EXHIBIT 4.3
FORM OF LOCK-UP AGREEMENT
September 9, 2009
Geron Corporation
230 Constitution Drive
Menlo Park, California 94025
Attention: Chief Financial Officer
Ladies and Gentlemen:
Geron Corporation, a Delaware corporation, (the
“Company”), and ________ (the “Investor”)
have entered into a Common Stock and Warrant Purchase Agreement
dated as of the date hereof (the “Purchase Agreement”),
providing for the purchase of _______ shares (the
“Shares”) of the Company’s common stock, par
value $0.001 (“Company Common Stock”) and a warrant
(the “Warrant”) to purchase _______ shares of Company
Common Stock (the “Warrant Shares”) by the Investor.
The Shares, the Warrant and the Warrant Shares are collectively
referred to herein as the “Securities.”
The Investor hereby agrees that, without the
prior written consent of the Company, it will not, during the
period commencing on the date hereof and ending on September 9,
2010 (such period referred to herein as the “Lock-Up
Period”), offer, sell, contract to sell, pledge or otherwise
dispose of, directly or indirectly, any of the Securities or
securities convertible into or exchangeable or exercisable for any
shares of Securities, enter into a transaction which would have the
same effect, or enter into any swap, hedge or other arrangement
that transfers, in whole or in part, any of the economic
consequences of ownership of the Sec
