Early Data on Amgen's Anti-Angiogenesis Pipeline Molecules Suggest Biologic Activity Across Tumor Types

AMG 386 Preclinical Data Suggests Greater Reduction in Tumor Growth when Angiopoietin 1/2 and VEGF Pathways are Both Inhibited

Abstract Numbers: 1113, 4887 and 5764

SAN DIEGO--(BUSINESS WIRE)--April 13, 2008--Amgen (NASDAQ:AMGN), today announced results from preclinical studies suggesting a significantly greater reduction in tumor growth when AMG 386, a recombinant Fc-peptide fusion protein (peptibody) designed to bind angiopoietins 1 and 2, thereby inhibiting Tie2 dependent stimulation of endothelial cells, was combined with either of two vascular endothelial growth factor (VEGF) inhibitors -- bevacizumab or motesanib diphosphate (AMG 706) -- compared with either treatment alone (p less than 0.05). Angiopoietins, together with VEGFs, are key cytokines that regulate neovascularization. The results of preclinical studies that investigated the growth of human colon tumor cells in this combination were presented at the 2008 American Association for Cancer Research (AACR) Annual Meeting in San Diego.

"Tumors depend on a reliable blood supply to grow and survive. By targeting angiogenesis - the process underlying the formation and growth of new blood vessels - we hope to achieve clinically meaningful control of many cancers," said Roger M. Perlmutter, Amgen's executive vice president of Research and Development. "What's encouraging about these early results is that they indicate that blocking more than one angiogenesis pathway may offer enhanced potential to inhibit tumor growth. We look forward to investigating this finding further."

The data were generated from three blinded studies of preclinical models of colon carcinoma randomized into three experimental groups. The models were treated with suboptimal doses of motesanib diphosphate (37.5 - 75 mg/kg QD, PO), bevacizumab (2.8 ug twice per week), AMG 386 (2.8 - 14 ug twice per week) or combinations thereof. In all three studies, greater reduction in tumor growth was observed when AMG 386 was combined with either motesanib diphosphate or with bevacizumab, compared to the tumor growth reduction seen with either VEGF inhibitor alone.

Amgen's Commitment to Angiogenesis Research

Angiogenesis, the process of new blood vessel formation, plays a critical role in many diseases, including cancer. New blood vessels constantly form during an embryo's development, but in adults angiogenesis normally only takes place as part of specific processes such as recovering from an injury, when the growth of new blood vessels promotes wound healing. In cancer, tumors grow and metastasize in part by secreting angiogenic substances, such as VEGF, that can induce capillary growth into the tumor.

Anti-angiogenesis research is an important area of research for Amgen. In 2007, Amgen initiated four Phase 2 studies of AMG 386 for the treatment of renal cell, metastatic breast, ovarian and gastric cancers.

About Motesanib Diphosphate

Motesanib diphosphate is a highly selective, investigational oral agent that is being evaluated for its ability to inhibit angiogenesis and lymphangiogenesis by targeting VEGF 1, 2 and 3. It is also under investigation for its potential direct anti-tumor activity by targeting platelet-derived growth factor receptor ("PDGFR") and stem cell factor receptor ("c-kit") signaling. A Phase 3 study examining the potential utility of motesanib diphosphate in the treatment of non-small-cell lung cancer (NSCLC) is currently ongoing, as are Phase 2 studies in patients with metastatic breast cancer or NSCLC comparing the activity of motesanib diphosphate with that observed using bevacizumab. In February 2008, Amgen announced the establishment of a partnership with Takeda supporting the worldwide development and commercialization of motesanib diphosphate, and the development and commercialization of up to 13 Phase 2 molecules, including AMG 386, in Japan. Studies highlighting the in vitro activity of motesanib diphosphate against imatinib-resistant gastrointestinal stromal tumors will be presented on Tuesday, April 15 (Abstract no. 4887). The effect of motesanib diphosphate on radiation responses in preclinical head and neck cancer models will be presented on Wednesday, April 16 (Abstract no. 5764).

About Amgen

Amgen discovers, develops, manufactures and delivers innovative human therapeutics. A biotechnology pioneer since 1980, Amgen was one of the first companies to realize the new science's promise by bringing safe and effective medicines from lab, to manufacturing plant, to patient. Amgen therapeutics have changed the practice of medicine, helping millions of people around the world in the fight against cancer, kidney disease, rheumatoid arthritis and other serious illnesses. With a deep and broad pipeline of potential new medicines, Amgen remains committed to advancing science to dramatically improve people's lives. To learn more about our pioneering science and our vital medicines, visit www.amgen.com.

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    SOURCE: Amgen