Affymax Inc (AFFY) SEC Filing 10-K Annual report for the fiscal year ending Monday, December 31, 2012

Exhibit 99.1

Corporate Contact:

Herb Cross

Chief Financial Officer

Affymax, Inc.

650-812-8847

AFFYMAX REPORTS FOURTH QUARTER AND YEAR-END 2012 FINANCIAL RESULTS

PALO ALTO, Calif., April 2, 2013 —

On February 23, 2013, Affymax and its partner, Takeda Pharmaceutical Company Limited (Takeda) announced a nationwide voluntary recall of OMONTYS as a result of postmarketing reports regarding safety concerns, including anaphylaxis, which can be life-threatening or fatal.  We and Takeda are actively investigating the cause of these reactions but there can be no assurance that a solution will be found. As of the result of the recall, we re-evaluated a number of estimates made as of period-end and recorded financial statement adjustments to reflect changes in those estimates as to the recoverability of inventory and deposits made to our contract manufacturing organizations, or CMOs, potential losses on firm purchase commitments and changes in the short-term and long-term classification of certain liabilities.  In the aggregate, we recorded $45.0 million in impairment due to inventory and firm purchase commitments in the quarter ended December 31, 2012, with no comparable charge in the prior year.

Earlier this month, the Company began reorganizing its operations in order to significantly reduce operating costs and negotiating with Takeda to collaboratively focus on the OMONTYS safety and other related FDA issues associated with the recall of the product. In addition to the significant reduction in force of approximately 230 employees (75% of the Company’s workforce), including the commercial and medical affairs field forces as well as other officers and employees throughout the organization, the Company is continuing to transition many of the ongoing activities to Takeda and negotiating with Takeda on costs allocated between the parties under the collaboration arrangement. In connection with this restructuring, the Board