IMMUNEX' GM-CSF CLEARS INITIAL HURDLE OF MANUFACTURING FACILITY INSPECTION

IMMUNEX' GM-CSF CLEARS INITIAL HURDLE OF MANUFACTURING FACILITY INSPECTION, which resulted in only "minor" and "basic" observations, according to Immunex Chief Operating Officer Michael Kranda. He said the company already has corrected most of the items noted by FDA. The inspection of the production facility was conducted the week of Aug. 20. Immunex has filed a Treatment IND application and product license application for its granulocyte macrophage-colony stimulating factor in treating engraftment failure following bone marrow transplants. The PLA was filed Feb. 21. The Treatment IND application was filed July 23, but FDA asked for a 30-day extension of its consideration deadline so that the agency could compile results of the inspection, Kranda said. GM-CSF was recommended for Treatment IND status by FDA's Biological Response Modifiers Advisory Committee at its July 31 meeting ("The Pink Sheet" Aug. 6, p. 8). Immunex is conducting an additional analysis of its historical control data in response to suggestions the advisory committee made following review of the PLA data. The company is also collecting data on additional patients enrolled in its multi-center trial. At a late August meeting of the International Society for Experimental Hematology, Immunex reported that it had genetically engineered a fusion molecule, called PIXY-321, made of GM-CSF and Interleukin-3. In a press release on the presentation, Immunex said that "in vitro studies have shown the fusion molecule to be 10 times more active than combinations of GM-CSF and IL-3 in its ability to promote bone marrow cell growth." Immunex stated that "clinical studies of PIXY-321 are planned for 1991." GM-CSF is currently in Phase III trials to reverse neutropenia caused by radiation or chemotherapy. Phase I/II studies of IL-3 in treating neutropenia and platelet deficiencies are ongoing. Combination studies of GM-CSF and IL-3 "are planned to begin" in the U.S., the firm advised. At the 13th International Congress of the Transplantation Society in San Francisco, Immunex presented results of preclinical studies that show that a soluble IL-4 receptor may prevent organ transplant rejection at doses 2,000 times lower than doses of monoclonal antibodies used to achieve similar results. Immunex noted in a release that the research could lead to a treatment for organ transplant rejection, graft-versus-host disease, allergy and other autoimmune diseases.