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Forty Seven

Biotech & Life Sciences · Menlo Park, United States · Founded 2015 · IPO 2018

Forty Seven, Inc. was a clinical-stage immuno-oncology company that operated as a developer of therapies targeting cancer immune evasion pathways. The company was founded in 2015 by a team of scientists from Stanford University: Irving Weissman, Ravi Majeti, Mark Chao, and Jens-Peter Volkmer. Their work originated from years of research at Stanford into the CD47 protein's role in helping cancer cells evade the immune system. Dr. Weissman, a prominent stem cell pioneer, and his colleagues discovered that most cancer cells overexpress CD47, which broadcasts a "don't eat me" signal to macrophages, a type of white blood cell that would otherwise engulf and destroy abnormal cells. The company's business model was centered on the research, clinical development, and eventual commercialization of novel antibody therapeutics. Its primary focus was on patients with various forms of cancer, including both solid tumors and hematological malignancies like myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). Forty Seven's core strategy involved developing its lead product candidate, magrolimab, both as a standalone therapy and in combination with other existing cancer treatments to enhance their effectiveness. The company's name itself is a direct reference to the CD47 protein it targeted. Magrolimab, Forty Seven's lead asset, is a humanized monoclonal antibody designed to block the CD47 "don't eat me" signal. By interfering with the interaction between CD47 on cancer cells and the SIRPα receptor on macrophages, the antibody allows the patient's own immune system to recognize and eliminate cancer cells. This approach represented a significant development in immuno-oncology by engaging the innate immune system. Clinical trials showed promising results, particularly in treating MDS and AML, which led to Fast Track and Orphan Drug designations from the U.S. Food and Drug Administration (FDA). A pivotal milestone for the company occurred in March 2020, when Gilead Sciences announced its intention to acquire Forty Seven for approximately $4.9 billion. The acquisition was completed in April 2020, making Forty Seven a wholly-owned subsidiary of Gilead, which aimed to integrate magrolimab into its oncology portfolio to advance the fight against cancer. Keywords: immuno-oncology, CD47, magrolimab, macrophage, cancer therapy, Gilead acquisition, clinical-stage, monoclonal antibody, myelodysplastic syndrome, acute myeloid leukemia, cancer immune evasion, Stanford University spin-off, Irving Weissman, Mark Chao, phagocytosis, innate immune system, hematological malignancies, solid tumors, antibody therapeutics, checkpoint inhibitor