Amgen announces positive Phase 3 results for SCF.

THOUSAND OAKS, Calif.--(BUSINESS WIRE)--Jan. 10, 1997--Amgen (NASDAQ: AMGN) Friday announced positive results of a Phase 3 clinical trial of Stem Cell Factor, the early-acting blood cell growth factor discovered by Amgen scientists.

Stem Cell Factor reduced the number of blood cell collection procedures required to help cancer patients overcome potentially toxic doses of chemotherapy. In this study, a median of approximately one-third fewer blood collection procedures were required using a combination of Stem Cell Factor (SCF) and G-CSF (NEUPOGEN(R), Filgrastim), compared to NEUPOGEN alone.

In this pivotal Phase 3 trial of 205 patients with breast cancer, patients receiving NEUPOGEN plus SCF required a median of two fewer blood collection procedures known as aphereses to collect the optimum number of progenitor cells, compared to those receiving NEUPOGEN alone. Both groups showed rapid blood cell recovery when these progenitor cells were reinfused. Confirming results of earlier trials, SCF appeared safe and generally well-tolerated.

Amgen said it plans to file for FDA approval in the next few months. It is anticipated that detailed results of this trial will be submitted for presentation at the December meeting of the American Society of Hematology and will be published in a peer-reviewed medical journal.

"We are very pleased with the results of this pivotal trial. We are particularly proud that this growth factor was discovered and developed at Amgen and we look forward to SCF coming to market as Amgen's third hematopoietic growth factor," said Gordon Binder, chairman and chief executive officer.

During aphereses, early-acting peripheral blood progenitor cells (PBPCs) are collected from the blood and then reinfused to help patients avoid a variety of serious side effects of chemotherapy. PBPC transplants have largely replaced bone marrow transplants (BMTs) in this country and in Europe. In 1995, the Food and Drug Administration licensed NEUPOGEN for use in PBPC transplants.

As part of the PBPC transplant, SCF and NEUPOGEN are administered and stem cells are collected via apheresis procedures until sufficient cells have been obtained to aid recovery from chemotherapy. The stem cells are then frozen, and the patient receives a potentially toxic dose of chemotherapy. The collected stem cells are then reinfused and the patient receives additional doses of NEUPOGEN to hasten blood cell recovery.

Because the cells are collected from blood and reinfused, PBPC collection and transplantation are much less invasive than BMT procedures. They are also about one-third less costly.

SCF is a major regulator of progenitor cells, often called stem cells. These stem cells develop to form a variety of more mature blood cells including red cells, white cells and platelets. SCF works synergistically in combination with other blood cell growth factors to generate mature, functional blood cells.

Facilitating blood cell recovery is critical to minimizing the period of time during which patients are at risk for serious side effects of chemotherapy, among them potentially fatal systemic infections, anemia and thrombocytopenia (too few platelets) which can lead to internal bleeding.

Amgen is a global biotechnology company that discovers, develops, manufactures and markets human therapeutics based on advances in cellular and molecular biology. -0-

Note to Editors: This news release contains forward-looking statements that involve risks and uncertainties, including risks associated with regulatory approvals and other risks described from time to time in the SEC reports filed by Amgen, including the most recently filed form 10-Q.

CONTACT: Amgen, Thousand Oaks

David Kaye, 805/447-6692 (media)

Denise Powell, 805/447-4346 (investors)