EXHIBIT 4.1


                         COMMON STOCK PURCHASE AGREEMENT

         THIS COMMON STOCK PURCHASE AGREEMENT ("Agreement") is made and entered
into as of October 3, 2008 (the "Effective Date"), by and between GERON
CORPORATION, a Delaware corporation having its principal place of business at
230 Constitution Drive, Menlo Park, California 94025 ("Geron"), and Lonza
Walkersville, Inc., a Delaware corporation having its principal place of
business at 8830 Biggs Ford Road, Walkersville, Maryland 21793 ("Lonza").
Capitalized terms not otherwise defined herein shall have the meaning set forth
in the MSA and Project Order No. 1.

     A.   Geron and Cambrex Bio Science Walkersville, Inc. ("CBSW") entered that
          certain Master Services Agreement,  dated as of September 1, 2005 (the
          "MSA"),  pursuant to which CBSW agreed to perform certain  services on
          behalf of Geron  related to the  manufacture  of a product  containing
          human cells  intended for  therapeutic  use in humans on the terms set
          forth therein.

     B.   Geron  and  CBSW  entered  into  Project  Order  No. 1 to the MSA (the
          "Project Order No. 1") effective  September 1, 2005, pursuant to which
          Geron  is  entitled,   subject  to  certain  conditions,  to  pay  any
          compensation  owed to CBSW for Services  performed under Project Order
          No. 1 either in cash or in Geron's common stock (the "Common Stock").

     C.   Subject to the terms and conditions of the Second Amendment to Project
          Order No.1,  dated as of March 1, 2006  ("Amendment No. 2"), Geron and
          CBSW  agreed  that Geron  shall,  subject to  certain  conditions,  be
          entitled to pay up to  US$4,500,000  for Services  under Project Order
          No. 1 by delivery of Shares.

     D.   Effective  February 6, 2007,  Lonza completed its acquisition of CBSW,
          and  assumed  all  rights  and  obligations  of CBSW under the MSA and
          Project Order No. 1, as amended.

     E.   Subject to the terms and conditions of the Sixth  Amendment to Project
          Order No.1,  dated as of November 9, 2007, Geron and Lonza have agreed
          that Geron shall, subject to certain conditions, be entitled to pay an
          additional  US$4,000,000  for Services  under  Project  Order No. 1 by
          delivery  of  Shares,  for an  aggregate  total of up to  US$8,500,000
          payable in Stock.

THE PARTIES AGREE AS FOLLOWS:

   1. ISSUANCE OF SHARES; ADJUSTMENTS.

         1.1      As payment of the seventh Installment Payment specified in
                  Project Order No. 1, Geron will issue and deliver certificates
                  for 255,754 shares of Common Stock (the "Shares"). Upon
                  issuance and delivery of the certificate(s) for the Shares,
                  all Shares shall be duly authorized and validly issued and
                  represent fully paid shares of Geron's Common Stock.

   2. CLOSING; DELIVERY.

         2.1      The consummation of the transaction contemplated by this
                  Agreement (a "Closing") shall be held at such time and place
                  as is mutually agreed upon between the parties, but in any
                  event no later than five (5) business days after the Effective
                  Date of this Agreement (the "Closing Date"). At the Closing,
                  Geron shall deliver to Lonza one or more certificates
                  representing all of the Shares, which Shares shall be issued
                  in the name of Lonza or its designee and in such denominations
                  as Lonza shall specify.

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         2.2      Geron's obligations to issue and deliver the stock
                  certificate(s) representing the Shares to Lonza at the Closing
                  shall be subject to the following conditions, which may be
                  waived by Geron:

                  2.2.1    the covenants and obligations that Lonza is required
                           to perform or to comply with pursuant to this
                           Agreement, at or prior to the Closing, must have been
                           duly performed and complied with in all material
                           respects; and

                  2.2.2    the representations and warranties made by Lonza
                           herein shall be true and correct in all material
                           respects as of the Closing Date.

         2.3      Lonza's obligation to accept delivery of the stock
                  certificate(s) representing the Shares at the Closing shall be
                  subject to the following conditions, any one or more of which
                  may be waived by Lonza:

                  2.3.1    the covenants and obligations that Geron is required
                           to perform or to comply with pursuant to this
                           Agreement, at or prior to the Closing, must have been
                           duly performed and complied with in all material
                           respects;

                  2.3.2    Geron shall have available under its Certificate of
                           Incorporation sufficient authorized shares of Common
                           Stock to issue the Shares to Lonza; and

                  2.3.3    the representations and warranties made by Geron
                           herein shall be true and correct in all material
                           respects as of the Closing Date.

   3. RESTRICTIONS ON RESALE OF SHARES.

         3.1      Legends. Lonza understands and acknowledges that the Shares
                  are not registered under the Securities Act of 1933 (the
                  "Act"), and that under the Act and other applicable laws Lonza
                  may be required to hold such Shares for an indefinite period
                  of time. Each stock certificate representing Shares shall bear
                  the following legends:

                  "THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED
                  UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE "ACT"). ANY
                  TRANSFER OF SUCH SECURITIES SHALL BE INVALID UNLESS A
                  REGISTRATION STATEMENT UNDER THE ACT IS IN EFFECT AS TO SUCH
                  TRANSFER OR, IN THE OPINION OF COUNSEL REASONABLY ACCEPTABLE
                  TO GERON, SUCH REGISTRATION IS UNNECESSARY FOR SUCH TRANSFER
                  TO COMPLY WITH THE ACT. THE SECURITIES REPRESENTED HEREBY ARE
                  SUBJECT TO THE TERMS OF THE COMMON STOCK PURCHASE AGREEMENT BY
                  AND BETWEEN GERON AND LONZA, DATED OCTOBER 3, 2008. A COPY OF
                  THE AGREEMENT CAN BE OBTAINED FROM THE SECRETARY OF GERON."

         3.2      Limits on Sales. Lonza agrees that if it decides to resell
                  some or all of the Shares, it will do so only in an
                  appropriate manner through orderly sales executed through a
                  top-tier brokerage firm, and based upon whether the shares are
                  registered or unregistered, i.e., on the Nasdaq Global Market
                  or in a Rule 144A compliant transaction.

         3.3      Further Limitations. Geron shall not be required (i) to
                  transfer on its books any Shares that have been sold or
                  otherwise transferred in violation of any of the provisions of
                  this Agreement or applicable securities laws; or (ii) to treat
                  as owner of such Shares or to accord the right to vote or pay
                  dividends to any purchaser or other transferee to whom such
                  Shares shall have been so transferred in violation of any of
                  the provisions of this Agreement or applicable securities
                  laws.

   4. REGISTRATION RIGHTS

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<PAGE>

         4.1      Geron agrees to make commercially reasonable efforts to file
                  with the Securities and Exchange Commission (the "Commission")
                  within ten (10) business days after the Closing Date, a
                  registration statement under the Act (the "Registration
                  Statement"), on Form S-3 or other appropriate form, so as to
                  permit a non-underwritten public offering and resale of the
                  Shares under the Act by Lonza. Geron agrees to diligently
                  pursue making the Registration Statement effective. Geron will
                  make commercially reasonable efforts to notify Lonza of the
                  effectiveness of the Registration Statement within one (1)
                  business day of receiving notice from the Commission declaring
                  the Registration Statement effective, but no later than the
                  close of business (Pacific Time) of the second business day
                  after receipt of such notice from the Commission.

         4.2      Geron shall notify Lonza as promptly as possible of any review
                  initiated by the Commission with respect to any such
                  Registration Statement.

         4.3      Geron will maintain the Registration Statement and any
                  post-effective amendment thereto filed under this Section 4
                  effective under the Act until the earliest of (i) the date
                  that none of the Shares covered by such Registration Statement
                  are issued and outstanding, (ii) the date that all of the
                  Shares have been sold pursuant to such Registration Statement,
                  (iii) the date Lonza receives an opinion of counsel to Geron,
                  which counsel shall be reasonably acceptable to Lonza, that
                  the Shares may be sold under the provisions of Rule 144 or any
                  similar provision then in effect under the Act, or (iv) the
                  date that all Shares have been otherwise transferred to
                  persons who may trade such shares without restriction under
                  the Act, and Geron has delivered a new certificate or other
                  evidence of ownership for such securities not bearing a
                  restrictive legend.

         4.4      Geron, at its expense, shall furnish to Lonza with respect to
                  the Shares registered under the Registration Statement such
                  reasonable number of copies of the Registration Statement,
                  prospectuses and preliminary prospectuses in conformity with
                  the requirements of the Act and such other documents as Lonza
                  may reasonably request, in order to facilitate the public sale
                  or other disposition of all or any of the Shares by Lonza,
                  provided, however, that the obligation of Geron to deliver
                  copies of prospectuses or preliminary prospectuses to Lonza
                  shall be subject to the receipt by Geron of reasonable
                  assurances from Lonza that Lonza will comply with the
                  applicable provisions of the Act and of such other securities
                  or blue sky laws as may be applicable in connection with any
                  use of such prospectuses or preliminary prospectuses.

         4.5     All fees, disbursements and out-of-pocket expenses and costs
                 incurred by Geron in connection with the preparation and filing
                 of the Registration Statement under Section 4.1 and in
                 complying with applicable securities and Blue Sky laws
                 (including, without limitation, all attorneys' fees of Geron)
                 shall be borne by Geron. Lonza shall bear the cost of all fees
                 and expenses of Lonza's counsel.

         4.6     Geron will advise Lonza promptly after it shall receive notice
                 or obtain knowledge of the issuance of any stop order by the
                 Commission delaying or suspending the effectiveness of the
                 Registration Statement or of the initiation of any proceeding
                 for that purpose, and Geron will use its commercially
                 reasonable efforts to prevent the issuance of any stop order or
                 to obtain its withdrawal as promptly as possible if such stop
                 order should be issued.

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<PAGE>

         4.7     With a view to making available to Lonza the benefits of Rule
                 144 (or its successor rule) and any other rule or regulation of
                 the Commission that may at the time permit Lonza to sell the
                 Shares to the public without registration, Geron covenants and
                 agrees to: (i) make and keep public information available, as
                 those terms are understood and defined in Rule 144, until the
                 earliest of (A) such date as all of the Shares may be resold
                 pursuant to Rule 144 or any other rule of similar effect or (B)
                 such date as all of the Shares shall have been resold; and (ii)
                 file with the Commission in a timely manner all reports and
                 other documents required of Geron under the Act and under the
                 Exchange Act of 1934, as amended.

         4.8      Lonza will cooperate with Geron in all respects in connection
                  with this Agreement, including timely supplying all
                  information reasonably requested by Geron (which shall include
                  all information regarding Lonza and proposed manner of sale of
                  the Shares required to be disclosed in any Registration
                  Statement) and executing and returning all documents
                  reasonably requested in connection with the registration and
                  sale of the Shares and entering into and performing their
                  obligations under any underwriting agreement, if the offering
                  is an underwritten offering, in usual and customary form, with
                  the managing underwriter or underwriters of such underwritten
                  offering. Nothing in this Agreement shall obligate Lonza to
                  consent to be named as an underwriter in any Registration
                  Statement.

   5. INDEMNIFICATION.

         5.1      Geron agrees to indemnify and hold harmless Lonza (and each
                  person, if any, who controls Lonza within the meaning of
                  Section 15 of the Act, and each officer and director of Lonza)
                  against any and all losses, claims, damages or liabilities (or
                  actions or proceedings in respect thereof), joint or several,
                  directly or indirectly based upon or arising out of (i) any
                  untrue statement or alleged untrue statement of any material
                  fact contained in the Registration Statement, any preliminary
                  prospectus, final prospectus or summary prospectus contained
                  therein or used in connection with the offering of the Shares,
                  or any amendment or supplement thereto, or (ii) any omission
                  or alleged omission to state a material fact required to be
                  stated therein or necessary to make the statements therein not
                  misleading; and Geron will reimburse each such indemnified
                  party for any legal or any other expenses reasonably incurred
                  by them in connection with investigating, preparing, pursuing
                  or defending any such loss, claim, damage, liability, action
                  or proceeding, except insofar as any such loss, claim, damage,
                  liability, action, proceeding or expense arises out of or is
                  based upon (A) an untrue statement or alleged untrue statement
                  or omission or alleged omission made in the Registration
                  Statement, any such preliminary prospectus, final prospectus,
                  summary prospectus, amendment or supplement in reliance upon
                  and in conformity with written information furnished to Geron
                  by or on behalf of Lonza expressly for use in the preparation
                  thereof, (B) the failure of Lonza to comply with its covenants
                  and agreements contained in Sections 7.1 or 7.5.2 hereof or
                  (C) any misstatement or omission in any prospectus that is
                  corrected in any subsequent prospectus that was delivered to
                  Lonza prior to the pertinent sale or sales by Lonza. Such
                  indemnity shall remain in full force and effect, regardless of
                  any investigation made by such indemnified party and shall
                  survive the transfer of the Shares by Lonza.

         5.2      Lonza agrees to indemnify and hold harmless Geron (and each
                  person, if any, who controls Geron within the meaning of
                  Section 15 of the Act, and each officer and director of Geron)
                  from and against losses, claims, damages or liabilities (or
                  actions or proceedings in respect thereof), joint or several,
                  directly or indirectly based upon or arising out of, (i) any
                  failure of Lonza to comply with the covenants and agreements
                  contained in Sections 7.1 and 7.5.2 hereof or (ii) any untrue
                  statement of a material fact contained in the Registration
                  Statement or any omission of a material fact required to be
                  stated in the Registration Statement or necessary in order to
                  make the statements in the Registration Statement not
                  misleading if such untrue statement or omission was made in
                  reliance upon and in conformity with written information
                  furnished to Geron by or on behalf of Lonza specifically for
                  use in preparation of the Registration Statement; provided,
                  however, that Lonza shall not be liable in any such case for
                  (A) any untrue statement or omission in the Registration
                  Statement, prospectus, or other such document which statement
                  is corrected by Lonza and delivered to Geron prior to the sale
                  from which such loss occurred, (B) any untrue statement or
                  omission in any prospectus which is corrected by Lonza in any
                  subsequent prospectus, or supplement or amendment thereto, and
                  delivered to Geron prior to the sale or sales from which a
                  loss or liability arose, or (C) any failure by Geron to
                  fulfill any of its obligations under Section 5.1 hereof.

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<PAGE>

         5.3      Promptly after receipt by any indemnified person of a notice
                  of a claim or the beginning of any action in respect of which
                  indemnity is to be sought against an indemnifying person
                  pursuant to this Section 5, such indemnified person shall
                  notify the indemnifying person in writing of such claim or of
                  the commencement of such action, but the omission to so notify
                  the indemnifying party will not relieve it from any liability
                  which it may have to any indemnified party under this Section
                  5 (except to the extent that such omission materially and
                  adversely affects the indemnifying party's ability to defend
                  such action) or from any liability otherwise than under this
                  Section 5. Subject to the provisions hereinafter stated, in
                  case any such action shall be brought against an indemnified
                  person, the indemnifying person shall be entitled to
                  participate therein, and, to the extent that it shall elect by
                  written notice delivered to the indemnified party promptly
                  after receiving the aforesaid notice from such indemnified
                  party, shall be entitled to assume the defense thereof, with
                  counsel reasonably satisfactory to such indemnified person.
                  After notice from the indemnifying person to such indemnified
                  person of its election to assume the defense thereof, such
                  indemnifying person shall not be liable to such indemnified
                  person for any legal expense subsequently incurred by such
                  indemnified person in connection with the defense thereof,
                  provided, however, that if there exists or shall exist a
                  conflict of interest that would make inappropriate, in the
                  reasonable opinion of counsel to the indemnified person, for
                  the same counsel to represent both the indemnified person and
                  such indemnifying person or any affiliate or associate
                  thereof, the indemnified person shall be entitled to retain
                  its own counsel at the expense of such indemnifying person;
                  provided, however, that no indemnifying person shall be
                  responsible for the fees and expenses of more than one
                  separate counsel (together with appropriate local counsel) for
                  all indemnified parties. In no event shall any indemnifying
                  person be liable in respect to any amounts paid in settlement
                  of any action unless the indemnifying person shall have
                  approved the terms of such settlement. No indemnifying person
                  shall, without the prior written consent of the indemnified
                  person, effect any settlement of any pending or threatened
                  proceeding in respect of which any indemnified person is a
                  party, unless such settlement includes an unconditional
                  release of such indemnified person from all liability on
                  claims that are the subject matter of such proceeding.

         5.4      The provisions of this Section 5 shall survive the termination
                  of this Agreement.

   6. REPRESENTATIONS AND ACKNOWLEDGEMENT OF GERON.

         Geron hereby represents, warrants and covenants to Lonza as follow:

         6.1      Organization, Good Standing and Qualification. Geron 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 as now conducted and as presently proposed to be
                  conducted. Geron is duly qualified to transact business and is
                  in good standing as a foreign corporation in each jurisdiction
                  in which the failure to so qualify would have a material
                  adverse effect on its business or properties.

         6.2      Authorization. Geron has full right, power, authority and
                  capacity to enter into this Agreement and to consummate the
                  transactions contemplated hereby and thereby and has taken all
                  necessary action to authorize the execution, delivery and
                  performance of this Agreement. Upon execution and delivery,
                  this Agreement will constitute a valid and binding obligation
                  of Geron enforceable against Geron in accordance with its
                  terms, except as such enforceability may be limited by
                  applicable bankruptcy, insolvency, reorganization, moratorium,
                  fraudulent transfer, liquidation or similar laws relating to,
                  or affecting generally, the enforcement of creditor's rights
                  and remedies or by other equitable principles of general
                  application from time to time in effect.

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<PAGE>

         6.3      Valid Issuance of Common Stock. The Shares, when issued, sold
                  and delivered in accordance with the terms hereof for the
                  consideration expressed herein, will be duly and validly
                  authorized and issued, fully paid and nonassessable and free
                  of restrictions on transfer other than restrictions on
                  transfer under this Agreement and applicable state and federal
                  securities laws.

         6.4      Legal Proceedings and Orders. There is no action, suit,
                  proceeding or investigation pending or threatened against
                  Geron that questions the validity of this Agreement or the
                  right of Geron to enter into this Agreement or to consummate
                  the transactions contemplated hereby, nor is Geron aware of
                  any basis for any of the foregoing. Geron is neither a party
                  nor subject to the provisions of any order, writ, injunction,
                  judgment or decree of any court or government agency or
                  instrumentality that would affect the ability of Geron to
                  enter into this Agreement or to consummate the transactions
                  contemplated hereby.

    7. REPRESENTATIONS AND ACKNOWLEDGMENTS OF LONZA.

         Lonza hereby represents, warrants, acknowledges and agrees that:

         7.1      Investment. Lonza is acquiring the Shares for Lonza's own
                  account, and not directly or indirectly for the account of any
                  other person. Lonza is acquiring the Shares for investment and
                  not with a view to distribution or resale thereof, except in
                  compliance with the Act and any applicable state law
                  regulating securities.

         7.2      Access to Information. Lonza has consulted with its own
                  attorney, accountant, or investment advisor as Lonza has
                  deemed advisable with respect to the investment and has
                  determined its suitability for Lonza. Lonza has had the
                  opportunity to ask questions of, and to receive answers from,
                  appropriate executive officers of Geron with respect to the
                  terms and conditions of the transactions contemplated hereby
                  and with respect to the business, affairs, financial condition
                  and results of operations of Geron. In connection with the
                  transactions contemplated hereunder, Geron may disclose to
                  Lonza information which may constitute material, non-public
                  information regarding Geron, and Lonza agrees to maintain in
                  confidence any such information; provided, however, such
                  information shall not include information (a) that is or
                  becomes part of the public domain, (b) that was in Lonza's
                  possession without any obligation of confidentiality prior to
                  the date Geron disclosed such information to Lonza, or (c)
                  that is supplied to Lonza by a third party which is not
                  subject to any restriction of confidentiality or
                  non-disclosure. Lonza has had access to such financial and
                  other information as is necessary in order for Lonza to make a
                  fully informed decision as to investment in Geron, and has had
                  the opportunity to obtain any additional information necessary
                  to verify any of such information to which Lonza has had
                  access. Lonza acknowledges that neither Geron nor any of its
                  officers, directors, employees, agents, representatives, or
                  advisors have made any representation or warranty other than
                  those specifically expressed herein.

         7.3      Business and Financial Expertise. Lonza further represents and
                  warrants that it has such business or financial expertise as
                  to be able to evaluate its investment in Geron and purchase of
                  the Shares.

         7.4      Speculative Investment. Lonza acknowledges that the investment
                  in Geron represented by the Shares is highly speculative in
                  nature and is subject to a high degree of risk of loss in
                  whole or in part; the amount of such investment is within
                  Lonza's risk capital means and is not so great in relation to
                  Lonza's total financial resources as would jeopardize the
                  personal financial needs of Lonza in the event such investment
                  were lost in whole or in part.

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<PAGE>

         7.5      Unregistered Securities.  Lonza acknowledges that:

                  7.5.1    Lonza must bear the economic risk of investment for
                           an indefinite  period of time because the Shares
                           have  not been  registered  under  the Act and
                           therefore  cannot  and will not be sold unless they
                           are subsequently  registered  under the Act or an
                           exemption from such  registration is available. Geron
                           has made no agreements,  covenants or undertakings
                           whatsoever to register any of the Shares  under the
                           Act,  except as  provided  in  Section 4 above. Geron
                           has made no representations,  warranties or covenants
                           whatsoever as to whether any exemption from the Act,
                           including,  without  limitation,  any  exemption  for
                           limited  sales  in  routine  brokers' transactions
                           pursuant to Rule 144 under the Act,  will become
                           available.  Any such  exemption pursuant to Rule 144,
                           if available at all, will not be available  unless:
                           (i) a public trading market  then exists in Geron's
                           Common  Stock,  (ii) Geron has  complied  with the
                           information requirements  of Rule  144, and (iii) all
                           other  terms and  conditions  of Rule 144 have been
                           satisfied.

                  7.5.2    Transfer of the Shares has not been registered or
                           qualified under any applicable state law regulating
                           securities and, therefore, the Shares cannot and will
                           not be sold unless they are subsequently registered
                           or qualified under any such act or an exemption
                           therefrom is available. Geron has made no agreements,
                           covenants or undertakings whatsoever to register or
                           qualify any of the Shares under any such act. Geron
                           has made no representations, warranties or covenants
                           whatsoever as to whether any exemption from any such
                           act will become available.

                  7.5.3    Lonza hereby certifies that it is an "Accredited
                           Investor" as that term is defined in Rule 501 under
                           the Act.

         7.6      Authorization. Lonza has full right, power, authority and
                  capacity to enter into this Agreement and to consummate the
                  transactions contemplated hereby and thereby and has taken all
                  necessary action to authorize the execution, delivery and
                  performance of this Agreement. Upon execution and delivery,
                  this Agreement will constitute a valid and binding obligation
                  of Lonza enforceable against Lonza in accordance with its
                  terms, except as such enforceability may be limited by
                  applicable bankruptcy, insolvency, reorganization, moratorium,
                  fraudulent transfer, liquidation or similar laws relating to,
                  or affecting generally, the enforcement of creditor's rights
                  and remedies or by other equitable principles of general
                  application from time to time in effect.

    8.   TAX ADVICE. Lonza acknowledges that Lonza has not relied and will not
         rely upon Geron or Geron's counsel with respect to any tax consequences
         related to the ownership, purchase, or disposition of the Shares. Lonza
         assumes full responsibility for all such consequences and for the
         preparation and filing of all tax returns and elections which may or
         must be filed in connection with the Shares.

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<PAGE>

    9.   NOTICES. Any notice or other communication required or permitted
         hereunder shall be in writing and shall be deemed to have been duly
         given on the date of delivery if delivered personally or by facsimile,
         or one day, not including Saturdays, Sundays, or national holidays,
         after sending if sent by national overnight delivery service, or five
         days, not including Saturdays, Sundays, or national holidays, after
         mailing if mailed by first class United States mail, certified or
         registered with return receipt requested, postage prepaid, and
         addressed as follows:

                  To Geron at:              Geron Corporation
                                            230 Constitution Drive
                                            Menlo Park, California  94025
                                            Attention: Chief Financial Officer
                                            Telephone:        (650) 473-7700
                                            Facsimile:        (650) 473-7750



                  With a copy to:           Geron Corporation
                                            230 Constitution Drive
                                            Menlo Park, California  94025
                                            Attention: Senior Director, Legal
                                            Telephone:        (650) 473-7775
                                            Facsimile:        (650) 566-7181



                  To Lonza at:              Lonza Walkersville, Inc.
                                            8830 Biggs Ford Road
                                            Walkersville, Maryland 21793
                                            Attention:  Tim Harrigan
                                            Telephone:        (301) 898-7025
                                            Facsimile:        (301) 845-6099

                  With a copy to:           Lonza America Inc.
                                            25 Commerce Drive
                                            Allendale, New Jersey 07401
                                            Attention: Assistant General Counsel
                                            Telephone:        (201) 316-9422
                                            Facsimile:        (201) 378-5630

    10.  BINDING EFFECT. This Agreement shall be binding upon the heirs, legal
         representatives and successors of Geron and of Lonza.

    11.  GOVERNING LAW. This Agreement shall be governed by and construed in
         accordance with the laws of the State of Delaware, without giving
         effect to its conflicts of laws provisions.

    12.  INVALID PROVISIONS. In the event that any provision of this Agreement
         is found to be invalid or otherwise unenforceable by a court or other
         tribunal of competent jurisdiction, such invalidity or unenforceability
         shall not be construed as rendering any other provision contained
         herein invalid or unenforceable, and all such other provisions shall be
         given full force and effect to the same extent as though the invalid
         and unenforceable provision was not contained herein.

    13.  COUNTERPARTS. This Agreement may be executed in any number of identical
         counterparts, each of which shall be deemed an original, but all of
         which together shall constitute one and the same instrument.

    14.  AMENDMENTS. This Agreement or any provision hereof may be changed,
         waived, or terminated only by a statement in writing signed by the
         party against whom such change, waiver or termination is sought to be
         enforced.

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    15.  FUTURE COOPERATION. Each of the parties hereto agrees to cooperate at
         all times from and after the date hereof with respect to all of the
         matters described herein, and to execute such further assignments,
         releases, assumptions, amendments of the Agreement, notifications and
         other documents as may be reasonably requested for the purpose of
         giving effect to, or evidencing or giving notice of, the transactions
         contemplated by this Agreement.

    16.  ENTIRE AGREEMENT. This Agreement, and the MSA, and Project Order No. 1
         thereto as amended, constitute the entire agreement of the parties
         pertaining to the Shares and supersede all prior and contemporaneous
         agreements, representations, and understandings of the parties with
         respect thereto.



                      REST OF PAGE INTENTIONALLY LEFT BLANK

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<PAGE>

         IN WITNESS WHEREOF, the parties hereto have executed this Agreement as
of the Effective Date.

                                     Geron Corporation



                                        /s/ David L. Greenwood
                                     -------------------------------------------
                                     By:      David L. Greenwood
                                     Title:   Executive Vice President and Chief
                                              Financial Officer

                                     LonzaWalkersville, Inc.



                                        /s/ Shawn P. Cavanagh
                                     -------------------------------------------
                                     By:      Shawn P. Cavanagh
                                     Title:   President


                                     LonzaWalkersville, Inc.



                                        /s/ Vinny DiVito
                                     -------------------------------------------
                                     By:      Vinny DiVito
                                     Title:   Chief Financial Officer


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