of  its  SEC  Filings.

     1.31  "Material  Breach" shall have the meaning set forth in Section 12.2.1
of  the  Development  Agreement.

     1.32  "Material  Event"  shall have the meaning set forth in Section 7.1.4.

     1.33  "National  Securities  Market"  shall mean the Nasdaq National Market
System,  The  Nasdaq  SmallCap  Market  and any other national public securities
exchange.

     1.34  "Officer's  Certificate"  shall have the meaning set forth in Section
6.1.2.

     1.35  "Operating  Documents"  shall  mean  Exelixis'  amended  and restated
certificate  of  incorporation, as filed with the State of Delaware, amended and
restated  bylaws,  and  all  modifications  and  amendments  thereto.

     1.36  "Option"  shall  have  the  meaning  set  forth  in  Section  2.3.

     1.37  "Option  Closing  Date"  shall  have the meaning set forth in Section
3.3.2.

     1.38  "Option  Exercise  Date"  shall have the meaning set forth in Section
3.3.1.

     1.39  "Option  Shares"  shall  have the meaning set forth in Section 2.3.2.

     1.40  "Permitted  Transferee"  shall  have the meaning set forth in Section
7.4.3.

     1.41  "Person"  means  an  individual,  corporation,  partnership,  limited
liability  company,  joint  venture,  association,  trust,  unincorporated
organization  or  other  entity.

     1.42  "Registrable  Shares"  shall  have  the  meaning set forth in Section
7.1.1(a).

     1.43  "Registration  Expenses"  shall have the meaning set forth in Section
7.1.3.

     1.44  "Resale  Registration  Statement" shall have the meaning set forth in
Section  7.1.1(a).

     1.45  "Registration  Trigger  Date"  shall  have  the  meaning set forth in
Section  7.1.1(a).

     1.46 "Restricted Period" shall have the meaning set forth in Section 7.4.1.

     1.47  "Rule  144"  shall  have  the  meaning  set  forth  in  Section  5.3.

     1.48  "SEC"  means  the  United  States Securities and Exchange Commission.

     1.49  "SEC  Affiliate"  shall  have  the  meaning  ascribed  to  the  term
"affiliate"  under  Rule  144  of  the  Securities  Act.

     1.50  "SEC  Filings"  shall  have  the  meaning set forth in Section 4.5.1.

     1.51  "Securities  Act"  means  the Securities Act of 1933, as amended from
time  to  time,  and  the  rules  and  regulations  promulgated  thereunder.

     1.52  "Selling Expenses" shall have the meaning set forth in Section 7.1.3.

     1.53  "Shares"  shall  have  the  meaning  set  forth  in  Section  2.1.

     1.54  "Standstill  Period" shall have the meaning set forth in Section 7.5.

     1.55  "Stock  Repayment"  shall  have the meaning set forth in Section 2.4.

     1.56  "Stock  Repayment Amount" shall have the meaning set forth in Section
2.4.

     1.57  "Stock  Repayment  Closing  Date" shall have the meaning set forth in
Section  3.4.2.

     1.58  "Stock  Repayment Notice" shall have the meaning set forth in Section
3.4.1.

     1.59 "Stock Repayment Shares" shall have the meaning set forth in Recital D

     1.60 "Transaction Documents" shall have the meaning set forth in Recital A.

     1.61  "Third  Party"  shall  mean any Person other than GSK or Exelixis and
their  respective  Affiliates.

     1.62  "Trading  Day" means a day on which the principal National Securities
Market  on which Exelixis Common Stock is trading or listed is open for trading.

     1.63  "United  States"  or  "U.S." shall mean the United States of America.

                                    ARTICLE 2
                    AUTHORIZATION AND ISSUANCE OF THE SHARES

     2.1  Authorization.  Exelixis  has,  or  shall  have  prior  to  the
applicable issuance, authorized the issuance and sale of the Initial Shares, the
Option  Shares  and  the  Stock  Repayment  Shares  (collectively, the "Shares")
pursuant  to  the  terms  and  conditions  hereof.

     2.2  Issuance  and  Sale  of  the  Initial Shares. Subject to the terms and
conditions of this Stock Purchase Agreement, on the date of the Initial Closing,
Exelixis  shall issue and sell to GSK, and GSK shall purchase from Exelixis, the
Initial Shares, at a purchase price per share equal to Seven Dollars ($7.00) per
share, or a total purchase price of Fourteen Million Dollars ($14,000,000.00) in
the  aggregate.

     2.3  Issuance,  Sale,  Pricing  and  Conditions  of  the  Option  Shares.
Subject  to  the  terms  and  conditions  set  forth  in this Section 2.3 and in
Sections  2.5  and  3.3  hereof, Exelixis, in its sole discretion, shall have an
option  to  issue  and  sell to GSK (the "Option"), and upon the exercise of the
Option  by  Exelixis,  GSK  shall  be  obligated  to purchase from Exelixis, the
Expanded  Program Option Shares or the Limited Program Option Shares as follows.

          2.3.1 The Expanded Program Option. Subject to the terms and conditions
hereof  and  Section  2.3.2  below,  if  GSK selects its Expanded Program Option
pursuant  to  Section 3.5.1(b) of the Development Agreement, Exelixis shall have
the  Option  to require GSK to purchase from Exelixis up to [*] shares of Common
Stock  (the  "Expanded  Program  Option  Shares"), at a purchase price per share
equal  to  [*]  of  the average of the opening and closing sale prices of Common
Stock  as  reported  by the National Securities Market on which the Common Stock
trades or is listed for the first twenty (20) consecutive Trading Days following
the date which is two (2) Trading Days after Exelixis' filing of its most recent
Form  10-Q or Form 10-K; provided, however, that in the event that the per share
price of the Expanded Program Option Shares would result in an aggregate payment
by  GSK  of  greater than [*], then the number of Expanded Program Option Shares
shall  be  reduced  to the nearest such number of whole shares and payment shall
approach  as  closely  as possible, but not exceed, [*]. Exelixis shall exercise
its  option to require GSK to purchase the Expanded Program Option Shares, if at
all, not later than thirty (30) Trading Days after the date that GSK selects the
Expanded  Program Option, by notifying GSK of the number of shares it wishes GSK
to  purchase.  The purchase of the Expanded Program Option Shares shall close on
the  date  which  is  fifteen  (15) Trading Days after the date of such Exercise
Notice.

          2.3.2 The Limited Program Option. Notwithstanding Section 2.3.1 above,
if GSK selects or is deemed to have selected the Limited Program Option pursuant
to Section 3.5.1(a) of the Development Agreement, Exelixis shall have the Option
to  require  GSK to purchase from Exelixis up to [*] shares of Common Stock (the
"Limited  Program  Option  Shares"),  (the Expanded Program Option Shares or the
Limited  Program  Option  Shares,  each  sometimes  referred  to  as the "Option
Shares"),  instead of the Expanded Program Option Shares at a purchase price per
share  equal  to  [*]  of  the average of the opening and closing sale prices of
Common  Stock  as reported by the National Securities Market on which the Common
Stock  trades  or  is  listed for the first twenty (20) consecutive Trading Days
following  the  date which is two (2) Trading Days after Exelixis' filing of its
most  recent  Form  10-Q or Form 10-K; provided, however, that in the event that
the  per  share  price  of  the Limited Program Option Shares would result in an
aggregate payment by GSK of greater than [*], then the number of Limited Program
Option  Shares  shall  be reduced to the nearest such number of whole shares and
payment  shall  approach  as  closely as possible, but not exceed, [*]. Exelixis
shall  exercise its option to require GSK to purchase the Limited Program Option
Shares,  if  at  all, not later than thirty (30) Trading Days after the date GSK
selects  or  is deemed to have selected the Limited Program Option, by notifying
GSK  of  the  number  of  shares  it wishes GSK to purchase. The purchase of the
Limited  Program  Option  Shares  shall  close on the date which is fifteen (15)
Trading  Days  after  the  date  of  such  Exercise  Notice.

     2.4  Issuance  of  the  Stock  Repayment  Shares.  Subject  to  the  terms
and  conditions  set  forth  in  this  Stock  Purchase  Agreement  and  the Loan
Agreement,  Exelixis  shall  have  an option to issue to GSK the Stock Repayment
Shares  in payment of all or any portion of the then due principal amount of any
Advance  (as  defined  in  the Loan Agreement) and all accrued interest relating
thereto up to and including any of the Payment Dates described in Section 5.1(a)
of  the  Loan Agreement (the "Stock Repayment Amount") (each such instance being
hereinafter  referred to as a "Stock Repayment"). The number of shares of Common
Stock  comprising  the  Stock Repayment Shares issuable in connection with Stock
Repayments  shall  be  equal  to  the quotient of the applicable Stock Repayment
Amount  divided  by  the  Fair  Market  Value (as defined below) of one share of
Common  Stock.  No  fractional shares shall be issued in connection with a Stock
Repayment.  The  "Fair  Market  Value" of the Common Stock shall be deemed to be
the  average  of  the  opening  and  closing  sale prices of the Common Stock as
reported  by  the National Securities Market on which the Common Stock trades or
is  listed  for  the  first  twenty  (20)  consecutive  Trading Days immediately
following  the  date which is two (2) Trading Days after Exelixis filed its most
recent  Form  10-Q or Form 10-K prior to the date of the Stock Repayment Notice.

     2.5  Conditional  Limitation  on  Ownership.  Notwithstanding  anything  to
the  contrary  contained  in  this Stock Purchase Agreement, the total number of
shares  of  Common  Stock  owned  by  GSK  acquired  pursuant to the Transaction
Documents shall at all times be less than twenty percent (20%) of Exelixis' then
outstanding Common Stock, as reported in Exelixis' most recent Form 10-Q or Form
10-K.  In  the  event  that  any  purchase of Option Shares or the acceptance of
Stock Repayment Shares would cause GSK to be a holder of twenty percent (20%) or
more  of  Exelixis'  then outstanding Common Stock, GSK shall be relieved of its
obligations  to  make  such purchase(s) or accept such Stock Repayment Shares to
the extent that the Shares acquired by GSK pursuant to the Transaction Documents
would  be  equal  to  or  exceed  such  twenty  percent  (20%)  threshold.  For
clarification,  the  twenty  percent (20%) ownership test shall be calculated in
each  instance  immediately  prior  to  the purchase of the Option Shares or the
acceptance  of any Stock Repayment Shares but shall include the number of Shares
being  purchased  or  accepted.

                                    ARTICLE 3
                            CLOSING; DELIVERY; NOTICE

     3.1  Initial  Closing.  The  closing  of  the  purchase  and  sale  of  the
Initial  Shares  (the  "Initial  Closing")  shall be held on November 1, 2002 at
10:00  a.m.,  California  time, or within five (5) calendar days of such date as
all applicable consents and approvals of Governmental Authorities required to be
obtained  in  connection  with  the  Transaction  Documents  have been obtained,
including  without  limitation,  the  expiration  or  termination of the HSR Act
waiting  period,  if  any, or on such date Exelixis and GSK may otherwise agree.

     3.2  Payment  and  Delivery  of  the  Initial  Shares.

          3.2.1  Payment.  Subject  to  the  terms  and conditions of this Stock
Purchase  Agreement,  on  the  date  of  the  Initial Closing, GSK shall pay the
purchase  price  of  the  Initial  Shares, as determined pursuant to Section 2.2
hereof,  by  wire  transfer  in  immediately  available  funds to the account of
Exelixis,  in accordance with the wire instructions provided to GSK by Exelixis.

          3.2.2  Delivery.  Subject  to  the  terms and conditions of this Stock
Purchase  Agreement,  on the date of the Initial Closing, Exelixis shall deliver
to  GSK  a  copy  of  the instructions from Exelixis to Exelixis' stock transfer
agent  dated  no  later  than  the  date  of  the Initial Closing, which directs
Exelixis'  transfer  agent  to  prepare  and  deliver to GSK a stock certificate
representing  the Initial Shares as soon as possible, but in no event later than
ten  (10)  Trading  Days  following  the  Initial  Closing.

     3.3  Payment  and  Delivery  of  the  Option  Shares.

          3.3.1  Notice.  Subject  to  the  terms  and  conditions of this Stock
Purchase  Agreement, if Exelixis elects, in its sole discretion, to exercise the
Option,  then  no  later than thirty (30) Trading Days after either (i) the date
GSK selects the Expanded Program Option pursuant to the Development Agreement or
(ii)  the  date  GSK  selects  or is deemed to have selected the Limited Program
Option  pursuant  to  the  Development  Agreement (either such date, the "Option
Exercise  Date"),  Exelixis shall deliver to GSK written notice of such exercise
(the  "Exercise  Notice"),  as  applicable.

          3.3.2  Payment. GSK shall pay the purchase price of the Option Shares,
as  applicable, as determined pursuant to Section 2.2 hereof, on or prior to the
date  which  is  fifteen (15) Trading Days after the date of the Exercise Notice
(an  "Option  Closing Date"). Such purchase price shall be paid by wire transfer
in  immediately  available  funds to the account of Exelixis, in accordance with
the  wire  instructions  provided  to  GSK  by  Exelixis.

          3.3.3  Delivery.  Upon  receipt  of  the  applicable  purchase  price,
Exelixis shall issue instructions, dated not later than the Option Closing Date,
to  Exelixis' stock transfer agent directing Exelixis' transfer agent to prepare
and  deliver  to  GSK  a stock certificate representing the applicable number of
Option  Shares,  as soon as possible, but in no event later than two (2) Trading
Days  following  the  Option  Closing  Date.

     3.4  The  Stock  Repayment  Shares.

          3.4.1  Notice.  Subject  to,  and  in  accordance  with, the terms and
conditions  of this Stock Purchase Agreement and the Loan Agreement, if Exelixis
elects to issue any of the Stock Repayment Shares, Exelixis shall deliver to GSK
written  notice  of  such  election (the "Stock Repayment Notice") no later than
thirty  (30) days prior to a Payment Date (as defined in Section 5.1 of the Loan
Agreement).  Each  Stock  Repayment  Notice  shall set forth the Stock Repayment
Amount  applicable  to  each respective Stock Repayment and the closing date for
such  Stock  Repayment.

          3.4.2 Stock Repayment Closings. Each closing date of a Stock Repayment
shall  be referred to as a "Stock Repayment Closing Date," and together with the
Initial  Closing  and  the Option Closing Date shall be collectively referred to
herein as a "Closing"; provided, however, that each Stock Repayment Closing Date
shall  be  the  applicable Payment Date under Section 5.1 of the Loan Agreement,
unless  the  Parties  otherwise  mutually  agree.

          3.4.3 Delivery; Satisfaction of Obligation. At least three (3) Trading
Days  in  advance  of  any  Stock  Repayment  Closing Date, Exelixis shall issue
instructions  as  follows:

               (a)  if  GSK  is  not  a SEC Affiliate of Exelixis, then Exelixis
shall  issue  instructions to Exelixis' stock transfer agent directing Exelixis'
transfer  agent  to  prepare  and  deliver to the account of GSK by an automated
share transfer through the Depository Trust Company system ("DWAC"), that number
of  shares  of  Exelixis  representing  the applicable Stock Repayment Shares no
later  than  the  Stock  Repayment  Closing  Date;  or

               (b)  if  GSK  is a SEC Affiliate of Exelixis as of the applicable
Stock  Repayment  Closing  Date,  then  Exelixis  shall  issue  instructions  to
Exelixis'  stock  transfer  agent,  directing  the transfer agent to prepare and
deliver  to  Exelixis  a  stock  certificate  evidencing  that  number of shares
representing  the applicable Stock Repayment Shares, as soon as possible, but in
no  event later than one (1) Trading Day prior to the applicable Stock Repayment
Closing  Date,  which stock certificate shall be delivered by Exelixis to GSK on
the applicable Stock Repayment Closing Date; provided however, that Exelixis may
only  issue  Stock  Repayment  Shares in accordance with Section 5.6 of the Loan
Agreement.

               (c)  Subject  to  GSK's  receipt of the stock certificate or DWAC
transfer,  as  the  case may be, for the Stock Repayment Shares, the outstanding
Obligations  (as  defined in the Loan Agreement) due under the terms of the Loan
Agreement  prior to such Stock Repayment shall be deemed repaid to the extent of
the  applicable  Stock  Repayment  Amount.

     3.5  Location.  Each  Closing  shall  be  held  at  the  principal  offices
of  Cooley  Godward  LLP, 3175 Hanover Street, Palo Alto, California, or at such
other  place  as  Exelixis  and  GSK  may  agree.

                                    ARTICLE 4
                   REPRESENTATIONS AND WARRANTIES OF EXELIXIS

     Exelixis  hereby  represents  and warrants to GSK as of the Effective Date,
the  Initial  Closing, the Option Closing Date and Stock Repayment Closing Date,
as  applicable,  as  follows:

     4.1  Organization,  Good  Standings  and  Qualification.  Exelixis:

               (a) is a corporation duly organized, validly existing, authorized
to  exercise  all  its  corporate  powers,  rights  and  privileges, and in good
standing  under  the  laws  of  the  State  of  Delaware;

               (b) has all requisite corporate power and authority to own, lease
and  operate its properties and to carry on its business as now conducted and as
proposed  to  be  conducted;  and

               (c)  is  duly  qualified  as  a  foreign  corporation and in good
standing  in  each  jurisdiction in which the failure to so qualify would have a
Material  Adverse  Effect.

     4.2  Authorization;  Due  Execution.  Exelixis  has  the  requisite
corporate  power  and  authority  to enter into the Transaction Documents and to
perform  its  obligations  under  the  terms  of the Transaction Documents.  All
corporate  action  on  the  part  of  Exelixis,  its  officers,  directors  and
stockholders  necessary  for  the  authorization,  execution and delivery of the
Transaction  Documents  has  been taken.  This Stock Purchase Agreement has been
and  shall  be duly authorized, executed and delivered by Exelixis and, upon due
execution  and delivery by GSK of this Stock Purchase Agreement, will be a valid
and  binding  agreement  of  Exelixis, enforceable in accordance with its terms,
except  as  enforceability  may  be  limited  by  bankruptcy,  insolvency,
reorganization, moratorium or similar laws affecting creditors' rights generally
or  by  equitable  principles.

     4.3  Capital  Stock.  At  September  30, 2002, the authorized capital stock
of Exelixis consisted of 100,000,000 shares of Common Stock, of which 57,196,682
shares  were  outstanding,  and 10,000,000 shares of preferred stock, $0.001 par
value  per  share,  of  which  no shares were outstanding.  Except for shares of
capital  stock  issued  pursuant to employee benefit plans, no shares of capital
stock  of  Exelixis  have been issued, other than as reported in the most recent
SEC Filing which includes information regarding Exelixis' capital stock.  All of
the outstanding shares of Exelixis' capital stock are validly issued, fully paid
and  nonassessable and were issued in compliance with all applicable federal and
state securities laws. Except as set forth in the SEC Filings, as defined below,
and  in  the Transaction Documents, Exelixis has not agreed to register the sale
of  any of its securities under the Securities Act, and there are no outstanding
subscriptions,  options,  warrants,  calls,  contracts,  demands,  commitments,
conversion rights or other agreements or arrangements of any character or nature
whatever  under which Exelixis is or may be obligated to issue its Common Stock,
preferred  stock  or  warrants  or options to purchase Common Stock or preferred
stock.  Except  as  set  forth  in the SEC Filings, no holder of any security of
Exelixis  is  entitled  to  any  rights  of first refusal, preemptive or similar
rights  to  purchase  any securities of Exelixis (including, without limitation,
the  Shares).  In  the  event  GSK's beneficial ownership of Exelixis' shares of
Common Stock exceeds five percent (5%), Exelixis represents and warrants, except
as  otherwise disclosed on Schedule 4.3, there are no outstanding subscriptions,
options,  warrants,  calls,  contracts,  demands,  commitments,  convertible
securities, proxy or stockholder agreements, or other agreements or arrangements
of  any  character  or nature whatever, other than in connection with this Stock
Purchase  Agreement,  pursuant  to  which  Exelixis  is  obligated  to issue any
securities  of  any  kind representing an ownership interest in it.  Neither the
offer  nor  the  issuance  or  sale of the Shares constitutes an event under any
anti-dilution  provisions  of  any  securities  issued  (or issuable pursuant to
outstanding  rights,  warrants  or  options)  by Exelixis or any agreements with
respect  to  the  issuance of securities by Exelixis, which will either increase
the  number  of  securities issuable pursuant to such provisions or decrease the
consideration  per share to be received by Exelixis pursuant to such provisions.

     4.4  Validity  of  Shares.  The  Shares, when issued, sold and delivered in
accordance with the terms of, and for the consideration set forth in, this Stock
Purchase Agreement, shall be duly authorized and validly issued and outstanding,
fully  paid,  nonassessable,  and  free  and  clear  of  all  pledges,  liens,
encumbrances  and restrictions other than the restrictions on transfer set forth
in  Sections  5.3  and  7.4.

     4.5  SEC  Filings;  Financial  Statements.

          4.5.1 SEC Filings. Exelixis has timely filed with the SEC all reports,
registration statements and other documents required to be filed by it (the "SEC
Filings")  under  the Securities Act and the Exchange Act.  The SEC Filings were
prepared  in  accordance  and,  as of the date on which each such SEC Filing was
filed  with  the  SEC,  complied  in  all  material respects with the applicable
requirements  of the Securities Act, the Exchange Act, or the Sarbanes-Oxley Act
of  2002,  as  the  case  may  be.  None of such SEC Filings, including, without
limitation,  any  Financial  Statements, exhibits and schedules included therein
and  documents  incorporated  therein  by reference, at the time filed, declared
effective  or  mailed,  as  the  case may be, contained an untrue statement of a
material  fact or omitted to state a material fact required to be stated therein
or  necessary  in  order  to  make  the  statements  therein,  in  light  of the
circumstances  under which they were made, not misleading.  Except to the extent
information  contained  in any of the SEC Filings has been revised, corrected or
superseded  by any Exelixis' press releases provided to GSK or a later filing of
any such form, report or document, none of the SEC Filings currently contains an
untrue  statement  of a material fact or omits to state a material fact required
to  be  stated  therein or necessary in order to make the statements therein, in
light  of  the  circumstances  under  which  they  were  made,  not  misleading.

          4.5.2  Financial  Statements.  Each  of  the  financial  statements
(including,  in  each case, any notes, exhibits and schedules thereto) contained
in  the  SEC  Filings  was prepared (i) in the case of Forms 10-Q, in accordance
with  United  States  generally accepted accounting principles as promulgated by
the  SEC under Regulation S-X (ii) in the case of Forms 10-K, in accordance with
United  States  generally  accepted  accounting  principles,  including  those
promulgated  by  the SEC under Regulation S-X, with such principles applied on a
consistent  basis  throughout the periods indicated and (iii) in the case of any
other  SEC Filing which contains financial statements, in accordance with United
States  generally accepted accounting principles as promulgated by the SEC under
Regulation  S-X (the "Financial Statements"). The Financial Statements comply in
all  material  respects  with  applicable  accounting requirements and rules and
regulations  of  the  SEC,  and  each  fairly  presented the financial position,
results  of  operations  and changes in the financial position of Exelixis as of
the  respective  dates thereof and for the respective periods indicated therein.

          4.5.3  No  Material  Adverse  Effect. Except as disclosed in Exelixis'
most  recent  SEC  Filings,  specifically  including,  but  not  limited to, the
Financial Statements contained in such SEC Filings, if any, or other information
provided  to  GSK  in  contemplation of the Transaction Documents, there has not
been  (i)  any  Material  Adverse Effect, (ii) other than as contemplated in the
Transaction Documents, any obligation, direct or contingent, that is material to
Exelixis  considered as one enterprise, incurred by Exelixis, except obligations
incurred  in the ordinary course of business, (iii) any dividend or distribution
of any kind declared, paid or made on the capital stock of Exelixis, or (iv) any
loss  or  damage  (whether  or not insured) to the physical property of Exelixis
which  has  been  sustained  which  has  a  Material  Adverse  Effect.

     4.6  Litigation.  Other  than  as  described  in  the  SEC  Filings,  there
are  no  material  Legal  Proceedings  pending  or,  to  Exelixis'  knowledge,
threatened;  nor,  except  as  disclosed  on  Schedule 4.6, are there any formal
inquiries  or  notices  which  may  lead  to  the  institution  of  such  Legal
Proceedings,  against  Exelixis  or its properties, assets or business, which if
adversely  decided,  would,  individually  or  in the aggregate, have a Material
Adverse  Effect  or prevent or adversely affect the transactions contemplated by
this  Stock  Purchase  Agreement.

     4.7  Governmental  Consents.  No  consent,  approval,  order  or
authorization  of,  or  registration, qualification, designation, declaration or
filing  with,  any federal, state, local or provincial governmental authority on
the  part  of  Exelixis  is  required in connection with the consummation of the
transactions  contemplated  by  this  Stock  Purchase Agreement, except for such
approvals or consents required under the HSR Act, if any, and such other notices
required  or  permitted  to  be  filed with certain state and federal securities
commissions  after  the  Effective Date, which notices will be filed on a timely
basis.

     4.8  Compliance  with  Applicable  Laws  and Other Instruments. Exelixis is
not  in  violation  of  or  default  under its Operating Documents or, except as
disclosed  in  the SEC Filings, of any Material Agreement to which it is a party
or  by  which  it  is  bound,  or  to  its  knowledge or to the knowledge of its
executive  officers,  of any provision of federal or state law, or any judgment,
order,  writ,  decree,  statute,  rule or regulation applicable to Exelixis, the
violation  of  which,  with  respect to each of the  above clauses, would have a
Material  Adverse  Effect.  Neither  the  execution  or  delivery  of,  nor  the
performance of or compliance with this Stock Purchase Agreement, the issuance of
the  Shares  nor the consummation of the transactions contemplated by this Stock
Purchase  Agreement  will,  with  or  without the giving of notice or passage of
time,  result  in any breach of, or constitute a default under, or result in the
imposition  of  any  lien  or encumbrance upon any asset or property of Exelixis
pursuant  to, any Material Agreement to which Exelixis is a party or by which it
or  any  of  its  properties,  assets  or  rights is bound or affected or to its
knowledge  any  provision  of federal or state law or any judgment, order, writ,
decree,  statute,  rule  or  regulation  applicable to Exelixis the violation of
which  would  have a Material Adverse Effect, and will not violate the Exelixis'
Operating  Documents.

     4.9  Compliance  with  Environmental  Laws.  Except as disclosed in the SEC
Filings,  Exelixis  is  not,  to  its  knowledge, in violation of any applicable
statute,  law  or  regulation relating to the environment or occupational health
and  safety  which  would  have  a  Material  Adverse  Effect,  and  no material
expenditures  are  or will be required in order to comply with any such existing
statute,  law  or  regulation.  To  its  knowledge,  Exelixis  does not have any
material  liability  to  any Governmental Authority or other Third Party arising
under  or  as  a result of any such past or existing statute, law or regulation.

     4.10  Taxes.  Exelixis,  and its majority-owned subsidiaries have filed all
necessary  federal,  state and foreign income and franchise tax returns and have
paid or accrued all taxes shown as due thereon, and Exelixis has no knowledge of
any  tax deficiency which has been or might be asserted or threatened against it
or  its  majority-owned subsidiaries which would have a Material Adverse Effect.

     4.11  Insurance.  Exelixis,  and  its  majority-owned subsidiaries maintain
insurance  of  the  types  and  in the amounts generally deemed adequate for its
business,  including,  but  not  limited  to,  insurance  covering  all real and
personal  property  owned  or  leased  by  Exelixis  and  its  majority-owned
subsidiaries against theft, damage, destruction, acts of vandalism and all other
risks  customarily  insured against, all of which insurance is in full force and
effect.

     4.12  Properties.  Exelixis  has  good  and  marketable title to all of the
properties and assets reflected as owned in the Financial Statements included in
the  SEC  Filings,  and  such properties and assets are not subject to any lien,
mortgage,  pledge,  charge  or encumbrance of any kind except (i) those, if any,
reflected  in such Financial Statements, or (ii) those which are not material in
amount  and do not adversely affect the use made and promised to be made of such
property  by  Exelixis.  Exelixis  holds  its  leased properties under valid and
binding  leases,  with  such  exceptions  as  are  not materially significant in
relation  to  the business of Exelixis.  Except as disclosed in the SEC Filings,
Exelixis  owns  or leases all such properties as are necessary to its operations
as  now  conducted  or  as  proposed  to  be  conducted.

     4.13  Intellectual  Property.  To the best of the knowledge of Exelixis and
its  majority-owned  subsidiaries  (other  than  Artemis  Pharmaceuticals GmbH),
respectively, Exelixis, and such majority-owned subsidiaries (other than Artemis
Pharmaceuticals  GmbH): (i) own, or have obtained licenses or rights to use, all
of  the  Intellectual  Property  necessary  to  carry  out  Exelixis'  and  its
majority-owned subsidiaries (other than Artemis Pharmaceuticals GmbH) respective
businesses  as  currently  conducted  or as Exelixis contemplates conducting its
business  from time to time in the future and as contemplated by the Transaction
Documents;  (ii)  are  not aware of any notice asserting any ownership rights to
the  Intellectual  Property;  (iii)  are not aware of sales of any products that
would  constitute an infringement by Third Parties of the Intellectual Property;
(iv)  are aware of no pending or threatened action, suit, proceeding or claim by
a  Third  Party  challenging  the ownership rights in, validity or scope of, the
Intellectual  Property;  and  (v)  are  not  aware  of any pending or threatened
action,  suit,  proceeding  or claim by a Third Party asserting that Exelixis or
its  majority-owned  subsidiaries  (other  than  Artemis  Pharmaceuticals  GmbH)
infringe  or otherwise violate any patent, trademark, copyright, trade secret or
other  proprietary  right  of any Third Party as would reasonably be expected to
result  in  a  Material  Adverse  Effect.

     4.14 Effect of Representations and Warranties. None of the representations,
warranties  or  statements  made  to  GSK  in the Stock Purchase Agreement or in
connection  with  the Stock Purchase Agreement contain any untrue statement of a
material  fact,  or omit to state a material fact necessary in order to make the
statements  made  not  misleading.

                                    ARTICLE 5
                     REPRESENTATIONS AND WARRANTIES OF GSK;
                     RESTRICTIONS ON TRANSFER OF THE SHARES

     5.1  Representations  and  Warranties.  GSK  hereby  represents  and
warrants  to Exelixis, as of the Effective Date, the Initial Closing, the Option
Closing  Date  and  Stock  Repayment  Closing  Date,  as applicable, as follows:

          5.1.1  Corporate Organization and Authority. GSK is a corporation duly
organized,  validly  existing,  authorized to exercise all its corporate powers,
rights  and  privileges,  and  in  good standing under the laws of Pennsylvania.

          5.1.2  Authorization;  Due  Execution. GSK has the requisite corporate
power  and  authority  to  enter  into  this  Stock  Purchase  Agreement and the
Transaction  Documents  and  to  perform its obligations under the terms of this
Stock  Purchase  Agreement  and  the  other Transaction Documents. All corporate
action  on  the  part of GSK, its officers, directors and stockholders necessary
for  the  authorization, execution and delivery of this Stock Purchase Agreement
and  the Transaction Documents has been taken. This Stock Purchase Agreement has
been  and  shall be duly authorized, executed and delivered by GSK and, upon due
execution  and  delivery by Exelixis of this Stock Purchase Agreement shall be a
valid  and  binding  agreement of GSK, enforceable in accordance with its terms,
except  as  enforceability  may  be  limited  by  bankruptcy,  insolvency,
reorganization, moratorium or similar laws affecting creditors' rights generally
or  by  equitable  principles.

          5.1.3  Investment Only. This Stock Purchase Agreement is made with GSK
in  reliance  upon  its representations to Exelixis, which by GSK's execution of
this  Stock  Purchase  Agreement  GSK  hereby  confirms,  that  the Shares to be
received by GSK shall be acquired for investment for GSK's own account, not as a
nominee  or  agent,  and not with a view to the sale or distribution of any part
thereof,  and  that GSK does not have any present intention of selling, granting
any participation in or otherwise distributing the same. By executing this Stock
Purchase Agreement, GSK further represents that it has no contract, undertaking,
agreement  or  arrangement  with  any  Person  to  sell,  transfer  or  grant
participation  to such Person or to any third Person, with respect to any of the
Shares.

          5.1.4  Experience.  GSK represents that it: (i) has such knowledge and
experience  in financial and business matters as to be capable of evaluating the
merits  and risks of its prospective investment in the Shares; (ii) has received
all  the  information  it has requested from Exelixis and considers necessary or
appropriate  for  deciding  whether  to  purchase  the Shares; (iii) has had the
opportunity  to  discuss  Exelixis'  business  and  financial  affairs  with its
management;  (iv)  has the ability to bear the economic risks of its prospective
investment;  and  (v)  is  able,  without  materially  impairing  its  financial
condition,  to  hold the Shares for an indefinite period of time and to suffer a
complete  loss  on  its  investment.

          5.1.5  Accredited  Purchaser.  GSK certifies that it presently is, and
shall  as of the Effective Date, the Initial Closing, the Option Closing Date or
Stock Repayment Closing Date, as applicable, be, an "accredited investor" within
the  meaning  of Regulation D of the rules and regulations promulgated under the
Securities  Act.

     5.2  No  Registration.  GSK  understands  that  the  Shares,  other  than
the Stock Repayment Shares, have not been registered under the Securities Act on
the  grounds  that  the  offer and sale of securities contemplated by this Stock
Purchase  Agreement are exempt from registration pursuant to Section 4(2) of the
Securities  Act,  and  that Exelixis' reliance upon such exemption is predicated
upon  GSK's  representations  set  forth  in  this  Stock  Purchase  Agreement.

     5.3  Limitations  on  Transfer.  GSK  covenants  that,  subject  to  other
restrictions  on  transfer set forth elsewhere in this Stock Purchase Agreement,
in  no  event shall it dispose of any of the Shares (other than pursuant to Rule
144  promulgated by the SEC under the Securities Act ("Rule 144") or any similar
or analogous rule), unless and until (a) GSK shall have notified Exelixis of the
proposed disposition, and (b) if requested by Exelixis, GSK shall have furnished
Exelixis  with  an  opinion  of  counsel  reasonably  satisfactory  in  form and
substance to Exelixis and Exelixis' counsel, in the reasonable exercise of their
judgment, to the effect that (i) such disposition shall not require registration
under  the  Securities  Act and (ii) appropriate action necessary for compliance
with  the Securities Act and any applicable state, local or foreign law has been
taken.  Notwithstanding  the  foregoing, GSK may sell the Stock Repayment Shares
at  any  time  and  may  transfer  any  Shares  to  a  Permitted  Transferee.

     5.4  Legend.  Each  certificate  representing  the  Shares,  other than the
Stock  Repayment  Shares,  shall  be  endorsed  with substantially the following
legends:
     (i)  THE  SECURITIES EVIDENCED BY THIS CERTIFICATE HAVE NOT BEEN REGISTERED
     UNDER  THE  SECURITIES  ACT  OF  1933,  AS  AMENDED,  AND  MAY NOT BE SOLD,
     TRANSFERRED OR ASSIGNED UNLESS THERE IS AN EFFECTIVE REGISTRATION STATEMENT
     UNDER SUCH ACT COVERING SUCH SECURITIES, THE TRANSFER IS MADE IN COMPLIANCE
     WITH  RULE  144  PROMULGATED  UNDER  SUCH  ACT,  OR THE COMPANY RECEIVES AN
     OPINION OF COUNSEL REASONABLY SATISFACTORY TO THE COMPANY STATING THAT SUCH
     SALE,  TRANSFER  OR ASSIGNMENT IS EXEMPT FROM THE REGISTRATION AND DELIVERY
     REQUIREMENTS  OF  SUCH  ACT;  and

     (ii)  THE SECURITIES EVIDENCED BY THIS CERTIFICATE ARE SUBJECT TO A LOCK-UP
     AGREEMENT  AND  MAY  NOT  BE  SOLD,  TRANSFERRED  OR ASSIGNED OTHER THAN IN
     ACCORDANCE WITH THE TERMS OF THAT CERTAIN STOCK PURCHASE AND STOCK ISSUANCE
     AGREEMENT, DATED OCTOBER 28, 2002, WITHOUT THE PRIOR WRITTEN CONSENT OF THE
     COMPANY;  and

     (iii)  ANY  LEGEND  REQUIRED  TO  BE PLACED ON THE STOCK CERTIFICATES UNDER
     APPLICABLE  STATE  SECURITIES  LAWS.

                                    ARTICLE 6
                              CONDITIONS TO CLOSING

     6.1  Conditions  to  Obligations  of  GSK  to  Consummate  each  Closing.
The obligation of GSK to consummate each Closing and to purchase and pay for, or
otherwise  accept, as applicable, the Shares being issued pursuant to this Stock
Purchase  Agreement  is subject to the satisfaction or GSK's waiver, on or prior
to  each  Closing,  of  each  of  the  following  conditions,  as  applicable:

          6.1.1 Exelixis' representations and warranties contained in this Stock
Purchase  Agreement,  as  updated  by Exelixis' most recent SEC Filings, are and
will  be  true and correct as of the date of the Initial Closing and each of the
Option  Closing Dates or Stock Repayment Closing Dates, as applicable, as though
made  on  and  as  of  that  date.

          6.1.2  An  officer's certificate executed by Exelixis' Chief Executive
Officer  or  Chief  Financial  Officer  shall  have  been  delivered to GSK (the
"Officer's  Certificate") in the form attached hereto as Exhibit "A" certifying,
among  other  things,  that the representations and warranties contained in this
Stock Purchase Agreement are true and correct as of the Closing Date and that no
events  which  had a Material Adverse Effect, occurred during the period used to
calculate  the  purchase  price  of  the  Shares  subject  to  the  Closing.

          6.1.3 The Transaction Documents shall have been executed and delivered
by  Exelixis.

          6.1.4  Exelixis  and  GSK shall have obtained all consents (including,
without limitation, the expiration or termination of the HSR Act waiting period,
if any, and all governmental or regulatory consents, approvals or authorizations
required  in  connection  with  the  valid  execution and delivery of this Stock
Purchase  Agreement  or any Closing hereunder), permits and waivers necessary or
appropriate  for  consummation  of  the  transactions contemplated by this Stock
Purchase  Agreement.

          6.1.5  No  Governmental  Authority  shall  have  enacted,  issued,
promulgated,  enforced  or  entered  any law, rule, regulation, executive order,
decree,  injunction or other order which is then in effect and has the effect of
making  illegal  the purchase of, or payment for, the Shares by GSK or otherwise
preventing  the  consummation of any of the transactions contemplated under this
Stock  Purchase  Agreement.

          6.1.6  There  shall  be  no  Legal  Proceeding  challenging this Stock
Purchase  Agreement  or  the  transactions  contemplated  by this Stock Purchase
Agreement,  or  seeking  to  prevent  or  delay the consummation of any Closing,
instituted  and  pending  before  any  court  or  Government  Authority.

          6.1.7  The  Common  Stock  of Exelixis shall be trading or listed on a
National  Securities  Market.

          6.1.8  Exelixis shall not be insolvent, filed a petition for voluntary
bankruptcy  or  have become the subject of an involuntary bankruptcy proceeding,
made  an  assignment  for  the  benefit  of  creditors,  been  voluntarily  or
involuntarily  dissolved  or  has had a receiver, trustee or other court officer
appointed  for  its  property.

          6.1.9  A  Change  of  Control  shall not have occurred as described in
Section  13.1  of  the  Development  Agreement.

          6.1.10  All  Stock  Repayment Shares issued to GSK pursuant to Section
2.4  of  this  Stock  Purchase  Agreement  shall  have been registered under the
Securities  Act  on  any SEC registration statement form used to register shares
that  Exelixis  is  eligible  to  use  prior  to  GSK's acceptance of such Stock
Repayment  Shares and shall be immediately available for transfer or disposal by
GSK,  subject to GSK not being deemed a SEC Affiliate of Exelixis, in which case
the  stock  certificates  shall  contain  appropriate  legends.

          6.1.11 GSK shall have received an opinion of Cooley Godward LLP, dated
as of the date of the Initial Closing or an applicable Closing, in substantially
the  form  attached  hereto  as  Exhibit  "B".

          6.1.12  Exelixis  shall  have  promptly delivered to GSK copies of any
amendments  or  modifications  to  its  Operating  Documents  certified  by  the
Secretary  of  State of Delaware, and, with respect to the bylaws, the Secretary
of  Exelixis.

          6.1.13  With  respect  to  the Stock Repayment Shares, the Development
Agreement  shall  not  have  been terminated by GSK pursuant to Sections 12.2.1,
12.3.1  or  12.4  of  the  Development  Agreement.

          6.1.14  There  shall  not  have occurred a Material Breach by Exelixis
that  has  not been cured in accordance with the provisions of Section 12.2.1 of
the  Development  Agreement.

     6.2  Conditions  to  Obligations  of  Exelixis  to  Consummate  each
Closing.  The obligations of Exelixis to consummate each Closing and to sell and
issue the Shares is subject to the satisfaction or Exelixis' waiver, on or prior
to  each  Closing,  of  each  of  the  following  conditions,  as  applicable:

          6.2.1  GSK's  representations  and  warranties contained in this Stock
Purchase  Agreement  are  true and correct as of the date of the Initial Closing
and  each  of  the  Option  Closing  Dates  or Stock Repayment Closing Dates, as
applicable,  as  though  made  on  and  as  of  that  date.

          6.2.2 The Transaction Documents shall have been executed and delivered
by  GSK.

          6.2.3  Exelixis  and  GSK  shall have obtained all consents (including
without limitation, the expiration or termination of the HSR Act waiting period,
if any, and all governmental or regulatory consents, approvals or authorizations
required  in  connection  with  the  valid  execution and delivery of this Stock
Purchase  Agreement  or any Closing hereunder), permits and waivers necessary or
appropriate  for  consummation of the transactions contemplated under this Stock
Purchase  Agreement.

          6.2.4  No  Governmental  Authority  shall  have  enacted,  issued,
promulgated,  enforced,  or  entered any law, rule, regulation, executive order,
decree,  injunction or other order which is then in effect and has the effect of
making  illegal  the purchase of, or payment for, the Shares by GSK or otherwise
preventing  the  consummation of any of the transactions contemplated under this
Stock  Purchase  Agreement.

          6.2.5  There  shall  be  no  Legal  Proceeding  challenging this Stock
Purchase  Agreement  or  the  transactions  contemplated  by this Stock Purchase
Agreement,  or  seeking  to  prevent  or  delay the consummation of any Closing,
instituted  and  pending  before  any  court  or  Government  Authority.

                                    ARTICLE 7
                   ADDITIONAL AGREEMENTS; LOCK UP; STANDSTILL

     7.1  Registration  of  Shares.

          7.1.1  Registration  Requirements.

               (a)  Required  Registration. In the event that any of the Initial
Shares  or  the Option Shares (the "Registrable Shares") issued pursuant to this
Stock Purchase Agreement have not been held by GSK, or a Permitted Transferee of
GSK,  for  over  one  (1) year (if GSK is not a SEC Affiliate under Rule 144) or
over  two  (2) years (if GSK is a SEC Affiliate under Rule 144), at such time as
they  become available for resale in accordance with the terms and conditions of
Section 7.4 hereof (the "Registration Trigger Date"), Exelixis shall either: (i)
work  diligently  using  its  reasonable  efforts,  and  as  soon  as reasonably
practicable  after  the  Registration  Trigger  Date (but in no event later than
forty-five  (45) days after the Registration Trigger Date), to file with the SEC
a  registration  statement  on  Form  S-3,  covering the Registrable Shares (the
"Resale  Registration  Statement"),  and  shall  secure the effectiveness of the
Resale  Registration  Statement  as soon as reasonably practicable thereafter or
(ii)  for  shares  held  at  least two (2) years, provide GSK with a replacement
stock  certificate  without  legends in a form ready for transfer or disposal or
deliver  the shares to the account of GSK by an automated share transfer through
the  DWAC  in  uncertificated  form  and remove any stop transfer order attached
thereto  in  order  to  ensure  that  such  shares  are  freely  tradable.

               (b)  Effectiveness.  Subject  to Section 7.1.4, Exelixis shall be
obligated to maintain the effectiveness of the Resale Registration Statement and
any  registration  statement  filed in connection with the issuance of the Stock
Repayment Shares (together with the Resale Registration Statement referred to in
this  Section  7.1  as  the  "Registration  Statements")  with the SEC until the
earlier  of  (i)  the sale of all of the Registrable Shares or (ii) the time all
otherwise  unsold  Registrable  Shares  may  be  sold  pursuant  to Rule 144(k).

               (c)  Repurchase.  If  Exelixis  is  unable  to  cause  the Resale
Registration  Statement to become effective within one hundred eighty (180) days
of the Registration Trigger Date, Exelixis, subject to applicable law, shall, if
GSK  so requests in writing not later than ninety (90) days after the expiration
of  such  one hundred eighty (180) day period, purchase from GSK the Registrable
Shares  for  a purchase price equal to GSK's purchase price for such Registrable
Shares.  Such repurchase shall be effected not later than thirty (30) days after
Exelixis'  receipt of GSK's request therefor; provided, however, that if, at any
time  prior  to  the  date  such  repurchase is being effected, such Registrable
Shares  may  be  sold  pursuant  to  Rule  144,  then Exelixis' obligation to so
repurchase  shall  be  of  no  force  and  effect.

          7.1.2  Incidental  Registration.  If Exelixis at any time (but subject
to  Section  7.4  hereof)  proposes  to register any of its securities under the
Securities  Act  for  sale to the public, whether for its own account or for the
account  of  other security holders or both (except with respect to registration
statements  on  Forms  S-4  or S-8 or another form not available for registering
Registrable Shares for sale to the public), each such time it will promptly give
written  notice  of  its intentions to GSK (an "Incidental Registration").  Upon
the  written request of GSK, received by Exelixis within ten (10) days after the
giving  of  any such notice by Exelixis, to register any of its securities which
are  not  yet registered under the Securities Act (which request shall state the
intended  method  of  disposition  thereof),  Exelixis  will  use its reasonable
efforts to cause the Registrable Shares as to which registration shall have been
so  requested to be included in the securities to be covered by the registration
statement  proposed  to  be  filed  by  Exelixis, all to the extent requisite to
permit  the  sale  or  other  disposition by GSK (in accordance with its written
request)  of  such  Registrable  Shares  so  registered.  In  the event that any
registration  pursuant  to  this  Section  shall  be,  in  whole  or in part, an
underwritten  public  offering  of  Common  Stock,  the  number  of  shares  of
Registrable  Shares to be included in such an underwriting may be reduced if and
to  the  extent  that the managing underwriter shall be of the opinion that such
inclusion  would  adversely affect the marketing of the securities to be sold by
Exelixis; and subject to the foregoing, any reduction of the number of shares of
Registrable  Shares  shall  be accomplished by excluding all or a portion of the
shares  proposed  to  be  included  by  holders  of Registrable Shares and other
securities  with  registration  rights  who  have elected to participate in such
registration,  with  such  reduction  in  the  number  of shares in the offering
required  by  the  managing underwriter because of market conditions to be borne
pro-rata  by  all holders of Registrable Shares and other securities who elected
to  participate in such registration, with each holder of Registrable Shares and
other  securities that is participating in the offering sharing the reduction in
the  ratio that the number of shares proposed to be registered by such holder of
Registrable  Shares  or  other securities bears to the total number of shares of
Registrable  Shares or other securities proposed to be registered by all holders
of  Registrable  Shares  or  other  securities.  Notwithstanding  the  foregoing
provisions, Exelixis may withdraw any registration statement referred to in this
Section  7.1.2  without  thereby  incurring  any  liability  to  the  holders of
Registrable  Shares.

          7.1.3  Registration  Expenses.  Exelixis  shall  pay  all Registration
Expenses  (as  defined below) in connection with any registration, qualification
or  compliance  hereunder,  and  GSK  shall pay all Selling Expenses (as defined
below)  that  relate to the Registrable Shares or the Stock Repayment Shares, as
applicable.  "Registration Expenses" shall mean all expenses, except for Selling
Expenses,  incurred  by  Exelixis  in complying with the registration provisions
herein  described,  including,  without  limitation,  all  registration,
qualification,  compliance  and  filing  fees,  printing  expenses,  fees  and
disbursements of counsel for Exelixis, blue sky fees and expenses and accounting
fees (including the expense of any special audits incident to or required by any
such  registration).  "Selling Expenses" shall mean all fees of counsel for GSK,
selling  commissions,  underwriting  fees and stock transfer taxes applicable to
the  Registrable  Shares  or  the  Stock  Repayment  Shares,  as  applicable.

          7.1.4  Registration  Suspension. Exelixis shall, upon (i) the issuance
by  the  SEC  of  a  stop order suspending the effectiveness of the Registration
Statements  or  the  initiation  of proceedings with respect to the Registration
Statements under Section 8(d) or 8(e) of the Securities Act, (ii) the occurrence
of  any  event  or the existence of any fact (a "Material Event") as a result of
which  the  Registration  Statements  or  the  related  preliminary  or  final
prospectuses  shall  contain  any untrue statement of a material fact or omit to
state  any  material fact required to be stated therein or necessary to make the
statements  therein,  in  the  light  of the circumstances under which they were
made,  not  misleading,  or  (iii)  the  occurrence  or existence of any pending
corporate  development  that, in the reasonable discretion of Exelixis, makes it
appropriate  to  suspend the availability of the Registration Statements and the
related  prospectuses:

               (a)  in  the  case  of  clause  (ii) above, subject to the clause
(iii),  as  promptly  as  practicable prepare and file, if necessary pursuant to
applicable  law,  a post-effective amendment to the Registration Statements or a
supplement  to  the related prospectuses or any document incorporated therein by
reference  or  file  any  other  required document that would be incorporated by
reference  into the Registration Statements and the related prospectuses so that
the  Registration  Statements  and  the  related prospectuses do not contain any
untrue  statement of a material fact or omit to state any material fact required
to  be  stated therein or necessary to make the statements therein, in the light
of  the  circumstances under which they were made, not misleading, as thereafter
delivered  to  the  purchasers  of the Registrable Shares or the Stock Repayment
Shares,  as  applicable,  being  sold  thereunder,  and,  in  the  case  of  a
post-effective  amendment  to  the  Registration Statements, subject to the next
sentence,  use  its  reasonable  efforts to cause it to be declared effective as
promptly  as  is  practicable,  and

               (b)  give notice to GSK that the availability of the Registration
Statements  is suspended (a "Deferral Notice") and, upon receipt of any Deferral
Notice,  GSK  agrees  not  to sell any Registrable Shares or the Stock Repayment
Shares,  as  applicable, pursuant to the Registration Statements until such time
as  GSK receives copies of the supplemented or amended prospectuses provided for
in  clause  (a)  above,  or  until it is advised in writing by Exelixis that the
prospectuses  may  be  used,  and  has  received  copies  of  any  additional or
supplemental  filings  that are incorporated or deemed incorporated by reference
in  such  prospectuses. Exelixis shall use all reasonable efforts to ensure that
the  use  of  the prospectuses may be resumed (x) in the case of clauses (i) and
(ii)  above,  as promptly as is practicable, and (y) in the case of clause (iii)
above,  as soon as, in the reasonable judgment of Exelixis, public disclosure of
such  Material Event would not be prejudicial to or contrary to the interests of
Exelixis  or,  if  necessary to avoid unreasonable burden or expense, as soon as
practicable  thereafter.  Exelixis shall be entitled to exercise its right under
this  Section  7.1.4  to  suspend  the  availability of each of the Registration
Statements  or any related prospectuses no more than two (2) times in any twelve
(12)  month  period,  and  any  such period during which the availability of the
Registration Statements and any related prospectuses is suspended (the "Deferral
Period")  shall  not  exceed  thirty  (30) days. The period of any such Deferral
Period  shall  be  added  to  the period of time Exelixis has agreed to keep the
Registration  Statements effective. Exelixis shall use all reasonable efforts to
limit  the  duration  and number of any Deferral Periods. GSK hereby agrees that
upon  receipt  of  any Deferral Notice from Exelixis, GSK shall, and shall cause
each  of  its  officers,  directors, employees, affiliates, advisors, agents and
representatives  to,  keep  confidential  all nonpublic information set forth in
such  notice  including  the  existence  or  terms  of  such  Deferral  Notice.

          7.1.5  Registration  Procedures.  In  the  case  of  any  registration
effected  by Exelixis pursuant to Section 7.1, Exelixis shall use all reasonable
efforts:

               (a)  to  respond  promptly to any comments of the SEC relating to
the  Registration  Statements,  and  to  prepare  and  file  with  the  SEC such
amendments  (including  post-effective  amendments)  and  supplements  to  the
Registration  Statements  and  the  related  prospectuses as may be necessary to
comply with the provisions of the Securities Act with respect to the disposition
of  the Registrable Shares or the Stock Repayment Shares, as applicable, covered
by  the  Registration  Statements;

               (b)  to  furnish such number of Registration Statements and other
documents  incident  thereto,  including  any  amendment of or supplement to the
Registration  Statements  or related prospectuses, as GSK may reasonably request
to  facilitate  the  public  sale  or  other  disposition  of  all or any of the
Registrable  Shares  or  the  Stock  Repayment  Shares,  as  applicable;  and

               (c)  to file the documents required of Exelixis and otherwise use
all  reasonable  efforts  to  register and qualify the Registrable Shares or the
Stock  Repayment  Shares,  as applicable, covered by the Registration Statements
under  such  other securities or blue sky laws of such jurisdictions as shall be
reasonably  appropriate  in  the  opinion  of  Exelixis; provided, however, that
Exelixis  shall  not  be required to qualify to do business or to file a general
consent  to  service of process in any state in which it is not now so qualified
or  has  not  so  consented  except  as  may  be required by the Securities Act.

          7.1.6  Indemnification.

               (a) Indemnification by Exelixis. Exelixis agrees to indemnify and
hold harmless GSK (and its officers, directors, Affiliates and agents), from and
against any and all losses, claims, damages, liabilities or expenses (or actions
or  proceedings  in  respect  thereof)  to  which any of them may become subject
(under the Securities Act or otherwise) insofar as such losses, claims, damages,
liabilities or expenses (or actions or proceedings in respect thereof) arise out
of,  or are based upon (i) any untrue statement or alleged untrue statement of a
material  fact or omission or alleged omission to state a material fact required
to  be  stated  therein or necessary to make the statements therein, in light of
the  circumstances  in which they were made, not misleading, in the Registration
Statements  (on  the  respective  effective  dates  thereof),  or  the  related
prospectuses  and  any amendments or supplements thereto, or (ii) any failure by
Exelixis  to  fulfill  any  undertaking included in the Registration Statements.
Exelixis  shall,  as  incurred, reimburse the indemnified parties herein for any
legal  or  other  expenses  reasonably  incurred  in investigating, defending or
preparing  to defend any such claims, actions or proceedings in respect thereof;
provided,  however, that the indemnity agreement contained in this Section 7.1.6
shall  not  apply to amounts paid in settlement of any such loss, claim, damage,
liability  or  expense,  if  such  settlement is effected without the consent of
Exelixis  (which such consent shall not be unreasonably withheld) and, provided,
further,  that  Exelixis shall not be liable in any such case to the extent that
such  loss,  claim, damage, liability or expense arises out of, or is based upon
(A)  any  untrue  statement or omission of a material fact required to be stated
therein  or  necessary  to  make  the  statements  therein,  in  light  of  the
circumstances  in  which  they  were  made,  not misleading, in the Registration
Statements  (on  the  respective  effective  dates  thereof),  or  the  related
prospectuses  and  any  amendments or supplements thereto, made in reliance upon
and  in  conformity  with  written  information  furnished  to  Exelixis  by GSK
specifically for use in preparation of such document, or (B) an untrue statement
or  omission  in  the  related  prospectuses  and  any amendments or supplements
thereto,  that  is  corrected  in  any  subsequent  prospectus, or supplement or
amendment  thereto,  that  was  delivered to GSK prior to the sale or sales from
which  a  loss  or  liability  arose.

               (b)  Indemnification  by  GSK.  GSK  agrees to indemnify and hold
harmless Exelixis (and its officers, directors, Affiliates and agents), from and
against  any  losses,  claims,  damages,  liabilities or expenses (or actions or
proceedings  in  respect thereof) to which any of them may become subject (under
the  Securities  Act  or  otherwise)  insofar  as  such losses, claims, damages,
liabilities or expenses (or actions or proceedings in respect thereof) arise out
of,  or  are  based  upon  any  untrue  statement or omission of a material fact
required  to  be  stated therein or necessary to make the statements therein, in
light  of  the  circumstances  in  which  they were made, not misleading, in the
Registration  Statements  (on  the  respective  effective dates thereof), or the
related prospectuses and any amendments or supplements thereto, made in reliance
upon  and  in conformity with written information furnished to Exelixis by or on
behalf  of  GSK  specifically for use in preparation of such document; provided,
however, that the indemnity agreement contained in Section 7.1.6 shall not apply
to  amounts  paid  in  settlement  of any such loss, claim, damage, liability or
expense,  if  such settlement is effected without the consent of GSK (which such
consent  shall not be unreasonably withheld) and that GSK shall not be liable in
any  such  case  for  any  (A)  untrue statement or omission in the Registration
Statements  or  the  related  prospectuses  and  any  amendments  or supplements
thereto,  which statement or omission has been corrected, in writing, by GSK and
delivered  to  Exelixis  ten  (10)  days  before  the  sale from which such loss
occurred,  or  (B)  untrue statement or omission in the related prospectuses and
any  amendments  or  supplements  thereto or that is corrected in any subsequent
prospectus,  or  amendment  or supplement thereto, and delivered to GSK prior to
the sale or sales from which a loss or liability arose.  GSK shall, as incurred,
reimburse  the  indemnified  parties  herein  for  any  legal  or other expenses
reasonably  incurred in investigating, defending or preparing to defend any such
claims,  actions  or  proceedings  in  respect  thereof.

               (c)  Indemnification  Procedure.  Promptly  after  receipt by any
indemnified  party  of  a  notice  of  a claim or the beginning of any action in
respect  of  which  indemnity  is  to  be  sought  against an indemnifying party
pursuant  to  this  Section  7.1.6(c),  such  indemnified party shall notify the
indemnifying  party  in  writing  of  such  claim or of the commencement of such
action,  and,  subject  to  the  provisions hereinafter stated, in case any such
action shall have been brought against an indemnified party and the indemnifying
party shall have been notified thereof, the indemnifying party shall be entitled
to  participate  therein,  and,  to the extent that it shall wish, to assume the
defense  of such action, with counsel reasonably satisfactory to the indemnified
party. After notice from the indemnifying party to such indemnified party of the
indemnifying  party's  election  to assume the defense thereof, the indemnifying
party  shall  not  be  liable  to  such indemnified party for any legal expenses
subsequently  incurred  by such indemnified party in connection with the defense
thereof;  provided,  however,  that if there exists or shall exist a conflict of
interest  that  would  make  it  inappropriate in the reasonable judgment of the
indemnified  party  for the same counsel to represent both the indemnified party
and  such  indemnifying  party  or  any  affiliate  or  associate  thereof,  the
indemnified  party shall be entitled to retain its own counsel at the expense of
such  indemnifying  party.  Failure  of any indemnifying party to give notice as
provided  herein  shall  not  relieve  the indemnifying party of its obligations
under  this  Section  7.1.6.  No  indemnifying party, in the defense of any such
claim  or  action,  except  with  the  consent  of each indemnified party, shall
consent  to  entry  of  any  judgment  or  enter  into  any  settlement.

               (d)  Other  Liability.  The obligations of Exelixis and GSK under
Section  7.1  shall  be  in addition to any liability which Exelixis and GSK may
otherwise  have  to  each  other.

     7.2  Filings.  Exelixis  covenants  and  agrees  to  use  all  reasonable
efforts  to:  (i) make and keep public information available, as those terms are
understood  and  defined  in Rule 144, (ii) file with the SEC in a timely manner
all  reports  and  other documents required of Exelixis under the Securities Act
and  Exchange  Act,  and  (iii)  provide GSK, upon written request, with written
assurance  that Exelixis has made and kept such public information available and
has  timely filed all reports and other documents required of Exelixis under the
Securities  Act  and  Exchange  Act.

     7.3  Other  Actions.  Upon  the  terms  and  subject  to  the  conditions
hereof,  each  of the Parties hereto shall in good faith, use reasonable efforts
to take, or cause to be taken, all appropriate action, and to do, or cause to be
done,  all  things  necessary,  proper  or  advisable  under applicable laws and
regulations  to consummate and make effective the transaction contemplated under
this  Stock  Purchase Agreement, including, without limitation, using reasonable
efforts  to  obtain  all licenses, permits, consents, approvals, authorizations,
qualifications  and  orders of Governmental Authorities and parties to contracts
with  Exelixis  as  are necessary for the execution, delivery and performance of
this  Stock  Purchase  Agreement.

     7.4  Lock  Up  and  Selling  Restrictions.

          7.4.1  Subject  to  Section  7.9,  GSK agrees that for a period of [*]
following  the  date  of the Initial Closing or [*] following the Option Closing
Date,  as  applicable,  (the  "Restricted  Period"), neither GSK, nor any of its
Affiliates,  shall  offer,  sell,  contract  to sell, pledge, grant an option to
purchase, make a short sale or otherwise dispose of any Initial Shares or Option
Shares  held by GSK or any of its Affiliates, or grant an option or other rights
to  any Person to acquire any Initial Shares or Option Shares, without the prior
written  consent  of  Exelixis.

          7.4.2  GSK  agrees  that in each full calendar year from and after the
earlier  to  occur  of  (i)  the expiration of the Restricted Period or (ii) [*]
(either  such date, the "Limited Release Date"), GSK and/or its Affiliates shall
not  offer,  sell, contract to sell, pledge, grant an option to purchase, make a
short  sale  or otherwise dispose of greater than [*] of the total number of any
Initial  Shares  and  Option  Shares  purchased  by  GSK  pursuant to this Stock
Purchase  Agreement.  For  periods after the Limited Release Date of less than a
full calendar year, GSK shall be permitted to dispose of that pro-rata number of
Initial Shares and Option Shares which shall be determined by multiplying [*] of
the  total  number  of  Initial  Shares and Option Shares, purchased by GSK by a
fraction, the numerator of which is total number of days in that given year from
the  Limited  Release Date to the last calendar day in such year and denominator
of which is three hundred and sixty-five (365). The restrictions imposed by this
Section  7.4.2  shall  terminate  on  [*],  subject  to  extension by [*] if the
Restricted  Period  is  extended pursuant to the provisions set forth in Section
7.4.4  of  this  Stock  Purchase  Agreement.

          7.4.3  During the Restricted Period, the consent of Exelixis shall not
be  required  for  the transfers by GSK of all or a portion of the Shares to its
Affiliates  (a  "Permitted  Transferee"); provided, however, that such Affiliate
agrees to become a party to, and be bound by, all of the terms and conditions of
this  Stock  Purchase  Agreement by duly executing and delivering to Exelixis an
Instrument  of  Adherence  in  the  form  attached  as  Exhibit  "C"  hereto.

          7.4.4  Notwithstanding  anything  to  the  contrary  contained in this
Section  7.4  or  Section  7.9  hereof,  in  the  event  of  termination  of the
Development  Agreement  by  either:  (A)  GSK  pursuant to Section 12.3.2 of the
Development  Agreement;  or  (B)  Exelixis (i) pursuant to Section 12.2.1 of the
Development  Agreement upon Material Breach by GSK; or, (ii) pursuant to Section
12.4  of  the  Development Agreement upon the insolvency of GSK, as set forth in
Section  12.6.4  of  the Development Agreement, in each of clause (A), (B)(i) or
(B)(ii),  the  Restricted Period shall be extended for a period of [*] following
the  effective  date  of  such  termination  by  GSK or Exelixis, as applicable.

     7.5  Standstill.  Subject  to  Section  7.6,  prior to [*] (the "Standstill
Period"),  neither  GSK nor any of its Affiliates shall, in any manner, directly
or  indirectly, except as agreed by Exelixis in writing or as provided expressly
under  this  Stock  Purchase  Agreement:

          7.5.1  make, effect, initiate, cause or participate in any acquisition
of  beneficial  ownership  of  any  securities  or any assets of Exelixis or any
securities  or  any  assets  of any Exelixis' majority-owned subsidiaries or any
other  Affiliate  of  Exelixis;

          7.5.2  form,  join  or  participate  in  a  "group" (as defined in the
Exchange  Act)  with  respect  to  the beneficial ownership of any securities of
Exelixis;

          7.5.3  agree  or  offer  to take, or encourage or propose (publicly or
otherwise) the taking of any action referred to in subsections 7.5.1 or 7.5.2 of
this  Section  7.5;  or

          7.5.4  assist, induce or encourage any other Person to take any action
of  the  type  referred  to in subsections 7.5.1, 7.5.2 or 7.5.3 of this Section
7.5.

     7.6  Conditions  Eliminating  Standstill.  Notwithstanding  the
restrictions  set  forth  in  Section  7.5,  the  obligations  of GSK during the
Standstill  Period  as set forth in Section 7.5 shall not apply and will have no
force  or  effect  under  the  following  circumstances; provided, however, that
neither  GSK,  nor any of it Affiliates, shall take any action that would impair
GSK's  obligations  to purchase, or otherwise accept, the Shares under the terms
of  this  Stock  Purchase  Agreement:  [*]

     7.7  Conditions  Eliminating  Lock  Up.  Notwithstanding  the  restrictions
set  forth in Section 7.4.1, the obligations of GSK during the Restricted Period
as  set  forth in Section 7.4.1 shall not apply and will have no force or effect
under  the  following  circumstances:  [*]

     7.8  Use  of  Proceeds.  Exelixis  shall  use  the  proceeds  received
from  the  issuance  of the Shares for the funding of activities contemplated in
the  Development  Agreement  over  the  course  of  its  term.

     7.9          Exelixis  Repurchase  Option.  In  the event of termination of
the  Development  Agreement  by either (A) GSK pursuant to Section 12.3.2 of the
Development  Agreement  or  (B)  Exelixis  pursuant  to  Section  12.2.1  of the
Development Agreement upon Material Breach by GSK or pursuant to Section 12.4 of
the  Development  Agreement upon the insolvency of GSK,  as set forth in Section
12.6.4  of the Development Agreement, Exelixis shall have the right, but not the
obligation,  subject to applicable law, to repurchase from GSK, for a [*] period
following notice by the terminating Party that it is terminating the Development
Agreement,  any or all of the Initial Shares or Option Shares held by GSK at the
time  of  such  termination  as  follows:

          7.9.1 In the event of termination by GSK pursuant to Section 12.3.2 of
the  Development  Agreement,  then  Exelixis  may  repurchase  any or all of the
Initial  Shares  or Option Shares then held by GSK at a price per share equal to
[*],  as  applicable.

          7.9.2  In  the  event  of  termination by Exelixis pursuant to Section
12.2.1  of the Development Agreement upon Material Breach by GSK or Section 12.4
of  the Development Agreement upon GSK's insolvency, then in accordance with the
provisions  set  forth  in Section 12.6.4 of the Development Agreement, Exelixis
may  repurchase  any  or all of the Initial Shares or Option Shares then held by
GSK  at  a  price  per share equal to [*] of the Repurchase Market Value of such
shares  as  of  the  effective  date of such termination. The "Repurchase Market
Value"  of the Common Stock shall be deemed to be the average of the opening and
closing  sale  prices of the Common Stock as reported by the National Securities
Market  on  which  the  Common Stock trades or is listed for the [*] consecutive
Trading  Days  immediately  preceding  and  the  [*]  consecutive  Trading  Days
immediately  following  the  effective  date  of termination of such Development
Agreement.

          7.9.3  Exelixis  shall give GSK a written notice, of not less than [*]
Trading  Days,  of  its intent to effect a repurchase pursuant to either Section
7.9.1  or  Section  7.9.2, which notice shall specify the number of shares being
repurchased, the aggregate repurchase price determined and payable in accordance
with  the  terms set forth in Section 7.9.1 or Section 7.9.2, as applicable, and
the  time,  place and date for settlement of such repurchase. On such settlement
date,  Exelixis  shall  deliver to GSK the repurchase price for the shares being
repurchased  in  accordance with the terms set forth in Section 7.9.1 or Section
7.9.2,  as  applicable,  and  GSK  shall  surrender  to  Exelixis  the  stock
certificate(s)  or other evidence representing such shares. Upon delivery of the
notice  and  payment  of  the  repurchase  price pursuant to this Section 7.9.3,
Exelixis  shall  become  the  legal  and  beneficial  owner  of the shares being
repurchased and all rights and interest therein or related thereto, and Exelixis
shall  have  the right to transfer to its own name the shares being repurchased.

                                    ARTICLE 8
                                  MISCELLANEOUS

     8.1  Publicity.  Neither  Party  shall  originate  any  written
publicity,  news  release  or  other  announcement  or statement relating to the
announcement or terms of this Stock Purchase Agreement except in compliance with
the  provisions  set  forth  in  Section  14.1  of  the  Development  Agreement.
Notwithstanding anything to the contrary set forth above, the provisions of this
Section  8.1  shall  not  apply  to  Exelixis'  SEC  Filings.

     8.2  Dispute  Resolution.  Prior  to  the  commencement  of  any
litigation  under  this  Stock  Purchase Agreement, the Parties shall follow the
provisions  set  forth  in  Section  14.2  of  the  Development  Agreement.

     8.3  Governing  Law.  This  Stock  Purchase  Agreement  and  any  dispute
arising from the performance or breach hereof shall be governed by and construed
and  enforced  in  accordance  with  the  laws of the State of Delaware, U.S.A.,
without  reference  to  conflicts  of  laws  principles.

     8.4  Assignment.  This  Stock  Purchase Agreement may be assigned by GSK to
an  Affiliate  without  the  written  consent  of  Exelixis;  but  shall  not be
assignable  by Exelixis, to an Affiliate, or by either Party to any Third Party,
without  the  prior  written consent of the other Party hereto.  Notwithstanding
the  foregoing,  either  Party may assign this Stock Purchase Agreement, without
the  written  consent  of  the other Party, to an Affiliate or to an entity that
acquires  all  or  substantially  all  of  the  business or assets of such Party
(whether  by merger, reorganization, acquisition, sale or otherwise), and agrees
in  writing  to  be  bound  by  the  terms  and conditions of the Stock Purchase
Agreement.  No  assignment  and transfer shall be valid and effective unless and
until  (a)  the  assignee/transferee  shall  agree in writing to be bound by the
provisions of the Stock Purchase Agreement, (b) with respect to an assignment or
transfer  by  Exelixis,  the Loan Documents are assigned/transferred to the same
assignee/transferee concurrently with this Stock Purchase Agreement and (c) with
respect  to  an  assignment  or transfer by Exelixis, the assignee or transferee
shall  have  executed  and  recorded  such  documents  as may be required in the
reasonable  judgment of GSK to perfect GSK's interest in the Collateral (as that
term  in defined in the Loan Agreement) under the Loan Documents.  The terms and
conditions  of the Stock Purchase Agreement shall be binding on and inure to the
benefit  of  the  permitted  successors  and  assigns  of  the  Parties.

     8.5  Performance  Warranty.  Each  Party  hereby  warrants  and  guarantees
the  performance  of  any  and  all  obligations  by  its  Affiliate(s).

     8.6  Notices.  Any  notice  or  request  required  or permitted to be given
under  or  in  connection  with this Stock Purchase Agreement shall be deemed to
have  been  sufficiently given if in writing and personally delivered or sent by
certified  mail  (return  receipt  requested),  facsimile  transmission (receipt
verified),  or  overnight express courier service (signature required), prepaid,
to  the  Party  for  which such notice is intended, at the address set forth for
such  Party  below:

     If  to  Exelixis,
     addressed  to:        Exelixis,  Inc.
                           170  Harbor  Way
                           PO  Box  511
                           South  San  Francisco,  CA  94083
                           Attention:  Chief  Financial  Officer
                           Telephone: [*]
                           Telecopy:  [*]

     with  a  copy  to:    Cooley  Godward  LLP
                           Five  Palo  Alto  Square
                           3000  El  Camino  Real
                           Palo  Alto,  CA  94306
                           Attention:  Robert  L.  Jones,  Esq.
                           Telephone: [*]
                           Telecopy:  [*]

     If  to  GSK,
     addressed  to:        SmithKline  Beecham  Corporation,
                           doing  business  as  GlaxoSmithKline
                           2301  Renaissance  Blvd.  (Bldg.  #510)
                           King  of  Prussia,  Pennsylvania  19406
                           Attention:  Vice  President,  Alliance  and
                           Joint  Venture  Management
                           Telephone: [*]
                           Telecopy:  [*]

     with  a  copy  to:    GlaxoSmithKline
                           Corporate  Legal  Department
                           One  Franklin  Plaza
                           200  N.  16th  Street  /  FP  2355  (DP)
                           Philadelphia,  PA  19103
                           Attention:  Vice  President
                           and  Associate  General  Counsel
                           Telephone: [*]
                           Telecopy:  [*]

or  to  such  other  address  for  such Party as it shall have specified by like
notice  to the other Parties, provided that notices of a change of address shall
be effective only upon receipt thereof.  If delivered personally or by facsimile
transmission,  the date of delivery shall be deemed to be the date on which such
notice  or request was given.  If sent by overnight express courier service, the
date  of  delivery shall be deemed to be the next business day after such notice
or request was deposited with such service.  If sent by certified mail, the date
of  delivery  shall  be deemed to be the third business day after such notice or
request  was  deposited  with  the  U.S.  Postal  Service.

     8.7  Force  Majeure.  No  Party  shall  be  held  liable  or  responsible
to  the  other  Party  nor be deemed to be in default under, or in breach of any
provision  of,  this Stock Purchase Agreement for failure or delay in fulfilling
or  performing any obligation of this Stock Purchase Agreement when such failure
or  delay  is  due  to force majeure, and without the fault or negligence of the
Party  so  failing  or delaying.  For purposes of this Stock Purchase Agreement,
force  majeure  is defined as causes beyond the control of the Party, including,
without  limitation,  acts of God; acts, regulations, or laws of any government;
war; civil commotion; destruction of production facilities or materials by fire,
flood, earthquake, explosion or storm; labor disturbances; epidemic; and failure
of public utilities or common carriers.  In the event of force majeure, Exelixis
or  GSK,  as  the  case may be, shall immediately notify the other Party of such
inability  and  of  the period for which such inability is expected to continue.
The  Party  giving  such  notice  shall  thereupon  be  excused from such of its
obligations  under  this Stock Purchase Agreement as it is thereby disabled from
performing  for  so long as such Party is so disabled, up to a maximum of ninety
(90)  days,  after  which time, the Party not affected by the force majeure, may
terminate  this  Stock  Purchase  Agreement.  To the extent possible, each Party
shall  use  reasonable  efforts  to  minimize the duration of any force majeure.

     8.8  Waiver.  Neither  Party  may  waive  or  release  any of its rights or
interests  in  this  Stock Purchase Agreement except in writing.  The failure of
either  Party  to assert a right hereunder or to insist upon compliance with any
term or condition of this Stock Purchase Agreement shall not constitute a waiver
of that right or excuse a similar subsequent failure to perform any such term or
condition.  No  waiver  by  either  Party of any condition or term in any one or
more  instances  shall  be construed as a continuing waiver of such condition or
term  or  of  another  condition  or  term.

     8.9  Severability.  If  any  provision  hereof  should  be  held  invalid,
illegal  or  unenforceable  in  any jurisdiction, the Parties shall negotiate in
good  faith a valid, legal and enforceable substitute provision that most nearly
reflects  the  original  intent  of  the Parties and all other provisions hereof
shall  remain  in  full  force  and  effect  in  such  jurisdiction and shall be
liberally  construed  in order to carry out the intentions of the Parties hereto
as  nearly  as may be possible.  Such invalidity, illegality or unenforceability
shall  not  affect the validity, legality or enforceability of such provision in
any  other  jurisdiction.

     8.10  Entire  Agreement.  This  Stock Purchase Agreement, together with the
schedules  and  exhibits  hereto, and the accompanying Development Agreement and
Loan  Agreement  set  forth all the covenants, promises, agreements, warranties,
representations,  conditions  and  understandings between the Parties hereto and
supersede  and  terminate  all  prior  agreements  and understanding between the
Parties.  There  are  no  covenants,  promises,  agreements,  warranties,
representations,  conditions  or understandings, either oral or written, between
the  Parties  other  than  as  set  forth  herein  and  therein.  No  subsequent
alteration, amendment, change or addition to this Stock Purchase Agreement shall
be  binding  upon the Parties hereto unless reduced to writing and signed by the
respective  authorized  officers  of  the  Parties.

     8.11  Headings. Headings used herein are for convenience only and shall not
in  any  way  affect  the  construction  of  or  be  taken into consideration in
interpreting  this  Stock  Purchase  Agreement.

     8.12 Use of Name. Any rights or restrictions concerning the use of the name
or  other designation of the Parties or any other trade name, trademark or logos
of  the  Parties  for  any purpose shall be governed by the provision pertaining
thereto  as  set  forth  in  the  Development  Agreement.

     8.13  Further  Actions.  Each  Party shall execute, acknowledge and deliver
such  further  instruments,  and  do all such other acts, as may be necessary or
appropriate in order to carry out the purposes and intent of this Stock Purchase
Agreement.  The  Parties  shall  cooperate  fully  in obtaining any governmental
approvals or consents as may be necessary in order to carry out the purposes and
intent  of  this  Stock  Purchase  Agreement,  including  without limitation any
filings  and  approvals  as  may  be  required  under  the  HSR  Act.

     8.14  Survival  of  Representations and Warranties. All representations and
warranties  contained  herein  shall  survive the execution and delivery of this
Stock  Purchase Agreement, any investigation at any time made by or on behalf of
GSK,  and  the  sale  and  issuance of the Shares and payment therefor until the
earlier  of  (a) the resale of any Shares issued pursuant to this Stock Purchase
Agreement,  or  (b)  the  first  anniversary  of  the  last  Closing.

     8.15  Parties  in  Interest.  All of the terms and provisions of this Stock
Purchase  Agreement  shall  be  binding  upon,  inure  to  the benefit of and be
enforceable  by the Parties hereto and their respective permitted successors and
assigns.

     8.16  Construction  of  Agreement.  The  terms and provisions of this Stock
Purchase Agreement represent the results of negotiations between the Parties and
their  representatives, each of which has been represented by counsel of its own
choosing,  and  neither  of  which has acted under duress or compulsion, whether
legal,  economic  or  otherwise.  Accordingly,  the terms and provisions of this
Stock  Purchase  Agreement shall be interpreted and construed in accordance with
their usual and customary meanings, and each of the Parties hereto hereby waives
the  application  in connection with the interpretation and construction of this
Stock  Purchase  Agreement  of  any  rule of law to the effect that ambiguous or
conflicting terms or provisions contained in this Stock Purchase Agreement shall
be  interpreted  or  construed  against  the  Party  whose attorney prepared the
executed  draft  or  any  earlier  draft  of  this  Stock  Purchase  Agreement.

     8.17  Counterparts.  This  Stock  Purchase  Agreement  may  be  signed  in
counterparts,  each  and  every  one  of  which  shall  be  deemed  an original,
notwithstanding  variations  in format or file designation which may result from
the  electronic  transmission,  storage  and  printing  of  copies of this Stock
Purchase  Agreement  from  separate computers or printers.  Facsimile signatures
shall  be  treated  as  original  signatures.

     8.18  Finder's  Fees.

          8.18.1  Exelixis  (i)  represents and warrants that it has retained no
investment  bankers,  finders  or  brokers  in  connection with the transactions
contemplated  by  this  Stock  Purchase  Agreement  and  (ii)  hereby  agrees to
indemnify  and to hold GSK harmless of and from any costs, expenses or liability
for  any  commission  or  compensation  in  the  nature of a finder's fee to any
investment  banker, finder, broker or other Person or firm (including legal fees
and  other  costs  and  expense  of defending against such liability or asserted
liability)  for  which  it,  or  any  of  its  employees or representatives, are
responsible.

          8.18.2  GSK  (i)  represents  and  warrants  that  it  has retained no
investment  bankers,  finders  or  brokers  in  connection with the transactions
contemplated  by  this  Stock  Purchase  Agreement  and  (ii)  hereby  agrees to
indemnify  and  hold  Exelixis  harmless  of  and  from  any  costs, expenses or
liability  for any commission or compensation in the nature of a finder's fee to
any  investment  banker, finder, broker or other Person or firm (including legal
fees and other costs and expense of defending against such liability or asserted
liability)  for  which  it,  or  any  of  its  employees or representatives, are
responsible.

     8.19  Waiver  of  Jury  Trial.  EACH  PARTY  HERETO  HEREBY  WAIVES, TO THE
FULLEST  EXTENT  PERMITTED BY APPLCABLE LAW, ANY RIGHT IT MAY HAVE TO A TRIAL BY
JURY  IN  RESPECT TO ANY LITIGATION DIRECTLY OR INDIRECTLY ARISING OUT OF, UNDER
OR  IN  CONNECTION  WITH  THIS STOCK AGREEMENT.  EACH PARTY HERETO (i) CERTIFIES
THAT  NO  REPRESENTATIVE,  AGENT OR ATTORNEY OF ANY OTHER PARTY HAS REPRESENTED,
EXPRESSLY  OR  OTHERWISE,  THAT  SUCH  OTHER  PARTY  WOULD  NOT, IN THE EVENT OF
LITIGATION, SEEK TO ENFORCE THAT FOREGOING WAIVER, AND (ii) ACKNOWLEDGES THAT IT
AND  THE  OTHER  PARTIES  HERETO  HAVE  BEEN  INDUCED  TO  ENTER INTO THIS STOCK
AGREEMENT  AND  ANY  RELATED INSTRUMENTS, AS APPLICABLE, BY, AMONG OTHER THINGS,
THE  MUTUAL  WAIVERS  AND  CERTIFICATIONS  IN  THIS  SECTION  8.19.

                   [BALANCE OF PAGE INTENTIONALLY LEFT BLANK]

<PAGE>
     IN WITNESS WHEREOF, the Parties have executed this Stock Purchase Agreement
by  their  duly  authorized  representatives as of the date first written above.

EXELIXIS,  INC.                          SMITHKLINE  BEECHAM  CORPORATION

By:     /s/  Bob  Myers                  By:     /s/  Donald  F.  Parman
        ---------------------------              --------------------------

Title:  Executive  Vice  President,      Title: Vice President & Secretary
        ---------------------------             ---------------------------
        Pharmaceuticals
        ---------------

[  *  ] = Certain confidential information contained in this document, marked by
brackets, has been omitted and filed separately with the Securities and Exchange
Commission  pursuant  to  Rule  24b-2 of the Securities Exchange Act of 1934, as
amended.

<PAGE>

                                  SCHEDULE 4.3

                       SCHEDULE OF OUTSTANDING SECURITIES

Not  applicable  at  the  Initial  Closing.

<PAGE>

                                  SCHEDULE 4.6

                      DISCLOSURE OF OUTSTANDING LITIGATION

None.

<PAGE>

                                    EXHIBIT A

                          FORM OF OFFICER'S CERTIFICATE

     TO:     SMITHKLINE  BEECHAM  CORPORATION

I  am the duly appointed [Chief Financial Officer] of Exelixis, Inc., a Delaware
corporation ("Exelixis"), and am duly authorized to execute this certificate for
and  on  behalf  of  Exelixis.  For  the  purposes  of  this certificate, "Stock
Purchase  Agreement" means the Stock Purchase and Stock Issuance Agreement dated
as  of  October  28,  2002  by  and  between  SmithKline Beecham Corporation and
Exelixis  and, unless the context otherwise requires, the capitalized terms used
in  this  certificate  shall  have  the  meanings  ascribed to them in the Stock
Purchase  Agreement.

I  do hereby certify in my capacity as [Chief Financial Officer] of Exelixis, on
behalf  of  Exelixis  and  not  in  my  personal  capacity,  as  follows.

1.   The  representations  and  warranties of Exelixis as set forth in the Stock
     Purchase  Agreement are true and correct as of the Closing Date, as if made
     as  of  such  date;  and

2.   No  events  which  have  had  a  Material  Adverse  Effect on Exelixis have
     occurred  during  the  period  used  to calculate the purchase price of the
     shares  of  Common  Stock  of  Exelixis  subject  to  the  Closing.

DATED  at  ______________,  California,  this  __  day  of  _________,  200_.

EXELIXIS,  INC.
by  its  authorized  signatory:

_______________________________________

<PAGE>
                                    EXHIBIT B

                       FORM OF COOLEY GODWARD LLP OPINION

1.   Exelixis,  Inc.  (the  "Company") has been duly incorporated and is validly
     existing  as  a corporation in good standing under the laws of the State of
     Delaware.  The Company is qualified as a foreign corporation to do business
     and  is in good standing in the State of California and, to the best of our
     knowledge,  is  not  required  to  qualify  as  a foreign corporation to do
     business  in  any  other  jurisdiction  in  the  United  States.

2.   The  Company  has  the  corporate  power  and authority to own or lease its
     property  and  to  conduct  its  business  as  currently  conducted  and as
     described  in  the  SEC  Filings,  and  to  enter  into  the Stock Purchase
     Agreement,  issue  the  Shares and to carry out and perform its obligations
     under  the  Stock  Purchase  Agreement.

3.   The  Stock  Purchase  Agreement  has  been  duly  authorized,  executed and
     delivered  by, and is a legal, valid and binding agreement of, the Company,
     enforceable  in  accordance  with  its  terms, except as enforcement may be
     limited  by  applicable  bankruptcy,  insolvency  or similar laws affecting
     creditors' rights generally and subject to general principles of equity and
     to  limitations  on  availability  of  equitable relief, including specific
     performance,  and  except  as  rights  to  indemnification in Section 7.1.6
     thereof  may  be  limited  under  applicable  law.

4.   The  Shares  have  been  duly  authorized and, when issued and delivered in
     accordance  with the terms of the Stock Purchase Agreement, will be validly
     issued, fully paid and non-assessable, and the issuance of such Shares will
     not  be  subject  to  any  preemptive or, to our knowledge, similar rights.

5.   With  respect  to  the  issuance of Initial Shares and Option Shares: Based
     upon  the  representations, warranties and agreements of SmithKline Beecham
     Corporation (the "Purchaser") in Article 5 of the Stock Purchase Agreement,
     the  offer and sale of the Shares to the Purchaser under the Stock Purchase
     Agreement  are  exempt from the registration requirements of the Securities
     Act.

     With  respect  to  the issuance of Stock Repayment Shares: The registration
     statement  covering  the Shares was declared effective under the Securities
     Act  at  ______ [a.m./p.m.] on ___________, 20__, and, to our knowledge, no
     stop  order suspending the effectiveness of such registration statement has
     been  issued  and,  to  our  knowledge,  no  proceeding by the SEC for that
     purpose  is  pending.

6.   The  execution and delivery of the Stock Purchase Agreement will not result
     in any violation of, be in conflict with, or constitute a default under (i)
     any  provision  of  the  Company's  Amended  and  Restated  Certificate  of
     Incorporation  or  Amended and Restated Bylaws or (ii) any provision of any
     judgment, decree or order to which the Company is a party or by which it is
     bound  and  of  which  we  have  knowledge.

<PAGE>
                                    EXHIBIT C

                             INSTRUMENT OF ADHERENCE

     Reference  is hereby made to that certain Stock Purchase and Stock Issuance
Agreement,  dated  as  of  October  28, 2002, between Exelixis, Inc., a Delaware
corporation  ("Exelixis"), and SmithKline Beecham Corporation ("GSK"), as may be
amended  and  in  effect  from  time  to  time (the "Stock Purchase Agreement").
Capitalized  terms  used  herein  without  definition  shall have the respective
meanings  ascribed  thereto  in  the  Agreement.

     The  undersigned, in order to become the owner or holder of _______________
shares  (the  "Transferred  Shares")  of Common Stock of Exelixis, hereby agrees
that,  from and after the date hereof, the undersigned has become a party to the
Stock  Purchase Agreement in the capacity of a Permitted Transferee with respect
to such Transferred Shares, and is entitled to all of the benefits under, and is
subject  to  all  of the obligations, restrictions and limitations set forth in,
the Stock Purchase Agreement that are applicable to Permitted Transferees.  This
Instrument  of  Adherence shall take effect and shall become a part of the Stock
Purchase  Agreement  immediately  upon  execution.

     Executed  under  seal  as  of  the  date  set forth below under the laws of
________________.

                                         Signature:_____________________
                                                   Name:
                                                   Title:

Accepted:

Exelixis,  Inc.

By:________________________
   Name:
   Title:
   Date:[  *  ] = Certain confidential information contained in this document, marked by
brackets, has been omitted and filed separately with the Securities and Exchange
Commission  pursuant  to  Rule  24b-2 of the Securities Exchange Act of 1934, as
amended.

                                                                   Exhibit 10.38

                           LOAN AND SECURITY AGREEMENT

                                     BETWEEN

                         SMITHKLINE BEECHAM CORPORATION

                                       AND

                                 EXELIXIS, INC.

                                   DATED AS OF

                                OCTOBER 28, 2002

<PAGE>
                                  TABLE OF CONTENTS

ARTICLE 1 DEFINITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . .    1
     Advance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    1
     Affiliate. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    1
     Biotechnology Company. . . . . . . . . . . . . . . . . . . . . . . . .    2
     Borrowing Date . . . . . . . . . . . . . . . . . . . . . . . . . . . .    2
     Borrowing Notice . . . . . . . . . . . . . . . . . . . . . . . . . . .    2
     Business Day . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    2
     Capital Equipment. . . . . . . . . . . . . . . . . . . . . . . . . . .    2
     Change in Control. . . . . . . . . . . . . . . . . . . . . . . . . . .    2
     Change in Control Rate of Interest . . . . . . . . . . . . . . . . . .    2
     Collateral . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    2
     Common Stock . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    2
     Contract Year. . . . . . . . . . . . . . . . . . . . . . . . . . . . .    2
     Default Rate of Interest . . . . . . . . . . . . . . . . . . . . . . .    2
     Deposit Account. . . . . . . . . . . . . . . . . . . . . . . . . . . .    2
     Development Agreement. . . . . . . . . . . . . . . . . . . . . . . . .    2
     Development Candidate. . . . . . . . . . . . . . . . . . . . . . . . .    2
     Development Candidate Inventory. . . . . . . . . . . . . . . . . . . .    3
     Development Compound . . . . . . . . . . . . . . . . . . . . . . . . .    3
     Development Expiration Date. . . . . . . . . . . . . . . . . . . . . .    3
     Development Program. . . . . . . . . . . . . . . . . . . . . . . . . .    3
     Development Term . . . . . . . . . . . . . . . . . . . . . . . . . . .    3
     Dollars. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    3
     DWAC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    3
     Effective Date . . . . . . . . . . . . . . . . . . . . . . . . . . . .    3
     Environmental Laws . . . . . . . . . . . . . . . . . . . . . . . . . .    3
     ERISA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    3
     Event of Default . . . . . . . . . . . . . . . . . . . . . . . . . . .    3
     Exchange Act . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    3
     Excluded Collateral. . . . . . . . . . . . . . . . . . . . . . . . . .    3
     Executive Officers . . . . . . . . . . . . . . . . . . . . . . . . . .    3
     Expanded Program Option. . . . . . . . . . . . . . . . . . . . . . . .    3
     Extension Period . . . . . . . . . . . . . . . . . . . . . . . . . . .    3
     Fair Market Value. . . . . . . . . . . . . . . . . . . . . . . . . . .    3
     GAAP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    4
     General Advance(s) . . . . . . . . . . . . . . . . . . . . . . . . . .    4
     Governmental Entity. . . . . . . . . . . . . . . . . . . . . . . . . .    4
     HSR Act. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    4
     Included Compounds . . . . . . . . . . . . . . . . . . . . . . . . . .    4
     Initial Advance. . . . . . . . . . . . . . . . . . . . . . . . . . . .    4
     Intellectual Property. . . . . . . . . . . . . . . . . . . . . . . . .    4
     Legal Proceeding . . . . . . . . . . . . . . . . . . . . . . . . . . .    4
     LIBOR. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    4
     Limited Program Option . . . . . . . . . . . . . . . . . . . . . . . .    4
     Loan Agreement . . . . . . . . . . . . . . . . . . . . . . . . . . . .    4
     Loan Documents . . . . . . . . . . . . . . . . . . . . . . . . . . . .    4
     Major Pharmaceutical Company . . . . . . . . . . . . . . . . . . . . .    5
     Material Adverse Effect. . . . . . . . . . . . . . . . . . . . . . . .    5
     Maturity Date. . . . . . . . . . . . . . . . . . . . . . . . . . . . .    5
     Maximum Loan Amount. . . . . . . . . . . . . . . . . . . . . . . . . .    5
     National Securities Market . . . . . . . . . . . . . . . . . . . . . .    5
     Note . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    5
     Obligations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    5
     Operating Documents. . . . . . . . . . . . . . . . . . . . . . . . . .    5
     OSHA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    5
     Party. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    5
     Patents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    5
     Patent Office Filing . . . . . . . . . . . . . . . . . . . . . . . . .    5
     Payment Date . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    5
     Person . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    6
     Proceeds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    6
     Product Specific Advance(s). . . . . . . . . . . . . . . . . . . . . .    6
     Repayment Period . . . . . . . . . . . . . . . . . . . . . . . . . . .    6
     SEC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    6
     SEC Affiliate. . . . . . . . . . . . . . . . . . . . . . . . . . . . .    6
     SEC Filings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    6
     Securities Account Control Agreement . . . . . . . . . . . . . . . . .    6
     Securities Act . . . . . . . . . . . . . . . . . . . . . . . . . . . .    6
     Stock Purchase Agreement . . . . . . . . . . . . . . . . . . . . . . .    6
     Stock Repayment. . . . . . . . . . . . . . . . . . . . . . . . . . . .    6
     Stock Repayment Amount . . . . . . . . . . . . . . . . . . . . . . . .    6
     Stock Repayment Closing Date(s). . . . . . . . . . . . . . . . . . . .    6
     Stock Repayment Notice . . . . . . . . . . . . . . . . . . . . . . . .    6
     Stock Repayment Shares . . . . . . . . . . . . . . . . . . . . . . . .    6
     Tangible Net Worth . . . . . . . . . . . . . . . . . . . . . . . . . .    6
     Term . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    7
     Third Party. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    7
     Total Advance Amount . . . . . . . . . . . . . . . . . . . . . . . . .    7
     Trading Day. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    7
     Transaction Documents. . . . . . . . . . . . . . . . . . . . . . . . .    7
     UCC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    7
     UCC Financing Statement(s) . . . . . . . . . . . . . . . . . . . . . .    7
     United States or U.S.. . . . . . . . . . . . . . . . . . . . . . . . .    7
     Working Capital. . . . . . . . . . . . . . . . . . . . . . . . . . . .    7
     Accounting Terms . . . . . . . . . . . . . . . . . . . . . . . . . . .    7
     Other Definitional Provisions. . . . . . . . . . . . . . . . . . . . .    7
ARTICLE 2 AMOUNT AND TERMS OF CREDIT. . . . . . . . . . . . . . . . . . . .    8
     Commitment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    8
       General Advances . . . . . . . . . . . . . . . . . . . . . . . . . .    8
       Product Specific Advances. . . . . . . . . . . . . . . . . . . . . .    8
     Borrowing Notices. . . . . . . . . . . . . . . . . . . . . . . . . . .    8
     Disbursement of Advances . . . . . . . . . . . . . . . . . . . . . . .    9
SECURITY INTEREST . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    9
     Grant of Security Interest . . . . . . . . . . . . . . . . . . . . . .    9
       Development Patents. . . . . . . . . . . . . . . . . . . . . . . . .    9
       Other Intellectual Property. . . . . . . . . . . . . . . . . . . . .    9
       Deposit Account. . . . . . . . . . . . . . . . . . . . . . . . . . .    9
       Development Candidate Inventory. . . . . . . . . . . . . . . . . . .    9
       Capital Equipment. . . . . . . . . . . . . . . . . . . . . . . . . .    9
       Proceeds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    9
ARTICLE 4 INTEREST. . . . . . . . . . . . . . . . . . . . . . . . . . . . .    9
       Advances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    9
       Default Rate of Interest . . . . . . . . . . . . . . . . . . . . . .   10
       Change of Control Rate of Interest . . . . . . . . . . . . . . . . .   10
       Interest Computations. . . . . . . . . . . . . . . . . . . . . . . .   10
ARTICLE 5 REPAYMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . .   10
     Repayment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   10
     Payments on Non-Business Day . . . . . . . . . . . . . . . . . . . . .   10
     Cash Payment Procedures. . . . . . . . . . . . . . . . . . . . . . . .   10
     Milestone Payments . . . . . . . . . . . . . . . . . . . . . . . . . .   10
     Optional Cash Prepayments. . . . . . . . . . . . . . . . . . . . . . .   11
     Repayment By Common Stock. . . . . . . . . . . . . . . . . . . . . . .   11
       Exercise of Issuance Rights. . . . . . . . . . . . . . . . . . . . .   11
       Limitation on Ownership. . . . . . . . . . . . . . . . . . . . . . .   11
       Stock Repayment Notice . . . . . . . . . . . . . . . . . . . . . . .   11
       Delivery of Stock Repayment Shares . . . . . . . . . . . . . . . . .   12
       Conditions Precedent to Each Issuance of Stock Repayment Shares. . .   12
ARTICLE 6 CONDITIONS PRECEDENT. . . . . . . . . . . . . . . . . . . . . . .   13
     Conditions Precedent to Initial Advance. . . . . . . . . . . . . . . .   13
       Loan Documents . . . . . . . . . . . . . . . . . . . . . . . . . . .   13
       Supporting Documents . . . . . . . . . . . . . . . . . . . . . . . .   13
       Perfection of Liens. . . . . . . . . . . . . . . . . . . . . . . . .   13
     Conditions Precedent to All Advances . . . . . . . . . . . . . . . . .   13
       Borrowing Notice . . . . . . . . . . . . . . . . . . . . . . . . . .   14
       No Event of Default. . . . . . . . . . . . . . . . . . . . . . . . .   14
       No Termination under the Development Agreement . . . . . . . . . . .   14
       Correctness of Representations . . . . . . . . . . . . . . . . . . .   14
       No Material Adverse Effect . . . . . . . . . . . . . . . . . . . . .   14
       Limitations Not Exceeded . . . . . . . . . . . . . . . . . . . . . .   14
       Use of Proceeds. . . . . . . . . . . . . . . . . . . . . . . . . . .   14
       Additional Documents . . . . . . . . . . . . . . . . . . . . . . . .   14
CHANGE OF CONTROL . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   14
     Condition Precedent to Disbursement of Second General Advance. . . . .   14
       Exelixis Expenditures. . . . . . . . . . . . . . . . . . . . . . . .   14
     Conditions Precedent to Disbursement of All Product Specific Advances.   15
       Exelixis' Selection of a Development Candidate . . . . . . . . . . .   15
       Marketable Title to Development Candidate Intellectual Property. . .   15
REPRESENTATIONS AND WARRANTIES OF EXELIXIS . . .. . . . . . . . . . . . . .   15
     Organization, Good Standing and Qualification. . . . . . . . . . . . .   15
     Authorization; Due Execution . . . . . . . . . . . . . . . . . . . . .   16
     Valid Issuance of Stock. . . . . . . . . . . . . . . . . . . . . . . .   16
     SEC Filings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   16
     Governmental Consents. . . . . . . . . . . . . . . . . . . . . . . . .   16
     No Conflict. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   16
     Litigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   17
     Compliance with Law. . . . . . . . . . . . . . . . . . . . . . . . . .   17
     Title to the Collateral. . . . . . . . . . . . . . . . . . . . . . . .   17
     No Event of Default/Breach . . . . . . . . . . . . . . . . . . . . . .   17
     Intellectual Property. . . . . . . . . . . . . . . . . . . . . . . . .   17
     Effect of Representations and Warranties . . . . . . . . . . . . . . .   18
ARTICLE 8 REPRESENTATIONS AND WARRANTIES OF GSK . . . . . . . . . . . . . .   18
     Authorization; Due Execution . . . . . . . . . . . . . . . . . . . . .   18
ARTICLE 9 COVENANTS . . . . . . . . . . . . . . . . . . . . . . . . . . . .   18
     Keeping of Books . . . . . . . . . . . . . . . . . . . . . . . . . . .   18
     SEC Reporting Requirem . . . . . . . . . . . . . . . . . . . . . . . .   19
     Maintenance of Rights and Existence. . . . . . . . . . . . . . . . . .   19
     Governmental and Other Approvals . . . . . . . . . . . . . . . . . . .   19
     Use of Proceeds. . . . . . . . . . . . . . . . . . . . . . . . . . . .   19
     Further Assurances . . . . . . . . . . . . . . . . . . . . . . . . . .   19
     Compliance with the Laws . . . . . . . . . . . . . . . . . . . . . . .   19
     Litigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   20
     Payment of Taxes . . . . . . . . . . . . . . . . . . . . . . . . . . .   20
     Access to Records and Property . . . . . . . . . . . . . . . . . . . .   20
     Preservation of Title to Collateral. . . . . . . . . . . . . . . . . .   20
     Insurance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   20
     Intellectual Property. . . . . . . . . . . . . . . . . . . . . . . . .   20
     Fees and Expenses in Protecting Rights . . . . . . . . . . . . . . . .   21
     Capital Equipment. . . . . . . . . . . . . . . . . . . . . . . . . . .   21
     Deposit Account. . . . . . . . . . . . . . . . . . . . . . . . . . . .   21
     Duration of Covenants. . . . . . . . . . . . . . . . . . . . . . . . .   21
ARTICLE 10 COVENANTS REGARDING PROHIBITED TRANSACTIONS. . . . . . . . . . .   21
     Permitted Liens. . . . . . . . . . . . . . . . . . . . . . . . . . . .   22
     Impairment of Title to Collateral. . . . . . . . . . . . . . . . . . .   22
     Settlements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   22
     Change of Location or Name . . . . . . . . . . . . . . . . . . . . . .   22
     Inconsistent Agreement . . . . . . . . . . . . . . . . . . . . . . . .   22
     Violation of Representations, Warranties and Covenants . . . . . . . .   22
ARTICLE 11 FINANCIAL COVENANTS . . .. . . . . . . . . . . . . . . . . . . .   22
     Working Capital. . . . . . . . . . . . . . . . . . . . . . . . . . . .   22
     Tangible Net Worth . . . . . . . . . . . . . . . . . . . . . . . . . .   23
ARTICLE 12 EVENTS OF DEFAULT. . . . . . . . . . . . . . . . . . . . . . . .   23
     Events of Default. . . . . . . . . . . . . . . . . . . . . . . . . . .   23
       Failure to Pay . . . . . . . . . . . . . . . . . . . . . . . . . . .   23
       Other Defaults under the Loan Documents. . . . . . . . . . . . . . .   23
       Termination of Development Agreement . . . . . . . . . . . . . . . .   23
       Other Specific Events. . . . . . . . . . . . . . . . . . . . . . . .   23
       Insolvency; Bankruptcy . . . . . . . . . . . . . . . . . . . . . . .   23
ARTICLE 13 GSKRIGHTS AND REMEDIES UPON DEFAULT. . . . . . . . . . . . . . .   24
     Rights and Remedies. . . . . . . . . . . . . . . . . . . . . . . . . .   24
     Application of Proceeds of Disposition of Collateral . . . . . . . . .   25
     Notice of Disposition of Collateral. . . . . . . . . . . . . . . . . .   25
     Marshalling of Assets. . . . . . . . . . . . . . . . . . . . . . . . .   25
     Waiver of Defaults . . . . . . . . . . . . . . . . . . . . . . . . . .   26
     Remedies Cumulative. . . . . . . . . . . . . . . . . . . . . . . . . .   26
     Waiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   26
ARTICLE 14 GSKRIGHTS AND REMEDIES EXCLUSIVE OF DEFAULT. . . . . . . . . . .   26
     UCC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   26
     Preservation of Collateral . . . . . . . . . . . . . . . . . . . . . .   26
     Power of Attorney. . . . . . . . . . . . . . . . . . . . . . . . . . .   27
ARTICLE 15 INDEMNIFICATION. . . . . . . . . . . . . . . . . . . . . . . . .   27
     Indemnification of GSK . . . . . . . . . . . . . . . . . . . . . . . .   27
ARTICLE 16 MISCELLANEOUS. . . . . . . . . . . . . . . . . . . . . . . . . .   27
     Publicity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   27
     Dispute Resolution . . . . . . . . . . . . . . . . . . . . . . . . . .   27
     Choice of Law. . . . . . . . . . . . . . . . . . . . . . . . . . . . .   28
     Subordination. . . . . . . . . . . . . . . . . . . . . . . . . . . . .   28
     Notices. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   28
     Severability . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   29
     Entire Agreement . . . . . . . . . . . . . . . . . . . . . . . . . . .   29
     Headings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   29
     Use of Name. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   29
     Further Actions. . . . . . . . . . . . . . . . . . . . . . . . . . . .   29
     Waiver of Jury Trial . . . . . . . . . . . . . . . . . . . . . . . . .   30
     Parties in Interest. . . . . . . . . . . . . . . . . . . . . . . . . .   30
     Construction of Agreement. . . . . . . . . . . . . . . . . . . . . . .   30
     No Liability for GSK . . . . . . . . . . . . . . . . . . . . . . . . .   30
     Survival of Representations. . . . . . . . . . . . . . . . . . . . . .   30
     No Usury . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   30
     Assignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   31
COUNTERPARTS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   31
COUNTERPARTS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   31
EXHIBIT A PROMISSORY NOTE . . . . . . . . . . . . . . . . . . . . . . . . .  1-A
SCHEDULE 1-PROMISSORY NOTE. . . . . . . . . . . . . . . . . . . . . . . . .  1-B
SCHEDULE OF GENERAL ADVANCES. . . . . . . . . . . . . . . . . . . . . . . .  1-B
SCHEDULE OF PRODUCT SPECIFIC ADVANCES . . . . . . . . . . . . . . . . . . .  1-B
EXHIBIT B FORM OF PATENT OFFICE FILING. . . . . . . . . . . . . . . . . . .  1-C
ARTICLE 1 DEFINITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . .  1-C
     Affiliate. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  1-C
CAPITAL EQUIPMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  2-C
     Collateral . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  2-C
DEPOSIT ACCOUNT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  2-C
     Development Agreement. . . . . . . . . . . . . . . . . . . . . . . . .  2-C
DEVELOPMENT CANDIDATE . . . . . . . . . . . . . . . . . . . . . . . . . . .  2-C
DEVELOPMENT CANDIDATE INVENTORY . . . . . . . . . . . . . . . . . . . . . .  2-C
DEVELOPMENT COMPOUND . .  . . . . . . . . . . . . . . . . . . . . . . . . .  2-C
ENVIRONMENTAL LAWS. . . . . . . . . . . . . . . . . . . . . . . . . . . . .  2-C
     Event of Default . . . . . . . . . . . . . . . . . . . . . . . . . . .  2-C
Included Compounds . .  . . . . . . . . . . . . . . . . . . . . . . . . . .  2-C
Intellectual Property . . . . . . . . . . . . . . . . . . . . . . . . . . .  2-C
     Loan Agreement . . . . . . . . . . . . . . . . . . . . . . . . . . . .  2-C
     Loan Documents . . . . . . . . . . . . . . . . . . . . . . . . . . . .  2-C
Material Adverse Effect . . . . . . . . . . . . . . . . . . . . . . . . . .  2-C
     Obligations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  3-C
     Patents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  3-C
     Patent Office Filing . . . . . . . . . . . . . . . . . . . . . . . . .  3-C
     Person . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  3-C
     Proceeds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  3-C
     Stock Purchase Agreement . . . . . . . . . . . . . . . . . . . . . . .  3-C
     Third Party. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  3-C
     Transaction Documents. . . . . . . . . . . . . . . . . . . . . . . . .  3-C
     United States or U.S.. . . . . . . . . . . . . . . . . . . . . . . . .  3-C
     UCC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  3-C
     UCC Financing Statement(s) . . . . . . . . . . . . . . . . . . . . . .  3-C
     Other Definitional Provisions. . . . . . . . . . . . . . . . . . . . .  3-C
ARTICLE 2 GRANT OF SECURITY . . . . . . . . . . . . . . . . . . . . . . . .  3-C
ARTICLE 3 REPRESENTATIONS, WARRANTIES and covenants OF EXELIXIS . . . . . .  4-C
     Title to the Collateral. . . . . . . . . . . . . . . . . . . . . . . .  4-C
     Infringement of the Collateral . . . . . . . . . . . . . . . . . . . .  5-C
     Further Assurances . . . . . . . . . . . . . . . . . . . . . . . . . .  5-C
     Fees and Expenses in Protecting Rights . . . . . . . . . . . . . . . .  5-C
     Pledge of Additional Collateral. . . . . . . . . . . . . . . . . . . .  6-C
     Impairment of Title to Collateral. . . . . . . . . . . . . . . . . . .  6-C
     Preservation of Title to Collateral. . . . . . . . . . . . . . . . . .  6-C
ARTICLE 4 GSK'S APPOINTMENT AS ATTORNEY-IN-FACT.  . . . . . . . . . . . . .  6-C
APPOINTMENT OF GSK AS ATTORNEY-IN-FACT. . . . . . . . . . . . . . . . . . .  6-C
ARTICLE 5 EVENTS OF DEFAULT . . . . . . . . . . . . . . . . . . . . . . . .  7-C
ARTICLE 6 REMEDIES. . . . . . . . . . . . . . . . . . . . . . . . . . . . .  7-C
ARTICLE 7 EXECUTION OF SPECIAL POWER OF ATTORNEY. . . . . . . . . . . . . .  7-C
ARTICLE 8 MISCELLANEOUS . . . . . . . . . . . . . . . . . . . . . . . . . .  8-C
     Amendments and Modification. . . . . . . . . . . . . . . . . . . . . .  8-C
     Parties in Interest. . . . . . . . . . . . . . . . . . . . . . . . . .  8-C
     Governing Law. . . . . . . . . . . . . . . . . . . . . . . . . . . . .  8-C
     Notices. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  8-C
     Counterparts . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  8-C
     Headings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  8-C
     Acknowledgment of Receipt. . . . . . . . . . . . . . . . . . . . . . .  8-C
     No Waiver. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  8-C
     Severability . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  8-C
     Interest Granted to GSK. . . . . . . . . . . . . . . . . . . . . . . .  9-C
     WAIVER OF JURY TRIAL . . . . . . . . . . . . . . . . . . . . . . . . .  9-C
Schedule 2.1.1 of the Patent Agreement. . . . . . . . . . . . . . . . . . .  1-D
     PATENTS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  1-D
     Pending Patent Applications. . . . . . . . . . . . . . . . . . . . . .  1-D
EXHIBIT A OF THE PATENT AGREEMENT . . . . . . . . . . . . . . . . . . . . .  1-E
     FORM OF SPECIAL POWER OF ATTORNEY. . . . . . . . . . . . . . . . . . .  1-E
     FORM OF SECURITIES ACCOUNT CONTROL AGREEMENT . . . . . . . . . . . . .  1-F
EXHIBIT D. . . . . . . . . . . . . . . . .  . . . . . . . . . . . . . . . .  1-G
     FORM OF BORROWING NOTICE . . . . . . . . . . . . . . . . . . . . . . .  1-G
EXHIBIT E. . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . .  1-H
     FORM OF STOCK REPAYMENT NOTICE . . . . . . . . . . . . . . . . . . . .  1-H
SCHEDULE 3.1.1 PATENTS. . . . . . . . . . . . . . . . . . . . . . . . . . .  1-I
SCHEDULE 3.1.3 DEPOSIT ACCOUNT. . . . . . . . . . . . . . . . . . . . . . .  1-J
SCHEDULE 9.1 LOCATION OF THE COLLATERAL . . . . . . . . . . . . . . . . . .  1-K
SCHEDULE 9.16 PERMITTED INVESTMENTS . . . . . . . . . . . . . . . . . . . .  1-L
SCHEDULE 16.4 INDEBTEDNESS. . . . . . . . . . . . . . . . . . . . . . . . .  1-M

<PAGE>

                                LIST OF EXHIBITS

EXHIBIT  A                                NOTE

EXHIBIT  B                                PATENT  OFFICE  FILING

EXHIBIT  C                                SECURITIES  ACCOUNT CONTROL AGREEMENT

EXHIBIT  D                                BORROWING  NOTICE

EXHIBIT  E                                STOCK  REPAYMENT  NOTICE

                                LIST OF SCHEDULES

SCHEDULE  3.1.1                           PATENTS

SCHEDULE  3.1.3                           DEPOSIT  ACCOUNT

SCHEDULE  9.1                             LOCATION  OF  THE  COLLATERAL

SCHEDULE  9.16                            PERMITTED INVESTMENTS

SCHEDULE  16.4                            INDEBTEDNESS

[  *  ] = Certain confidential information contained in this document, marked by
brackets, has been omitted and filed separately with the Securities and Exchange
Commission  pursuant  to  Rule  24b-2 of the Securities Exchange Act of 1934, as
amended.

                           LOAN AND SECURITY AGREEMENT

     THIS  LOAN  AND SECURITY AGREEMENT (the "Loan Agreement") is executed as of
the  28th  day  of October, 2002 (the "Effective Date") by and between Exelixis,
Inc., a Delaware corporation ("Exelixis"), and SmithKline Beecham Corporation, a
Pennsylvania  corporation,  doing business as GlaxoSmithKline ("GSK").  Exelixis
and GSK are each referred to herein by name or as a "Party" or, collectively, as
"Parties".

                                    RECITALS

     A.  Exelixis  and  GSK  have  entered into that certain Product Development
and  Commercialization  Agreement  of  even  date  herewith  (the  "Development
Agreement") and that certain Stock Purchase and Stock Issuance Agreement of even
date  herewith  (the  "Stock  Purchase  Agreement");

     B.  In  connection  with,  and as a condition of, Exelixis and GSK entering
into  the  Development  Agreement and the Stock Purchase Agreement, Exelixis and
GSK have agreed to enter into this Loan Agreement pursuant to which Exelixis may
obtain  during  the  Development  Term  (as  defined  below), from time to time,
certain  loans  from  GSK, subject to the terms and conditions stated herein for
amounts  up  to  the  Maximum  Loan  Amount  (as  defined  below);  and

     C.  GSK  is  willing  to  provide such loans to, and in favor of, Exelixis,
subject  to  the  terms  and  conditions  of  this  Loan  Agreement.

     NOW,  THEREFORE,  in  consideration  of  the  premises and mutual covenants
herein contained, and for other good and valuable consideration, the receipt and
sufficiency  of  which  are  hereby  acknowledged,  the Parties, intending to be
legally  bound,  hereto  agree  as  follows:

                                    ARTICLE 1
                                   DEFINITIONS

     Unless  otherwise  defined  in  this  Loan Agreement, all capitalized terms
shall  have  the  meanings  given them in the Development Agreement or the Stock
Purchase  Agreement,  as  applicable.  As  used  in  this  Loan  Agreement,  the
following  terms  shall  have  the  following  respective  meanings:

     1.1  "Advance"  shall  mean  a  loan  made,  or  to  be  made,  pursuant to
Article  2,  which may be in the form of a General Advance or a Product Specific
Advance.

     1.2  "Affiliate"  shall mean any Person, whether de jure or de facto, which
directly  or  indirectly  through  one  (1)  or more intermediaries controls, is
controlled  by,  or is under common control with, a Party to the Loan Documents.
A Person shall be deemed to "control" another Person if it (a) owns, directly or
indirectly,  beneficially  or  legally,  at  least  fifty  percent  (50%) of the
outstanding  voting securities or capital stock (or such lesser percentage which
is  the maximum allowed to be owned by a Person in a particular jurisdiction) of
such  other  Person,  or has other comparable ownership interest with respect to
any  Person  other than a corporation; or (b) has the power, whether pursuant to
contract,  ownership  of  securities  or otherwise, to direct the management and
policies  of  the  Person.

     1.3  "Biotechnology  Company"  shall  mean  any  Person  other than a Major
Pharmaceutical  Company.

     1.4  "Borrowing  Date"  shall  mean  any  Business  Day on which an Advance
occurs.

     1.5  "Borrowing  Notice"  shall  have  the meaning assigned to such term in
Section  2.2.

     1.6  "Business  Day"  shall  mean any day, other than a Saturday, Sunday or
other  day  in  which  commercial banks are authorized or required in the United
States  to  be  closed.

     1.7  "Capital  Equipment"  shall  have the meaning assigned to such term in
Section  3.1.5.

     1.8  "Change  in  Control"  shall  mean a transaction in which [ * ].

     1.9  "Change  in  Control  Rate  of  Interest" shall mean the fixed rate of
interest  per  annum  equal  to  [*].

     1.10  "Collateral"  shall have the meaning assigned to such term in Section
3.1.

     1.11  "Common  Stock"  shall  mean  the common stock of Exelixis, par value
$0.001  per  share.

     1.12  "Contract Year" shall mean a year of 365 days (or 366 in a leap year)
beginning  on  the  Effective  Date and ending one (1) year thereafter and so on
year-by-year  during  the  Term.  "Contract  Year One" shall mean the first such
year;  "Contract  Year  Two"  shall  mean  the  second  such  year,  and  so on,
year-by-year.

     1.13  "Default  Rate of Interest" shall mean the fixed rate of interest per
annum  equal  to  [*].

     1.14  "Deposit  Account"  shall  have  the meaning assigned to such term in
Section  3.1.3.

     1.15  "Development  Agreement" shall have the meaning assigned to such term
in  the  Recitals.

     1.16  "Development  Candidate" shall have the meaning assigned to such term
in  the  Development  Agreement.

     1.17  "Development  Candidate Inventory" shall have the meaning assigned to
such  term  in  Section  3.1.4.

     1.18 "Development Compound" shall have the meaning assigned to such term in
the  Development  Agreement.

     1.19  "Development  Expiration  Date"  shall  mean  the  earliest  of  the
following:  [*]

     1.20  "Development Program" shall have the meaning assigned to such term in
the  Development  Agreement.

     1.21 "Development Term" shall have the meaning assigned to such term in the
Development  Agreement.

     1.22  "Dollars"  and the sign "$" shall mean the lawful money of the United
States.

     1.23  "DWAC"  shall  have  the  meaning  assigned  to  such term in Section
5.6.4(a).

     1.24  "Effective Date" shall mean the date of this Loan Agreement set forth
in  the  Preamble.

     1.25  "Environmental Laws" shall mean any federal, state, county, municipal
or  other  laws,  ordinances  or  regulations  pertaining  to  health  or  the
environment.

     1.26  "ERISA"  shall  mean  the  Employee Retirement Income Security Act of
1974,
as  amended.

     1.27 "Event of Default" shall mean any of those conditions or events listed
in  Article  12.

     1.28 "Exchange Act" shall have the meaning assigned to such term in Section
7.4.

     1.29  "Excluded  Collateral"  shall  mean  [*].

     1.30  "Executive  Officers"  shall  mean  the  Chief  Executive  Officer of
Exelixis, or such other person holding a similar position designated by Exelixis
from  time  to time, and the Chairman, Research and Development, Pharmaceuticals
of  GSK,  or such other person holding a similar position designated by GSK from
time  to  time.

     1.31 "Expanded Program Option" shall have the meaning assigned to such term
in  the  Development  Agreement.

     1.32 "Extension Period" shall have the meaning assigned to such term in the
Development  Agreement.

     1.33  "Fair  Market  Value" shall have the meaning assigned to such term in
Section  5.6.1.

     1.34  "GAAP"  shall  mean  United  States  generally  accepted  accounting
principles (including principles of consolidation), in effect from time to time,
consistently  applied.

     1.35  "General  Advance(s)"  shall  mean  a  loan  pursuant to the terms of
Section
2.1.1 that GSK agrees to provide to Exelixis solely for research and development
activities  pursuant  to  the terms and conditions of the Development Agreement.

     1.36  "Governmental  Entity" shall mean any nation or government, any state
or other political subdivision thereof, any central bank (or similar monetary or
regulatory  authority)  thereof,  any  entity exercising executive, legislative,
judicial, regulatory or administrative functions of or pertaining to government,
and  any  corporation  or  other  entity  owned  or controlled, through stock or
capital  ownership  or  otherwise,  by  any  of  the  foregoing.

     1.37  "HSR Act" shall mean the Hart-Scott Rodino Antitrust Improvements Act
of  1976,  as  amended.

     1.38  "Included  Compounds" shall have the meaning assigned to such term in
the  Development  Agreement.

     1.39  "Initial  Advance"  shall  have  the meaning assigned to such term in
Section  6.1.

     1.40  "Intellectual  Property" shall have the meaning assigned to such term
in  Section  3.1.2.

     1.41  "Legal  Proceeding"  shall  mean  any  action,  suit,  litigation,
arbitration,  proceeding  (including  any  civil,  criminal,  administrative,
governmental  or  appellate proceeding), hearing, inquiry, audit, examination or
investigation  commenced, brought, conducted or heard by or before, or otherwise
involving,  any  court  or  other  Governmental  Entity  or  any  arbitrator  or
arbitration  panel.

     1.42  "LIBOR"  shall  mean, with respect to the Default Rate of Interest or
Change  in Control Rate of Interest, the London inter-bank offered rate at which
United  States  Dollar deposits for a period equal to six (6) months are offered
as  such  rate  is  published in The Wall Street Journal on the date an Event of
Default  or  Change  in  Control  occurs.

     1.43  "Limited Program Option" shall have the meaning assigned to such term
in  the  Development  Agreement.

     1.44  "Loan Agreement" shall mean this loan and security agreement together
with  all  recitals  and  exhibits, schedules and attachments hereto, as each of
them  may  be  amended,  modified,  supplemented, or restated from time to time.

     1.45  "Loan  Documents"  shall  mean collectively, this Loan Agreement, the
Note,  the  UCC  Financing  Statement(s),  the  Patent  Office  Filing(s),  the
Securities  Account  Control Agreement and any other agreements, certificates or
instruments  executed  now  or  hereafter  evidencing, describing, certifying or
securing  the  Obligations,  as  such  documents  may  be  amended,  modified,
supplemented  or  restated  from  time  to  time.

     1.46  "Major  Pharmaceutical  Company" shall mean any Person that, together
with  its  Affiliates, has annual worldwide pharmaceutical sales of [*] or more.

     1.47  "Material  Adverse Effect" shall mean any material adverse effect (a)
upon  the  validity,  or  enforceability of the Loan Documents (b) on any of the
transactions  contemplated  by  the  Loan  Documents,  (c)  on  the  business,
operations,  condition  (financial  or  otherwise), performance or properties of
Exelixis  taken  as  a whole, or (d) upon the ability of Exelixis to fulfill any
Obligations.

     1.48  "Maturity  Date" shall mean the date that is three (3) years from the
Development  Expiration  Date.

     1.49  "Maximum Loan Amount" shall mean the maximum principal loan amount of
either  (a) Eighty-Five Million Dollars ($85,000,000) if GSK does not select the
Expanded  Program  Option  or  [*].

     1.50  "National  Securities  Market"  shall mean the Nasdaq National Market
System,  the  Nasdaq  Small  Cap Market and any other national public securities
exchange.

     1.51  "Note"  shall mean the promissory note together with all recitals and
exhibits,  schedules  and  attachments thereto, executed by Exelixis in favor of
GSK,  substantially in the form of Exhibit A attached hereto, as may be amended,
modified,  supplemented  or  restated  from  time  to  time.

     1.52  "Obligations"  shall  mean  all  Advances,  Total  Advance  Amount,
liabilities,  obligations, covenants and duties arising under the Loan Documents
owed  by  Exelixis  to  GSK  whether direct or indirect, absolute or contingent.

     1.53  "Operating  Documents"  shall  mean  Exelixis'  amended  and restated
certificate  of incorporation, as currently filed with the State of Delaware and
its  amended  and  restated  bylaws  in  current  form,  each  with  all  future
modifications  and  amendments  thereto.

     1.54  "OSHA"  shall mean the federal Occupational Safety and Health Act, as
amended.

     1.55  "Party"  or "Parties" shall have the meaning assigned to such term in
the  Preamble.

     1.56  "Patents"  shall  have  the  meaning assigned to such term in Section
3.1.1.

     1.57  "Patent  Office  Filing"  shall  mean  any  and all patent collateral
mortgage agreements and cover sheets between GSK and Exelixis and its Affiliates
which grant GSK a security interest, first in priority, in the Patents by filing
such  patent  collateral  mortgage agreements with the United States and foreign
Patent  and  Trademark  Offices, substantially in the form of Exhibit B attached
hereto, as may be amended, modified, supplemented or restated from time to time.

     1.58  "Payment  Date"  shall  mean any of the dates on which payment of the
Advances  and  accrued  interest  is  due  as  set  forth  in  Section  5.1.

     1.59  "Person" shall mean any individual, corporation, firm, partnership or
other  entity.

     1.60  "Proceeds"  shall  have the meaning assigned to such term in the UCC.

     1.61 "Product Specific Advance(s)" shall mean a loan pursuant the terms set
forth  in  Section  2.1.2  that  GSK  agrees  to  advance to Exelixis solely for
research  and  development  activities  with respect to a particular Development
Compound  that Exelixis elects to become a Development Candidate pursuant to the
terms  and  conditions  of  the  Development  Agreement.

     1.62 "Repayment Period" shall mean the [*] period immediately following the
Development  Expiration  Date.

     1.63 "SEC" shall mean the United States Securities and Exchange Commission.

     1.64  "SEC  Affiliate"  shall  have  the  meaning  ascribed  to  the  term
"affiliate"  under  Rule  144  of  the  Securities  Act.

     1.65  "SEC Filings" shall have the meaning assigned to such term in Section
7.4.

     1.66  "Securities  Account  Control  Agreement"  shall  mean  [*],  as such
securities  account  control agreement may be amended, modified, supplemented or
restated  from  time  to  time.

     1.67  "Securities  Act"  shall  have  the  meaning assigned to such term in
Section  7.4.

     1.68  "Stock  Purchase  Agreement"  shall have the meaning assigned to such
term  in  the  Recitals.

     1.69  "Stock  Repayment"  shall  have  the meaning assigned to such term in
Section  5.6.1.

     1.70  "Stock Repayment Amount" shall have the meaning assigned to such term
in  Section  5.6.1.

     1.71  "Stock  Repayment  Closing  Date(s)"  shall mean the Business Day set
forth  in  the  Stock  Repayment  Notice  as  the  stock repayment closing date;
provided  that each such stock repayment closing date shall be no later than the
applicable  Payment  Date.

     1.72  "Stock Repayment Notice" shall have the meaning assigned to such term
in  Section  5.6.1.

     1.73  "Stock  Repayment  Shares"  shall  mean  the  shares  of Common Stock
issuable  by  Exelixis  to GSK to pay all or any portion of the then outstanding
principal  balance  of the Advances and all accrued interest thereon pursuant to
Section  5.6.

     1.74  "Tangible  Net Worth" shall have the meaning assigned to such term in
Section  11.2.

     1.75  "Term"  shall mean the period from the Effective Date until the later
of  (a)  the  Maturity  Date  or (b) when the aggregate principal balance of all
Advances  outstanding  and  any  interest  accrued  thereon  has  been  paid.

     1.76  "Third  Party" shall mean any entity other than Exelixis or GSK or an
Affiliate  of  Exelixis  or  GSK.

     1.77 "Total Advance Amount" shall have the meaning assigned to such term in
Section  5.1  hereof.

     1.78  "Trading  Day"  shall  mean  a  day  in which the National Securities
Markets  are  open  for  trading.

     1.79  "Transaction  Documents"  shall  mean  this  Loan  Agreement,  the
Development Agreement and the Stock Purchase Agreement, as such documents may be
amended,  modified,  supplemented  or  restated  from  time  to  time.

     1.80 "UCC" shall mean the Uniform Commercial Code as the same may from time
to  time be in effect in Exelixis' state of incorporation; provided, however, in
the  event  that,  by  reason of mandatory provisions of law, such as may be the
case  with  the  Deposit  Account,  any  or all of the attachment, perfection or
priority  of  GSK's security interest in any Collateral shall be governed by the
Uniform  Commercial  Code  as  in  effect in a jurisdiction other than Exelixis'
state  of  incorporation,  in  which case, the term "UCC" shall mean the Uniform
Commercial  Code  as  in  effect  at  such  time  in such other jurisdiction for
purposes  of  the  provisions  hereof relating to such attachment, perfection or
priority  and  for  purposes  of  definitions  related  to  such  provisions.

     1.81  "UCC  Financing Statement(s)" shall mean a record or records composed
of  an  initial financing statement and any filed record relating to the initial
financing  statement  filed  in Exelixis' state of incorporation or elsewhere to
perfect  GSK's  lien  on  the  Collateral.

     1.82  "United  States"  or  "U.S." shall mean the United States of America.

     1.83  "Working  Capital"  shall  have  the meaning assigned to such term in
Section  11.2.

     Accounting  Terms.  All  accounting  terms  not specifically defined in the
Loan  Documents  shall  be  determined  and  construed  in accordance with GAAP.

     Other  Definitional  Provisions.  Where  the  context  herein requires, the
singular  number  shall  be  deemed  to include the plural, the masculine gender
shall  include  the  feminine  and  neuter  genders,  and  vice versa. The words
"hereof,"  "herein" and words of similar import when used in this Loan Agreement
shall  refer  to  this  Loan  Agreement  as  a  whole  and not to any particular
provision  of  this  Loan Agreement. All section, schedule or exhibit references
are to this Loan Agreement unless otherwise specified. All terms used herein and
defined in the UCC shall have the meaning given therein unless otherwise defined
herein.

                                    ARTICLE 2
                           AMOUNT AND TERMS OF CREDIT

     2.1  Commitment.  Subject  to  Exelixis'  observance  of,  and  performance
with,  all  terms,  conditions, warranties, representations and covenants of the
Loan  Documents,  in  the  absence  of  an  Event of Default, GSK agrees to make
Advances  to  Exelixis  up  to  the  Maximum  Loan Amount, in increments of Five
Million  Dollars  ($5,000,000) or greater, from time to time, from the Effective
Date  until  the  Development  Expiration  Date;  provided,  however, GSK has no
obligation  whatsoever  to  make  Advances  to Exelixis which exceed Eighty-Five
Million  Dollars  ($85,000,000)  prior  to such time as GSK selects the Expanded
Program Option and, if GSK fails to select the Expanded Program Option, then GSK
shall  not  be obligated to make any further Advances to Exelixis after Contract
Year  Two; [*].  Exelixis hereby irrevocably authorizes GSK to make (or cause to
be  made) appropriate notations regarding (a) the Borrowing Date, (b) the amount
and  type  (i.e.,  General or Product Specific) of the Advance and (c) the total
Product Specific Advances advanced as of the Borrowing Date for each Development
Candidate  or  the  total General Advances advanced as of the Borrowing Date, as
the  case may be, and in substantially the form set forth on Schedule 1 attached
to  the Note, which notations, if made, shall be rebuttably presumptive evidence
of,  inter alia, such information set forth therein. The aggregate amount of all
Advances  made  from  time  to  time  from the Effective Date to the Development
Expiration Date shall not at any time exceed the applicable Maximum Loan Amount.
If  Advances  are  prepaid  pursuant to Section 5.5 or if milestone payments are
credited  against  Advances  pursuant  to  Section  5.4,  such sums shall not be
available  for future Advances.  Subject to Article 6, Advances shall be made as
follows:

          2.1.1  General  Advances.  Subject  to  Section 2.1, commencing on the
Effective  Date  and  prior  to  January  1,  2003, GSK agrees to make available
General  Advances  to  Exelixis  in  an amount up to Twenty-Five Million Dollars
($25,000,000)  and,  after  the First Contract Year and prior to the Development
Expiration  Date,  GSK  agrees  to make available additional General Advances to
Exelixis  in  amounts  up  to  Twenty  Million  Dollars  ($20,000,000);[*];  and

          2.1.2  Product  Specific Advances. Subject to Section 2.1, upon, or at
any  time after, a Development Compound is selected by Exelixis as a Development
Candidate  pursuant to Section 3.3.2 of the Development Agreement, GSK agrees to
make available to Exelixis one or more Product Specific Advances with respect to
such  Development  Candidate[*].

          2.2  Borrowing Notices. Subject to this Article 2, Exelixis may notify
GSK  to  make  available  an Advance (each such notice, a "Borrowing Notice") by
delivering  to  GSK  a  written  request  substantially in the form of Exhibit D
attached  hereto.  The  Borrowing  Notice  shall state the amount, the Borrowing
Date  of  such  Advance (which Borrowing Date must be a Business Day not earlier
than fifteen (15) Business Days after the Borrowing Notice is effective pursuant
to  Section  16.5)  and all other documents and instruments required pursuant to
the  terms  and  conditions of the Loan Documents.  GSK is entitled to rely upon
the  Borrowing  Notice  and  the  covenants  of Exelixis' officers who sign such
Borrowing Notices.  If GSK requires additional documentation pursuant to Section
6.2.8, GSK shall provide a list to Exelixis not less than five (5) Business Days
prior  to  the  Borrowing  Date.

     2.3  Disbursement  of  Advances. Subject to the terms and conditions of the
Loan  Documents,  GSK  shall make available to Exelixis the Advance requested by
Exelixis  on the Borrowing Date specified in each applicable Borrowing Notice by
wire  transfer  to  the  Deposit  Account.

                                    ARTICLE 3
                                SECURITY INTEREST

     3.1  Grant  of  Security  Interest.  To  secure the payment and performance
by  Exelixis  of the Obligations to GSK, Exelixis and, to the extent applicable,
its  Affiliates  hereby  pledge, set over, assign, deliver and grant a first and
only  priority  security  interest to GSK in all of Exelixis' and, to the extent
applicable,  its  Affiliates' right, title and interest in the following assets,
wherever  located  and whether now existing or hereafter created and whether now
owned  or hereafter acquired, of every description, tangible and intangible (the
"Collateral"):

          3.1.1  [*];

          3.1.2  [*];

          3.1.3  Deposit  Account.  That certain deposit account with a mutually
agreed  upon  bank  or  financial  institution, initially [*], more particularly
described  on Schedule 3.1.3 (the "Deposit Account") maintained by Exelixis into
which  the  proceeds  of  the  Advances, including without limitation investment
property,  shall  be deposited and, subject to Section 9.5, maintained, with all
dividends  and  distributions,  whether  payable  in  cash,  securities or other
investment  property accruing on the balance therein, all of which are described
and  governed  by  the  Control  Agreement;

          3.1.4  [*];

          3.1.5  Capital  Equipment. All capital equipment (currently defined as
equipment  with  a  purchase  price  per item in excess of Five Thousand Dollars
($5,000)),  purchased  by  Exelixis  with the proceeds of the Advances, having a
specific use solely to perform the activities contemplated under the Development
Agreement,  in all cases however and wherever arising (the "Capital Equipment");
and

          3.1.6  Proceeds.  All  Proceeds  and  products  of  the  Intellectual
               Property,  the
Deposit  Account,  the  Development  Candidate  Inventory  and/or  the  Capital
Equipment.

                                    ARTICLE 4
                                    INTEREST

     4.1  Interest

          4.1.1  Advances  Each  Advance  shall  bear interest on the sum of the
unpaid principal balance thereof outstanding on each day until repaid, at a rate
per  annum  equal  to  four  percent  (4.0%).

          4.1.2  Default  Rate of Interest. Notwithstanding the rate of interest
specified  in  Section  4.1.1,  effective  immediately upon the occurrence of an
Event  of Default under Article 12, and for so long thereafter as any such Event
of Default shall be continuing and to the extent permitted by law, the aggregate
principal  balance of all Advances then outstanding and, to the extent permitted
by  applicable  law,  any  accrued  interest thereon, shall bear interest at the
Default  Rate  of  Interest.  Exelixis hereby acknowledges that (a) such Default
Rate  of  Interest is a material inducement to GSK to make Advances available to
Exelixis;  (b) GSK would not have made the Advances available to Exelixis in the
absence  of  the agreement of Exelixis to pay such Default Rate of Interest; (c)
such  Default Rate of Interest represents compensation for increased risk to GSK
that  the  Advances  will not be repaid and (d) such Default Rate of Interest is
not  a  penalty  and  represents a reasonable estimate of (i) the cost to GSK in
allocating  its  resources  (both personnel and financial) to the administration
and  collection of the Advances and (ii) compensation to GSK for losses that are
difficult  to  ascertain.

          4.1.3  Change of Control Rate of Interest. In the event of termination
of  the  Development  Agreement  as  provided  in  Sections  13.1.2(d)(i)  or
13.1.2(d)(ii)  of  the Development Agreement, the aggregate principal balance of
all  Advances  then  outstanding and, to the extent permitted by applicable law,
any  accrued interest thereon, shall bear interest at the Change of Control Rate
of  Interest  from  and  after  the  date  of  such  termination.

          4.1.4  Interest  Computations.  All interest chargeable under the Loan
Documents shall be computed on the basis of a three hundred sixty (360) day year
for  the  actual  number  of  days  elapsed.

                                    ARTICLE 5
                                    REPAYMENT

     5.1  Repayment.  Payment  hereunder  may  be  made  by  Exelixis  in  cash
pursuant  to  Section  5.3,  Common  Stock  pursuant  to  Section  5.6,  or by a
combination  of  the foregoing.  Unless earlier paid through offsets pursuant to
Section  5.4  or  pursuant  to  Section  5.5 below, all Advances made hereunder,
together  with  all accrued and unpaid interest, shall be due and payable to GSK
on  the  earlier  of  [*],  or  (b) demand made in accordance with Section 13.1.

     5.2  Payments  on  Non-Business  Day.  In  the  event  that  any payment of
principal,  interest,  fees or any other amounts payable by Exelixis pursuant to
the Loan Documents shall become due on any day which is not a Business Day, such
due  date  shall  be  extended  to the next succeeding Business Day, and, to the
extent  applicable,  interest  shall  continue  to  accrue and be payable at the
applicable  rate  for  and  during  any  such  extension.

     5.3  Cash  Payment  Procedures. All sums payable by Exelixis to GSK in cash
under  the  Loan  Documents, whether principal, interest, or otherwise, shall be
paid  in  lawful money of the United States and payable in immediately available
funds,  when  due,  by  wire transfer to an account of GSK as GSK may reasonably
direct, without setoff, deduction or counterclaim (except as provided in Section
5.4  below).

     5.4  Milestone  Payments. Upon the satisfaction of the conditions set forth
therein,  GSK  is  obligated  to  make  certain  milestone  payments to Exelixis
pursuant  to  the  terms  of  the Development Agreement.  All Product Acceptance
Milestone  payments  under  Section  6.2.1  of  the  Development  Agreement  and
commercialization  milestone  payments  under  Section  6.2.3 of the Development
Agreement  to  be made to Exelixis may, at GSK's option, be immediately credited
against  the  Advances  and accrued interest then outstanding under the Note, by
direct  offset.  All such credits shall be applied first to expenses or charges,
then  to  accrued  interest,  and  then  to principal on the date such milestone
payments  are  first  due  and  payable.  Any such credits to the Total Advanced
Amount shall not entitle Exelixis to obtain any additional Advances.  During the
Repayment  Period,  milestone  payments  shall be applied to payments due in the
direct  order  of  maturity.  GSK  shall  promptly provide Exelixis in writing a
reconciliation  of  the  amount  of  each such credit and its application to the
amounts  payable  under  the  Note.

     5.5  Optional  Cash  Prepayments.  Exelixis may prepay, in cash, the unpaid
principal  amount  of any Advance in whole or in part without penalty or premium
at  any time and from time to time, in cash only, and as provided for in Section
5.3.  Partial  prepayments  shall be applied first to expenses and charges, then
to  interest and then to principal, and during the Repayment Period, to payments
due  in  direct  order  of  maturity.

     5.6  Repayment  By  Common  Stock.

          5.6.1  Exercise of Issuance Rights. Subject to Section 5.6.6, prior to
a Payment Date, upon notice to GSK pursuant to Section 5.6.3 (a "Stock Repayment
Notice"),  Exelixis  shall  have  the option to issue to GSK the Stock Repayment
Shares in payment of all or any portion of the then outstanding principal amount
of  any  Advance,  and all accrued interest relating thereto up to and including
the  Payment  Date  (the  "Stock  Repayment  Amount")  (each such instance being
hereinafter  referred  to  as "Stock Repayment"). The number of shares of Common
Stock  comprising  the  Stock Repayment Shares issuable in connection with Stock
Repayments  shall  be  equal  to  the quotient of the applicable Stock Repayment
Amount  divided  by  the  Fair  Market  Value (as defined below) of one share of
Common  Stock.  No  fractional shares shall be issued in connection with a Stock
Repayment.  The  "Fair  Market  Value" of the Common Stock shall be deemed to be
the  average  of  the  opening  and  closing  sale prices of the Common Stock as
reported  by  the National Securities Market on which the Common Stock trades or
is  listed  for  the  first  twenty  (20)  consecutive  Trading Days immediately
following  the  date which is two (2) Trading Days after Exelixis filed its most
recent  periodic  disclosure on Form 10-Q or Form 10-K prior to the date of each
Stock  Repayment  Notice.

          5.6.2  Limitation  on  Ownership.  Notwithstanding  anything  to  the
contrary  contained in this Loan Agreement, the total number of shares of Common
Stock owned by GSK that have been acquired pursuant to the Transaction Documents
shall  at  all  times  be  less  than  twenty  percent  (20%)  of Exelixis' then
outstanding  Common  Stock,  as  reported in the most recent quarterly or annual
report  form  of  Exelixis filed with the SEC. In the event that any purchase of
Option  Shares  (as  defined in the Stock Purchase Agreement) or Stock Repayment
Shares  would  cause  GSK  to  be  a  holder  of twenty percent (20%) or more of
Exelixis'  then  outstanding  Common  Stock,  GSK  shall  be  relieved  of  its
obligations to make such purchase(s) or from accepting such repayment in lieu of
cash,  to  the  extent  of  the  overage.

          5.6.3  Stock  Repayment Notice. A Stock Repayment Notice substantially
in  the  form  attached  hereto  as Exhibit E shall be delivered pursuant to the
notice  provisions  set  forth  in  Section 16.5 not later than thirty (30) days
prior  to a Stock Repayment Closing Date. Each such Stock Repayment Notice shall
state  the  Stock  Repayment  Amount  applicable  to  the  Stock  Repayment.

          5.6.4  Delivery  of Stock Repayment Shares. At least three (3) Trading
Days  in  advance  of  any  Stock  Repayment  Closing Date, Exelixis shall issue
instructions  as  follows:

               (a)  If  GSK  is  not an SEC Affiliate of Exelixis, then Exelixis
shall  issue  instructions to Exelixis' stock transfer agent directing Exelixis'
transfer  agent  to  prepare  and  deliver to the account of GSK by an automated
share transfer through the Depository Trust Company system ("DWAC"), that number
of  shares of Common Stock representing the applicable Stock Repayment Shares no
later  than  the  Stock  Repayment  Closing  Date;

               (b)  If  GSK is an SEC Affiliate of Exelixis as of the applicable
Stock  Repayment  Closing  Date,  then  Exelixis  shall  issue  instructions  to
Exelixis'  stock  transfer  agent,  directing  the transfer agent to prepare and
deliver  to  Exelixis  a stock certificate representing that number of shares of
Common  Stock  representing  the  applicable  Stock Repayment Shares, as soon as
possible, but in no event later than one (1) Trading Day prior to the applicable
Stock  Repayment  Closing  Date,  which  stock certificate shall be delivered by
Exelixis  to  GSK  on  the  applicable  Stock  Repayment  Closing Date; provided
however,  that Exelixis may only issue Stock Repayment Shares in accordance with
this  Section  5.6;  or

               c)  Subject  to  GSK's  receipt  of  the  stock  certificate  or
DWAC  transfer,  as  the  case  may  be,  for  the  Stock  Repayment Shares, the
outstanding  Obligations prior to such Stock Repayment shall be deemed repaid to
the  extent  of  the  applicable  Stock  Repayment  Amount.

          5.6.5  No  Rights  as  Stockholders.  GSK shall not be entitled to any
voting  rights  or other rights as a stockholder of Exelixis except as otherwise
provided  in  the  Stock  Purchase  Agreement.

          5.6.6  Conditions  Precedent  to  Each  Issuance  of  Stock  Repayment
Shares.  The  right of Exelixis to issue Stock Repayment Shares shall be subject
to  the following conditions precedent and if Exelixis is unable to satisfy such
conditions  precedent  on  the date of the Stock Repayment Notice, then Exelixis
shall  make  such  payment  due  in  cash  pursuant  to  Section  5.3:

               (a)  satisfaction of each of the conditions set forth in Sections
5.6.1,  5.6.2  and  5.6.3;

               (b)  no Event of Default shall have occurred and be continuing or
would  reasonably  be likely to be caused by the making of such Stock Repayment;

               (c)  satisfaction  of each of the conditions set forth in Section
6.1  of  the  Stock  Purchase  Agreement;

               (d)  no  Change  of  Control  as described in Section 13.1 of the
Development  Agreement  shall  have  occurred;  and

               (e)  no  termination  of  the  Development  Agreement  shall have
occurred;  provided,  however,  if  the  Development  Agreement is terminated by
Exelixis  pursuant to Section 12.2.1 of the Development Agreement for a Material
Breach  (as  defined  in the Development Agreement) by GSK or by GSK pursuant to
Section  12.3.2 then this Section 5.6.6(e) shall not be a condition precedent to
Exelixis'  right  to  issue  Stock  Repayment  Shares.

                                    ARTICLE 6
                               CONDITIONS PRECEDENT

     6.1  Conditions  Precedent  to  Initial  Advance. In addition to all of the
obligations  set  forth  in  the  Loan  Documents, GSK will not make the initial
Advance (the "Initial Advance") under and pursuant to this Loan Agreement unless
and  until  the following conditions and obligations have been satisfied, all in
form  and  substance  satisfactory  to  GSK:

          6.1.1  Loan Documents. Exelixis shall have duly executed and delivered
the  Loan  Documents,  all  in  form  and  substance  satisfactory  to  GSK.

          6.1.2  Supporting  Documents.  Exelixis  shall  deliver or cause to be
delivered  to  GSK  the  following  documents:

               (a)  a  copy  of  the  Operating  Documents  and  a good standing
certificate  of Exelixis from the State of Delaware and for each jurisdiction in
which  it  is  qualified  to  transact  business;

               (b)  an  incumbency certificate with certified resolutions of the
board  of  directors  of  Exelixis, signed by an authorized officer of Exelixis,
authorizing  the  execution,  delivery  and  performance  of  the Loan Documents
(including  Borrowing  Notices);

               (c)  a  legal  opinion  of  counsel  to Exelixis addressed to GSK
regarding  such  matters  as  GSK  and  its  counsel may reasonably request; and

               (d)  UCC  searches,  federal,  state and local judgment searches,
federal and state tax lien searches, bankruptcy searches, pending suit searches,
searches  with the United States and foreign Patent & Trademark Offices, and all
other  applicable  lien  searches  showing  no existing security interests in or
liens  on  the  Collateral  other than liens permitted pursuant to Section 10.1.

          6.1.3  Perfection  of  Liens.  UCC  Financing  Statements, the Control
Agreement,  and  filings  with  the United States and foreign Patent & Trademark
Offices covering the Collateral shall have been duly executed, recorded or filed
with  the  appropriate  parties  in  the  manner  and  places required by law to
establish,  preserve,  protect  and  perfect the interests and rights created or
intended  to  be  created  by  the Loan Documents; and all taxes, fees and other
charges  in  connection  with  the  execution,  delivery  and filing of the Loan
Documents  shall  have  been  duly  paid.

     6.2  Conditions  Precedent  to  All  Advances. The following conditions, in
addition  to  any  other  requirements,  including those for the Initial Advance
hereunder,  shall  have  been  met  or  performed by the Borrowing Date and each
Borrowing Notice shall be deemed to be a representation that all such conditions
have  been  satisfied:

          6.2.1  Borrowing  Notice.  Exelixis  shall  have  delivered  to  GSK a
Borrowing  Notice;

          6.2.2  No  Event  of Default. No Event of Default, and no event which,
with  the passage of time, or the giving of notice, or both, would be reasonably
likely  to  give  rise  to  an  Event  of  Default,  shall  have occurred and be
continuing, or be reasonably likely to be caused by the making of the Advance in
question,  and  Exelixis shall have delivered an officer's certification to such
effect,  which  may  be  incorporated  in  the  Borrowing  Notice;

          6.2.3  No  Termination under the Development Agreement. There has been
no  termination  of  the  Development  Agreement;

          6.2.4  Correctness  of  Representations.  All  representations  and
warranties  made  by  Exelixis  herein shall be true and correct in all material
respects  with  the same effect as though the representations and warranties had
been  made  on and as of the proposed Borrowing Date, and Exelixis has delivered
an  officer's  certificate  to  such  effect,  which  may be incorporated in the
Borrowing  Notice;

          6.2.5  No Material Adverse Effect. There has been no event which would
be  reasonably  be  likely  to  have  a  Material  Adverse  Effect;

          6.2.6  Limitations  Not Exceeded. The proposed Advance shall not cause
     the outstanding Total Advance Amount to exceed the applicable Maximum Loan
Amount and/or the limits specified in Sections 2.1.1 and 2.1.2;

          6.2.7  Use  of  Proceeds.  Exelixis  shall  have  delivered  to  GSK a
certification  from  an officer of Exelixis that the proceeds of the Advance are
to  be utilized by Exelixis solely in furtherance of the obligations of Exelixis
under the Development Agreement over the course of the Term, which certification
may  be  incorporated  in  the  Borrowing  Notice;

          6.2.8  Additional  Documents. Exelixis shall have delivered to GSK all
additional  opinions,  documents,  certificates and other assurances that GSK or
its  counsel  may  reasonably  request  pursuant  to  Section  2.2;  and

          6.2.9 Change of Control. There shall have been no Change of Control as
described  in  Section  13.1  of  the  Development  Agreement.

     6.3  Condition  Precedent  to  Disbursement  of Second General Advance. The
obligation  of  GSK  to  make any second General Advance shall be subject to the
satisfaction  of  the following condition precedent on or before any such second
General  Advance:

          6.3.1  Exelixis  Expenditures.  Exelixis shall have delivered to GSK a
certification  from an officer of Exelixis that Exelixis has spent not less than
Twenty  Million  Dollars  ($20,000,000)  in furtherance of Exelixis' obligations
under  the  Development  Agreement from sources other than GSK to Exelixis under
the Development Agreement, the Stock Purchase Agreement and this Loan Agreement,
which  certification  may  be  incorporated  in  the  Borrowing  Notice.

     6.4  Conditions  Precedent  to  Disbursement  of  All  Product  Specific
Advances.  The  obligation  of GSK to make any Product Specific Advance shall be
further  subject to the satisfaction of the following conditions precedent on or
before  any  such  Product  Specific  Advance:

          6.4.1  Exelixis'  Selection  of  a Development Candidate. In the event
that  a  Development  Candidate  meets  and continues to meet the Developability
Criteria  established  by  the  Collaboration  Committee  for the advancement to
Development Candidate status and Exelixis selects Development Compound to become
a  Development  Candidate  under  the Development Program, Exelixis shall notify
GSK,  in  writing  of such selection, which notification shall be within no more
than  thirty  (30)  days  after  such  selection;  and

          6.4.2 Marketable Title to Development Candidate Intellectual Property.
Exelixis shall provide a representation in the Borrowing Notice for each Product
Specific Advance that, other than the security interest of GSK, the title to the
Intellectual Property pertaining to such Development Candidate is free and clear
of  all  assignments,  mortgages,  pledges,  liens,  security interests, leases,
claims  or  any  other  encumbrances.

                                    ARTICLE 7
                   REPRESENTATIONS AND WARRANTIES OF EXELIXIS

     Exelixis hereby represents and warrants to GSK as of the Effective Date and
as  of  each  Borrowing  Date  that:

     7.1  Organization,  Good  Standing  and  Qualification.  Exelixis  is  a
corporation duly organized, validly existing and in good standing under the laws
of  the State of Delaware and has all requisite corporate power and authority to
carry  on  its business.  The spelling and the identification of Exelixis on the
signature page hereof are accurate in all respects and consistent with Exelixis'
registration.  Exelixis  is duly qualified to transact business as a corporation
and  is in good standing in each jurisdiction in which qualification is required
by law.  Exelixis has full corporate power and authority to own its property and
to  carry on business in all jurisdictions where it is doing business.  Exelixis
possesses  all  licenses,  permits, franchises, patents, copyrights, trademarks,
and trade names, or rights thereto, to conduct its business substantially as now
conducted  and as presently proposed to be conducted, and is not in violation of
rights  of  others  with respect to the foregoing.  GSK has been provided with a
true  copy  of Exelixis' Operating Documents which are in full force and effect.
GSK  may rely on the accuracy and the integrity of the Operating Documents filed
with  the  SEC and all amendments thereto which have not been filed with the SEC
as of each Borrowing Date shall be certified to GSK by a duly authorized officer
of  Exelixis  in  the  Borrowing  Notice.  There  has  been  no  certificate  of
dissolution  filed  or  cancellation  filed  on  the  behalf of Exelixis nor has
Exelixis  been  dissolved  by  any event such as death, retirement, resignation,
expulsion,  bankruptcy  or  dissolution of any shareholder, partner or member or
event  which would cause the dissolution of Exelixis pursuant to applicable law.

     7.2  Authorization;  Due  Execution.  Exelixis  has the requisite corporate
power  and authority to execute, deliver and carry out the Loan Documents and to
perform  its  obligations under the terms of the Loan Documents and, at the time
of  a Stock Repayment pursuant to Section 5.6, will have the requisite corporate
power  to  issue  Stock  Repayment  Shares.  All corporate action on the part of
Exelixis,  its  officers,  directors  and  stockholders  necessary  for  the
authorization, execution and delivery of the Loan Documents has been taken.  The
Loan Documents have been and shall be duly authorized, executed and delivered by
Exelixis  and,  upon due execution and delivery by GSK of the Loan Documents (as
applicable)  will each be a valid and binding agreement of Exelixis, enforceable
in accordance with its respective terms, except as enforceability may be limited
by  bankruptcy, insolvency, reorganization, moratorium or similar laws affecting
creditors'  rights  generally  or  by  equitable  principles.

     7.3  Valid Issuance of Stock. The Stock Repayment Shares, when issued, sold
and  delivered  in  accordance  with  the terms of Section 5.6, will be duly and
validly  authorized and issued, fully paid, and nonassessable and will be issued
in  compliance  with  all  applicable  federal  and  state  securities  laws.

     7.4  SEC  Filings.  Exelixis  has  timely  filed  with the SEC all reports,
registration statements and other documents required to be filed by it (the "SEC
Filings")  under  the  Securities  Act  of  1933,  as amended, and the rules and
regulations  promulgated  thereunder  (the  "Securities Act") and the Securities
Exchange  Act  of  1934,  as  amended, and the rules and regulations promulgated
thereunder  (the  "Exchange  Act").  The SEC Filings were prepared in accordance
and,  as  of  the  date  on  which  each such SEC Filing was filed with the SEC,
complied  in  all  material  respects,  with  the applicable requirements of the
Securities  Act,  the  Exchange  Act,  and,  to  the  best of its knowledge, the
Sarbanes-Oxley  Act  of  2002,  as  the  case may be.  None of such SEC Filings,
including,  without limitation, any financial statements, exhibits and schedules
included  therein  and  documents incorporated therein by reference, at the time
filed,  declared  effective  or  mailed, as the case may be, contained an untrue
statement  of a material fact or omitted to state a material fact required to be
stated therein or necessary in order to make the statements therein, in light of
the  circumstances  under  which  they were made, not misleading.  Except to the
extent  information  contained  in  any  of  the  SEC  Filings has been revised,
corrected  or superseded by a later filing of any such form, report or document,
none  of  the  SEC  Filings currently contains an untrue statement of a material
fact  or  omits  to  state  a  material  fact  required  to be stated therein or
necessary in order to make the statements therein, in light of the circumstances
under  which  they  were  made,  not  misleading.

     7.5 Governmental Consents. No consent, approval, order or authorization of,
or  registration,  qualification,  designation,  declaration or filing with, any
federal,  state, local or provincial Governmental Entity on the part of Exelixis
is required in connection with the consummation of the transactions contemplated
by  the Loan Documents, except for such approvals or consents required under the
HSR  Act  and  such other notices required or permitted to be filed with certain
state and federal securities commissions after the Effective Date, which notices
will  be  filed  on  a  timely  basis.

     7.6  No Conflict. Exelixis' execution, delivery and performance of the Loan
Documents  does  not  violate any provision of Exelixis' Operating Documents, as
amended,  any  provision  of  any  Third Party agreement, order, writ, judgment,
injunction,  decree,  determination  or award to which Exelixis is a party or by
which  it  is  bound,  or,  to  Exelixis' knowledge, any law, rule or regulation
currently  in  effect  having  applicability  to  Exelixis.

     7.7  Litigation.  Except  as  disclosed  in  the  SEC Filings, there are no
judgments,  lawsuits, judicial proceedings, investigations or complaints pending
or  overtly  threatened  against  Exelixis,  by  any Third Party or Governmental
Entity,  for  amounts in excess of Five Million Dollars ($5,000,000) relating to
any  aspect of Exelixis' business or properties or its ability to consummate the
transactions  contemplated  by  the  Loan  Documents.

     7.8  Compliance  with  Law.  Exelixis  is  in  compliance with all material
respects with all laws, including, without limitation ERISA, OSHA, Environmental
Laws and the other governmental rules and regulations applicable to its business
and  properties.  Exelixis  is  in  compliance  with  all  requirements  of  the
Americans with Disabilities Act of 1990, 42 U.S.C. 12101 et seq., including, but
not  limited  to,  those  regulations  promulgated  by  the  Architectural  and
Transportation  Barrier  Compliance  Board  at  36  CFR  1191 et seq. and by the
Department  of  Justice  at  28  CFR  36  et  seq.

     7.9  Title  to  the  Collateral.  To  its  knowledge, Exelixis has good and
marketable  title  and  rights  to  the  Intellectual  Property,  except for the
security  interest  granted  to  GSK by Exelixis pursuant to the Loan Documents.
Exelixis  has  good and marketable title and rights to the Development Candidate
Inventory,  Capital  Equipment  and  Deposit  Account  except  for  the security
interest  granted  to GSK by Exelixis pursuant to the Loan Documents.  As of the
Effective  Date,  title  to  the  Collateral  and all rights thereunder shall be
exclusively  vested  in  Exelixis  with  no  rights whatsoever to the Collateral
vested  in  any  Affiliate.  Exelixis has the right and corporate power to grant
the  security  interests  in and to the Collateral provided by or referred to in
the  Loan Documents.  Except as herein provided, none of the Collateral is or is
about  to  become  subject  to  any  other  assignment,  mortgage, pledge, lien,
security  interest,  lease  or  encumbrance  by  virtue  of  the  execution  or
performance  of  the  Loan  Documents.  No lien or claim has been attached to or
made  against  the  Collateral for: (a) tax liabilities which have been assessed
against  Exelixis  which  remain  unpaid;  or (b) damages or cleanup and removal
costs,  as  those  terms  are  defined by any Environmental Laws arising from an
intentional  or  unintentional act or omission of Exelixis or any previous owner
or  operator  of  its  real  or  personal  property  resulting in the releasing,
spilling,  pumping,  pouring,  emitting,  emptying,  discharging  or  dumping of
hazardous  substances,  hazardous wastes, pollutants or other related substances
as  those  terms  are  defined  by  any  Environmental Laws which would create a
Material  Adverse  Effect.

     7.10  No  Event  of  Default/Breach.  Exelixis has reviewed the Transaction
Documents and represents that no Event of Default has occurred and is continuing
under  the  Loan  Documents  and  no  breach  by  Exelixis  has  occurred and is
continuing  under  the  Development  Agreement.

     7.11  Intellectual  Property.  To the best of the knowledge of Exelixis and
its  majority-owned  subsidiaries  (other  than  Artemis  Pharmaceuticals GmbH),
respectively, Exelixis, and such majority-owned subsidiaries (other than Artemis
Pharmaceuticals  GmbH): (i) own, or have obtained licenses or rights to use, all
of  the  Intellectual  Property  necessary  to  carry  out  Exelixis'  and  its
majority-owned subsidiaries (other than Artemis Pharmaceuticals GmbH) respective
businesses  as  currently  conducted  or as Exelixis contemplates conducting its
business  from time to time in the future and as contemplated by the Transaction
Documents;  (ii)  are  not aware of any notice asserting any ownership rights to
the  Intellectual  Property;  (iii)  are not aware of sales of any products that
would  constitute an infringement by Third Parties of the Intellectual Property;
(iv)  are aware of no pending or threatened action, suit, proceeding or claim by
a  Third  Party  challenging  the ownership rights in, validity or scope of, the
Intellectual  Property;  and  (v)  are  not  aware  of any pending or threatened
action,  suit,  proceeding  or claim by a Third Party asserting that Exelixis or
its  majority-owned  subsidiaries  (other  than  Artemis  Pharmaceuticals  GmbH)
infringe  or otherwise violate any patent, trademark, copyright, trade secret or
other  proprietary  right  of any Third Party as would reasonably be expected to
result  in  a  Material  Adverse  Effect.

     7.12 Effect of Representations and Warranties. None of the representations,
warranties or statements made to GSK in the Loan Documents or in connection with
the  Loan  Documents contain any untrue statement of a material fact, or omit to
state  a  material  fact  necessary  in  order  to  make the statements made not
misleading.

                                    ARTICLE 8
                      REPRESENTATIONS AND WARRANTIES OF GSK

     GSK  hereby  represents  and  warrants to Exelixis as of the Effective Date
that:

     8.1  Authorization;  Due  Execution.  GSK  has  the  requisite  corporate
power  and  authority  to  enter  into  this  Loan  Agreement and to perform its
obligations under the terms of the Loan Documents and, at the time of each Stock
Repayment  pursuant  to  Section 5.6, will have the requisite corporate power to
accept the Stock Repayment Shares.  All corporate action on the part of GSK, its
officers,  directors and stockholders necessary for the authorization, execution
and  delivery  of  the  Loan Documents have been taken.  The Loan Documents have
been duly authorized, executed and delivered by GSK, and, upon due execution and
delivery  by  Exelixis, the Loan Documents will be a valid and binding agreement
of  GSK,  enforceable in accordance with its terms, except as enforceability may
be limited by bankruptcy, insolvency, reorganization, moratorium or similar laws
affecting  creditors'  rights  generally  or  by  equitable  principles.

                                    ARTICLE 9
                                    COVENANTS

     Exelixis covenants and agrees to comply with the following covenants at all
times  during  which  Advances  are  outstanding:

     9.1  Keeping  of  Books.  Keep  proper books of record and account in which
full  and correct entries shall be made of all of its financial transactions and
its  assets and businesses in accordance with GAAP so as to permit the filing of
its  financial  information  with  the SEC in accordance with all applicable SEC
rules  and regulations.  Exelixis shall keep accurate records of the Collateral,
which  records  are  at  all  times  to  be physically located at the address of
Exelixis or its Affiliates set forth on the signature page hereto or on Schedule
9.1.  All  tangible  Collateral  shall  be physically located at the address set
forth  on  the  signature page hereto or on Schedule 9.1, and Exelixis agrees to
promptly  inform  GSK of all changes to the location of the tangible Collateral.

     9.2 SEC Reporting Requirements. Furnish to GSK, or cause to be furnished to
GSK,  as  soon  as  available and in no event later than three (3) Business Days
after  they  are  sent,  made  available  or  filed,  copies of all SEC Filings.

     9.3  Maintenance  of  Rights  and  Existence. Maintain and preserve in full
force and effect all rights, contracts, licenses, leases, privileges, franchises
and  other  authority  necessary  for  the proper conduct of its business except
where  the  lapsing  of  any  of  the  foregoing  would not cause or result in a
Material  Adverse  Effect.  Exelixis  shall  continue  to  be  duly  licensed or
qualified to do business in each jurisdiction in which qualification is required
by law except where such lack of qualification would not have a Material Adverse
Effect,  and  to  continue  to  be  in  good  standing and to preserve its legal
existence.

     9.4  Governmental  and  Other Approvals. Apply for, obtain, and maintain in
effect,  as  applicable,  all  authorizations,  consents,  approvals,  licenses,
qualifications,  exemptions,  filings,  declarations  and registrations (whether
with  any  court, governmental agency, regulatory authority, National Securities
Market  or  otherwise)  which  are  necessary  in connection with the execution,
delivery  and performance by Exelixis of the Loan Documents and the transactions
consummated  or  to  be  consummated  thereunder.

     9.5  Use  of  Proceeds.  Use  the  proceeds  of  the  Advances hereunder in
furtherance  of the obligations of Exelixis under the Development Agreement over
the  course  of  the  Term.

     9.6  Further Assurances. In addition to the obligations and documents which
the  Loan  Documents  expressly requires Exelixis and, to the extent applicable,
its  Affiliates  to  execute,  acknowledge,  deliver and perform, Exelixis shall
execute  and  acknowledge (or cause to be executed and acknowledged) and deliver
to  GSK all documents, and take all actions, that may be reasonably requested by
GSK from time to time to confirm the rights created or now or hereafter intended
to be created under the Loan Documents or otherwise to carry out the purposes of
the  Loan  Documents and the transactions contemplated hereunder and thereunder.
Exelixis hereby agrees to execute, file and/or deliver (or cause its Affiliates,
as applicable, to execute, file and/or deliver) to GSK the Patent Office Filings
and  such  other  security agreements as GSK shall deem necessary or appropriate
from  time  to  time.  The  security  interest  pledged,  set over, assigned and
granted  by  Exelixis and, to the extent applicable, its Affiliates to GSK shall
be  a  first and only priority security interest pursuant to applicable law, and
Exelixis  shall  take  all such action (or cause its Affiliates to take all such
action)  to  create and perfect for the benefit of GSK a first priority security
interest  in  the  Collateral;  and  in  the  case  of  Capital  Equipment being
purchased,  a  purchase-money  security  interest  pursuant  to  Section  9.15.

     9.7  Compliance  with  the  Laws.  Exelixis  shall  comply  with  all laws,
including  without  limitation,  Environmental  Laws,  ordinances,  rules  and
regulations,  now  or hereafter in effect, applicable to it, of any Governmental
Entity  applicable  to its business and properties, the noncompliance with which
would  reasonably  be  expected  to  cause  a  Material  Adverse  Effect.

     9.8  Litigation.  Exelixis shall promptly notify GSK (a) of any litigation,
actions,  proceedings,  claims  or  investigations pending or threatened against
Exelixis,  wherein  claimant  seeks  to  recover  [*],  (b)  of the entry of any
judgment  [*]  against  Exelixis;  (c)  the  entry  of any liens, other than the
permitted  liens  (as  set forth in Section 10.1) against the Collateral; or (d)
upon  learning  of  any  circumstances  or transactions that would reasonably be
expected  to  be  a  violation  of  any  Environmental  Laws.

     9.9 Payment of Taxes. Exelixis shall pay and discharge, as they become due,
all taxes, assessments, debts, claims and other governmental or non-governmental
charges lawfully imposed upon it or incurred by it or its properties and assets,
except  taxes, assessments, debts, claims and charges contested in good faith in
appropriate proceedings, and provide GSK, if reasonably requested, with evidence
of  said taxes, assessments, debts, claims, and charges, and of payment thereof.

     9.10  Access to Records and Property. Upon reasonable prior written notice,
Exelixis  shall  give  any  representatives  of  GSK  or independent contractors
selected  by  GSK  reasonable  access during normal business hours (and after an
Event of Default and while it is continuing at any time) to examine, audit, copy
or  make  extracts  from,  any  and  all  books,  records  and  documents in its
possession  relating  to  the  Collateral  and  to inspect any of its properties
wherever  located.

     9.11  Preservation  of  Title to Collateral. Exelixis agrees to immediately
notify  GSK  of  any  material  loss or damage to, or any occurrence which would
materially  and  adversely  affect  the  security  interest of GSK in and to the
Collateral.  The  Collateral  shall  be  free  and  clear  of  all  assignments,
mortgages,  pledges,  liens, security interests, leases, or encumbrances, except
as  otherwise  provided  in  this  Loan  Agreement.  Exelixis  shall continue to
maintain  good  and  marketable  title  to  the  Collateral, except as otherwise
provided  in  the  Loan  Documents,  at  the  sole  expense  of  Exelixis.

     9.12  Insurance.  Exelixis  shall  maintain,  at  its  cost,  adequate
insurance  (a)  against liability and other risks associated with the activities
contemplated under the Development Agreement and (b) to protect the value of the
Collateral, in such amounts and on such terms as are reasonably customary in the
biotechnology  industry  for  the  activities  to  be  conducted by it under the
Development  Agreement.  Such  insurance  policy shall name GSK as an additional
insured  party  as  its  interest  may  appear in such insurance policies.  At a
minimum,  Exelixis  shall  maintain,  at  its  cost,  a general liability policy
providing  coverage of at least One Million Dollars ($1,000,000) per occurrence,
Two  Million  Dollars  ($2,000,000)  in  the  aggregate and Five Million Dollars
($5,000,000)  excess.  Exelixis  shall provide to GSK evidence of such insurance
policy,  upon  request.

     9.13  Intellectual  Property.  To  the  extent  the  Collateral consists of
Intellectual  Property,  Exelixis  shall be required to (and shall cause, to the
extent  applicable, its Affiliates to): (a) comply with all applicable laws from
any applicable Governmental Entity regulating the maintenance and quality of the
Intellectual  Property;  (b)  execute such documents and take such other actions
necessary  to  extend  the  Collateral  to  any  now  existing  or  newly issued
Intellectual Property, including, without limitation, promptly disclosing to GSK
the  existence  of  any  new  Intellectual Property created by any Affiliate and
causing  such  Affiliate to become a party to this Loan Agreement solely for the
purposes of the requirements, restrictions and limitations set forth in Sections
3.1.1,  3.1.2,  3.1.6,  9.11,  and 9.13 of this Loan Agreement; (c) maintain the
rights  to  use  the  Intellectual  Property  consistent  with  the  Development
Agreement;  and  (d)  execute such documents to permanently assign to GSK all of
Exelixis' rights to the Intellectual Property upon the occurrence of an Event of
a  Default.  Among  other things, Exelixis shall (and shall cause its Affiliates
to)  execute  assignments  to  GSK  following  an  Event  of  Default.

     9.14  Fees  and  Expenses in Protecting Rights. If in the Event of Default,
GSK  employs  counsel  or  any  other professionals or consultants for advice or
other  representation:  (a)  with  respect to the Collateral, the Obligations of
Exelixis  to  GSK or the Loan Documents; (b) to represent GSK in any litigation,
contest,  dispute,  suit or proceeding or to commence, defend or intervene or to
take  any  other  action in or with respect to any litigation, contest, dispute,
suit  or  proceeding  (whether  instituted  by  GSK, Exelixis or any other Third
Party)  in any way or respect relating to the Collateral, the Obligations of the
Exelixis to GSK, the Loan Documents; (c) to protect, collect, sell, liquidate or
otherwise dispose of the Collateral; (d) to attempt to or to enforce GSK's liens
and  security  interests  in the Collateral; and/or (e) in otherwise protecting,
enforcing  or exercising its interests, rights or remedies created by, connected
with  or  provided  in  the  Loan Documents, or performance pursuant to the Loan
Documents; then, the reasonable attorneys' fees, costs and expenses arising from
such  services,  and all other expenses, costs, charges and other fees of GSK in
any  way  or respect arising in connection with or relating to any of the events
described  in  this Section 9.14 shall be added to the amount of the Obligations
of  Exelixis  to  GSK, and shall be payable on demand. Any amounts due hereunder
not  paid  on  demand shall bear interest from the date of demand at the Default
Rate  of Interest.  Any of the amounts payable hereunder by Exelixis may be paid
by  GSK,  and  if  and  when  so  paid, shall be deemed to be a General Advance.

     9.15  Capital  Equipment.  If  at  any  time  Exelixis  purchases  Capital
Equipment, Exelixis shall promptly, and in any event no later than ten (10) days
after  such  purchase,  notify  GSK  so  that GSK may file any and all necessary
documentation  including a UCC Financing Statement within twenty (20) days after
the  acquisition  of  such  Capital  Equipment,  and  take  all other reasonably
necessary  steps  to  perfect  a purchase-money security interest in the Capital
Equipment.  Exelixis  agrees  to  execute  all  necessary  documentation  and to
cooperate  with  GSK  in  perfecting  GSK's  security  interest  in such Capital
Equipment.

     9.16  Deposit  Account and Investment Property. Exelixis shall maintain (a)
the  Deposit  Account  for the General and Product Specific Advances and (b) the
money  in  the  Deposit Account as invested in the permitted types of securities
set  forth on Schedule 9.16 attached hereto and made a part hereof.  The Deposit
Account  shall  be  maintained  at  a  mutually  agreed  upon  bank or financial
institution  pursuant  to  the  Control  Agreement.

     9.17  Duration of Covenants. The covenants made in this Article 9 are to be
true,  accurate and complete for the duration of the Term of the Loan Documents,
including,  without  limitation,  at  the  time  of  each  Advance.

                                   ARTICLE 10
                   COVENANTS REGARDING PROHIBITED TRANSACTIONS

     In  order  to  induce GSK to execute the Loan Documents, Exelixis makes the
following  negative  covenants  at  all  times  in  which  there are outstanding
Advances:

     10.1  Permitted  Liens.  Neither  Exelixis  nor  it Affiliates shall incur,
create  or  permit  to  exist  any  mortgage, assignment, pledge, hypothecation,
security  interest,  lien or other encumbrance on any of the Collateral, whether
now  owned or hereafter acquired, except (a) liens for taxes not delinquent; (b)
those  liens in favor of GSK created by the Loan Documents; and (c) those liens,
such  as  carrier,  warehousemen,  unemployment  or retirement liens, arising by
operation  of  law  in  the ordinary course of business if subordinated on terms
acceptable  to  GSK  or  reserves  are  established  to the satisfaction of GSK.

     10.2 Impairment of Title to Collateral. Neither Exelixis nor its Affiliates
shall  sell,  conditionally  sell,  sell  on approval, consign, lease, encumber,
transfer,  remove  from  its  premises  any Collateral without the prior written
consent  of  GSK.

     10.3  Settlements.  Exelixis  shall  not  compromise,  settle or adjust any
claims  in  a material amount relating to the Intellectual Property, without the
prior  written  consent  of  GSK.

     10.4  Change  of  Location  or  Name. Exelixis' taxpayer identification and
organizational  identification  numbers  are  set  forth  on the signature page.
Exelixis'  chief  executive office and principal place of business are presently
located  at  the  address  set  forth on the signature page.  Exelixis shall not
change  the  place  where its books and records are maintained, change its name,
change  its  state  of incorporation, change the location of its chief executive
office  or  principal  place  of  business,  as  such terms are now or hereafter
defined  in  the  UCC,  or  transact business under any other name without prior
written notice to GSK.  Within four (4) months of any permitted change, Exelixis
shall  authenticate or otherwise cooperate in any action deemed necessary by GSK
to maintain its rights and security interests as provided in the Loan Documents.

     10.5  Inconsistent  Agreement.  Neither  Exelixis  nor its Affiliates shall
enter  into any agreement containing any provision that would be violated by the
performance  of  Exelixis'  obligations  under  the  Loan  Documents.

     10.6 Violation of Representations, Warranties and Covenants. Exelixis shall
not  take  any  action  or omit to take any action which is reasonably likely to
render  any  of  its  representations,  warranties  or covenants to be untrue or
incapable  of  performance.

                                   ARTICLE 11
                               FINANCIAL COVENANTS

     Exelixis  covenants  and  agrees  to  comply  with  the following financial
covenants  during  the  Term:

     11.1  Working  Capital.  Exelixis  shall  not  cause  or  permit  Working
Capital  to be less than [*], the term "Working Capital" meaning, as of the time
of  any determination thereof, the amount determined in accordance with GAAP, by
which  the  current  assets  of  Exelixis  exceed  its  current  liabilities.

          11.2  Tangible  Net Worth. Exelixis shall not cause or permit Tangible
Net  Worth to be less than [*], the term "Tangible Net Worth" meaning, as of the
time  of  any determination thereof, total stockholder equity less good will and
other  intangible  assets as reported by Exelixis in its SEC Filings prepared in
accordance  with  GAAP.

                                   ARTICLE 12
                                EVENTS OF DEFAULT

     12.1  Events  of  Default.  The  occurrence  or  existence  of  any  of the
following conditions or events shall constitute an "Event of Default" hereunder:

          12.1.1 Failure to Pay. Exelixis shall fail to pay (a) within three (3)
Business  Days  following  the  date  due under Article 5 or (b) within ten (10)
Business  Days  of  any  demand  pursuant  to  Section  13.1.1 of any principal,
interest  or  other  sums  due  to  GSK;

          12.1.2  Other Defaults under the Loan Documents. Any default or breach
in  the  observance  or  performance  of  any  of  the  other  conditions,
representations,  warranties,  covenants  or agreements of Exelixis set forth in
the  Loan  Documents,  and continuance thereof for a period of thirty (30) days;

          12.1.3  Termination  of Development Agreement. GSK or Exelixis, as the
case  may  be,  shall  terminate  the Development Agreement pursuant to Sections
12.2.1,  12.3.1,  12.3.2,  or  12.4  thereof;

          12.1.4  Other  Specific  Events.

               (a)  [*];

               (b)  the  submission to GSK of any materially false or fraudulent
statement  by  Exelixis,  in  connection  with  this  Loan  Agreement;

               (c)  upon  any  Material  Adverse  Effect;

               (d)  [*];  or

               (e)  a  reportable event under ERISA which continues for ten (10)
days  after  such  occurrence;  or

          12.1.5  Insolvency;  Bankruptcy.  If (i) Exelixis becomes insolvent or
generally  fails to pay, or admits in writing its inability to pay, its debts as
they  mature, or applies for, consents to, or acquiesces in the appointment of a
trustee,  receiver,  liquidator, conservator or other custodian for itself, or a
substantial  part of its property, or makes a general assignment for the benefit
of  creditors;  (ii)  Exelixis  files  a  voluntary  petition in bankruptcy or a
trustee,  receiver,  liquidator, conservator or other custodian is appointed for
Exelixis  or  for  a  substantial  part  of  its  property,  and the same is not
discharged  within  sixty  (60) days; (iii) any bankruptcy, reorganization, debt
arrangement, or other proceedings under any bankruptcy or insolvency law, or any
dissolution or liquidation proceeding, is instituted by or against Exelixis, and
the  same  is  consented  to  or  acquiesced  by  Exelixis, or otherwise remains
undismissed  for  sixty  (60)  days; or (iv) any warrant of attachment is issued
against  any  substantial part of the property of Exelixis which is not released
within  sixty  (60)  days  of  service  thereof.

                                   ARTICLE 13
                     GSK'S RIGHTS AND REMEDIES UPON DEFAULT

     13.1  Rights  and  Remedies.  Upon  the  occurrence  of,  and  during  the
continuance  of,  an  Event of Default, GSK may, at its election, without notice
of  its election and without demand, do any one or more of the following, all of
which  are  authorized  by  Exelixis:

          13.1.1  declare  all  Obligations,  evidenced  by  the Loan Documents,
immediately  due  and payable (provided, that upon the occurrence of an Event of
Default  described  in  Section 12.1.5, all Obligations shall become immediately
due  and  payable  without  any  action  by  GSK);

          13.1.2 cease advancing money or extending credit to or for the benefit
of  Exelixis  under  this  Loan  Agreement;

          13.1.3  cease  accepting  Stock  Repayments  pursuant  to Section 5.6;

          13.1.4  institute legal or deficiency proceedings or otherwise enforce
its rights to collect the Total Advance Amount with all accrued interest thereon
against  Exelixis  which  becomes  immediately due and payable. If a judgment is
entered  in  favor of GSK, the lien of the judgment relates back to the earliest
date  of  perfection  of  GSK's  security  interests  hereunder;

          13.1.5  charge,  setoff  and  withdraw  from  any credit balance which
Exelixis  may  then have with GSK or with any Affiliate thereof, such amounts as
may  be  necessary to satisfy the Total Advance Amount with all accrued interest
thereon;

          13.1.6  terminate  and  cancel any existing commitment to Exelixis for
future  Advances;

          13.1.7  with  or  without judicial process, to the extent permitted by
law,  and subject to the final sentence of this Section 13.1.7, (i) to seize the
Collateral  or  to require Exelixis to assemble the Collateral or (ii) to render
the Collateral unusable without need for GSK to post a bond or security or (iii)
demand  Exelixis  to make the Collateral available at a GSK designated place for
sale, license or other disposition by GSK (and if such disposition is to GSK, at
a  public auction unless the Collateral is that customarily sold on a recognized
market  or  the  subject  of  widely distributed standard price quotations) (iv)
exercise its rights to seize the Collateral and any remedies set forth under the
Control  Agreement  and/or  the  Patent Office Filing to satisfy the Obligations
with  all accrued interest thereon without any right of Exelixis to adjourn such
disposition.  Any  such  sale,  license  or other disposition may be made of the
Collateral  in  its  present  condition or following any commercially reasonable
preparation  or  processing at the expense of Exelixis. Notwithstanding anything
contained  herein,  GSK  shall have no immediate right to proceed against any of
the  Excluded Collateral if GSK alleges an Event of Default pursuant to Sections
12.1.2,  12.1.4(b)  or  12.1.4(c),  prior  to  the  completion  of  the  dispute
resolution  process in accordance with Section 16.2, undertaken to determine the
existence  of  such  alleged  Event of Default pursuant to such sections, and if
such  dispute  resolution  process  conclusively  determines the existence of an
Event of Default by Exelixis under such sections, then, GSK shall be entitled to
proceed  against  the  Excluded  Collateral;  or

          13.1.8 to effectuate collection of any Collateral comprising accounts,
GSK  may  reassign  any  such account, to Exelixis (without recourse to GSK) and
require  Exelixis  to proceed with such legal or other action, at Exelixis' sole
liability, cost and expense, in which event all amounts collected by Exelixis on
such  items  are  to,  nevertheless,  be  treated  as Proceeds of Collateral. In
furtherance  of  GSK's  rights  and remedies hereunder, Exelixis hereby grants a
power  of  attorney  to  GSK  to  endorse  Exelixis'  name  on  checks,  notes,
acceptances,  drafts  and any other documents or instruments requiring Exelixis'
endorsement,  to  change  the address where Exelixis' mail should be sent and to
open  all  mail and to do such other acts and things necessary to effectuate the
purposes  of  the  Loan  Documents  when  so  permitted by the terms of the Loan
Documents.

     13.2  Application  of  Proceeds  of  Disposition  of  Collateral.  The
proceeds  of  any sale, license or other disposition of the Collateral are to be
applied  to  satisfy  the  following  items  in  the  following  order:

          13.2.1 First, to GSK's expenses in preserving its interests and rights
hereunder,  to  expenses  incurred  by  GSK in realizing upon security interests
created  or  referred  to herein, and expenses of GSK in enforcing and defending
its  rights  as  set  forth  in  Article  14;

          13.2.2  Second,  to the Total Advance Amount with all accrued interest
thereon  and  any  expenses  not  satisfied  under  Section  13.2.1;

          13.2.3  Third,  any  excess or amounts remaining are to be paid to any
subordinate  security  interest  or lien if the holder thereof supplies proof of
its  interest  or  lien  and if the holder thereof makes an authenticated demand
therefor  before  distribution  and  any  balance  thereafter  shall  be paid to
Exelixis  unless  GSK  reasonably  determines  that  reserves  are  warranted to
implement  the  indemnification  provisions  in  Article  15;  and

          13.2.4  Fourth,  a  transferee  who  purchases,  licenses or otherwise
receives  the  benefits of a disposition of Collateral after an Event of Default
takes  free  of  all Exelixis' rights and the rights of any subordinate security
interest  or  lien.  A  transferee  is  entitled  to the recording of a transfer
statement  to  document  public  notice  of  such  disposition.

     13.3  Notice  of  Disposition  of  Collateral. GSK shall give authenticated
reasonable  notice  to  Exelixis  and  any  other  party  entitled thereto under
applicable  law  of  the  time  and  place  of  a  public sale, license or other
disposition  of  the  Collateral.  Authenticated  notice  is  presumed  to  be
reasonable  (a) if given ten (10) days prior to such disposition, (b) if sent to
the  chief  executive officer and, if none, to the address of Exelixis set forth
in  Section  16.5  and  (c) if it contains a statement of the Collateral and its
intended  disposition,  the  time  and place of disposition and a statement that
Exelixis is entitled to an accounting of such disposition.  GSK may disclaim any
warranties  that  may  apply to any sale, lease, license or other disposition of
the  Collateral.

     13.4  Marshalling  of  Assets.  GSK has no obligation whatsoever to proceed
first  against  any of the Collateral before proceeding against any other of the
Collateral.  It  is  expressly  understood and agreed that all of the Collateral
stands  as  equal  security for Obligations and any interest accrued thereon and
that  GSK  has  the  right  to  proceed  against or dispose of any/or all of the
Collateral  or  other  collateral  in  any order as GSK, in its sole discretion,
determines.

     13.5  Waiver of Defaults. No Event of Default shall be waived by GSK except
in a written instrument specifying the scope and terms of such waiver and signed
by an authorized officer of GSK, and such waiver shall be effective only for the
specific  times and purposes given.  No single or partial exercise of any right,
power  or  privilege  hereunder,  nor  any  delay in the exercise thereof, shall
preclude  other  or further exercise of GSK's rights.  No waiver of any Event of
Default  shall  extend to any other or further Event of Default.  No forbearance
on the part of GSK in enforcing any of GSK's rights or remedies hereunder or any
of  the  Transaction Documents shall constitute a waiver of any of its rights or
remedies.

     13.6  Remedies  Cumulative.  GSK's  rights  and  remedies  under  the  Loan
Documents  and  all  other Transaction Documents shall be cumulative.  GSK shall
have  all  other  rights and remedies not expressly set forth herein as provided
under  applicable  law, or in equity.  No exercise by GSK of one right or remedy
shall  be  deemed  an  election, and no waiver by GSK of any Event of Default on
Exelixis'  part  shall  be  deemed  a  continuing waiver.  No delay by GSK shall
constitute a waiver, election, or acquiescence by it.  No waiver by GSK shall be
effective  unless  made  in  a written document signed on behalf of GSK and then
shall  be  effective  only in the specific instance and for the specific purpose
for  which  it  was  given.

     13.7  Waiver. Exelixis waives demand, protest, notice of protest, notice of
default  or  dishonor,  notice of payment and nonpayment, notice of any default,
nonpayment  at  maturity, release, compromise, settlement, extension, or renewal
of  accounts,  documents, instruments, chattel paper, and guarantees at any time
held  by  GSK  on  which  Exelixis  may  in  any  way  be  liable.

                                   ARTICLE 14
                 GSK'S RIGHTS AND REMEDIES EXCLUSIVE OF DEFAULT

     Exclusive  of  an  Event of Default, GSK possesses the following rights and
remedies:

     14.1  UCC.  At  all  times  prior to and following an Event of Default, GSK
is  entitled  to all the rights and remedies of a secured party under the UCC as
now  or  hereafter  enacted;

     14.2  Preservation  of  Collateral.  At  any time prior to and following an
Event  of  Default,  GSK, without notice, in its sole reasonable discretion, may
take  any  and all action which, in its sole reasonable discretion, is necessary
and  proper  to  preserve  the  Collateral,  or  GSK's interests under this Loan
Agreement,  including  without  limitation,  those duties of Exelixis imposed by
this  Loan  Agreement.  Any  sums  so  expended  by GSK are to be secured by the
Collateral and treated as though additional Advances for purposes of calculating
the  Total  Advance Amount. Such sums (including reasonable attorneys' fees) are
to  be payable on demand with interest at the Default Rate of Interest repaid by
Exelixis.  GSK  may  also  demand  that  escrow  accounts be established to fund
anticipated  future  expenditures;  or

     14.3  Power  of  Attorney.  GSK  is  hereby  irrevocably  appointed  and
authenticated  by  Exelixis  as  its  lawful attorney and agent in fact to file,
authenticate  or execute financing statements and other documents and agreements
as  GSK may deem necessary for the purpose of perfecting any security interests,
or  liens  under any applicable law.  All acts by GSK or its designee are hereby
ratified  and  approved,  and neither GSK, nor its designee, shall be liable for
any  acts  of  omission  or  commission, or for any error of judgment or mistake
unless  the  result  of  gross  negligence  of willful misconduct. The powers of
attorney  granted to GSK in this Loan Agreement are coupled with an interest and
are  irrevocable  during  the  Term.

                                  ARTICLE 15
                                 INDEMNIFICATION

     15.1  Indemnification  of  GSK.  Exelixis  agrees  to  and hereby indemnify
and  hold  GSK  harmless from and against, and to reimburse GSK with respect to,
any  and  all  claims,  demands, causes of action, losses, damages, liabilities,
costs  and  expenses (including consequential damages, attorneys' fees and court
costs)  of  any  and  every  kind  or  character,  known  or  unknown,  fixed or
contingent,  asserted  against  or  incurred by GSK at any time and from time to
time  by  reason  of  or  arising  out  of:

          15.1.1  the  breach  of  any  representation,  warranty or covenant of
Exelixis  set  forth  in  the  Loan  Documents;

          15.1.2  the  failure  of  Exelixis  to  perform  any obligation herein
required  to  be  performed  by  Exelixis;  or

          15.1.3  the ownership, construction, operation, use and maintenance of
the  Collateral  other  than  by  GSK.

          15.1.4  Duration  of  Indemnity.  This  covenant survives for the Term
notwithstanding whether Exelixis has been released and discharged or whether GSK
becomes  the  owner  of  the  Collateral.

                                   ARTICLE 16
                                  MISCELLANEOUS

     16.1  Publicity.  Neither  Party  shall  originate  any  written publicity,
news  release or other announcement or statement relating to the announcement or
terms of this Loan Agreement except as otherwise provided in Section 14.1 of the
Development  Agreement.

     16.2  Dispute Resolution. Prior to the commencement of any litigation under
this Loan Agreement, the Executive Officer of the Party considering commencement
of  such  litigation  shall notify the Executive Officer of the other Party that
such  litigation is being contemplated.  For at least [*] following the delivery
of  such notice, the Parties' Executive Officers shall use good faith efforts to
make  themselves  available  to  discuss  the dispute and attempt to resolve the
matter.  If  the  dispute  is not resolved within such [*], the Parties agree to
submit  the  dispute  for non-binding mediation (with the understanding that the
role of the mediator shall not be to render a decision but to assist the Parties
in reaching a mutually acceptable resolution), which shall occur within a period
of  not  more  than [*].  If the dispute is not resolved within such [*], either
Party  may commence litigation with respect to the subject matter of the dispute
and  with  respect  to any other claims it may have and thereafter neither Party
hereto  shall  have  any  further  obligation  under  this  Section  16.2.

     16.3  Choice  of  Law. This Loan Agreement and any dispute arising from the
performance  or breach hereof shall be governed by and construed and enforced in
accordance  with  the  laws of State of New York, U.S.A., unless such dispute is
governed  under  the  laws of the UCC in which case the UCC shall apply, without
reference  to  conflicts  of  laws  principles.

     16.4 Subordination. The Obligations are expressly made subordinate in right
of  payment to all other obligations and indebtedness of Exelixis existing as of
the  Effective  Date  and  listed  on  Schedule 16.4 and all refinancings (in an
amount  equal  to  or  less  than  the  original  indebtedness), extensions, and
renewals  thereof.   For  the sake of clarity, this Section 16.4 applies only to
GSK  rights  and  remedies  under  Section  13.1.4 and not to GSK's rights under
Section  13.1.7.

     16.5 Notices. Any notice or request required or permitted to be given under
or  in  connection  with  this  Loan  Agreement  shall  be  deemed  to have been
sufficiently  given  if in writing and personally delivered or sent by certified
mail  (return  receipt requested), facsimile transmission (receipt verified), or
overnight  express  courier  service (signature required), prepaid, to the Party
for  which  such  notice  is  intended,  at the address set forth for such Party
below:

If  to  Exelixis,  addressed  to:  Exelixis,  Inc.
                                   170 Harbor Way
                                   PO Box 511
                                   South San Francisco, CA 94083
                                   Attention: Chief Financial Officer
                                   Telephone: [ * ]
                                   Telecopy:  [ * ]

with  a  copy  to:                 Cooley  Godward  LLP
                                   Five Palo Alto Square
                                   3000 El Camino Real
                                   Palo Alto, CA 94306
                                   Attention: Robert Jones, Esq.
                                   Telephone: [ * ]
                                   Telecopy:  [ * ]

If  to  GSK,  addressed  to:       SmithKline  Beecham  Corporation,
                                   doing business as GlaxoSmithKline
                                   2301 Renaissance Blvd. (Bldg #510)
                                   King of Prussia, Pennsylvania 19406
                                   Attention: Vice President, Alliance
                                              and Joint Venture Management
                                   Telephone: [ * ]
                                   Telecopy:  [ * ]

with  a  copy  to:                 GlaxoSmithKline
                                   Corporate Legal Department
                                   One Franklin Plaza
                                   200 N. 16th Street / FP 2355 (DP)
                                   Philadelphia, PA 19103
                                   Attention: Senior Vice President and
                                              Associate General Counsel
                                   Telephone: [ * ]
                                   Telecopy:  [ * ]

or  to  such  other  address  for  such Party as it shall have specified by like
notice  to the other Parties, provided that notices of a change of address shall
be effective only upon receipt thereof.  If delivered personally or by facsimile
transmission,  the date of delivery shall be deemed to be the date on which such
notice  or request was given.  If sent by overnight express courier service, the
date  of  delivery shall be deemed to be the next business day after such notice
or request was deposited with such service.  If sent by certified mail, the date
of  delivery  shall  be deemed to be the third business day after such notice or
request  was  deposited  with  the  U.S.  Postal  Service.

     16.6  Severability.  If  any  provision  hereof  should  be  held  invalid,
illegal  or  unenforceable  in  any jurisdiction, the Parties shall negotiate in
good  faith a valid, legal and enforceable substitute provision that most nearly
reflects  the  original  intent  of  the Parties and all other provisions hereof
shall  remain  in  full  force  and  effect  in  such  jurisdiction and shall be
liberally  construed  in order to carry out the intentions of the Parties hereto
as  nearly  as may be possible.  Such invalidity, illegality or unenforceability
shall  not  affect the validity, legality or enforceability of such provision in
any  other  jurisdiction.

     16.7  Entire  Agreement.  This  Loan Agreement, including the schedules and
exhibits  hereto, together with the Stock Purchase Agreement and the Development
Agreement  set  forth  all  the  covenants,  promises,  agreements,  warranties,
representations,  conditions  and  understandings between the Parties hereto and
supersede  and  terminate  all  prior  agreements  and understanding between the
Parties.  There  are  no  covenants,  promises,  agreements,  warranties,
representations,  conditions  or understandings, either oral or written, between
the  Parties  other  than  as  set  forth  herein  and  therein.  No  subsequent
alteration,  amendment,  change  or  addition  to  this  Loan Agreement shall be
binding  upon  the  Parties  hereto  unless reduced to writing and signed by the
respective  authorized  officers  of  the  Parties.

     16.8  Headings. Headings used herein are for convenience only and shall not
in  any  way  affect  the  construction  of  or  be  taken into consideration in
interpreting  this  Loan  Agreement.

     16.9  Use of Name. Except as otherwise provided herein, no Party shall have
any  right,  express  or  implied,  to  use  in  any  manner  the  name or other
designation  of the other Parties or any other trade name, trademark or logos of
the  other  Parties  for  any purpose in connection with the performance of this
Loan  Agreement.

     16.10  Further  Actions.  Each Party shall execute, acknowledge and deliver
such  further  instruments,  and  do all such other acts, as may be necessary or
appropriate  in  order  to  carry  out  the  purposes  and  intent  of this Loan
Agreement.

     16.11 Waiver of Jury Trial. EACH PARTY HERETO HEREBY WAIVES, TO THE FULLEST
EXTENT  PERMITTED BY APPLICABLE LAW, ANY RIGHT IT MAY HAVE TO A TRIAL BY JURY IN
RESPECT  TO  ANY  LITIGATION  DIRECTLY OR INDIRECTLY ARISING OUT OF, UNDER OR IN
CONNECTION  WITH  THIS  LOAN AGREEMENT.  EACH PARTY HERETO (i) CERTIFIES THAT NO
REPRESENTATIVE,  AGENT OR ATTORNEY OF ANY OTHER PARTY HAS REPRESENTED, EXPRESSLY
OR  OTHERWISE, THAT SUCH OTHER PARTY WOULD NOT, IN THE EVENT OF LITIGATION, SEEK
TO  ENFORCE  THAT  FOREGOING WAIVER, AND (ii) ACKNOWLEDGES THAT IT AND THE OTHER
PARTIES  HERETO  HAVE  BEEN  INDUCED  TO  ENTER INTO THIS LOAN AGREEMENT AND ANY
RELATED  INSTRUMENTS,  AS APPLICABLE, BY, AMONG OTHER THINGS, THE MUTUAL WAIVERS
AND  CERTIFICATIONS  IN  THIS  SECTION  16.11.

     16.12  Parties  in  Interest.  All of the terms and provisions of this Loan
Agreement  shall  be binding upon, inure to the benefit of and be enforceable by
the  Parties  hereto  and  their  respective  permitted  successors and assigns.

     16.13  Construction  of  Agreement.  The  terms and provisions of this Loan
Agreement  represent  the  results of negotiations between the Parties and their
representatives,  each  of  which  has  been  represented  by counsel of its own
choosing,  and  neither  of  which has acted under duress or compulsion, whether
legal,  economic  or  otherwise.  Accordingly,  the terms and provisions of this
Loan Agreement shall be interpreted and construed in accordance with their usual
and  customary  meanings,  and  each  of  the  Parties  hereto hereby waives the
application  in connection with the interpretation and construction of this Loan
Agreement  of  any rule of law to the effect that ambiguous or conflicting terms
or provisions contained in this Loan Agreement shall be interpreted or construed
against  the  Party  whose  attorney  prepared the executed draft or any earlier
draft  of  this  Loan  Agreement.

     16.14 No Liability for GSK. Other than fulfilling its obligations under the
Development Agreement, GSK has no duty to preserve or protect the Collateral, to
preserve  the  rights  of  Exelixis  against Third Parties, or to sell, lease or
otherwise  dispose  of  any  or  all  of the Collateral, or its proceeds, in any
priority,  unless it elects to do so as provided in this Loan Agreement.  Except
as  expressly  provided, this Section 16.14 shall be deemed an express waiver of
the  defense  of  impairment  of  Collateral.

     16.15  Survival of Representations. All representations and warranties made
herein  shall  survive  the making of the Advances hereunder and the delivery of
the  Note,  and  shall  continue  in  full  force  and  effect  so  long  as any
indebtedness  is outstanding, there exists any commitment by GSK to Exelixis and
until  this  Loan  Agreement  terminates  or  expires.

     16.16  No  Usury. Regardless of any other provision of this Loan Agreement,
the Note or in any other Loan Document, if for any reason the effective interest
should  exceed  the  maximum  lawful  interest,  the effective interest shall be
deemed  reduced  to,  and  shall  be,  such maximum lawful interest, and (a) the
amount  which  would  be  excessive  interest  shall  be  deemed  applied to the
reduction  of  the  principal  balance  of  the  Note  and not to the payment of
interest,  and (b) if the loan evidenced by the Note has been or is thereby paid
in full, the excess shall be returned to the party paying same, such application
to the principal balance of the Note or the refunding of excess to be a complete
settlement  and  acquittance  thereof.

     16.17  Assignment.  This  Loan  Agreement  may  be  assigned  by  GSK to an
Affiliate  without  the written consent of Exelixis; but shall not be assignable
by Exelixis, to an Affiliate, or by either Party to any Third Party, without the
prior written consent of the other Party hereto.  Notwithstanding the foregoing,
either  Party may assign this Loan Agreement, without the written consent of the
other  Party, to an Affiliate or to an entity that acquires all or substantially
all  of the business or assets of such Party (whether by merger, reorganization,
acquisition,  sale or otherwise), and agrees in writing to be bound by the terms
and conditions of the Loan Agreement.  No assignment and transfer shall be valid
and  effective  unless  and  until  (a)  the  assignee/transferee shall agree in
writing to be bound by the provisions of the Loan Documents, (b) with respect to
an  assignment  or  transfer  by  Exelixis,  the  Stock  Purchase  Agreement  is
assigned/transferred to the same assignee/transferee concurrently with this Loan
Agreement,  and  (c)  with respect to an assignment or transfer by Exelixis, the
assignee or transferee shall have executed and recorded such documents as may be
required  in  the  reasonable  judgment  of GSK to perfect GSK's interest in the
Collateral.  The  terms and conditions of the Loan Agreement shall be binding on
and inure to the benefit of the permitted successors and assigns of the Parties.

     16.18 Counterparts. This Loan Agreement may be signed in counterparts, each
and  every  one of which shall be deemed an original, notwithstanding variations
in format or file designation which may result from the electronic transmission,
storage and printing of copies of this Loan Agreement from separate computers or
printers.  Facsimile  signatures  shall  be  treated  as  original  signatures.
                                  * - * - * - *

<PAGE>
In  Witness  Whereof,  each  of the Party's has caused this Loan Agreement to be
executed  and  delivered  by  its  duly authorized officer on the date first set
forth  above.

Address  of  Exelixis:                         Exelixis,  Inc.

170  Harbor  Way                               By: /s/  Glen  Y.  Sato
P.O.  Box  511                                     ----------------------------
South  San  Francisco,  CA 94083               Printed Name: Glen  Y.  Sato
Attention:   Chief  Executive  Officer                       ------------------
Telephone:   [*]                               Title: CFO & VP of Legal Affairs
Telecopy:    [*]                               -------------------------

Taxpayer  Identification Number of             Jurisdiction of Organization of
Grantor:                                       Grantor:

     [*]                                 Delaware
----------------------------------

SmithKline  Beecham  Corporation

By:     /s/  Donald  F.  Parman
        ----------------------------
Printed  Name: Donald  F.  Parman
               ---------------------
Title: Vice  President  &  Secretary
       -----------------------------

[  *  ] = Certain confidential information contained in this document, marked by
brackets, has been omitted and filed separately with the Securities and Exchange
Commission  pursuant  to  Rule  24b-2 of the Securities Exchange Act of 1934, as
amended.
<PAGE>

                                    EXHIBIT A
                                 PROMISSORY NOTE

[*]

                                                             _____________, 2002

Exelixis,  Inc., a Delaware corporation ("Exelixis"), for value received, hereby
promises  to  pay to the order of SmithKline Beecham Corporation, doing business
as  GlaxoSmithKline  ("GSK"),  the  principal  amount  of [*] (the "Maximum Loan
Amount"), together with interest as provided for below, payable on the dates, in
the  amounts  and  in  the  manner  set  forth  below.

     1.     Loan  Agreement.  This  Promissory  Note  (this  "Note") is the note
referred  to  in  that certain Loan and Security Agreement, dated as of the date
hereof,  by  and  between  Exelixis  and  GSK  (as  the  same  may  be  amended,
supplemented,  restated  or  otherwise  modified  from  time  to time, the "Loan
Agreement").  Capitalized  terms  used herein without definitions shall have the
meanings  given  to  such  terms  in  the  Loan  Agreement.

     2.     Advances.  Exelixis  may  obtain  an  Advance by delivering to GSK a
Borrowing  Notice  pursuant  to  Section  2.2  of  the  Loan  Agreement.

     3.     Principal Payments.  Subject to the terms and conditions of the Loan
Agreement,  the total outstanding principal balance of all Advances shall be due
and payable on the Payment Dates set forth in Section 5.1 of the Loan Agreement,
and may be paid in cash or Common Stock in accordance with the terms of Sections
5.3  and  5.6  of  the  Loan  Agreement.

     4.     Interest.  The  sum  of  the  daily  unpaid principal balance of all
outstanding Advances shall accrue interest on each day from the date the Advance
is  made  until  paid  at  the  rate  per annum set forth in the Loan Agreement.

     5.     Payment  on  Non-Business  Day.  In  the  event  that any payment of
principal,  interest,  fees  or  any  other amounts payable by Exelixis under or
pursuant  to  this Note shall become due on any day which is not a Business Day,
such due date shall be extended to the next succeeding Business Day, and, to the
extent  applicable,  interest  shall  continue  to  accrue and be payable at the
applicable  rate  for  and  during  any  such  extension.

     6.     Default.  Exelixis'  failure  to  pay  timely  any  of the principal
amount  due  under this Note when the same becomes due and payable or failure to
pay timely any accrued interest or other amounts due under this Note on the date
the  same  becomes  due  and payable thereafter shall constitute a default under
this  Note.  Upon  the  occurrence of a default hereunder or an Event of Default
under  the  Loan  Agreement  or  any  of  the  other  Loan Documents, all unpaid
principal,  accrued  interest  at the Default Rate of Interest and other amounts
owing  hereunder  shall be collectible by GSK pursuant to the Loan Documents and
applicable  law.

     7.     Waivers.  Exelixis  hereby  waives  presentment,  demand,  protest,
notice of dishonor, notice of demand or intent to demand, notice of acceleration
or  intent  to  accelerate,  and  all other notices, and Exelixis agrees that no
extension  or  indulgence  to  Exelixis  or  the  release,  substitution  or
nonenforcement  of  any  security,  or  the release or substitution of Exelixis,
whether  with  or without notice, shall affect the obligations of Exelixis.  The
right  to  plead  any and all statutes of limitation as a defense to any demands
hereunder  is  hereby  waived  by  Exelixis to the full extent permitted by law.

     8.     Governing  Law.  This  Note  shall  be  governed by and construed in
accordance with the laws of the State of New York without reference to conflicts
of  law  principles.

     9.     Successors  and Assigns.  The provisions of this Note shall inure to
the  benefit  of and be binding on any successor to Exelixis and shall extend to
any  holder  hereof.

     In Witness Whereof, the undersigned has caused this Note to be executed the
day  and  year  aforesaid.

Witness/Attest:                         Exelixis,  Inc.

                                        By:  ________________________________
                                        Name:  ______________________________
                                        Title: ______________________________

[  *  ] = Certain confidential information contained in this document, marked by
brackets, has been omitted and filed separately with the Securities and Exchange
Commission  pursuant  to  Rule  24b-2 of the Securities Exchange Act of 1934, as
amended
<PAGE>

                           SCHEDULE 1-PROMISSORY NOTE

                          SCHEDULE OF GENERAL ADVANCES

          --------------     -----------------     --------------------
          Borrowing Date     Amount of Advance     Total Advance Amount
          --------------     -----------------     --------------------
          --------------     -----------------     --------------------
          --------------     -----------------     --------------------
          --------------     -----------------     --------------------
          --------------     -----------------     --------------------
          --------------     -----------------     --------------------
          --------------     -----------------     --------------------
          --------------     -----------------     --------------------
          --------------     -----------------     --------------------
          --------------     -----------------     --------------------
          --------------     -----------------     --------------------

                      SCHEDULE OF PRODUCT SPECIFIC ADVANCES
                  FOR THE SPECIFIC DEVELOPMENT CANDIDATE [   ]

          Borrowing Date     Amount of Advance     Total Advance Amount
          --------------     -----------------     --------------------
          --------------     -----------------     --------------------
          --------------     -----------------     --------------------
          --------------     -----------------     --------------------
          --------------     -----------------     --------------------
          --------------     -----------------     --------------------
          --------------     -----------------     --------------------
          --------------     -----------------     --------------------
          --------------     -----------------     --------------------
          --------------     -----------------     --------------------
          --------------     -----------------     --------------------
          --------------     -----------------     --------------------
<PAGE>

                                    EXHIBIT B
                          FORM OF PATENT OFFICE FILING

                     PATENT SECURITY AGREEMENT AND MORTGAGE

     THIS  PATENT  SECURITY  AGREEMENT  AND MORTGAGE (the "Patent Agreement") is
executed  as of the  _____ day of _____________ , 2002, by and between Exelixis,
Inc.,  a Delaware corporation ("Exelixis") and SmithKline Beecham Corporation, a
Pennsylvania  corporation,  doing business as GlaxoSmithKline ("GSK").  Exelixis
and GSK are each referred to herein by name or as a "Party" or, collectively, as
"Parties".

                                    RECITALS

A.   Exelixis  is  the  owner and holder of the Patents listed on Schedule 2.1.1
     annexed  hereto  and made a part hereof, together with all right, title and
     interest  in and to the related inventions and any U.S. and foreign patents
     which  have  been  or  may  be  issued  thereon;

B.   Contemporaneously  with the execution of this Patent Agreement, the Parties
     have  executed:  (i)  a Product Development and Commercialization Agreement
     (the  "Development  Agreement");  (ii)  a Stock Purchase and Stock Issuance
     Agreement  (the  "Stock Purchase Agreement"); and (iii) a Loan and Security
     Agreement  (the  "Loan  Agreement"),  as  such  documents  may  be amended,
     modified,  supplemented  or  restated  from time to time (collectively, the
     "Transaction  Documents");  and

C.   To induce GSK to enter into the Transaction Documents, Exelixis has offered
     to execute and deliver this Patent Agreement to GSK, granting and conveying
     to GSK a security interest, first and only in priority, upon the Collateral
     (as  such  term  is  defined  in  Article  2).

     NOW,  THEREFORE, in consideration of the foregoing, in consideration of the
premises set forth in the Loan Agreement and in order to induce GSK to grant the
Advances  to  Exelixis  in  accordance  with the Loan Agreement, Exelixis hereby
agrees  with  GSK  for  its  benefit  as  follows:

                                    ARTICLE 1
                                   DEFINITIONS

     Unless  otherwise  defined  in this Patent Agreement, all capitalized terms
shall  have  the  meanings  given them in the Transaction Documents.  As used in
this  Patent  Agreement, the following terms shall have the following respective
meanings:

     1.1  "Affiliate"  shall  mean  any  Person,  whether  de  jure or de facto,
which directly or indirectly through one (1) or more intermediaries controls, is
controlled  by,  or is under common control with, a Party to the Loan Documents.
A Person shall be deemed to "control" another Person if it (a) owns, directly or
indirectly,  beneficially  or  legally,  at  least  fifty  percent  (50%) of the
outstanding  voting securities or capital stock (or such lesser percentage which
is  the maximum allowed to be owned by a Person in a particular jurisdiction) of
such  other  Person,  or has other comparable ownership interest with respect to
any  Person  other than a corporation; or (b) has the power, whether pursuant to
contract,  ownership  of  securities  or otherwise, to direct the management and
policies  of  the  Person.

     1.2  "Capital  Equipment"  shall  have the meaning assigned to such term in
Section  2.1.5.

     1.3 "Collateral" shall have the meaning assigned to such term in Article 2.

     1.4  "Deposit  Account"  shall  have  the  meaning assigned to such term in
Section  2.1.3.

     1.5 'Development Agreement" shall have the meaning assigned to such term in
the  Recitals.

     1.6 "Development Candidate" shall have the meaning assigned to such term in
the  Development  Agreement.

     1.7  "Development  Candidate  Inventory" shall have the meaning assigned to
such  term  in  Section  2.1.4.

     1.8  "Development Compound" shall have the meaning assigned to such term in
the  Development  Agreement.

     1.9  "Environmental  Laws" shall mean any federal, state, county, municipal
or  other  laws,  ordinances  or  regulations  pertaining  to  health  or  the
environment.

     1.10 "Event of Default" shall mean any of those conditions or events listed
in  Article  12  of  the  Loan  Agreement  or  Section  5.1  hereof.

     1.11  "Included  Compounds" shall have the meaning assigned to such term in
the  Development  Agreement.

     1.12  "Intellectual  Property" shall have the meaning assigned to such term
in  Section  2.1.2.

     1.13  "Loan  Agreement" shall have the meaning assigned to such term in the
Recitals.

     1.14  "Loan  Documents"  shall  mean  collectively, the Loan Agreement, the
Note,  the  UCC Financing Statement(s), the Patent Office Filing(s), the Control
Agreement  and any other agreements, certificates or instruments executed now or
hereafter  evidencing,  describing,  certifying  or securing the Obligations, as
such  documents  may be amended, modified, supplemented or restated from time to
time.

     1.15  "Material  Adverse Effect" shall mean any material adverse effect (a)
upon  the  validity,  or  enforceability of the Loan Documents (b) on any of the
transactions  contemplated  by  the  Loan  Documents,  (c)  on  the  business,
operations,  condition  (financial  or  otherwise), performance or properties of
Exelixis  taken  as  a whole, or (d) upon the ability of Exelixis to fulfill any
Obligations.

     1.16  "Obligations"  shall  mean  all  Advances,  Total  Advance  Amount,
liabilities,  obligations, covenants and duties arising under the Loan Documents
owed  by  Exelixis  to  GSK  whether direct or indirect, absolute or contingent.

     1.17  "Patents"  shall  have  the  meaning assigned to such term in Section
2.1.1.

     1.18  "Patent  Office  Filing" shall mean this Patent Agreement and any and
all other patent collateral mortgage agreements between GSK and Exelixis and its
Affiliates  which  grant to GSK a security interest, first and only in priority,
in  the Collateral, as such agreements may be amended, modified, supplemented or
restated  from  time  to  time.

     1.19  "Person"  shall  mean  any individual, corporation, firm, partnership
or  other  entity.

     1.20  "Proceeds"  shall  have the meaning assigned to such term in the UCC.

     1.21  "Stock  Purchase  Agreement"  shall have the meaning assigned to such
term  in  the  Recitals.

     1.22  "Third  Party" shall mean any entity other than Exelixis or GSK or an
Affiliate  of  Exelixis  or  GSK.

     1.23  "Transaction  Documents"  shall  have  the  meaning  assigned to such
terms  in  the  Recitals.

     1.24  "United  States  or  "U.S."  shall mean the United States of America.

     1.25 "UCC" shall mean the Uniform Commercial Code as the same may from time
to  time  be  in  effect  in  Exelixis'  state  of  incorporation.

     1.26  "UCC  Financing Statement(s)" shall mean a record or records composed
of  an  initial financing statement and any filed record relating to the initial
financing  statement  filed  in Exelixis' state of incorporation or elsewhere to
perfect  GSK's  lien  on  the  Collateral.

     Other  Definitional  Provisions.  Where  the  context  herein requires, the
singular  number  shall  be  deemed  to include the plural, the masculine gender
shall  include  the  feminine  and  neuter  genders,  and vice versa.  The words
"hereof,"  "herein"  and  words  of  similar  import  when  used  in this Patent
Agreement  shall  refer  to  this  Patent  Agreement  as  a whole and not to any
particular  provision  of this Patent Agreement and section, schedule or exhibit
references  are  to  this  Patent  Agreement  unless  otherwise  specified.

                                    ARTICLE 2
                                GRANT OF SECURITY

     2.1  Grant  of  Security  Interest.  To  secure the payment and performance
by  Exelixis  of the Obligations to GSK, Exelixis and, to the extent applicable,
its  Affiliates  hereby  pledge, set over, assign, deliver and grant a first and
only  priority  security  interest to GSK in all of Exelixis' and, to the extent
applicable,  its  Affiliates' right, title and interest in the following assets,
wherever  located  and whether now existing or hereafter created and whether now
owned  or hereafter acquired, of every description, tangible and intangible (the
"Collateral"):

          2.1.1  Development  Patents.  [*];

          2.1.2  Other  Intellectual  Property.  [*];

          2.1.3  Deposit  Account.  That certain deposit account with a mutually
agreed  upon  bank  or  financial  institution,  initially  [*], more
particularly  described in the Loan Agreement (the "Deposit Account") maintained
by  Exelixis  into  which  the  proceeds of the Advances shall be deposited and,
subject to Section 9.5 of the Loan Agreement, maintained, with all dividends and
distributions, whether payable in cash, securities or other property accruing on
the  balance  therein;

          2.1.4  Development  Candidate  Inventory.  [*];

          2.1.5  Capital  Equipment. All capital equipment (currently defined as
equipment  with  a  purchase  price  per item in excess of Five Thousand Dollars
($5,000)),  purchased  by  Exelixis  with the proceeds of the Advances, having a
specific use solely to perform the activities contemplated under the Development
Agreement  (the  "Capital  Equipment");  and

          2.1.6 Proceeds. All Proceeds of the Intellectual Property, the Deposit
Account,  the  Development  Candidate  Inventory  and/or  the Capital Equipment.

                                    ARTICLE 3
     REPRESENTATIONS,  WARRANTIES  AND  COVENANTS  OF  EXELIXIS

     Exelixis  hereby  represents,  warrants,  covenants  and agrees as follows:

     3.1     Title  to  the  Collateral. To its knowledge, Exelixis has good and
marketable  title  and  rights  to  the  Intellectual  Property,  except for the
security  interest  granted  to  GSK by Exelixis pursuant to the Loan Documents.
Exelixis  has  good and marketable title and rights to the Development Candidate
Inventory,  Capital  Equipment  and  Deposit  Account  except  for  the security
interest  granted  to  GSK by Exelixis pursuant to the Loan Documents.  Exelixis
has  the right and corporate power to grant the security interests in and to the
Collateral provided by or referred to in the Loan Documents.  Except as provided
in  the  Loan  Agreement  and  herein,  none of the Collateral is or is about to
become  subject  to  any  other  assignment,  mortgage,  pledge,  lien, security
interest,  lease or encumbrance by virtue of the execution or performance of the
Loan  Documents.  No  lien  or  claim  has  been attached to or made against the
Collateral  for:  (a)  tax liabilities which have been assessed against Exelixis
which remain unpaid; or (b) damages or cleanup and removal costs, as those terms
are  defined  by  any  Environmental  Laws  arising  from  an  intentional  or
unintentional  act  or omission of Exelixis or any previous owner or operator of
its  real  or  personal  property resulting in the releasing, spilling, pumping,
pouring,  emitting,  emptying,  discharging  or dumping of hazardous substances,
hazardous  wastes,  pollutants  or  other  related substances as those terms are
defined  by any Environmental Laws which would create a Material Adverse Effect.

     3.2  Infringement  of  the  Collateral.  To  the  best  of the knowledge of
Exelixis and its majority-owned subsidiaries (other than Artemis Pharmaceuticals
GmbH),  respectively,  Exelixis and such majority-owned subsidiaries (other than
Artemis  Pharmaceuticals  GmbH): (i) own, or have obtained licenses or rights to
use,  all  of  the  Collateral  necessary  to  carry  out  Exelixis'  and  its
majority-owned subsidiaries (other than Artemis Pharmaceuticals GmbH) respective
businesses  as  currently  conducted  or as Exelixis contemplates conducting its
business  from time to time in the future and as contemplated by the Transaction
Documents;  (ii)  are  not aware of any notice asserting any ownership rights to
the  Collateral;  (iii)  are  not  aware  of  sales  of  any products that would
constitute an infringement by Third Parties of the Collateral; (iv) are aware of
no  pending  or  threatened  action,  suit, proceeding or claim by a Third Party
challenging  the ownership rights in, validity or scope of, the Collateral;  and
(v) are not aware of any pending or threatened action, suit, proceeding or claim
by  a Third Party asserting that and its majority-owned subsidiaries (other than
Artemis  Pharmaceuticals  GmbH)  infringe  or  otherwise  violate  any  patent,
trademark, copyright, trade secret or other proprietary right of any Third Party
as  would  reasonably  be  expected  to  result  in  a  Material Adverse Effect.

     3.3  Further Assurances. In addition to the obligations and documents which
the  Loan  Documents  expressly requires Exelixis and, to the extent applicable,
its  Affiliates  to  execute,  acknowledge,  deliver and perform, Exelixis shall
execute  and  acknowledge (or cause to be executed and acknowledged) and deliver
to  GSK all documents, and take all actions, that may be reasonably requested by
GSK from time to time to confirm the rights created or now or hereafter intended
to be created under the Loan Documents or otherwise to carry out the purposes of
the  Loan  Documents and the transactions contemplated hereunder and thereunder.
Exelixis hereby agrees to execute, file and/or deliver (or cause its Affiliates,
as applicable, to execute, file and/or deliver) to GSK the Patent Office Filings
and  such  other  security agreements as GSK shall deem necessary or appropriate
from  time  to  time.  The  security  interest  pledged,  set over, assigned and
granted  by  Exelixis and, to the extent applicable, its Affiliates to GSK shall
be  a  first and only priority security interest pursuant to applicable law, and
Exelixis  shall  take  all such action (or cause its Affiliates to take all such
action)  to  create and perfect for the benefit of GSK a first priority security
interest  in  the  Collateral;  and  in  the  case  of  Capital  Equipment being
purchased,  a  purchase-money  security interest pursuant to Section 9.15 of the
Loan  Agreement.

     3.4 Fees and Expenses in Protecting Rights. If in the Event of Default, GSK
employs  counsel  or  any other professionals or consultants for advice or other
representation:  (a) with respect to the Collateral, the Obligations of Exelixis
to  GSK  or the Loan Documents; (b) to represent GSK in any litigation, contest,
dispute,  suit  or proceeding or to commence, defend or intervene or to take any
other  action  in  or  with respect to any litigation, contest, dispute, suit or
proceeding (whether instituted by GSK, Exelixis or any other Third Party) in any
way  or  respect  relating to the Collateral, the Obligations of the Exelixis to
GSK,  the  Loan Documents; (c) to protect, collect, sell, liquidate or otherwise
dispose  of  the  Collateral;  (d)  to  attempt to or to enforce GSK's liens and
security  interests  in  the  Collateral;  and/or  (e)  in otherwise protecting,
enforcing  or exercising its interests, rights or remedies created by, connected
with  or  provided  in  the  Loan Documents, or performance pursuant to the Loan
Documents; then, the reasonable attorneys' fees, costs and expenses arising from
such  services,  and all other expenses, costs, charges and other fees of GSK in
any  way  or respect arising in connection with or relating to any of the events
described in this Section 3.4 shall be added to the amount of the Obligations of
Exelixis  to  GSK, and shall be payable on demand. Any amounts due hereunder not
paid  on  demand shall bear interest from the date of demand at the Default Rate
of  Interest.  Any  of  the amounts payable hereunder by Exelixis may be paid by
GSK,  and  if  and  when  so  paid,  shall  be  deemed  to be a General Advance.

     3.5  Pledge  of  Additional  Collateral.  Pursuant  to  Section  8  of  the
Development  Agreement,  in  the  event  Exelixis,  either itself or through any
Affiliate  shall:

          3.5.1 file or record an application for the registration of any Patent
with  the  United  States  Patent  and Trademark Office or any similar office or
agency  of  the  United  States,  any State thereof, or any other country or any
political  subdivision  thereof;  or

          3.5.2  file  or record any assignment of any Patent which Exelixis may
acquire,  own  or  license from a Third Party, with the United States Patent and
Trademark Office or any similar office or agency of the United States, any State
thereof  or  any  other  country  or  any  political  subdivision  thereof;

Exelixis  shall promptly, but in no event more than fifteen (15) days subsequent
to such filing, notify GSK thereof, and, upon request of GSK shall promptly, but
in  no  event  more than twenty (20) days subsequent to such notice, execute and
deliver  any  and all assignments, agreements, instruments, documents and papers
as GSK may reasonably request to evidence GSK's interest in such Collateral, and
the  general  intangibles  of  Exelixis relating thereto or represented thereby.
Exelixis  hereby  grants  GSK  a  power  of  attorney,  irrevocable  until  the
Obligations  of  Exelixis  to  GSK  are fully paid and satisfied, to modify this
Patent  Agreement  by  amending Schedule 2.1.1 to include any future Collateral,
including,  without  limitation,  registrations  or  applications  appurtenant
thereto,  covered  by  this  Patent  Agreement.

     3.6  Impairment  of  Title  to  Collateral.  Neither  Exelixis  nor  its
Affiliates  shall  sell,  conditionally  sell, sell on approval, consign, lease,
encumber,  transfer,  remove  from its premises any Collateral without the prior
written  consent  of  GSK.

     3.7  Preservation  of  Title  to Collateral. Exelixis agrees to immediately
notify  GSK  of  any  material  loss or damage to, or any occurrence which would
materially  and  adversely  affect  the  security  interest of GSK in and to the
Collateral.  The  Collateral  shall  be  free  and  clear  of  all  assignments,
mortgages,  pledges,  liens, security interests, leases, or encumbrances, except
as  otherwise  provided  in  the  Loan  Documents.  Exelixis  shall  continue to
maintain  good  and  marketable  title  to  the  Collateral, except as otherwise
provided  in  the  Loan  Documents,  at  the  sole  expense  of  Exelixis.

                                    ARTICLE 4
                      GSK'S APPOINTMENT AS ATTORNEY-IN-FACT

     4.1  Appointment  of  GSK  as  Attorney-In-Fact.  GSK is hereby irrevocably
appointed and authenticated by Exelixis as its lawful attorney and agent in fact
to  file,  authenticate  or execute financing statements and other documents and
agreements  as GSK may deem necessary for the purpose of perfecting any security
interests,  or  liens under any applicable law.  All acts by GSK or its designee
are  hereby  ratified  and approved, and neither GSK, nor its designee, shall be
liable  for  any acts of omission or commission, or for any error of judgment or
mistake  unless the result of gross negligence of willful misconduct. The powers
of attorney granted to GSK in this Patent Agreement are coupled with an interest
and  are  irrevocable  during  the  Term.

                                    ARTICLE 5
                                EVENTS OF DEFAULT

     5.1  Events  of  Default  enumerated  in  Article  12 of the Loan Agreement
shall  constitute  Events  of  Default  under  this  Patent  Agreement.

                                    ARTICLE 6
                                    REMEDIES

     6.1  Upon  the  occurrence  of  an  Event  of  Default,  in addition to all
other rights and remedies of GSK, whether under law, in equity or otherwise (all
such  rights  and  remedies  being  cumulative,  not  exclusive  and enforceable
alternatively,  successively  or  concurrently) GSK shall have all of the rights
and  remedies  set  forth  in  Article  13  of  the  Loan  Agreement.

     6.2  Notwithstanding  anything  contained  in  this Patent Agreement to the
contrary, GSK shall not foreclose upon, dispose of or be deemed the owner of any
Collateral  unless  and  until  GSK  has  provided Exelixis with advance written
notice of its intent to foreclose upon, dispose of or take an ownership interest
in  any  Collateral.  Any  writing given by GSK to Exelixis under this Article 6
must  make  explicit  reference  to this Patent Agreement and of GSK's intent to
exercise  its  rights  and  remedies  hereunder.

                                    ARTICLE 7
                     EXECUTION OF SPECIAL POWER OF ATTORNEY

     Concurrently  with  the  execution  and  delivery of this Patent Agreement,
Exelixis is executing and delivering to GSK a certain Special Power of Attorney,
substantially  in  the  form attached hereto and made a part hereof as Exhibit A
(such  authority  becoming  effective  on  the occurrence of an Event of Default
pursuant  to Article 12 of the Loan Agreement; provided, however, if there is an
Event  of Default alleged pursuant to Sections 12.1.2, 12.1.4(b) or 12.1.4(c) of
the Loan Agreement, a dispute resolution process in accordance with Section 16.2
of  the  Loan  Agreement  shall be undertaken to determine the existence of such
alleged  Event  of  Default  pursuant  to  such  sections,  and  if such dispute
resolution  process conclusively determines the existence of an Event of Default
by Exelixis under such sections, then such authority shall become effective only
upon  such resolution) for the implementation of the sale, assignment, licensing
or  other  disposition  of  the  Collateral  pursuant  to this Patent Agreement.
Exelixis  agrees  to  pay when due all reasonable costs and expenses incurred in
any  such  transfer  of the Collateral, including any taxes, fees and reasonable
attorneys'  fees,  and  all  such  costs  shall  be  added to the Obligations of
Exelixis  to  GSK.  GSK  may  apply the Proceeds actually received from any such
license, assignment, sale or other disposition to the payment of the Obligations
of Exelixis to GSK as provided for in the Loan Agreement.  Exelixis shall remain
liable  for  any  deficiency with respect to the Obligations of Exelixis to GSK,
which  shall  bear interest and be payable at the Default Rate of Interest under
the  Loan  Agreement.  The  rights  of  Exelixis to receive any surplus shall be
subject  to  any  duty  of  GSK  imposed by law to the holder of any subordinate
security  interest  in  the  Collateral  known to GSK.  Nothing contained herein
shall  be  construed  as  requiring  GSK  to  take  any such action at any time.

                                    ARTICLE 8
                                  MISCELLANEOUS

     8.1  Amendments  and  Modification.  No  provision  hereof  shall  be
modified,  altered,  waived  or limited except by a written instrument expressly
referring  to  this  Patent  Agreement  and executed by the Party to be charged.

     8.2 Parties in Interest. All of the terms of this Patent Agreement shall be
binding  upon, inure to the benefit of, and be enforceable by all Parties hereto
and  their  respective  permitted  successors  and  assigns.

     8.3  Governing  Law. This Patent Agreement shall be construed in accordance
with  and  governed by the laws of the State of New York, unless such dispute is
governed  under  the  laws of the UCC in which case the UCC shall apply, without
giving  effect  to  the  conflict  of  law  principles  thereof.

     8.4  Notices.  All  notices,  requests,  demands  and  other communications
provided  for hereunder shall be in writing (unless otherwise expressly provided
herein)  and  shall  be  sent  and  deemed to have been received as set forth in
Section  16.5  of  the  Loan  Agreement.

     8.5  Counterparts.  This  Patent  Agreement may be executed in counterparts
each  and  every  one  of  which  shall  be  deemed an original, notwithstanding
variations  in  format  or file designation which may result from the electronic
transmission,  storage  and  printing  of  copies  of  this  Loan Agreement from
separate  computers  or  printers.  Facsimile  signatures  shall  be  treated as
original  signatures.

     8.6  Headings.  Section  headings  herein  are  included for convenience of
reference  only and shall not constitute a part of this Patent Agreement for any
other  purpose.

     8.7  Acknowledgment  of Receipt. Exelixis acknowledges receipt of a copy of
this  Patent  Agreement.

     8.8  No Waiver. No course of dealing between Exelixis and GSK, and no delay
or  omission  of GSK in exercising or enforcing any of GSK's rights and remedies
hereunder  shall  constitute a waiver thereof; and no waiver by GSK of any Event
of  Default  shall  operate  as  a  waiver  of  any  other  Event  of  Default.

     8.9  Severability.  If any provision hereof should be held invalid, illegal
or  unenforceable in any jurisdiction, the Parties shall negotiate in good faith
a  valid,  legal  and enforceable substitute provision that most nearly reflects
the  original intent of the Parties and all other provisions hereof shall remain
in  full  force and effect in such jurisdiction and shall be liberally construed
in  order  to carry out the intentions of the Parties hereto as nearly as may be
possible.  Such  invalidity, illegality or unenforceability shall not affect the
validity,  legality  or  enforceability  of  such  provision  in  any  other
jurisdiction.

     8.10  Interest Granted to GSK. Notwithstanding any provision of this Patent
Agreement  to  the  contrary,  the  interest  granted  to  GSK under this Patent
Agreement  is  intended  to  be  a  pledge and a security interest only, and the
execution  of this Patent Agreement is not intended to create an assignment or a
transfer  of  title  or  any  other  property  rights  to  the  Patents.

     8.11  WAIVER OF JURY TRIAL. EACH PARTY HERETO HEREBY WAIVES, TO THE FULLEST
EXTENT  PERMITTED BY APPLICABLE LAW, ANY RIGHT IT MAY HAVE TO A TRIAL BY JURY IN
RESPECT  TO  ANY  LITIGATION  DIRECTLY OR INDIRECTLY ARISING OUT OF, UNDER OR IN
CONNECTION  WITH THIS PATENT AGREEMENT.  EACH PARTY HERETO (i) CERTIFIES THAT NO
REPRESENTATIVE,  AGENT OR ATTORNEY OF ANY OTHER PARTY HAS REPRESENTED, EXPRESSLY
OR  OTHERWISE, THAT SUCH OTHER PARTY WOULD NOT, IN THE EVENT OF LITIGATION, SEEK
TO  ENFORCE  THAT  FOREGOING WAIVER, AND (ii) ACKNOWLEDGES THAT IT AND THE OTHER
PARTIES  HERETO  HAVE  BEEN  INDUCED TO ENTER INTO THIS PATENT AGREEMENT AND ANY
RELATED  INSTRUMENTS,  AS APPLICABLE, BY, AMONG OTHER THINGS, THE MUTUAL WAIVERS
AND  CERTIFICATIONS  IN  THIS  SECTION  8.11.

                   [BALANCE OF PAGE INTENTIONALLY LEFT BLANK.]

<PAGE>

     IN  WITNESS  WHEREOF,  Exelixis has caused this Patent Agreement to be duty
executed  as  of  the  day  and  year  first  above  written.

WITNESS:                                  EXELIXIS,  INC.

                                          By:  ________________________________
                                          Name:  ______________________________
                                          Title: ______________________________

                            CORPORATE ACKNOWLEDGMENT

STATE  OF _____________)
                    :ss.
COUNTY  OF  ___________)

     I  certify  that on _____________, 2002, __________________ personally came
before  me  and  this  person acknowledged under oath, to my satisfaction, that:

     (a)  this  person  signed  and  delivered  this  document  as
of  Exelixis,  Inc.,  the  corporation  named  in  this  document;  and

     (b)  this  document  was  signed  and  delivered  by the corporation as its
voluntary  act duly authorized by a proper resolution of its Board of Directors.

                                        ______________________________

[  *  ] = Certain confidential information contained in this document, marked by
brackets, has been omitted and filed separately with the Securities and Exchange
Commission  pursuant  to  Rule  24b-2 of the Securities Exchange Act of 1934, as
Amended
<PAGE>

                     Schedule 2.1.1 of the Patent Agreement

                                     PATENTS

                                 Issued Patents
                                 --------------

                   Country     Patent No./Title     Issue Date
                   -------     ----------------     ----------

                           Pending Patent Applications
                           ---------------------------
                                       [*]

[  *  ] = Certain confidential information contained in this document, marked by
brackets, has been omitted and filed separately with the Securities and Exchange
Commission  pursuant  to  Rule  24b-2 of the Securities Exchange Act of 1934, as
amended

<PAGE>

                        Exhibit A of the Patent Agreement

                        FORM OF SPECIAL POWER OF ATTORNEY

     KNOW  ALL  MEN  BY THESE PRESENTS, that as of this ______ day of _________,
2002,  Exelixis,  Inc.,  a  Delaware  corporation  with  its  principal place of
business  located at 170 Harbor Way, P.O. Box 511, South San Francisco, CA 94083
("Exelixis"),  pursuant  to  a certain Patent Security Agreement and Mortgage of
even  date  herewith (the "Patent Agreement") by Exelixis in favor of SmithKline
Beecham  Corporation,  a  Pennsylvania  corporation,  doing  business  as
GlaxoSmithKline,  with an office located at 709 Swedeland Road, King of Prussia,
PA  19406  ("GSK"),  hereby  appoints and constitutes GSK as its true and lawful
attorney,  with full power of substitution, and with full power and authority to
perform  the  following  acts  on  behalf  of  Exelixis, in accordance with, and
subject  to,  the  terms  and  provisions  of  the  Patent  Agreement:

     1.     Assigning,  selling  or  otherwise disposing or all right, title and
interest  of  Exelixis  in  and  to  the Patents, as such term is defined in the
Patent  Agreement,  including,  without  limitation,  those  Patents  listed  on
Schedule  2.1.1  annexed  to the Patent Agreement, any Patents that Exelixis may
now  or  hereafter acquire, and any Patents which may be added to Schedule 2.1.1
annexed  to the Patent Agreement subsequent to the date of this Special Power of
Attorney,  and all registrations and recordings of any of the foregoing, and for
the  purpose  of  the recording, registering and filing of, or accomplishing any
other  formality  with  respect to the foregoing, and to execute and deliver any
and  all  other agreements, documents, instruments or assignment or other papers
necessary  or advisable to effect such purpose, in each case, in accordance with
the  terms  and  provisions  of  the  Patent  Agreement;  and

     2.     To  execute any and all documents, statements, certificates or other
papers necessary or advisable in order to obtain the purposes described above or
any  other remedies that GSK may have under the Loan Documents as GSK may in its
sole  discretion  determine.

     This Special Power of Attorney is made pursuant to the Patent Agreement and
may  not be revoked until the Obligations, as such term is defined in the Patent
Agreement,  of  Exelixis  to  GSK  is  fully  paid  and  satisfied.

     IN  WITNESS  WHEREOF, Exelixis has caused this Special Power of Attorney to
be  duly  executed  as  of  the  day  and  year  first  above  written.

WITNESS:                                  EXELIXIS,  INC.

                                          By:  ________________________________
                                          Name:  ______________________________
                                          Title: ______________________________

                            CORPORATE ACKNOWLEDGMENT

STATE  OF _____________)
                    :ss.
COUNTY  OF  ___________)

     I  certify  that on __________, _________________ personally came before me
and  this  person  acknowledged  under  oath,  to  my  satisfaction,  that:

     (a)  this  person  signed  and  delivered  this  document  as _____________
of  Exelixis,  Inc.,  the  corporation  named  in  this  document;  and

     (b)  this  document  was  signed  and  delivered  by the corporation as its
voluntary  act duly authorized by a proper resolution of its Board of Directors.

                                        ______________________________
<PAGE>

                                    Exhibit C
                  FORM OF SECURITIES ACCOUNT CONTROL AGREEMENT

CUSTOMER:
          ---------------------

CREDITOR:
          ---------------------

DATE:
          ---------------------

This  Securities  Account  Control  Agreement  entered into as of the above date
(this  "Agreement")  is  among  SVB  Securities,  A Division of Alliant Partners
("SVBS"),  Banc  of America BrokerDealer Services, a division of Banc of America
Securities  LLC  ("BA-BDS"  or "Clearing Broker"), the Customer identified above
("Customer"),  and  the  Creditor  identified  above  ("Creditor").

                                    RECITALS
                                    --------

     A.  Customer  has  established  a securities account or securities accounts
("Account")  with  and/or  through  SVBS and BA-BDS pursuant to a SVB Securities
Client  Agreement  ("Client  Agreement").  The  account number and title for the
Account  (or  Accounts) are identified in EXHIBIT A to this Agreement. SVBS acts
as  the  introducing  broker.  BA-BDS acts as the clearing broker. Both SVBS and
Clearing  Broker  are  securities  intermediaries  pursuant  to Article 8 of the
California  Uniform  Commercial Code ("CUCC"). Customer maintains in the Account
securities,  financial  assets  and  other  investment property as defined under
Article  8  and  9  of  the  CUCC  (collectively,  the  "Securities").

     B.  Pursuant  to  a  security  agreement or similar agreement identified in
EXHIBIT  A  hereto(the "Security Agreement"), Customer has granted to Creditor a
security  interest  in  certain personal property of Customer, including without
limitation  (i)  the  Account;  (ii)  the  Securities,  (iii)  all dividends and
distributions,  whether  payable  in  cash,  securities,  or  other property, in
respect  of  the  Securities,  (iv)  all  of Customer's rights in respect of the
Securities and Account, and (iv) all products, proceeds and revenues of and from
any  of  the  foregoing  personal  property  in  sections  (i)  through  (iv)
(collectively,  the  "Collateral").

     C.  SVBS,  Clearing  Broker,  Customer  and Creditor are entering into this
Agreement in order to perfect Creditor's security interest in the Collateral and
the  Account  by  means  of  control  pursuant  to  Article  8  of  the  CUCC.

                                    AGREEMENT
                                    ---------

     The  parties  hereto  hereby  agree  as  follows:

     1. Defined Terms. All terms used in this Agreement which are defined in the
        --------------
CUCC  but  are  not otherwise defined herein shall have the meanings assigned to
such  terms in the CUCC, as in effect as of the date of this Agreement. While in
the  Account,  all  property  credited  to  the  Securities  will  be treated as
financial assets under Article 8 of the CUCC. By this Agreement. Customer grants
to  Creditor "control" over the Securities within the meaning of Section 8106 of
the  CUCC.

     2.  The Securities. SVBS and Clearing Broker represent to Creditor that, on
         ---------------
behalf  of  Customer,  Customer  maintains  the  Securities  in  the Account.

     3.  Acknowledgement  of  Security  Interest.  SVBS  and  Clearing  Broker
         ---------------------------------------
hereby  acknowledge  the security interest granted in the Collateral to Creditor
by  Customer.  Creditor hereby acknowledges the security interest granted in the
Collateral  to  SVBS  and  Clearing  Broker  by  Customer pursuant to the Client
Agreement.

     4.  Other Control Agreements. SVBS represents and warrants that, other than
         -------------------------
any  account  control agreement listed in EXHIBIT A hereto, SVBS has executed no
other  account  control agreement with any other party and SVBS is not presently
obligated  to  accept  any  entitlement  order  from  any  person other than the
Customer with respect to the Collateral. Clearing Broker represents and warrants
that,  other  than  any  account  control  agreement listed in EXHIBIT A hereto,
Clearing  Broker  has executed no other account control agreement with any other
party  and  Clearing Broker is not presently obligated to accept any entitlement
order  from  any  person other than the Customer with respect to the Collateral.

     5.  Future  Control  Agreements. Customer covenants and agrees that it will
         ---------------------------
not  enter  an account control agreement with any other party without Creditor's
prior  written  consent.  SVBS  agrees  that  it  will  not enter into a control
agreement  with  any  other party with respect to the Account without Creditor's
prior  written  consent.  Clearing  Broker  agrees that it will not enter into a
control  agreement  with  any  other  party  with respect to the Account without
Creditor's  prior  written  consent.

     6. Limitation on SVBS' and Clearing Broker's Rights in the Collateral. SVBS
        ------------------------------------------------------------------
and  Clearing  Broker  will not attempt to assert control and does not claim and
will  not  accept  any security or other interest in any part of the Collateral,
and SVBS and Clearing Broker will not exercise, enforce or attempt to enforce on
their  own  behalves  any  right  of setoff against the Collateral, or otherwise
charge  or deduct from the Collateral on SVBS' or Clearing Broker's behalves any
amount  whatsoever,  other  than  for:  security interests, liens, encumbrances,
                     -----------
claims  or  rights  of setoff for the payment of any amounts owed by Customer to
SVBS  and/or  Clearing  Broker  arising  in  connection  with SVBS' and Clearing
Broker's  customary  fees  and  commissions  pursuant  to  their  agreement with
Customer  or  for  the payment for financial assets and securities purchased for
the  Account  (the  "Account  Claims"). Customer and Creditor hereby acknowledge
that any security interests, liens, encumbrances, claims or rights of setoff for
the  payment of any amounts owed by Customer to SVBS and Clearing Broker arising
in  connection with the Account Claims shall at all times be prior to the rights
of  Creditor  in  the Collateral and Securities whether or not Creditor sends to
SVBS  a  Notice  of  Exclusive  Control  described  below.

     7.  Agreement  for  Control.
         -----------------------

     (a)  SVBS  and  Clearing  Broker  will  comply  with all entitlement orders
(including  requests  to  withdraw  Collateral  from  the Account) originated by
Customer  with  respect  to  the  Collateral,  or any portion of the Collateral,
without  further  consent  by  Creditor  until  such  time as SVBS receives from
Creditor  (in  accordance  with  Section 17 below) a written notice to SVBS that
Creditor  is thereby exercising exclusive control over the Account (a "Notice of
Exclusive  Control.").  The  Notice of Exclusive Control must be in the form set
forth in EXHIBIT B hereto. SVBS or Clearing Broker have no obligation whatsoever
to  confirm  that  Creditor is entitled to send a Notice of Exclusive Control in
connection  with the Account or that the Creditor's representative who signs any
Notice  of  Exclusive  Control  is authorized to do so. SVBS and Clearing Broker
(upon  instruction  from  SVBS)  will,  upon  SVBS'  receipt  of  such Notice of
Exclusive  Control,  proceed  in accordance with the remainder of this Section 7
even if Creditor's instructions are contrary to any instructions or demands that
Customer  may  give  to SVBS or Clearing Broker. After SVBS receives a Notice of
Exclusive  Control  and has had reasonable opportunity to comply with it, but no
later  than two (2) Business Days ("Business Days" means days which SVBS is open
to the public for business and are measured in 24 hour increments) after receipt
of  the  Notice of Exclusive Control (in accordance with Section 17 below), SVBS
and  Customer agree that SVBS and Clearing Broker will: (i) cease complying with
entitlement  orders  or  other  directions concerning the Account and Collateral
that  are  originated by Customer or its representatives until such time as SVBS
receives  a  written  notice  from  Creditor  rescinding the Notice of Exclusive
Control;  and  (ii) comply with the entitlement orders and instructions provided
to  SVBS  by  Creditor without investigating: the reason for any action taken by
Creditor; the amount of any obligations of Customer to Creditor; the validity of
any  of  Creditor's  agreements  with Customer; or the existence of any defaults
under  such  agreements.

     (b)  Notwithstanding  the  foregoing,  Creditor agrees that upon receipt of
Creditor's  Notice  of  Exclusive Control, SVBS and Clearing Broker may take all
steps necessary to satisfy or settle any Account Claims, may respond as required
pursuant  to  the  terms  of any other account control agreement with respect to
which  SVBS  believes  it  previously  received a Notice of Exclusive Control or
similar  notice,  and  may respond as required by law to any court or government
order, writ or other legal process received by SVBS or Clearing Broker. Creditor
also  agrees  that,  before  SVBS'  receipt  of  Creditor's  Notice of Exclusive
Control,  SVBS  and  Clearing  Broker  may be required to and may respond to (i)
Notices  of  Exclusive  Control or similar notices sent to SVBS by other parties
and (ii) a writ or other similar legal process served on SVBS or Clearing Broker
in connection with the Account and Collateral. SVBS and Clearing Broker agree to
use  good  faith efforts to promptly notify Creditor if any other party delivers
to  SVBS  a notice of exclusive control or any party other than Creditor or SVBS
asserts a claim against the Collateral by means of a writ or other similar legal
process, but failure to provide such notice does not constitute a breach of this
Agreement. Customer expressly agrees that SVBS, Clearing Broker and Creditor may
act  in  accordance  with  the  terms  of  this  Section  7.

     8.  Customer  Waiver  and  Authorization. Customer hereby waives any rights
         ------------------------------------
that  Customer may have under the Client Agreement to the extent such rights are
inconsistent  with  the provisions of this Agreement, and hereby authorizes SVBS
and  Clearing  Broker  to  comply  with  all instructions and entitlement orders
delivered  by  Creditor  to SVBS in accordance with the terms of this Agreement.

     9. Amendments to and Termination of Client Agreement. SVBS, Clearing Broker
        -------------------------------------------------
and  Customer  shall  not  amend,  supplement  or  otherwise  modify  the Client
Agreement  insofar as it pertains to the Collateral without prior written notice
to  Creditor.  Customer  may  not  terminate  the Client Agreement insofar as it
pertains to the Collateral without consent of Creditor. SVBS and Clearing Broker
agree  to  use  good faith efforts to notify Creditor if SVBS or Clearing Broker
terminate the Client Agreement, but SVBS' or Clearing Broker's failure to notify
Creditor  shall  not  be  a  breach  of  this  Agreement.

     10. Termination of this Agreement. Creditor may terminate this Agreement by
         --------------------------------
giving SVBS and Customer written notice of termination; provided that, by giving
such  notice,  Creditor acknowledges that it will thereby be confirming that, as
of the termination date, it will no longer have a perfected security interest in
the  Account  and Securities in the Collateral which is perfected by control via
this  Agreement,  although  Creditor  may  continue to have a perfected security
interest  in  the Account by other means. SVBS and Clearing Broker may terminate
this  Agreement  by giving Creditor and Customer 30 days prior written notice of
termination  (unless  a  shorter  notice  period is mandated by applicable law).
Customer may only terminate this Agreement with the written consent of Creditor;
provided  that,  by  giving  such  notice  with Creditor's written consent, both
Customer  and Creditor acknowledge that they will thereby be confirming that, as
of  the  termination  date,  Creditor  will  no longer have a perfected security
interest  in  the  Collateral  which  is  perfected  by control pursuant to this
Agreement,  although Creditor may continue to have a perfected security interest
in  the  Collateral  by  other  means.

     11  Delivery  of  Account  Statements.  SVBS and Clearing Broker are hereby
         ---------------------------------
authorized  by Customer and agree to send to Creditor at its address for notices
set  forth  below  Creditor's  signature  block  at  the  end of this Agreement,
concurrently  with  the sending thereof to Customer, duplicate copies of any and
all monthly statements or reports issued or sent to Customer with respect to the
Collateral  and  the  Account.  Until  this  Agreement  is  terminated, Customer
authorizes  SVBS  to  disclose to Creditor at Creditor's request any information
concerning  Customer's  Account and the Securities in the Account, including but
not  limited to the identity of any other party with which Customer and SVBS and
Clearing  Broker have executed account control agreements or similar agreements.

     12.  Responsibility  of  SVBS, Clearing Broker and Creditor. This Agreement
          ------------------------------------------------------
does  not  create any obligation or duty on the part of SVBS, Clearing Broker or
Creditor  other  than  those  expressly  set  forth  herein.

     13. No Waiver. Any forbearance or failure or delay by SVBS, Clearing Broker
         ----------
or  Creditor  in  exercising  any  right  hereunder shall not be deemed a waiver
thereof  and  any single or partial exercise of any right shall not preclude the
further  exercise  thereof.

     14.  Amendments.  This  Agreement  and  all exhibits attached hereto may be
          ----------
amended  only  in  writing  signed  by  all  parties  hereto.

     15.  Governing  Law.  Notwithstanding the terms of any other agreement, the
          --------------
parties  hereto  agree  that  this  Agreement  shall  be  governed  under and in
accordance  with  the  laws  of the State of California. All parties hereto each
submit  to  the  exclusive jurisdiction of the State and Federal courts in Santa
Clara  County,  California.

     16.  Integration Provision. This Agreement constitutes the entire agreement
          ---------------------
among  SVBS,  Clearing  Broker, Customer and Creditor with respect to Creditor's
control  over  the  Collateral and Securities and matters specifically set forth
herein,  and all prior communications, whether verbal or written, between any of
the  parties  hereto  with  respect  to the subject matter hereof shall be of no
further  effect  or  evidentiary  value.

     17.  Notices.
          -------

     (a)  Any  notice,  other  than  a  Notice  of  Exclusive  Control, or other
communication provided for or allowed hereunder shall be in writing and shall be
considered  to  have  been  validly  given  (a)  when  actually  received by the
recipient  at  the address or facsimile number, if delivered personally (whether
by  messenger,  air  courier  service  or otherwise) or sent by facsimile to the
address  or  facsimile  number  identified below the signature of the applicable
party's  signature  below  and  addressed  to the addressee identified below the
signature of the applicable party's signature below; or (b) 72 hours after being
deposited  in  the United States mail, registered or certified, postage prepaid,
return  receipt  requested,  if  sent  to the address and addressee as set forth
below  the  signature  of  the  applicable  party hereto. The addresses to which
notices or other communications are to be given may be changed from time to time
by  notice  served  as  provided  herein.

     (b)  A Notice of Exclusive Control shall be in writing, must be in the form
            ---------------------------
set  forth  in  EXHIBIT  B hereto, must be delivered to the address listed below
SVBS'  signature  block  at the end of this Agreement, must be delivered to SVBS
via  hand  delivery,  messenger,  overnight  delivery  or facsimile and shall be
considered  to  have  been  validly  given when actually received, except that a
                                                                   ------
facsimile  will  be considered to have been validly given only when acknowledged
in  writing  by  SVBS  (SVBS  agrees  that  it will use its good faith effort to
promptly acknowledge receipt of such facsimile). Creditor acknowledges that SVBS
may  not be able to respond to a Notice of Exclusive Control pursuant to section
7  above,  and Creditor agrees that SVBS will not be held liable for any failure
to  respond  to  a Notice of Exclusive Control, if the Creditor does not deliver
the  Notice  of  Exclusive  Control  as  set  forth in this Section 17 or to the
address  listed  below  SVBS'  signature  block  at  the  end of this Agreement.

     18.  Indemnification  and  Hold  Harmless  of  SVBS  and Clearing Broker by
          ----------------------------------------------------------------------
Customer.
--------
Customer  hereby agrees to indemnify and hold harmless SVBS and Clearing Broker,
and their respective affiliates and their respective directors, officers, agents
and employees (each, an "Indemnified Person") against any and all claims, causes
                         ------------------
of action, liabilities, lawsuits, demands and damages (each, a "Claim") asserted
by  Creditor or any other party, including without limitation, any and all court
costs and reasonable attorneys' fees, in any way related to or arising out of or
in  connection  with  this  Agreement  or any action taken or not taken pursuant
hereto,  including any claims arising as a result of SVBS' and Clearing Broker's
adherence  (or  alleged  failure  of  adherence)  to  the foregoing instructions
including,  without  limitation,  Claims that allegedly result from SVBS' and/or
Clearing  Broker's ceasing, based on this Agreement, to permit withdrawals of or
from the Collateral or resulting from SVBS' and/or Clearing Broker's paying over
or  delivering  all  or any part of the Collateral pursuant to the directions of
Creditor;  provided  that  no  Indemnified  Person  shall  be  entitled  to  be
           --------
indemnified  to  the extent that such Claims arise from the Indemnified Person's
own  gross  negligence  or  willful misconduct. Customer agrees that SVBS and/or
Clearing  Broker shall not be liable for delays or errors occurring by reason of
circumstances  beyond the control of SVBS or Clearing Broker, including, without
limitation,  acts  of  civil,  military,  or  banking  authorities,  national
emergencies,  market  disorder,  labor  difficulties,  fire,  flood  or  other
catastrophes,  acts  of  God,  terrorism,  insurrection,  war, riots, failure of
transportation  or  equipment,  or  failure  of  vendors, communication or power
supply.  Clearing  Broker  shall  have no responsibility or liability under this
Agreement to Customer for any acts or omissions by SVBS, its officers, employees
or  agents;  and  SVBS  shall  have  no  responsibility  or liability under this
Agreement  to  Customer  for  any  acts  or  omissions  by  Clearing Broker, its
officers,  employees  or  agents.

     19.  Indemnification  and  Hold  Harmless  of  SVBS  and Clearing Broker by
          ----------------------------------------------------------------------
Creditor.
--------
Creditor  hereby  agrees  to  indemnify  Indemnified Persons against any and all
Claims  asserted  by Customer or any other party (including, without limitation,
any  and all court costs and reasonable attorneys' fees) arising directly out of
SVBS'  and/or  Clearing Broker's adherence or failure of adherence to Creditor's
instructions  in its Notice of Exclusive Control, including, without limitation,
any  Claim  that  arises directly out of SVBS' and/or Clearing Broker's ceasing,
based  on  this  Agreement,  to  permit withdrawals of or from the Collateral or
resulting  from  SVBS' and/or Clearing Broker's paying over or delivering all or
any  part of the Collateral pursuant to Creditor's instructions in its Notice of
Exclusive  Control; provided, that no Indemnified Person shall be entitled to be
                    --------
indemnified  (a)  to  the  extent  that  such  Claim results from an Indemnified
Person's  gross  negligence  or  willful  misconduct;  or  (b)  for any special,
indirect,  consequential  or punitive damages asserted by Customer if the waiver
in Section 21 of this Agreement is enforceable. Creditor agrees that it will not
hold  Indemnified Persons liable for any Claim arising out of or relating to any
Indemnified  Person's performance or failure of performance under this Agreement
other  than  those Claims that result directly from the acts or omissions of the
Indemnified  Person which are deemed gross negligence or willful misconduct by a
civil  court  or  other  similar  judicial  body.  Clearing Broker shall have no
responsibility  or  liability  under  this Agreement to Creditor for any acts or
omissions  by  SVBS,  its  officers, employees or agents; and SVBS shall have no
responsibility  or  liability  under  this Agreement to Creditor for any acts or
omissions  by  Clearing  Broker,  its  officers,  employees  or  agents.

     20.  JURY  TRIAL  WAIVER. CUSTOMER, CREDITOR, SVBS AND CLEARING BROKER EACH
          -------------------
WAIVE THEIR RIGHT TO A JURY TRIAL OF ANY CLAIM OR CAUSE OF ACTION ARISING OUT OF
OR  BASED  UPON  THIS  AGREEMENT,  OR  ANY  CONTEMPLATED  TRANSACTION, INCLUDING
CONTRACT,  TORT,  BREACH OF DUTY AND ALL OTHER CLAIMS. THIS WAIVER IS A MATERIAL
INDUCEMENT FOR ALL PARTIES TO ENTER INTO THIS AGREEMENT. EACH PARTY HAS REVIEWED
THIS  WAIVER  WITH  ITS  COUNSEL.

     21.  WAIVER.  NOTWITHSTANDING  ANYTHING  TO  THE CONTRARY CONTAINED IN THIS
          ------
AGREEMENT  OR  ANYWHERE  ELSE, CUSTOMER WAIVES AND AGREES THAT IT SHALL NOT SEEK
FROM  SVBS, CLEARING BROKER OR CREDITOR UNDER ANY THEORY OF LIABILITY (INCLUDING
WITHOUT LIMITATION ANY THEORY IN TORTS), ANY SPECIAL, INDIRECT, CONSEQUENTIAL OR
PUNITIVE  DAMAGES.

     22. Unpaid Account Claims. Before Creditor exercises exclusive control over
         ---------------------
the  Account,  SVBS  and/or  Clearing  Broker  may,  in  the  ordinary course of
business,  debit  from  the  Account  any  unpaid Account Claims. After Creditor
exercises  exclusive control over the Account, if (a) funds are not available in
the  Account  to pay SVBS and/or Clearing Broker for any Account Claims, and (b)
Customer  fails  to pay such Account Claims within fifteen (15) Business days of
SVBS'  and/or  Clearing  Broker's written demand therefore, Creditor will pay to
SVBS  and/or  Clearing Broker, within ten (10) Business days of a written demand
by  SVBS  and/or Clearing Broker, any amounts owed for an Account Claim and that
is  not  paid  in  full by Customer up to the amount of the proceeds received by
Creditor  from  the  Account.

     23.  Attorneys'  Fees,  Costs  and  Expenses.  In  any action or proceeding
          ---------------------------------------
between  Customer  and  SVBS,  between  Customer  and  Clearing  Broker, between
Creditor  and SVBS, or between Creditor and Clearing Broker, arising out of this
Agreement,  the  prevailing  party  will  be  entitled to recover its reasonable
attorneys'  fees and other costs and expenses incurred, in addition to any other
relief  to  which  it  may  be  entitled,  whether  or  not  a lawsuit is filed.

     24.  No  Conflict.  To  the  extent  that  the  terms or conditions of this
          ------------
Agreement  are  inconsistent  with  the  Client Agreement or any other document,
instrument  or  agreement  between SVBS, Clearing Broker and Customer, the terms
and  conditions  of  this  Agreement  shall  prevail.

     25.  Successors.  The  terms  of  this Agreement shall be binding upon, and
          ----------
shall inure to the benefit of, the parties hereto and to each party's respective
successors  or  heirs  and personal representatives. The parties may assign this
Agreement  and  any rights under the Agreement only if that party's successor or
assign  assume  all  obligations  under  this  Agreement.

     26.  Counterparts.  This  Agreement  may  be  executed  in  any  number  of
          ------------
counterparts  and  by different parties on separate counterparts, each of which,
when  executed  and  delivered, are an original, and all taken together, are one
Agreement.

     27.  Survival.  Sections 15 and 18 through 25 shall survive the termination
          --------
of  this  Agreement.

     [The  rest  of  this  page  intentionally  left  blank.]

<PAGE>

     IN  WITNESS  WHEREOF,  the  parties hereto have caused this Agreement to be
executed  by  their  duly  authorized representatives as of the date first above
written.

CUSTOMER:
                                             -------------------------------
                                             By
                                                ----------------------------
                                             Name:
                                                   -------------------------
                                             Title:
                                                   -------------------------

                                             Address  for  Notices:
                                             ---------------------
                                             ---------------------
                                             ---------------------
                                             ---------------------
                                             Telephone:
                                             Facsimile:

CREDITOR:
                                             -------------------------------
                                             By
                                                ----------------------------
                                             Name:
                                                   -------------------------
                                             Title:
                                                   -------------------------

                                             Address  for  Notices:
                                             ---------------------
                                             ---------------------
                                             ---------------------
                                             ---------------------
                                             Telephone:
                                             Facsimile:

SVBS:                                        SVB  SECURITIES

                                             By
                                                ----------------------------
                                             Name:
                                                   -------------------------
                                             Title:   Operations  Manager

                                             Address  for  Notices:
                                             ---------------------
                                             SVB  Securities
                                             3003  Tasman  Drive
                                             Mail  Sort  HG250
                                             Santa  Clara,  CA  95054
                                             Attn:  Operations  Manager
                                             Telephone:  [*]
                                             Facsimile:  [*]

CLEARING  BROKER:                            BANC  OF AMERICA  SECURITIES  LLC

                                             By
                                                ----------------------------
                                             Name:
                                                   -------------------------
                                             Title:
                                                   -------------------------

<PAGE>
                                 SVB SECURITIES
                      SECURITIES ACCOUNT CONTROL AGREEMENT
                                    EXHIBIT A

1.   ACCOUNT  TITLE  AND  NUMBER:

     ACCOUNT  TITLE:
                     --------------------------------------------

     ACCOUNT  NUMBER:
                      --------------------------------------------

2.   "SECURITY  AGREEMENT"  (THIS  SECTION  TO  BE  COMPLETED  BY  CREDITOR):
                                                                   ---------

3.   ACCOUNT  CONTROL  AGREEMENTS  PREVIOUSLY  EXECUTED  BY  SVB  SECURITIES AND
     CLEARING  BROKER  WITH  OTHER  PARTIES ASSERTING AN INTEREST IN THE ACCOUNT
     (THIS  SECTION  TO  BE  COMPLETED  BY  SVBS):
                                            ----

<PAGE>
                                 SVB SECURITIES
                      SECURITIES ACCOUNT CONTROL AGREEMENT
                                    EXHIBIT B
                           NOTICE OF EXCLUSIVE CONTROL

To:    SVB SECURITIES ("SVBS")
From:  ("Creditor")
                    ---------------------
Re:    ("Customer")
                    -----------------------
Date:
       ----------------------------

Pursuant to the Securities Account Control Agreement dated         ("Agreement")
                                                          ---------
entered  among  SVBS, Clearing Broker (as defined in the Agreement) Customer and
Creditor,  Creditor  hereby  notifies  SVBS of Creditor's exercise of Creditor's
rights  under  the  Agreement  and  directs SVBS to cease complying with trading
instructions  or  any  entitlement  orders originated by Customer or its agents.

Creditor understands and agrees that SVBS and Clearing Broker shall have no duty
or  obligation  whatsoever of any kind or character to determine the validity of
Creditor's  exercise  of  its  rights  under  the Agreement or the certification
above,  to  determine  if  SVBS  and/or Clearing Broker is/are obligated to take
further instructions from Customer, or to determine whether Creditor has a right
to  all  or part of the Collateral. Creditor hereby agrees to indemnify and hold
harmless  SVBS  and  Clearing  Broker,  their  respective  affiliates, and their
respective  directors,  officers,  employees and agents pursuant to the terms of
Section  19  of  the  Agreement.

Creditor  agrees  that  upon  receipt of Creditor's Notice of Exclusive Control,
SVBS  and  Clearing  Broker  may exercise their rights and remedies as permitted
under  the  Agreement.

Creditor  hereby  certifies  that  the person executing this Notice of Exclusive
Control  is an officer, representative or agent of Creditor authorized to act on
the  behalf of Creditor and to make the representations and agreements contained
in  this  Notice  of  Exclusive  Control.

CREDITOR:
                                                ----------------------------

                                             By
                                                ----------------------------
                                             Title:

ACKNOWLEDGED  BY:                            SVB SECURITIES
(for  facsimile  only)
                                             By:
                                                ----------------------------
                                             Name:
                                             Title:
                                             Date:
                                             Time:

<PAGE>

                                    EXHIBIT D
                            FORM OF BORROWING NOTICE

VIA  FACSIMILE  TRANSMISSION

SmithKline  Beecham  Corporation,  doing  business  as          Fax:  [*]
GlaxoSmithKline
709  Swedeland  Road
King  of  Prussia,  Pennsylvania  19406
Attention:  Vice  President,  R&D  Structuring

Re:  Exelixis,  Inc.

Ladies  and  Gentlemen:

This  Borrowing  Notice  is  delivered  to  you  pursuant to Section 2.2 of that
certain  Loan and Security Agreement, dated as of October ___, 2002 (as amended,
restated,  supplemented  or  otherwise  modified  from  time  to time, the "Loan
                                                                            ----
Agreement"), by and between Exelixis, Inc., a Delaware corporation ("Exelixis"),
      ---                                                            --------
and  SmithKline  Beecham Corporation, a Pennsylvania corporation, doing business
as  GlaxoSmithKline  ("GSK").  Unless  otherwise  defined  herein or the context
                       ---
otherwise  requires,  terms used herein have the meanings assigned to such terms
in  the  Loan  Agreement.

     1.  Exelixis  hereby  requests  a  [General  Advance]  [Product  Specific
Advance]  be  made  in  the  aggregate  principal  amount  of  $____________ on
____________,  20_______ (the "Borrowing Date"), which Borrowing Date shall be a
                              ----------------
Business  Day  not earlier than fifteen (15) Business Days from the date of this
Borrowing Notice, or, if this Borrowing Notice is delivered to you other than by
facsimile  transmission,  the  Borrowing  Date  is not earlier than fifteen (15)
Business  Days  from the date of delivery as determined pursuant to Section 16.5
of  the  Loan  Agreement.  The  proceeds  from  such requested Advance should be
transferred  by  wire  transfer  of  funds  to  the  Deposit  Account.

     2.  The  undersigned  hereby  represents  that  he/she is a duly authorized
officer  of  Exelixis,  and  acknowledges  that,  each  of  the delivery of this
Borrowing Notice and the acceptance by Exelixis of the proceeds from the Advance
requested hereby constitutes a representation by Exelixis that, on the Borrowing
Date,  each  of  the  applicable  conditions  precedent  to Advances pursuant to
Article  6  of  the  Loan  Agreement,  have  been  met  or  performed.

     3.  The  undersigned  further represents that pursuant to Section 6.2.2 and
6.2.4  of  the  Loan  Agreement,  respectively,  each  of  the  delivery of this
Borrowing Notice and the acceptance by Exelixis of the proceeds from the Advance
requested  hereby constitutes a representation and warranty by Exelixis that, on
the  Borrowing  Date,  (i) no Event of Default has occurred and is continuing or
would  reasonably  be likely to be caused by the making of the Advance requested
hereby,  and  (ii)  the representations and warranties set forth in Article 7 of
the  Loan  Agreement  remain  true  and  correct  in  all  material  respects.

     4.  The  undersigned  further represents that, pursuant to Section 6.2.7 of
the  Loan Agreement, the proceeds from the requested Advance will be utilized by
Exelixis  solely  in  furtherance  of  the  obligations  of  Exelixis  under the
Development  Agreement  over  the  course  of  the  Term.

     5. [The undersigned further represents that, pursuant to Section 7.1 of the
Loan Agreement, attached hereto are true and correct copies of all amendments to
the  Operating  Documents  not  yet  filed  with  the  SEC.]

     6. [With respect to this Product Specific Advance, Exelixis represents that
it  has  title  to  the  Intellectual  Property  pertaining  to such Development
Candidate  selected as contemplated by Section 6.4.1 of the Loan Agreement, free
and  clear  of  all  assignments, mortgages, pledges, liens, security interests,
leases,  claims  or  any  other encumbrances, other than liens in favor of GSK.]

In  the  event  you  require  additional  documentation  in connection with this
requested  Advance,  in  accordance  with  Section  6.2.8 of the Loan Agreement,
please  provide a list of such requested documentation to Exelixis not less than
five  (5)  Business  Days  prior  to  the  proposed  Borrowing  Date.

IN WITNESS WHEREOF, Exelixis has caused this Borrowing Notice to be executed and
delivered,  and  the  certification and representations and warranties contained
herein  to  be made by its duly authorized officer, this ___day of ____________,
200__.

                                                  EXELIXIS,  INC.

                                                  By___________________________
                                                  Name:
                                                  Title:

[  *  ] = Certain confidential information contained in this document, marked by
brackets, has been omitted and filed separately with the Securities and Exchange
Commission  pursuant  to  Rule  24b-2 of the Securities Exchange Act of 1934, as
amended.
<PAGE>

                                    EXHIBIT E
                         FORM OF STOCK REPAYMENT NOTICE

VIA  FACSIMILE  TRANSMISSION
SmithKline  Beecham  Corporation,  doing  business  as          Fax:  [*]
GlaxoSmithKline
709  Swedeland  Road
King  of  Prussia,  Pennsylvania  19406
Attention:  Vice  President,  R&D  Structuring

Re:  Exelixis,  Inc.

Ladies  and  Gentlemen:

This  Stock  Repayment  Notice  is delivered to you pursuant to Section 5.6.3 of
that  certain  Loan  and  Security  Agreement, dated as of October ___, 2002 (as
amended,  restated,  supplemented  or  otherwise modified from time to time, the
"Loan  Agreement"),  by  and  between  Exelixis,  Inc.,  a  Delaware corporation
   -------------
("Exelixis"),  and  SmithKline  Beecham Corporation, a Pennsylvania corporation,
   -------
doing  business  as GlaxoSmithKline ("GSK").  Unless otherwise defined herein or
                                      ---
the  context  otherwise  requires,  terms  used  herein  shall have the meanings
assigned  to  such  terms  in  the  Loan  Agreement.

     1.  Pursuant  to  Section  5.6.1 of the Loan Agreement and Section 3.4.1 of
the  Stock  Purchase Agreement, Exelixis hereby exercises the option to issue to
GSK  Stock  Repayment  Shares  to  pay $_____________ of the current outstanding
principal  balance  of  the  Advances, and all accrued interest relating thereto
(the  "Stock  Repayment")  on the ____ day of ______, 20__ (the "Stock Repayment
       ----------------                                          ---------------
Closing  Date"),  which  Payment Date shall not be earlier than thirty (30) days
  -----------
from the date of this Stock Repayment Notice, or, if this Stock Repayment Notice
is  delivered  to  GSK other than by facsimile transmission, the Payment Date is
not  earlier  than  thirty  (30)  Business  Days  from  the  date of delivery as
determined  pursuant  to  Section  16.5  of  the  Loan  Agreement.

     2.  The  undersigned  hereby  represents  that  he/she is a duly authorized
officer of Exelixis, and acknowledges that, the delivery of this Stock Repayment
Notice  hereby  constitutes  a  representation  and  warranty  by Exelixis that,
pursuant  to  Section  5.6.2  of the Loan Agreement and Section 2.5 of the Stock
Purchase  Agreement, such Stock Repayment will not require GSK to acquire twenty
percent  (20%) or more of Exelixis' outstanding Common Stock, as reported in the
most  recent quarterly or annual report form of Exelixis filed with the SEC and,
in the event that any purchase of Stock Repayment Shares would cause GSK to be a
holder  of more than twenty percent (20%) of Exelixis' outstanding Common Stock,
GSK shall be relieved of its obligations to make such purchase(s), to the extent
of  the  overage.

     3. The undersigned further represents that pursuant to Section 5.6.4 of the
Loan Agreement, the delivery of this Stock Repayment Notice hereby constitutes a
representation  and  warranty  by  Exelixis that, on the Stock Repayment Closing
Date, each of the conditions precedent to the issuance of Stock Repayment Shares
pursuant  to  Section  5.6.6  of the Loan Agreement, have been met or performed.

     4.  [The  undersigned further represents that, pursuant to Section 5.6.4(a)
of  the  Loan Agreement and Section 3.4.3(a) of the Stock Purchase Agreement, if
GSK  is  not  an  SEC  Affiliate of Exelixis, at least three (3) Trading Days in
advance of the Stock Repayment Closing Date, Exelixis will issue instructions to
Exelixis' stock transfer agent directing Exelixis' transfer agent to prepare and
deliver  to  the  account  of  GSK  by  an  automated share transfer through the
Depository  Trust  Company  system  ("DWAC"),  that number of shares of Exelixis
representing  the  applicable  Stock  Repayment  Shares  no later than the Stock
Repayment  Closing  Date.]

     5.  [The  undersigned further represents that, pursuant to Section 5.6.4(b)
of  the  Loan Agreement and Section 3.4.3(b) of the Stock Purchase Agreement, if
GSK  is  an SEC Affiliate of Exelixis as of the Stock Repayment Closing Date, at
least  three  (3)  Trading  Days in advance of the Stock Repayment Closing Date,
Exelixis  will  issue  instructions to Exelixis' stock transfer agent, directing
the  transfer  agent  to  prepare  and  deliver  to Exelixis a stock certificate
representing  the  number  of  shares  evidencing the applicable Stock Repayment
Shares,  as  soon as possible, but in no event no later than one (1) Trading Day
prior  to  the  Stock  Repayment  Closing  Date, which stock certificate will be
delivered  by  Exelixis  to  GSK  on  the  Stock  Repayment  Closing  Date.]

IN  WITNESS  WHEREOF,  Exelixis  has  caused  this  Stock Repayment Notice to be
executed and delivered, and the certification and representations and warranties
contained  herein  to  be  made  by  its duly authorized officer, this ___day of
____________,  200__.

                                                  EXELIXIS,  INC.

                                                  By___________________________
                                                  Name:
                                                  Title:

[  *  ] = Certain confidential information contained in this document, marked by
brackets, has been omitted and filed separately with the Securities and Exchange
Commission  pursuant  to  Rule  24b-2 of the Securities Exchange Act of 1934, as
amended.1-I

<PAGE>
                                 SCHEDULE 3.1.1

                                     PATENTS

                                 Issued Patents
                                 --------------

                   Country     Patent No./Title     Issue Date
                   -------     ----------------     ----------

                           Pending Patent Applications
                           ---------------------------
                                       [*]

[  *  ] = Certain confidential information contained in this document, marked by
brackets, has been omitted and filed separately with the Securities and Exchange
Commission  pursuant  to  Rule  24b-2 of the Securities Exchange Act of 1934, as
amended.

<PAGE>

                                 Schedule 3.1.3

                                 DEPOSIT ACCOUNT

                                       [*]

[  *  ] = Certain confidential information contained in this document, marked by
brackets, has been omitted and filed separately with the Securities and Exchange
Commission  pursuant  to  Rule  24b-2 of the Securities Exchange Act of 1934, as
amended.
<PAGE>

                                  SCHEDULE 9.1

                           LOCATION OF THE COLLATERAL

LOCATION  OF  THE  RECORDS  OF  THE  COLLATERAL:

Exelixis,  Inc.
170  Harbor  Way
PO  Box  511
South  San  Francisco,  CA  94083

LOCATION  OF  THE  TANGIBLE  COLLATERAL:

Exelixis,  Inc.,  170  Harbor  Way,  South  San  Francisco,  CA

Exelixis,  Inc.,  169  Harbor  Way,  South  San  Francisco,  CA

Exelixis,  Inc.,  260  Littlefield  Avenue,  South  San  Francisco,  CA

<PAGE>
                                  SCHEDULE 9.16

                              PERMITTED INVESTMENTS

                                       [*]

[  *  ] = Certain confidential information contained in this document, marked by
brackets, has been omitted and filed separately with the Securities and Exchange
Commission  pursuant  to  Rule  24b-2 of the Securities Exchange Act of 1934, as
amended.
<PAGE>

                                  SCHEDULE 16.4

                                  INDEBTEDNESS

The  Obligations  are  expressly  made  subordinate  in  right of payment to the
following  obligations:

1.   Ordinary  trade  payables  incurred  in  ordinary  course  of  business.

2.   Loan  and  Security  Agreement  dated  May  22,  2002, between Exelixis and
     Silicon  Valley  Bank  for a maximum loan amount of Sixteen Million Dollars
     ($16,000,000),  as  modified  by  that  certain Loan Modification Agreement
     dated  October  1,  2002  between  Exelixis  and  Silicon  Valley  Bank.

3.   Master  Lease  Agreement  dated April 9, 2001, between Exelixis and General
     Electric  Capital  Corporation  for a maximum loan amount of Twelve Million
     Dollars  ($12,000,000).

4.   Convertible  Note  and  Note Purchase Agreement dated May 22, 2002, between
     Exelixis  and Protein Design Labs, Inc. for a maximum loan amount of Thirty
     Million  Dollars  ($30,000,000).

5.   Master  Lease  Agreement dated August 2, 2000, as amended, between Exelixis
     and  General  Electric  Capital Corporation (formerly Comdisco, Inc.) for a
     maximum  loan  amount  of  Thirteen  Million  One  Hundred Thousand Dollars
     ($13,100,000).

6.   Master  Loan  and  Security  Agreement  dated  August  3, 1998, as amended,
     between  Exelixis  and  Transamerica  Technology  Finance Corporation for a
     maximum  loan  amount  of  Three  Million  Dollars  ($3,000,000).

<PAGE>

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