Affymax(R) Announces Completion of Common Stock Offering

PALO ALTO, Calif., Dec 20, 2006 /PRNewswire-FirstCall via COMTEX News Network/ -- Affymax, Inc. (Nasdaq: AFFY), a clinical-stage pharmaceutical company, today announced the completion of its initial public offering of 3.7 million shares of its common stock and the exercise by the underwriters of their option to purchase an additional 555,000 shares solely to cover over-allotments. The aggregate net proceeds of the offering, including the shares issued upon exercise of the over-allotment option, are approximately $96 million after payment of estimated expenses and underwriting discounts and commissions.

Morgan Stanley & Co. Incorporated acted as the sole book-running manager for this offering. Cowen and Company, LLC, Thomas Weisel Partners LLC and RBC Capital Markets acted as co-managers for the offering.

Affymax's common stock is listed on the Nasdaq Global Market under the trading symbol "AFFY."
This press release does not constitute an offer to sell or the solicitation of an offer to buy nor shall there be any sale of these securities in any State in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such State. Any offer or sale will be made only by means of the written prospectus forming a part of the effective registration statement.

A copy of the prospectus relating to this offering may be obtained by contacting Morgan Stanley & Co. Incorporated, 180 Varick Street, New York, NY, 10014, Attention: Prospectus Department, by calling (866) 718-1649 or by emailing prospectus@morganstanley.com.

About Affymax, Inc.
Affymax, Inc. is a clinical-stage biopharmaceutical company developing novel peptide-based drugs to improve the treatment of serious and often life- threatening conditions. Affymax's lead product candidate, Hematide(™), is currently in Phase 2 clinical trials for the treatment of anemia associated with chronic kidney disease and cancer.