COMMON STOCK PURCHASE AGREEMENT

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.

1.

ISSUANCE OF SHARES; ADJUSTMENTS.

1.1.

As payment of the eighth Installment Payment specified in Project Order No. 1, Geron will issue and deliver certificates for 163,666 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.

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 JANUARY 27, 2009. 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 or Rule 144 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

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.

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 Securities Exchange Act of 1934, as amended (the “ Exchange Act ” ).

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, w