Affymax Begins Clinical Trial of Hematide(TM) to Treat Anemia in Patients With Pure Red Cell Aplasia

Apr 11, 2006, 01:00 ET from Affymax, Inc.

    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
     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
     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

SOURCE Affymax, Inc.