<PAGE>   1

                                                                   Exhibit 10.24
 

                                           *** Text Omitted and Filed Separately
                                                Confidential Treatment Requested
                                          Under 17 C.F.R. Sections 200.80(b)(4),
                                                            200.83 and 240.24b-2



                                 LOAN AGREEMENT



        THIS LOAN AGREEMENT is entered into as of October 23, 1998 (this "Loan
Agreement"), between COULTER PHARMACEUTICAL, INC., a corporation formed under
the laws of the State of Delaware, with its principal place of business at 550
California Avenue, Suite 200, Palo Alto, California 94306, USA ("Borrower"), and
SMITHKLINE BEECHAM CORPORATION, a corporation formed under the laws of the
Commonwealth of Pennsylvania, with its principal place of business at One
Franklin Plaza, Philadelphia, Pennsylvania 19101, USA ("Lender"). This Loan
Agreement shall not be effective until the Effective Date.

        1. DEFINITIONS. As used in this Loan Agreement and unless otherwise
defined herein, all initially capitalized terms shall have the meanings set
forth on EXHIBIT A attached hereto and incorporated herein by this reference.

        2. COMMITMENT. Subject to all the terms and conditions of this Loan
Agreement and prior to the termination of its commitment as hereinafter
provided, Lender hereby agrees to make loans (each a "Loan" and collectively
"Loans") to Borrower, from time to time and in such amounts as Borrower shall
request pursuant to SECTION 2(a) hereof up to, but not exceeding, an aggregate
unpaid principal balance of U.S. $15,000,000 (the "Commitment"). If at any time
or for any reason, the outstanding principal amount of the Loans is greater than
the Commitment, Borrower shall immediately pay to Lender the amount of such
excess. The Commitment of Lender, pursuant to the terms of this Loan Agreement,
to make Loans shall expire on the date that is twenty-four (24) months after the
Effective Date (the "Expiration Date"). Borrower promises to pay to Lender the
entire outstanding unpaid principal balance (and all accrued unpaid interest
thereon) of the Loans no later than the date that is sixty (60) months after the
Effective Date ("Maturity Date").

           (a) LOANS. At any time from the Effective Date and prior to the
Expiration Date, Borrower may from time to time request Loans from Lender for
the purpose of clinical development, process development, manufacture, and sales
and marketing of Bexxar, in accordance with the Collaboration Agreement.

           (b) PRINCIPAL PAYMENTS. (i) In the event that Borrower's EBITDA for
the twelve (12) month period ending September 30, 2001 exceeds U.S. $[...***...]
then on the date that is thirty-six (36) months after the Effective Date,
Borrower shall make a principal payment of an amount equal to [***]
percent ([...***...]%) of then outstanding principal balance of the Loans; 
(ii) in the event that Borrower's EBITDA for the twelve (12) month period 
ending September 30, 2002 exceeds U.S. $[...***...], then on the date that is 
forty-eight (48) months after the Effective Date, Borrower shall make a 
principal payment of an amount equal to [...***...]


*Confidential Treatment Requested

                                       1.

<PAGE>   2
percent ([...***...]%) of then outstanding principal balance of the Loans; and
(iii) Borrower shall repay the entire outstanding unpaid principal balance of
the Loans, together with all accrued unpaid interest thereon, on the Maturity
Date. At the Borrower's option under this SECTION 2(B), principal payments,
together with all accrued unpaid interest thereon, may be paid in cash or the
amount of Borrower's Common Stock ("Shares") equal to the quotient of the amount
repaid divided by the Share Price (as hereinafter defined). The "Share Price"
shall be the closing price of Borrower's Common Stock on the Nasdaq National
Market, as reported by the Wall Street Journal, Western Edition (the "Wall
Street Journal"), on the last trading day preceding the payment date. In the
event the number of Shares so calculated would include a fraction of a Share,
the number of Shares shall be decreased to the nearest whole number of Shares
and the balance of the amount to be repaid shall be paid in cash. Any Shares
delivered pursuant to this SECTION 2(b) shall be issued pursuant to an effective
registration statement under the Securities Act of 1933, as amended, and shall
be freely tradable.

           (c) PREPAYMENTS. Borrower may prepay the Loans in cash, or Shares
equal to the quotient of the amount repaid divided by the Share Price, at any
time (including, without limitation, upon the occurrence of an Event of Default)
in full, or in part, in minimum amounts of U.S. $100,000. In the event the
number of Shares so calculated would include a fraction of a Share, the number
of Shares shall be decreased to the nearest whole number of Shares and the
balance of the amount to be repaid shall be paid in cash. Any Shares delivered
pursuant to this SECTION 2(c) shall be issued pursuant to an effective
registration statement under the Securities Act of 1933, as amended, and shall
be freely tradable.

        3. PAYMENT OF INTEREST ON ALL LOANS.

           (a) INTEREST RATES. Each Loan shall bear interest on the outstanding
principal amount thereof from the date when made until paid in full at a fixed
rate per annum equal to the Prime Rate in effect on the date such Loan is
advanced, or the maximum permissible rate by law (which under the laws of the
State of Delaware shall be deemed to be the laws relating to the permissible
rate of interest on commercial loans), whichever is less.

           (b) INTEREST PAYMENT DATES. Interest on each Loan shall be paid in
cash in arrears on the last day of each March, June, September and December.
Interest shall also be paid in cash on the date of any prepayment of any Loans
pursuant to SECTION 2(c) of this Loan Agreement for the portion of the Loans so
prepaid and upon payment (including prepayment) in full thereof.

           (c) CALCULATION OF INTEREST. Interest on the Loans shall be computed
on the basis of a 365/366-day year and the actual number of days elapsed.

        4. CONDITIONS TO ADVANCE OF LOANS. The Borrower shall initiate an
advance under this Loan Agreement by written request to the Lender delivered not
less than three Business Days prior to the date of the requested advance. The
obligation of Lender to consummate the loan transaction contemplated under this
Loan Agreement and the other Loan Documents, and to advance each Loan hereunder
is subject to the satisfaction of the following conditions precedent:


*Confidential Treatment Requested


                                       2.
<PAGE>   3

           (a) Lender shall have received this Loan Agreement and all of the
other Loan Documents duly executed and delivered by Borrower.

           (b) There shall not exist a condition which would constitute an Event
of Default.

           (c) There shall not exist a breach of any of the financial covenants
set forth in SECTION 8 hereof.

           (d) All representations and warranties shall be and continue to be
true and correct.

           (e) Borrower shall have cash and marketable securities available for
sale in an aggregate amount not less than [...***...], net of the amount of any
Loans made during the immediately preceding ninety (90) day period.

           (f) The aggregate principal amount of Loans which would be
outstanding following any requested advance shall not exceed the Borrower's
share of the expenses approved by the JDC and/or the JCC in accordance with the
provisions of the Collaboration Agreement.

           (g) Borrower shall deliver a certificate in the form of Exhibit C
hereto signed by the Chief Financial Officer of the Borrower certifying
compliance by the Borrower with each of the conditions precedent set forth in
SECTIONS 4(A) through 4(E) as of the date of the requested advance.

           (h) Borrower shall have established the Cash Collateral Account.

        5. REPRESENTATIONS AND WARRANTIES. Borrower represents and warrants to
Lender: (a) Borrower is a corporation, duly organized, validly existing and in
good standing under the laws of the State of Delaware, U.S.A., and the
execution, delivery and performance of each of the Loan Documents to which it is
a party are within Borrower's powers, have been duly authorized and are not in
conflict with law or the terms of any articles of incorporation, bylaws or other
charter documents, or of any indenture, agreement or undertaking to which
Borrower is a party or by which Borrower is bound or affected; (b) this Loan
Agreement and the other Loan Documents to which it is a party constitute legal,
valid and binding obligations of Borrower enforceable against Borrower in
accordance with their respective terms; (c) except for Permitted Liens, Borrower
owns and has good title to or has valid leases or licenses for the use of all of
its Property free and clear of all Liens, and has not executed any security
documents or financing statements relating to such Property; (d) there is no
material litigation or other proceeding pending or threatened against or
affecting Borrower, and Borrower is not in default with respect to any order,
writ, injunction, decree or demand of any court or other governmental or
regulatory authority; (e) as of the date first written above the Borrower has no
Subsidiaries other than Coulter Pharma Belgium; (f) there exists no condition
which constitutes an Event of Default; and (g) there has been no material
adverse change in the financial condition, results or operations or


* CONFIDENTIAL TREATMENT REQUESTED


                                       3.
<PAGE>   4


prospects of the Borrower since the date of the Borrower's annual report on Form
10-K for the year ending December 31, 1997.

        6. AFFIRMATIVE COVENANTS. Borrower affirmatively covenants and agrees
that so long as any Obligations shall be outstanding or the Commitment shall be
available, it will:

           (a) Promptly notify Lender in writing of any attachment or other
legal process levied against any of the Collateral and any information received
by Borrower relative to the Collateral which may in any way affect the value of
the Collateral or the rights and remedies of Lender in respect thereto;

           (b) Maintain and preserve all rights, franchises and other authority
adequate and necessary for the conduct of its business and maintain and preserve
its existence in the State of its organization and any other state(s) in which
Borrower conducts its business, except with respect to such other state(s) in
which the failure to do so would not have a material adverse effect on the
business or financial condition of Borrower;

           (c) Maintain public liability, property damage and workers
compensation insurance and insurance on all its insurable property against fire
and other hazards with responsible insurance carriers to the extent usually
maintained by similar businesses;

           (d) Maintain its properties, equipment and facilities in good order
and repair;

           (e) Use all Loan proceeds solely for the purpose of clinical
development, process development, manufacture, and sales and marketing of
Bexxar, in accordance with the Collaboration Agreement; and

           (f) Cause each domestic Subsidiary of Borrower hereafter formed or
acquired to execute and deliver a Guaranty to Lender, such Guaranty to be in the
form attached hereto as Exhibit D.

        7. NEGATIVE COVENANTS. Borrower covenants and agrees that so long as any
Obligations shall be outstanding or the Commitment shall be available, Borrower
will not, without the prior written consent of Lender:

           (a) Create, incur, assume or permit to exist any Lien (including the
charge upon Property at any time purchased or acquired under conditional sale or
other title retention agreement) upon any asset now owned or hereafter acquired
by it, other than Permitted Liens and Liens in favor of Lender;

           (b) Sell, dispose of or grant a security interest in any of the
Collateral other than to Lender (other than the disposing of tangible assets
which are obsolete or otherwise considered surplus), or execute any financing
statements covering the Collateral in favor of any Person other than Lender or
the beneficiary of a Permitted Lien; and





                                       4.
<PAGE>   5

           (c) Borrow an aggregate principal amount of Loans during any twelve
(12) month period in excess of Borrower's share of the expenses for that period
approved by the JDC and/or the JCC in accordance with the provisions of the
Collaboration Agreement.

        8. FINANCIAL COVENANTS. Borrower covenants and agrees that so long as
any Obligations shall be outstanding or any Commitment shall be available,
Borrower shall maintain all of the following financial covenants; provided,
however, that in no event shall [...***...] the following financial covenants
[...***...]:

           (a) MINIMUM REMAINING MONTHS LIQUIDITY. Until such time as Borrower
maintains a Debt Service Coverage Ratio of not less than [...***...] for two (2)
consecutive Fiscal Quarters, maintain as at the end of each Fiscal Quarter, a
Remaining Months Liquidity of not less than six (6) months. 

           (b) MINIMUM DEBT SERVICE COVERAGE RATIO. Maintain as at the end of
each Fiscal Quarter, a Debt Service Coverage Ratio of not less than [...***...];
provided, however, that Borrower shall be deemed to satisfy this covenant so
long as Borrower maintains Remaining Months Liquidity of not less than six (6)
months.

           (c) MINIMUM CONSOLIDATED TANGIBLE NET WORTH. Maintain as at the end
of each Fiscal Quarter, Consolidated Tangible Net Worth of an amount not less
than [...***...].

           (d) MAXIMUM CONSOLIDATED LEVERAGE RATIO. Maintain as at the end of
each Fiscal Quarter, a Consolidated Leverage Ratio of not greater than
[...***...].

In the event that Borrower fails to maintain any of the foregoing financial
covenants, then no later than three Business Days after the date that Borrower
becomes aware of any such failure, Borrower shall deposit into the Cash
Collateral Account (as defined below) an amount of cash (the "Cash Collateral")
not less than the then-outstanding principal amount of the Loans, grant to
Lender a first priority perfected security interest in the Cash Collateral
Account, and provide to Lender any documentation required to evidence and
perfect such security interest under applicable law. The "Cash Collateral
Account" shall be a deposit account of any domestic commercial bank (or the
parent company of such bank) whose short-term commercial paper rating from
Standard & Poor's Rating Group is at least A-1 or the equivalent thereof or from
Moody's Investors Service, Inc. is at least P-1 or the equivalent thereof;
provided that the Cash Collateral Account shall be "blocked" such that Lender
shall have control, as defined under the Uniform Commercial Code of the
applicable jurisdiction, of the Cash Collateral Account at any time Borrower has
failed to maintain a financial covenant set forth in SECTION 8 hereof and until
such time as Borrower has cured such failure to maintain such financial
covenants. Notwithstanding anything to the contrary herein, so long as Borrower
has satisfied any contractual obligation to any Senior Lender to provide cash
collateral to secure such Senior Lender's Funded Indebtedness upon the failure
of Borrower to maintain financial covenants for the benefit of such Senior
Lender (and such Senior Lender has not waived such requirement prior to the date
upon which Borrower cures its failure to maintain such financial covenants),
then the



*CONFIDENTIAL TREATMENT REQUESTED


                                       5.
<PAGE>   6

principal amount of the required Cash Collateral shall be reduced by the value
of Product Accounts (as defined in the Security Agreement); provided, that if
Senior Lender thereafter waives Borrower's cash collateral requirement to such
Senior Lender, no later than three Business Days thereafter Borrower shall
deposit into the Cash Collateral Account cash in a principal amount not less
than the difference between the then-outstanding principal amount of the Loans
and any then-existing Cash Collateral; provided further, on the date upon which
Borrower cures its failure to maintain any of the financial covenants set forth
in this SECTION 8, Lender shall release its security interest in all of such
Cash Collateral, and shall notify the bank maintaining the Cash Collateral
Account that the triggering event has been cured and that Lender rescinds its
control of the Cash Collateral Account.

        9. FINANCIAL INFORMATION. Borrower covenants and agrees that so long as
any Obligations shall be outstanding or the Commitment shall be available,
Borrower shall provide the following financial information to Lender:

           (a) QUARTERLY FINANCIAL STATEMENTS. As soon as practicable and in any
event within forty-five (45) days after and as of the end of each Fiscal
Quarter, internally-prepared consolidated balance sheets, statements of income
and cash flow of Borrower as at the end of such period, all in reasonable detail
and certified by the chief financial officer of Borrower that they (i) are
complete and fairly present the financial condition of Borrower as at the dates
indicated and the results of its operations and changes in its cash flow for the
periods indicated, (ii) disclose all liabilities that are required to be
reflected or reserved against under GAAP, whether liquidated or unliquidated,
fixed or contingent, and (iii) have been prepared in accordance with GAAP,
subject to changes resulting from audit and normal year-end adjustment, together
with a Compliance Certificate in the form of Exhibit B to this Loan Agreement
duly completed and certified by the chief financial officer of Borrower.

           (b) ANNUAL AUDITED FINANCIAL STATEMENTS. As soon as practicable and
in any event within ninety (90) days after the end of each Fiscal Year,
consolidated balance sheets, statements of income and cash flow of Borrower as
at the end of such Fiscal Year, all in reasonable detail and accompanied by a
report thereon of independent public accountants of recognized national standing
selected by Borrower and reasonably satisfactory to Lender, which report shall
be unqualified and shall not contain an adverse opinion, or a disclaimer of
opinion, shall not express doubts about the ability of Borrower to continue as a
going concern, or be qualified or limited because of a restricted or limited
examination by such accountant of any material portion of Borrower's records and
shall state that such consolidated financial statements present fairly the
financial position of Borrower as at the dates indicated and the results of
operations and changes in financial position for the periods indicated in
conformity with GAAP applied on a basis consistent with prior years (except as
otherwise stated therein) and that the examination by which such auditors in
connection with such consolidated and consolidating financial statements has
been made in accordance with generally accepted auditing standards, together
with a Compliance Certificate in the form of Exhibit B to this Loan Agreement
duly completed and certified by the chief financial officer of Borrower.




                                       6.
<PAGE>   7


        10. EVENT OF DEFAULT. The occurrence of any one or more of the following
shall constitute an "Event of Default": (a) default be made in the payment of
any Obligation by Borrower under any Loan Document and such default shall not
have been cured within five (5) days after Borrower's receipt of written notice
from Lender; (b) except for any failure to pay as described in clause (a) above,
or any [.....***.....] in [.....***.....], above, breach be
made in any representation, warranty, statement, covenant, promise, term or
condition contained herein or in any other Loan Document and the same shall not
have been cured within thirty (30) days after Borrower's receipt of written
notice from Lender; (c) any statement, warranty or representation made by
Borrower at any time proves to have been false in any material aspect at the
time made; (d) there shall exist an uncured default or event of default by
Borrower in the performance of any obligation to SmithKline Beecham Corporation
(or its successors or assigns) under the Collaboration Agreement or otherwise;
(e) the Collaboration Agreement is terminated in accordance with the provisions
thereof for any reason other than a material breach by Lender; (f) Borrower
defaults in the repayment of any principal of or the payment of any interest on
any Funded Indebtedness or breaches or violates any term or provision of any
promissory note, loan agreement, mortgage, indenture or other evidence of such
Funded Indebtedness, if the effect of such breach is the acceleration of such
Funded Indebtedness; (g) Borrower becomes insolvent or makes an assignment for
the benefit of creditors; (h) any proceeding be commenced by Borrower under the
Bankruptcy Code or any reorganization, arrangement, readjustment of debt or
moratorium law or statute, or any such proceeding is commenced against Borrower
and is not dismissed or stayed within sixty (60) days; or (i) any failure to
provide the Cash Collateral to the Lender as set forth in SECTION 8, above.

        11. REMEDIES. Upon the occurrence and during the continuance of an Event
of Default, Lender may, at its option and without demand first made and without
notice to Borrower, do any one or more of the following: (a) terminate its
obligation to make Loans to Borrower as provided in SECTION 2 hereof; (b)
declare all sums secured hereby immediately due and payable; or (c) exercise any
remedies pursuant to the Security Agreement or any remedies of a secured party
under the Uniform Commercial Code. Lender shall have the right to enforce one or
more remedies hereunder successively or concurrently, and any such action shall
not estop or prevent Lender from pursuing any further remedy that it may have
hereunder or by law.

        12. MISCELLANEOUS PROVISIONS.

            (a) ENTIRE AGREEMENT. This Loan Agreement and each of the other Loan
Documents to which it is a party, taken together, constitute and contain the
entire agreement among Borrower and Lender and supersede any and all prior
agreements, negotiations, correspondence, understandings and communications
among the parties, whether written or oral, respecting the subject matter
hereof.

            (b) NO WAIVER. No failure or delay on the part of Lender in the
exercise of any power, right or privilege under this Loan Agreement or any of
the other Loan Documents shall impair such power, right or privilege or be
construed to be a waiver of any default or


*Confidential Treatment Requested

                                       7.
<PAGE>   8
acquiescence therein, nor shall any single or partial exercise of any such
power, right or privilege preclude other or further exercise thereof or of any
other right, power or privilege.

            (c) RELIANCE BY LENDER. All covenants, agreements, representations
and warranties made herein by Borrower shall, notwithstanding any investigation
by Lender be deemed to be material to and to have been relied upon by Lender.

            (d) HEADINGS. Section and subsection headings in this Loan Agreement
are included herein for convenience of reference only and shall not constitute a
part of this Loan Agreement for any other purpose or be given any substantive
effect.

            (e) SEVERABILITY. Whenever possible, each provision of this Loan
Agreement and each of the other Loan Documents shall be interpreted in such a
manner as to be valid, legal and enforceable under the applicable law of any
jurisdiction. Without limiting the generality of the foregoing sentence, in case
any provision of this Loan Agreement or any of the other Loan Documents shall be
invalid, illegal or unenforceable under the applicable law of any jurisdiction,
the validity, legality and enforceability of the remaining provisions, or of
such provision in any other jurisdiction, shall not in any way be affected or
impaired thereby.

            (f) GOVERNING LAW. Except as otherwise expressly provided in any of
the Loan Documents, in all respects, including all matters of construction,
validity and performance, this Loan Agreement and the Obligations arising
hereunder shall be governed by, and construed and enforced in accordance with,
the laws of the State of Delaware applicable to contracts made and performed in
such state, without regard to the principles thereof regarding conflict of laws,
and any applicable laws of the United States of America.

            (g) SUCCESSORS AND ASSIGNS. Neither party may assign or transfer
this Loan Agreement or any rights or obligations hereunder without the prior
written consent of the other which shall not be unreasonably withheld, except a
party may make such an assignment without the other party's consent to an
Affiliate or to a successor to substantially all of the pharmaceutical business
of such party, whether in a merger, sale of stock, sale of assets or other
transaction. Any permitted successor or assignee of rights and/or obligations
hereunder shall, in a writing to the other party, expressly assume performance
of such rights and/or obligations. Any permitted assignment shall be binding on
the successors of the assigning party. Any assignment or attempted assignment by
either party in violation of the terms of this SECTION 12(g) shall be null and
void and of no legal effect.

        COUNTERPARTS. This Loan Agreement may be executed in any number of
counterparts, each of which when so delivered shall be deemed an original, but
all such counterparts shall constitute but one and the same instrument. Each
such agreement shall become effective upon the execution of a counterpart hereof
or thereof by each of the parties hereto and telephonic notification that such
executed counterparts has been received by Borrower and Lender.




                                       8.
<PAGE>   9
BORROWER:                                   LENDER:

COULTER PHARMACEUTICAL, INC.                SMITHKLINE BEECHAM CORPORATION




By:                                         By:
   ---------------------------------           ---------------------------------


Printed Name:                               Printed Name:
             -----------------------                     -----------------------

Title:                                      Title:  
      ------------------------------              ------------------------------







                                       9.
<PAGE>   10


                         LIST OF EXHIBITS AND SCHEDULES



EXHIBIT A:     Definitions

        SCHEDULE 1 TO EXHIBIT A: List of Specific Permitted Indebtedness

        SCHEDULE 2 TO EXHIBIT A: List of Specific Permitted Liens

EXHIBIT B:     Form of Compliance Certificate re Financial Covenants

EXHIBIT C:     Form of Compliance Certificate re Conditions Precedent to Loans

EXHIBIT D:     Form of Guaranty to Be Executed by Borrower's Domestic
               Subsidiaries








                                      10.
<PAGE>   11

                                    EXHIBIT A

                                   DEFINITIONS


        "004 TRIAL" means Borrower's clinical trial with Protocol No. RIT-II-004
("Multicenter, Pivotal Phase III Study of Iodine-131 Anti-B1 Antibody (Murine)
Radioimmunotherapy for Chemotherapy-Refractory Low-Grade B-Cell Lymphomas and
Low-Grade Lymphomas That Have Transformed to Higher Grade Histologies") for
which enrollment and interim analysis was completed prior to the Effective Date.

        "AFFILIATE" means, in the case of either Borrower or Lender, any
corporation, joint venture or other business entity which directly or indirectly
controls, is controlled by, or is under common control with that party.
"CONTROL," as used in this definition, shall mean having the power to direct, or
cause the direction of, the management and policies of an entity, whether
through ownership of voting securities, by contract or otherwise.

        "BANKRUPTCY CODE" means the Bankruptcy Code of 1978, as amended, as
codified under Title 11 of the United States Code, and the Bankruptcy Rules
promulgated thereunder, as the same may be in effect from time to time.

        "BEXXAR" means B1 Murine Antibody conjugated with 131Iodine or
unconjugated, depending upon context.

        "B1 MURINE ANTIBODY" means the unconjugated IgG2a anti-CD20 murine
monoclonal antibody which is one of the active agents tested in the 004 Trial.

        "BUSINESS DAY" means any day which is not a Saturday, Sunday or a legal
holiday under the laws of the State of California or is not a day on which
banking institutions located in the State of California are authorized or
required by law or other governmental action to close.

        "CAPITAL LEASE" means, as to any Person, any lease of any Property by
such Person as lessee that is, or should be in accordance with Financing
Accounting Standards Board Statement No. 13, classified and accounted for as a
"capital lease" on the balance sheet of such Person prepared in accordance with
GAAP.

        "CAPITAL LEASE OBLIGATION" means, with respect to any Capital Lease, the
amount of the obligation of the lessee thereunder that, in accordance with GAAP,
would appear on a balance sheet of such lessee in respect of such Capital Lease
or otherwise be disclosed in a note to such balance sheet.

        "CASH COLLATERAL" shall have the meaning set forth in SECTION 8.

        "CASH COLLATERAL ACCOUNT" shall have the meaning set forth in SECTION 8.




                                       1.

<PAGE>   12


"Collaboration Agreement" means that certain Collaboration Agreement entered
into as of the same day as this Loan Agreement, between Coulter Pharmaceutical,
Inc. and SmithKline Beecham Corporation relating to Bexxar.

        "COLLATERAL" means any and all personal property of Borrower which is
assigned or hereafter is assigned to Lender as security or in which Lender now
has or hereafter acquires a security interest pursuant to the terms of the
Security Agreement or otherwise.

        "COMMITMENT" has the meaning set forth in SECTION 2.

        "CONSOLIDATED LEVERAGE RATIO" means the ratio of (a) Consolidated Total
Liabilities to (b) Consolidated Tangible Net Worth.

        "CONSOLIDATED TANGIBLE ASSETS" means, on a consolidated basis, as at any
date of determination, the difference between Consolidated Total Assets and all
intangible assets of Borrower, as determined and computed in accordance with
GAAP.

        "CONSOLIDATED TANGIBLE NET WORTH" means on a consolidated basis, as at
any date of determination, the difference between Consolidated Tangible Assets
and Consolidated Total Liabilities.

        "CONSOLIDATED TOTAL ASSETS" means on a consolidated basis, as at any
date of determination, all assets of Borrower, as determined and computed in
accordance with GAAP.

        "CONSOLIDATED TOTAL LIABILITIES" means on a consolidated basis, as at
any date of determination, all liabilities of Borrower, determined and computed
in accordance with GAAP.

        "CONTINGENT OBLIGATION" means, as applied to any Person, any direct or
indirect liability, contingent or otherwise, of that Person with respect to any
indebtedness, lease, dividend, letter of credit or other obligation of another,
including, without limitation, any such obligation directly or indirectly
guaranteed, endorsed (otherwise than for collection or deposit in the ordinary
course of business), co-made or discounted or sold with recourse by that Person,
or in respect of which that Person is otherwise directly or indirectly liable,
including, without limitation, any such obligation for which that Person is in
effect liable through any agreement (contingent or otherwise) to purchase,
repurchase or otherwise acquire such obligation or any security therefor, or to
provide funds for the payment or discharge of such obligation (whether in the
form of loans, advances, capital stock purchases, capital contributions or
otherwise), or to maintain the solvency of the obligor of such obligation, or to
make payment for any products, materials or supplies or for any transportation,
services or lease regardless of the non-delivery or non-furnishing thereof, in
any such case if the purpose or intent of such agreement is to provide assurance
that such obligation will be paid or discharged, or that any agreements relating
thereto will be complied with, or that the holders of such obligation will be
protected (in whole or in part) against loss in respect thereof. The amount of
any Contingent Obligation of any Person shall be deemed to be an amount equal to
the maximum amount of such Person's liability with respect to the stated or
determinable amount of the primary obligation for which such Contingent




                                       2.
<PAGE>   13

Obligation is incurred or, if not stated or determinable, the maximum reasonably
anticipated liability in respect thereof (assuming such Person is required to
perform thereunder).

        "DEBT SERVICE COVERAGE RATIO" means the ratio of (a) net profit plus
depreciation, amortization and other non-cash charges to (b) the current portion
of long term debt.

        "EBITDA" means, as at any date of determination, for any period, an
amount equal to the sum of (i) net income (without giving effect to any
extraordinary non-cash gains or extraordinary non-cash losses), plus (ii)
interest expense, plus (iii) provisions for income taxes, plus (iv)
depreciation, plus (v) amortization, each as determined and calculated in
accordance with GAAP

        "EFFECTIVE DATE" has the meaning set forth in the Collaboration
Agreement.

        "EXPIRATION DATE" has the meaning set forth in SECTION 2.

        "EVENT OF DEFAULT" has the meaning set forth in SECTION 10.

        "FISCAL QUARTER" means each fiscal quarter of Borrower ending on each
March 31, June 30, September 30 and December 31.

        "FISCAL YEAR" means each fiscal year of Borrower ending on December 31.

        "FUNDED INDEBTEDNESS" means, as to any Person, without duplication, (a)
all indebtedness of such Person for borrowed money, including, without
limitation, all of such indebtedness outstanding under this Loan Agreement and
any of the other Loan Documents; (b) all Capital Lease Obligations of such
Person; (c) to the extent of the outstanding indebtedness thereunder, any
obligation of such Person representing an extension of credit to such Person,
whether or not for borrowed money; (d) any obligation of such Person for the
deferred purchase price of Property or services (other than (i) trade or other
accounts payable in the ordinary course of business in accordance with customary
industry terms and (ii) deferred franchise fees); (e) all Contingent
Obligations; (f) any obligation of such Person of the nature described in
clauses (a), (b), (c), (d) or (e) above, that is secured by a Lien on assets of
such Person and which is non-recourse to the credit of such Person, but only to
the extent of the fair market value of the assets so subject to the Lien; (g)
obligations of such Person arising under acceptance facilities or under
facilities for the discount of accounts receivable of such Person; (h) any
obligation of such Person to reimburse the issuer of any letter of credit issued
for the account of such Person upon which a draw has been made; and (i) any
lease having the effect of indebtedness, whether or not the same shall be
treated as such on the balance sheet of Borrower under GAAP.

        "FUNDING DATE" means with respect to any proposed Loan hereunder, the
date funds are advanced to Borrower for such Loan.

        "GAAP" means generally accepted accounting principles set forth in the
opinions and pronouncements of the Accounting Principles Board of the American
Institute of Certified Public Accountants and statements and pronouncements of
the Financial Accounting Standards Board




                                       3.
<PAGE>   14


or in such other statements by such other Person as may be approved by the
significant segment of the accounting profession, which are applicable to the
circumstances as of the date of determination.

        "GUARANTY" means a Guaranty made by each domestic Subsidiary, in favor
of Lender.

        "JCC" means the Joint Commercialization Committee as defined in Section
1.36 of the Collaboration Agreement and appointed pursuant to the Collaboration
Agreement.

        "JDC" means the Joint Development Committee as defined in Section 1.37
of the Collaboration Agreement and appointed pursuant to the Collaboration
Agreement.

        "LIEN" means any mortgage, pledge, security interest, lien or other
charge or encumbrance, including the lien or retained security title of a
conditional vendor, upon or with respect to any property or assets.

        "LIQUIDITY" means the value of Borrower's cash, cash equivalents and
short-term investments (less restricted cash), plus [....***....]
of net trade receivables payable to Borrower by Lender, plus [...***...]
of net trade receivables payable to Borrower by Persons other than
Lender.

        "LOAN" and "LOANS" has the meaning set forth in SECTION 2.

        "LOAN DOCUMENTS" means this Loan Agreement, the Note and the Security
Agreement dated as of the date first written above, each as executed by Borrower
in favor of Lender, together with all other documents entered into or delivered
pursuant to any of the foregoing, including, without limitation, each Guaranty,
in each case as originally executed or as the same may from time to time be
supplemented, modified or amended.

        "MATURITY DATE" has the meaning set forth in SECTION 2.

        "OBLIGATIONS" means all loans, advances, debts, liabilities and
obligations, for monetary amounts owing by Borrower to Lender, whether due or to
become due, matured or unmatured, liquidated or unliquidated, contingent or
non-contingent, and all covenants and duties regarding such amounts, of any kind
or nature, present or future, whether or not evidenced by any note, agreement or
other instrument, arising under any of the Loan Documents. This term includes,
without limitation, all principal, interest (including interest that accrues
after the commencement against Borrower under the Bankruptcy Code), fees,
including, without limitation, any and all arrangement fees, closing fees,
prepayment fees, commitment fees, advisory fees, agent fees and attorneys' fees
and any and all other fees, expenses, costs or other sums (including all
reasonable fees and disbursements of any law firm or other external counsel to
Lender) chargeable to Borrower under any of the Loan Documents.


*Confidential Treatment Requested

                                       4.
<PAGE>   15

        "PERMITTED INDEBTEDNESS" means the following:

            (1) Indebtedness of Borrower or Subsidiaries in favor of Lender
arising under this Loan Agreement and the other Loan Documents;

            (2) the existing or anticipated Funded Indebtedness disclosed on
SCHEDULE 1 attached hereto and incorporated herein by this reference; provided
that the principal amount thereof is not increased and the terms thereof are not
modified to impose more burdensome terms upon Borrower or any of its
Subsidiaries;

            (3) the Subordinated Debt;

            (4) extensions, renewals or refinancings of Funded Indebtedness
permitted under this Loan Agreement;

            (5) accrued dividends on the preferred stock of Borrower;

            (6) interest rate and currency hedging agreements;

            (7) guaranties of any Subsidiary's suppliers in connection with the
purchase of supplies in the ordinary course of business;

            (8) [...***...] in the [...***...] and to the extent otherwise
permitted hereunder; and

            (9) Funded Indebtedness secured by Permitted Liens.

        "PERMITTED LIENS" means the following:

            (1) Liens existing as of this date or anticipated, and disclosed in
Schedule 2 attached hereto and incorporated herein by this reference;

            (2) Liens for taxes, fees, assessments or other governmental charges
or levies, either not delinquent or being contested in good faith by appropriate
proceedings;

            (3) Liens (a) upon or in [...***...] (other than [...***...] in
[...***...] of the [...***...]) [...***...] by Borrower to secure the
[...***...] of [...***...] for the purpose of [...***...] of [...***...] and in
[...***...] the [...***...] thereof or (b) existing on [...***...], provided
that the Lien is [...***...] to the [...***...] and [...***...] and the
[...***...] of such [...***...];

            (4) Liens consisting of leases or subleases and licenses and
sublicenses granted to others in the ordinary course of Borrower's business not
interfering in any material respect with the business of Borrower and any
interest or title of a lessor or licensor under any lease or license, as
applicable;

*Confidential Treatment Required

                                       5.
<PAGE>   16

            (5) Liens securing claims or demands of materialmen, mechanics,
carriers, warehousemen, landlords and other like persons or entities imposed
without action of such parties, provided that the payment thereof is not yet
required;

            (6) Liens incurred or deposits made in the ordinary course of
Borrower's business in connection with worker's compensation, unemployment
insurance, social security and other like laws;

            (7) Liens arising from judgments, decrees or attachments in
circumstances not constituting an Event of Default;

            (8) Easements, reservations, rights-of-way, restrictions, minor
defects or irregularities in title and other similar charges or encumbrances
affecting real property not interfering in any material respect with the
ordinary conduct of Borrower's business;

            (9) Liens in favor of customs and revenue authorities arising as a
matter of law to secure payment of customs duties in connection with the
importation of goods;

            (10) Liens which constitute rights of set-off of a customary nature;

            (11) Any interest or title of a lessor in equipment subject to any
Capital Lease otherwise permitted hereunder; and

            (12) Any Liens arising from the filing of any financing statements
relating to true leases otherwise permitted hereunder.

        "PERSON" means any individual, sole proprietorship, partnership, joint
venture, trust, unincorporated organization, association, corporation, limited
liability company, institution, public benefit corporation, firm, joint stock
company, estate, entity or governmental agency.

        "PRIME RATE" means the rate of interest that Bank of America N.T & S.A.
has announced as its prime lending rate on the last Business Day of the calendar
quarter immediately preceding a Loan advance, or if such rate is not available,
the prime rate of interest as printed in the Wall Street Journal, Western
Edition on the Last Business Day of such calendar quarter.

        "PROPERTY" means any interest in any kind of property or asset, whether
real, personal or mixed, whether tangible or intangible.

        "REMAINING MONTHS LIQUIDITY" means the ratio of (a) Liquidity to (b) the
average monthly change in net cash from Borrower's operations during the prior
three (3) month period; provided, however, that the impact of any manufacturing
or annual campaigns shall be annualized for purposes hereof.

        "SECURITY AGREEMENT" means that certain Security Agreement dated of even
date herewith, made by Borrower in favor of Lender.




                                       6.
<PAGE>   17
"SENIOR LENDER" has the meaning set forth in SCHEDULE 1 to EXHIBIT A of the Loan
Agreement.

        "SUBORDINATED DEBT" means indebtedness of Borrower, the repayment of
principal of which is fully subordinated in time and right of payment to the
Loans, and has been approved in Lender's sole and absolute discretion and in
writing.

        "SUBSIDIARIES" means each entity controlled, directly or indirectly, by
Borrower now existing or hereafter formed or acquired.






                                       7.
<PAGE>   18

                            SCHEDULE 1 TO EXHIBIT A

                         SPECIFIC PERMITTED INDEBTEDNESS



        1. Any and all Funded Indebtedness owing by Borrower to any Person
engaged in the lending of money in the ordinary course of business (each, a
"SENIOR LENDER"), in an aggregate principal amount with respect to all such
Senior Lenders not to exceed U.S. [...***...], which Liens may include a first
priority security interest in certain personal property of Borrower except the
Licensed Patents (as defined in the Security Agreement) and Know-How (as defined
in the Security Agreement) and the Equipment of Borrower described in Section
2(a)(ii) of the Security Agreement. This Schedule 1 shall be updated by Borrower
with respect to the identity of the Senior Lender(s) once this identity has been
established.

        2. Equipment Lease Financing Agreement dated as of December 6, 1996,
between Borrower and Lease Management Services, Inc.

        3. Letter of Credit pursuant to the Lease Agreement dated November 7,
1997, by and between HMS Gateway Office L.P. and Borrower.





*CONFIDENTIAL TREATMENT REQUESTED



                                       8.
<PAGE>   19

                            SCHEDULE 2 TO EXHIBIT A

                            SPECIFIC PERMITTED LIENS


        1. Liens granted to any Person or Persons to secure the Permitted
Indebtedness disclosed in SCHEDULE 1 to EXHIBIT A.

        2. Liens granted pursuant to the Facilities Agreement between MDS
Nordion, Inc. and Borrower dated August 31, 1998.







                                       1.



<PAGE>   20

                                   EXHIBIT B

                             COMPLIANCE CERTIFICATE

        COULTER PHARMACEUTICAL, INC. (the "Company") hereby certifies that:

        This Compliance Certificate is furnished pursuant to SECTION 9 of the
Loan Agreement dated as of October 23, 1998 (the "Loan Agreement"), by and among
the Company and SmithKline Beecham Corporation ("Lender"). Unless otherwise
defined herein, the terms used in this Certificate have the meanings given them
in the Loan Agreement.

        As required by SECTIONS 9(a) and 9(b), as applicable, of the Loan
Agreement, consolidated financial statements of the Company for the
[year/quarter] ended _______________ (the "Financial Statements") prepared in
accordance with generally accepted accounting principles consistently applied
accompany this Compliance Certificate. The Financial Statements present fairly
the consolidated financial position of the Company as at the date thereof and
the consolidated results of operations of the Company for the period covered
thereby (subject only to normal recurring year-end adjustments).

        The figures set forth in SCHEDULE 1 attached hereto to be submitted
quarterly for determining compliance by the Company with the financial covenants
and certain other covenants contained in SECTION 8 of the Loan Agreement are
true and complete as of the date first written above.

        The activities of the Company during the period covered by the Financial
Statements have been reviewed by the chief financial officer or by employees or
agents under his/her immediate supervision. Based on such review, to the best
knowledge and belief of the chief financial officer, and as of the date of this
Compliance Certificate, no Event of Default has occurred.

        WITNESS my hand this _____ day of _______________, ____.



                                            COULTER PHARMACEUTICAL, INC.




                                            By:
                                               ---------------------------------

                                            Printed Name:
                                                         -----------------------

                                            Title:  Chief Financial Officer



                                       1.

<PAGE>   21

                            SCHEDULE 1 TO EXHIBIT B

                               FINANCIAL COVENANTS



A.      MINIMUM REMAINING MONTHS LIQUIDITY (SECTION 8.A.)

        REQUIRED:     Until such time as Borrower maintains a Debt Service
                      Coverage Ratio of not less than [...***...] for two (2)
                      consecutive Fiscal Quarters, Borrower shall maintain
                      Remaining Months Liquidity of six (6) months.


<TABLE>
<S>                                                <C>                        <C>
ACTUAL:

(1)       Cash                                      $___________

(2)       Cash equivalents and short-term           $___________
          investments (less restricted cash)

(3)       [**] of net trade receivables payable     $___________
          by Lender

(4)       [**] of net trade receivables payable by  $___________
          Persons other then Lender

(5)       Sum of Lines (1) - (4)                                               $___________

(6)       Average monthly change in net cash from   $___________
          Borrower's operations during preceding
          three months

(7)       Line (5) divided by Line (6)                                         _________ MONTHS

                                                                 In Compliance     Yes ?   No ?

B.      MINIMUM DEBT SERVICE COVERAGE RATIO (SECTION 8.B.)

        REQUIRED: Borrower shall maintain a Debt Service Coverage Ratio of not
                  less than [...***...].

ACTUAL:
(1)       Net Profit                                $___________

(2)       Depreciation                              $___________

(3)       Amortization and other non-cash charges   $___________

(4)       Sum of Lines (1) - (3)                                               $___________

(5)       Current portion of long-term debt         $___________

(6)       Line (4) divided by Line (5)                                         $___________
</TABLE>





*CONFIDENTIAL TREATMENT REQUESTED

                                       1.
<PAGE>   22


                                                   In Compliance   Yes ?   No ?


C.      MINIMUM CONSOLIDATED TANGIBLE NET WORTH (SECTION 8.C.)

        REQUIRED: Borrower on a consolidated basis shall not permit the
                  Consolidated Tangible New Worth to be an amount less
                  than [...***...].

<TABLE>
<S>        <C>                                 <C>                   <C>
ACTUAL:

(1)         Consolidated Total Assets           $___________

(2)         Intangible assets                   $___________

(3)         Consolidated Total Liabilities      $___________

(4)         Total:  Line (1) minus Line (2)                           $___________
            minus Line (3)
                                                   In Compliance   Yes ?   No ?

D.      CONSOLIDATED LEVERAGE RATIO (SECTION 8.D.)

        REQUIRED: Borrower on a consolidated basis shall not permit the
                  Consolidated Leverage Ratio to be greater than [...***...].

ACTUAL:

(1)         Consolidated Total Liabilities      $___________

(2)         Consolidated Total Assets           $___________

(3)         Intangible assets                   $___________

(4)         Line (2) minus Line (3)                                   $___________

(5)         Line (1) divided by Line (4)                              $           :
                                                                       ===========  [...***...]

                                                   In Compliance   Yes ?   No ?
</TABLE>

        WITNESS my hand on this Compliance Certificate on this _____ day of
_______________,______.



*CONFIDENTIAL TREATMENT REQUESTED


                                       2.

<PAGE>   23


                                            COULTER PHARMACEUTICAL, INC.



                                            By:
                                               ---------------------------------
                                               Printed Name:
                                                            --------------------

                                               Title:  Chief Financial Officer





                                       3.

<PAGE>   24
                                   EXHIBIT C

                             COMPLIANCE CERTIFICATE
                          CONDITIONS PRECEDENT TO LOAN


        COULTER PHARMACEUTICAL, INC. (the "Company") hereby certifies that:

        This Compliance Certificate is furnished pursuant to SECTION 4 of the
Loan Agreement dated as of October 23, 1998 (the "Loan Agreement"), by and among
the Company and SmithKline Beecham Corporation ("Lender"). Unless otherwise
defined herein, the terms used in this Certificate have the meanings given them
in the Loan Agreement.

        Concurrently with delivery of this Compliance Certificate, the Company
has requested an advance under the Loan Agreement. The activities of the Company
during the period covered by the Financial Statements for the most recently
completed calendar quarter (i.e., March 31, June 30, September 30, or December
31) have been reviewed by the chief financial officer or by employees or agents
under his/her immediate supervision. Based on such review, to the best knowledge
and belief of the chief financial officer, as of the date of this Compliance
Certificate the Borrower satisfies each of the conditions precedent to the
requested advance as set forth in SECTIONS 4(a) through 4(e) of the Loan
Agreement.

        WITNESS my hand this _____ day of _______________, ____.


                                            COULTER PHARMACEUTICAL, INC.




                                            By:
                                               ---------------------------------

                                            Printed Name:
                                                         -----------------------

                                            Title:  Chief Financial Officer





                                       1.

<PAGE>   25

                                   EXHIBIT D

                       FORM OF GUARANTY TO BE EXECUTED BY
                        BORROWER'S DOMESTIC SUBSIDIARIES

                         XYZ COMPANY, INC. ("GUARANTOR")

                    SMITHKLINE BEECHAM CORPORATION ("LENDER")



        1. From and after the date hereof, Guarantor hereby unconditionally
guarantees the due and punctual payment of the principal and interest and all
other amounts due under the Loan Agreement between Coulter Pharmaceutical, Inc.
("Borrower") and Lender dated October 23, 1998 (the "Loan Agreement"), as and
when the same shall become due and payable, whether by acceleration or
otherwise, and the timely performance of all other obligations of Borrower under
the Loan Agreement (each a "Guarantee Obligation"); provided however, that
Guarantor shall not be liable to pay or perform any Guarantee Obligation until 5
business days following receipt by Guarantor of written notice from Lender that
payment or performance of such Guarantee Obligation is due.

        2. Guarantor's obligations hereunder are absolute and unconditional,
irrespective of the validity, regularity or enforceability of the Loan Agreement
or any other documents or agreements between Borrower and Lender, any change
therein or amendment thereto, the absence of any action to enforce the same, any
waiver or consent by Lender with respect to any provision thereof, the recovery
of any judgment against Borrower or any action to enforce the same, or any other
circumstances which may otherwise constitute a legal or equitable discharge or
defense of a guarantor; it being the intent and purpose hereof that the
obligation and liability of Guarantor hereunder shall not be impaired,
diminished, abated or otherwise affected by any setoff, defense or counterclaim
that [Borrower] or Guarantor may have or claim to have, at any time or from time
to time, against Lender or any other person or by the commencement by or against
[Borrower] or Guarantor of any proceedings under any bankruptcy or insolvency
law or laws, that Guarantor shall not be entitled to, and does hereby waive, any
and all defenses available to guarantors, sureties and other secondary parties
at law or in equity, and that Guarantor shall pay to Lender, as a payment
obligation directly due from Guarantor to Lender, amounts equal to all amounts
which Lender shall fail to properly pay when due under the Loan Agreement. Upon
payment by Guarantor of any sums to Lender hereunder, all rights of Guarantor
against Lender for reimbursement, whether arising by way of any statutory,
contractual or other right of subrogation, exoneration, contribution,
indemnification or otherwise, shall in all respects be subordinate and junior in
right of payment to the prior indefeasible payment and performance in full of
all the Guarantee Obligations. Guarantor waives all presentments, demands for
performance, notices of nonperformance, protests, notices of protest, notices of
dishonor, notices of acceptance of this Guaranty and of the Guarantee
Obligations; provided however, that nothing contained in this paragraph 2 shall
constitute a waiver by Guarantor of the notice requirement contained in
paragraph 1. This Guaranty will not terminate or be discharged except upon the
full and indefeasible payment and performance of the Guarantee Obligations and
the obligations of Guarantor hereunder.






                                       1.
<PAGE>   26

        3. Guarantor waives any right to require Lender to: (a) proceed against
Lender or any other guarantor of the Guarantee Obligations; (b) proceed against
or exhaust any security held from Borrower; (c) pursue any other remedy in
Lender's power whatsoever; (d) comply with any appraisement, valuation, stay,
extension, moratorium, redemption or similar law or similar rights for
marshaling; or (e) notify Guarantor as to the financial condition of Borrower or
any other guarantor of the Guarantee Obligation or of any circumstance that may
bear upon the risk of nonpayment or nonperformance of the Borrower's
obligations.

        4. Guarantor agrees that, in the event any payment or transfer made by
or on behalf of Borrower in respect of any of the Guarantee Obligations, or any
portion thereof, shall at any time be avoided or be returned by Lender pursuant
to any order (whether or not final) by a court of competent jurisdiction, or any
provision of the United States Bankruptcy Code, as now existing or hereafter
amended, or other applicable law, then the Guarantee Obligations shall not be
deemed to have been satisfied to the extent of the avoided or returned payment
or transfer, and the obligations of Guarantor hereunder shall continue in full
force and effect or be revived and reinstated, as the case may be, all as though
such payment or transfer had not been made.

        5. Guarantor represents and warrants that: (a) this Guaranty has been
duly executed and delivered by it and constitutes the legal, valid and binding
obligation of Guarantor, enforceable in accordance with its terms and (b)
Guarantor has, independently and without reliance on Lender and based on such
documents and information as it had deemed appropriate, made its own credit
analysis and decision to enter into this Guaranty, and Guarantor has established
adequate means of obtaining from Lessee on a continuing basis information
pertaining to, and is now and on a continuing basis will be completely familiar
with, the financial condition, operations, properties and prospects of Borrower.

        6. Guarantor shall be liable for all reasonable attorneys' fees and
other costs and expenses incurred by reason of any default or the exercise of
Lender's remedies thereunder.

        7. The obligations of Guarantor thereunder are independent of the
obligations of Borrower. A separate action or actions may be brought and
prosecuted against Guarantor, whether an action is brought against Borrower or
any other guarantor of the Guarantee Obligations or whether Borrower or any such
other guarantor be joined in any such action or actions.

        8. Notices, demands and other communications hereunder shall (a) be in
writing, (b) be delivered personally or sent by mail, overnight courier or
facsimile to the intended recipient at (i) if to Lender, SMITHKLINE BEECHAM
CORPORATION, ONE FRANKLIN PLAZA (FP1935), PHILADELPHIA, PA 19102, Attention:
________________ (Fax No.: (215) 751-4253) and (ii) if to Guarantor, at the
address set forth beneath its name below, or in each case to such other address
noticed as herein provided by the recipient to the other party, and (c) be
effective on receipt if delivered personally or by facsimile, three days after
dispatch if mailed and one business day after dispatch if sent by courier.

        9. Neither party may assign or transfer this Guaranty or any rights or
obligations hereunder without the prior written consent of the other which shall
not be unreasonably



                                       2.


<PAGE>   27

withheld, except a party may make such an assignment without the other party's
consent to an Affiliate (as defined in the Loan Agreement) or to a successor to
substantially all of the pharmaceutical business of such party, whether in a
merger, sale of stock, sale of assets or other transaction. Any permitted
successor or assignee of rights and/or obligations hereunder shall, in a writing
to the other party, expressly assume performance of such rights and/or
obligations. Any permitted assignment shall be binding on the successors of the
assigning party. Any assignment or attempted assignment by either party in
violation of the terms of this Section 9 shall be null and void and of no legal
effect. This Guaranty may not be amended or modified, nor may any of its terms
be waived, except by written instruments signed by Lender and Guarantor. Each
waiver or consent shall be effective only in the specific instances for the
purpose for which given. If at any time any provision of this Guaranty is or
becomes illegal, invalid or unenforceable in any respect under the law of any
jurisdiction, neither the illegality, validity or enforceability of the
remaining provisions of this Guaranty nor the legality, validity or
enforceability of such provision under the law of any other jurisdiction shall
in any way be affected or impaired thereby. This Guaranty shall be governed by,
and construed in accordance with, the laws of the Commonwealth of Delaware
(without giving effect to principles of conflicts of laws). GUARANTOR AND
LENDER, TO THE FULLEST EXTENT PERMITTED BY APPLICABLE LAW, HEREBY IRREVOCABLY
WAIVE THE RIGHT TO TRIAL BY JURY AS TO ANY ISSUE RELATING HERETO IN ANY ACTION,
PROCEEDING OR COUNTERCLAIM ARISING OUT OF OR RELATING TO THIS GUARANTY.





                                       3.
<PAGE>   28


        In Witness Whereof, the undersigned has duly executed this Guaranty as
of __________________.


                                            GUARANTOR:

                                            [--------------------]




                                            By:
                                               --------------------------------
                                            Title:
                                                  -----------------------------
                                            Address:
                                                    ---------------------------
                                            -----------------------------------
                                            -----------------------------------
                                            -----------------------------------
                                            Attention:
                                                      -------------------------
                                            Fax: 
                                                -------------------------------






                                       4.