PALO ALTO, Calif., April 11 /PRNewswire/ -- Affymax, Inc., a clinical-stage pharmaceutical company, today announced that it has initiated a clinical trial to evaluate the use of Hematide(TM) to treat anemia in chronic kidney disease (CKD) patients with pure red cell aplasia (PRCA). PRCA, a rare autoimmune disorder, occurs when the body produces neutralizing antibodies to recombinant human erythropoietin (EPO), thus suppressing the production of red blood cells by the bone marrow. Hematide is a synthetic, peptide-based, next-generation erythropoiesis-stimulating agent (ESA) with no sequence homology to human EPO. Hematide is designed to stimulate the production of red blood cells and is being evaluated in Phase 2 clinical trials to treat anemia in patients with CKD and cancer. "Although PRCA is a rare complication of treatment with recombinant EPO, it represents a significant adverse effect when it does occur. Patients with PRCA have no options to treat their anemia except regular blood transfusions, a kidney transplant, or immunosuppressive therapy in an attempt to suppress antibody production, all of which are associated with adverse consequences," said Anne-Marie Duliege, M.D., vice president of clinical, regulatory, and medical affairs at Affymax." Hematide may provide a treatment for these patients because antibodies generated to recombinant EPO have not been shown to cross-react with Hematide, and preclinical studies have shown that Hematide can effectively correct anemia caused by EPO-specific antibodies." PRCA Study Details The open-label, multi-center trial in PRCA patients will evaluate the efficacy and safety of Hematide administered subcutaneously every four weeks. The primary endpoint is the change in hemoglobin from baseline over time. Secondary endpoints include safety and the effectiveness of Hematide in reducing the frequency of red blood cell transfusions over time. "We expect that this trial will provide important information about the safety and potential efficacy of Hematide in this select, transfusion- dependent group of patients with EPO antibody-induced anemia," said Robert B. Naso, Ph.D., executive vice president of research and development at Affymax. "While we believe the PRCA population is too small to be considered as a target indication, we anticipate that the additional mechanistic information from this study may, if Hematide is approved by regulatory authorities, help us better differentiate Hematide from currently marketed recombinant EPO-based ESAs." About Hematide(TM) Hematide has a novel amino acid sequence that is unrelated to EPO, a hormone that stimulates red blood cell formation, or to any other known naturally-occurring human sequences. Compared to therapeutic proteins, Hematide has the potential properties of a simple dosing schedule characterized by once-monthly administration, uncomplicated chemical synthesis, and room temperature storage. In addition to the trial in patients with PRCA, Hematide is currently being studied in a Phase 2b open-label, repeat dose, dose-finding study in the U.S. in hemodialysis patients with end-stage CKD; separately in a Phase 2b multi-center, open-label, repeat dose, dose-finding trial in Europe in CKD patients who are not on dialysis and who have not been treated previously with an ESA; and in a Phase 2 open-label, multi-center, dose-escalation trial in Europe in cancer patients receiving chemotherapy. Affymax recently announced a collaboration agreement with Takeda Pharmaceutical Company Limited to develop and commercialize Hematide in Japan. About PRCA Patients with CKD frequently develop anemia because of a reduction in native EPO production by dysfunctional kidneys. Since the late 1980s, recombinant EPO has been used successfully to treat anemia-associated EPO deficiency. Between 1998 and 2004, an increase was observed in the number of CKD patients with antibody-mediated PRCA, a type of anemia that develops when patients mount a neutralizing antibody response to recombinant EPO used to treat the anemia associated with CKD. These neutralizing antibodies were found to neutralize not only the recombinant EPO but also to cross-neutralize the natural EPO produced by the patients, leading to a state of absolute EPO resistance and transfusion dependence. Since 2004, the incidence of PRCA has decreased dramatically, but there continue to be sporadic reports of full-blown, antibody-mediated PRCA associated with commercially available EPO preparations. Concern over PRCA has recently prompted the addition of warnings in the prescribing information of all EPO-based products marketed in the U.S. Although the cause of this immune reaction to recombinant EPO is not known, several factors have been implicated. Product-related factors include minor but potentially immunogenic differences between recombinant human EPO and natural EPO, differences in the manufacturing, handling, or route of administration of various brands of recombinant human EPO, and changes associated with certain formulations that may occur upon storage of the drug. Patient-related factors include immune status and treatment history. About Affymax Affymax, Inc. is a clinical-stage pharmaceutical company that is developing a rich pipeline of synthetic peptide-based drugs against clinically validated targets for the treatment of kidney diseases and cancer. Hematide(TM), the Company's first product candidate to enter the clinic, is a novel peptide-based drug designed to stimulate the production of red blood cells. Hematide has been approved for use only in clinical trials. Currently, it is in Phase 2 trials for the treatment of anemia associated with chronic kidney disease and cancer. For more information go to www.affymax.com.
SOURCE Affymax, Inc.