Affymax Begins a Phase 2 Trial of Hematide(TM) for Treatment of Anemia in Patients With Chronic Kidney Disease on Hemodialysis

PALO ALTO, Calif., July 11 /PRNewswire/ — Affymax, Inc. today announced that it has begun enrollment of patients in a second Phase 2 trial of its lead investigational product Hematide(TM), a synthetic, peptide-based erythropoiesis stimulating agent (ESA), which is being developed to stimulate production of red blood cells for the treatment of anemia in patients with chronic kidney disease (CKD) and cancer. This open-label, multi-center, dose-finding study is being conducted at several clinical sites in the U.S. under an FDA-approved Investigational New Drug (IND) application. The study will evaluate the safety, pharmacodynamics and pharmacokinetics of repeat intravenous injections of Hematide in the maintenance of hemoglobin (the oxygen-carrying protein in red blood cells) levels in patients on hemodialysis.

“This clinical trial will provide critical information about Hematide dosing in patients with CKD who have advanced to chronic hemodialysis and will serve to supplement dosing data from our other ongoing Phase 2 trial in Great Britain in patients with CKD who have not yet started dialysis,” said Arlene M. Morris, president and chief executive officer of Affymax. “We plan to initiate a dose-finding Phase 2 study of Hematide for treatment of anemia in cancer patients later this year.”

Results of a Phase 1 clinical trial of Hematide in healthy volunteers were reported in March 2005. That study demonstrated that single doses of Hematide resulted in dose-dependent increases in circulating reticulocytes in healthy volunteers. At the highest dose tested, Hematide also achieved a clinically and statistically significant increase in hemoglobin from baseline that was sustained for at least a month. Increases in hemoglobin and reticulocytes are indications of red blood cell production. In the Phase 1 study, single intravenous doses of Hematide were well tolerated at the doses tested, with a safety profile similar to placebo.

Hematide has a completely novel amino acid sequence that is unrelated to recombinant or naturally-occurring forms of erythropoietin, a hormone that stimulates red blood cell formation. In animal and laboratory studies Hematide has demonstrated an excellent safety and efficacy profile, superior stability, and an extended duration of action compared to currently marketed recombinant erythropoietin products.

Anemia, Chronic Kidney Disease (CKD) and Effective Treatment

Anemia, a deficiency of red blood cells in the blood, is becoming increasingly prevalent in the United States and has been described as a “hidden epidemic” by the National Anemia Action Council.

Anemia is a frequent and serious complication associated with a number of increasingly common and severe diseases, including cancer and CKD. It can also occur in patients with chronic diseases that cause inflammation, infection or bleeding. CKD, which affects more than 6 million Americans, often leads to debilitating and life-threatening anemia. One of the most common and life-threatening forms of anemia is in CKD patients with end-stage renal disease. Virtually all end-stage renal disease patients are on renal dialysis therapy and are anemic as a result of their disease and the dialysis treatment.

Erythropoiesis (red blood cell production) stimulating agents (ESAs) have been used successfully to manage anemia in patients with chronic kidney disease and cancer-related anemia, constituting $11 billion in worldwide sales in 2004. ESA therapy has dramatically reduced the need for blood transfusions and the frequency and severity of anemia associated morbidity, resulting in an improved quality of life for patients. Hematide represents a next-generation ESA product that, if proven safe and effective in clinical trials, may improve the management of anemia and offer patients and physicians an alternative therapy.

About Affymax

Affymax, Inc. is a development stage pharmaceutical company that is developing novel peptide drugs for the treatment of various blood, cancer and kidney diseases. Affymax is building a rich pipeline of synthetic peptide-based drugs against clinically validated targets that will provide superior product profiles over therapeutic proteins. Advantages of peptide-based drugs can include reduced immunogenicity, reduced dosing frequency, flexible storage and uncomplicated chemical synthesis. Hematide(TM), the company’s first product candidate to enter the clinic, is a peptide-based drug designed to stimulate the production of red blood cells. It is being developed for the treatment of anemia associated with chronic kidney disease and cancer, an $11 billion worldwide market. In addition, the company is also advancing research on Gematide(TM), a peptide-based agonist of the Granulocyte Colony Stimulating Factor receptor, and on Keratide(TM), a peptide-based agonist of the Keratinocyte Growth Factor receptor, and has entered into a research collaboration with EntreMed, Inc. for the synthesis and development of novel peptides that prevent blood vessel formation in tumors.

Affymax, Inc.

CONTACT: Mary Fermi, Senior Director, Commercial Development of Affymax,Inc., +1-650-812-8700; or media, Daryl Messinger of WeissComm Partners, Inc.,+1-415-999-2361, or daryl@weisscommpartners.com, for Affymax, Inc.

Web site: http://www.affymax.com/