Press Releases

August 5, 2010

Affymax, Inc.
Takeda Pharmaceutical Company Limited

AFFYMAX AND TAKEDA ANNOUNCE PRELIMINARY U.S. REGISTRATION STRATEGY FOR INVESTIGATIONAL DRUG, HEMATIDE^™/PEGINESATIDE, TO TREAT ANEMIA IN CHRONIC RENAL FAILURE

PALO ALTO, Calif., and OSAKA, Japan, August 5, 2010 – Affymax, Inc. (Nasdaq:AFFY) and Takeda Pharmaceutical Company Limited (TSE, 4502), today announced that the companies have decided on a preliminary strategic path forward for the investigational drug, Hematide^™/peginesatide, for the treatment of anemia in chronic renal failure patients in the United States.

Affymax and Takeda are continuing to conduct further analysis of the PEARL and EMERALD studies which evaluated the efficacy and safety of Hematide in chronic renal failure patients with anemia. Before year end, the companies plan to discuss with the FDA the U.S. registration strategy for Hematide. Subject to feedback from the FDA, the plan is to pursue a New Drug Application (NDA) for treatment of anemia in dialysis patients, while continuing to evaluate the non-dialysis indication. The timeline for possible submission of the NDA will be aimed for first half of 2011, but will be finalized after the FDA meeting.

Results of Phase 3 Program

As previously announced, the primary efficacy endpoint, the mean change in hemoglobin (Hb) from baseline, in each of the four Phase 3 studies (EMERALD 1, EMERALD 2, PEARL 1 and PEARL 2) met the statistical criteria for non-inferiority, when Hematide was compared to epoetin and darbepoetin, in correcting and/or maintaining Hb in the target range. Hematide also met the statistical criterion for non-inferiority in the combined four studies for the adjudicated cardiovascular composite safety endpoint (CSE), which was composed of death, stroke, myocardial infarction, congestive heart failure, unstable angina, and arrhythmia (hazard ratio (HR) 1.06, 90 percent confidence interval (CI) 0.91 – 1.22). The median duration of follow-up for patients on study drug in the four trials was 1.3 years.

In a subgroup analysis of CSE events in the EMERALD studies in maintenance treatment of anemia in dialysis patients, the frequency of CSE events was balanced between Hematide and the comparator (HR 0.95, 90 percent CI 0.79 – 1.13).

A difference in CSE events was noted, however, when a subgroup analysis was conducted in non-dialysis patients. In the PEARL trials, which evaluated correction and maintenance treatment of anemia in non-dialysis patients, the frequency of CSE events was higher in the Hematide group (21.6 percent) versus the comparator (17.1 percent) (HR 1.34, 90 percent CI 1.03 – 1.73).

The Hematide Phase 3 program, which involved 2,609 randomized patients, consisted of four open-label, randomized active-controlled clinical trials in the U.S. and Europe, including two studies in non-dialysis patients (PEARL 1 and 2) and two others in dialysis patients (EMERALD 1 and 2). In all studies, Hematide was dosed once every four weeks while comparator drugs were dosed more frequently according to their product labels. In these studies, epoetin was dosed one-to three-times per week and darbepoetin was dosed every two weeks. The Hb target range was 11-12 g/dL for non-dialysis patients and 10-12 g/dL for those on dialysis.

Further investigation into these data is ongoing. For a more complete discussion of the phase 3 data, please see the press release issued on June 21, 2010 by visiting http://www.investors.affymax.com/releasedetail.cfm?ReleaseID=481068.

About Hematide

Hematide is a novel investigational synthetic, PEGylated peptidic compound that binds to and activates the erythropoietin receptor and thus acts as an ESA.
Affymax and Takeda are collaborating on the development of Hematide and plan to co-commercialize the product once approved in the United States. Phase 3 clinical trials investigated the potential for Hematide to treat anemia associated with chronic renal failure. The product, upon approval, will be commercialized outside the United States (in the European Union and Japan) by Takeda.

About Affymax, Inc.

Affymax, Inc. is a biopharmaceutical company committed to developing novel drugs to improve the treatment of serious and often life-threatening conditions. For additional information, please visit www.affymax.com.

About Takeda Pharmaceutical Company Limited

Located in Osaka, Japan, Takeda is a research-based global company with its main focus on pharmaceuticals. As the largest pharmaceutical company in Japan and one of the global leaders of the industry, Takeda is committed to strive towards better health for patients worldwide through leading innovation in medicine. Additional information about Takeda is available through its corporate website, www.takeda.com.

This release contains forward-looking statements, including statements regarding timing, scope and results of an NDA filing for Hematide, the continuation and success of the companies’ collaboration, the design, timing and results of the clinical trials and drug development program and registration strategy, and the likelihood and timing of the commercialization of Hematide. The companies’ actual results may differ materially from those indicated in these forward-looking statements due to risks and uncertainties, including the FDA’s interpretation of the data from the Phase 3 studies, in particular with respect to the subgroup analyses in the non-dialysis groups, the risks relating to the continued safety and efficacy of Hematide in clinical development, the potential for once per month dosing and room temperature stability, regulatory requirements and approvals, research and development efforts, the factors affecting the commercial potential of Hematide, industry and competitive environment, intellectual property rights and disputes, financing requirements and ability to access capital, and other matters that are described in Affymax's quarterly report on Form 10-Q filed with the Securities and Exchange Commission. The scientific information discussed in this release related to Hematide is preliminary and investigative. Hematide has not been approved by the U.S. Food and Drug Administration or any other regulatory body, and no conclusion can be drawn regarding the safety or effectiveness of Hematide to treat anemia associated with chronic renal failure in dialysis or non dialysis patients. Investors are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date of this release. The companies undertake no obligation to update any forward-looking statement in this press release.

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