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

PALO ALTO, Calif., April 7 /PRNewswire/ — Affymax, Inc. today announced that it has initiated a 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. The randomized, double-blind, placebo-controlled, sequential dose escalation study will evaluate the safety, pharmacodynamics and pharmacokinetics of a single intravenous injection of Hematide in patients with CKD who are not on dialysis and have not had prior ESA treatment.

“The initiation of the Phase 2 program of Hematide in patients with chronic kidney disease marks an important milestone as we continue to make excellent progress moving this novel, peptide-based product candidate forward in the clinic,” said Arlene M. Morris, president and chief executive officer of Affymax.

Previously announced results from the Phase 1 dose-finding trial 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.

“The Hematide Phase 1 results provided initial proof-of-concept, and we anticipate that the Phase 2 trial will provide data on the safety of Hematide and its effect on erythropoiesis in patients afflicted with anemia resulting from their reduced kidney function,” said Robert B. Naso, Ph.D, executive vice president, research and development at Affymax. “Patients with anemia from chronic kidney disease would benefit from improvements in treatment options, such as those that we believe Hematide may offer.”

Hematide has a completely novel amino acid sequence that is unrelated to erythropoietin, a hormone that stimulates red blood cell formation, or to any other known naturally-occurring human sequences. 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.

Affymax anticipates that this dose finding trial in CKD patients will be followed later this year by repeat dose studies in pre-dialysis CKD patients and in end-stage renal disease patients on hemodialysis. Also the company plans to initiate Phase 2 studies of Hematide in cancer patients with chemotherapy-related anemia.

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 over six million Americans, often leads to debilitating and life-threatening anemia. One of the most common and life-threatening forms of anemia is 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 $10 billion in worldwide sales in 2003. 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. In addition, the company is also advancing Gematide(TM), a peptide-based agonist of the G-CSF receptor, and also 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 Daryl Messinger of WeissComm Partners, Inc.,+1-415-999-2361, or daryl@weisscommpartners.com