One of the largest biotech companies in the country will spend nearly $5 billion to acquire a firm developing a new form of cancer immunotherapy.
Foster City, California-based Gilead Sciences said Monday that it would acquire Menlo Park, California-based Forty Seven for $4.9 billion. The latter company’s shares were up more than 61% on the Nasdaq when markets opened Monday. Gilead’s shares were up about 2.5%.
Forty Seven’s lead product candidate is magrolimab, a monoclonal antibody targeting the cell-surface protein CD47 in Phase Ib development for blood cancers like acute myeloid leukemia (AML), myelodysplastic syndrome (MDS) and diffuse large B-cell lymphoma (DLBCL).
“This agreement builds on Gilead’s presence in immuno-oncology and adds significant potential to our clinical pipeline,” Gilead CEO Daniel O’Day said in a statement. “Magrolimab complements our existing work in hematology, adding a non-cell therapy program that complements [Kite Pharma’s] pipeline of cell therapies for hematological cancers.”
O’Day was referring to the cell therapy company that Gilead acquired in 2017 and that originally developed Yescarta (axicabtagene ciloleucel), a CAR-T cell therapy that targets the CD19 antigen and is approved for DLBCL.
Data from the Phase Ib trial of magrolimab combined with Bristol-Myers Squibb’s Vidaza (azacitidine) in patients with untreated AML or higher-risk MDS were presented at the American Society of Hematology meeting in December. Among 22 AML patients, the overall response rate was 64%, with 41% of patients showing complete responses, meaning no measurable tumor. Among the 24 MDS patients, the overall response rate was 92%, with 50% showing a complete response. There was no evidence of increased toxicity compared with Vidaza alone.
Sometimes called the “don’t eat me” signal, CD47 is expressed by normal cells, but also overexpressed by cancer cells, enabling them to avoid detection by the immune system. Targeting the CD47/SIRPa axis works by using the antibody to target CD47 on cancerous cells and enabling myeloid cells to detect and kill them via their corresponding receptor, SIRPa.
By contrast, the checkpoint inhibitors currently on the market, particularly those that target PD-1 and CTLA-4, work by stimulating the adaptive immune system, shutting off their respective targets and allowing T cells to attack cancer cells. Another company developing CD47-targeting drugs is ALX Oncology, based in Burlingame, California. ALX raised $105 million in a Series C funding round last month and has its lead drug candidate, ALX148, in Phase I testing for solid tumors and blood cancers.
Photo: Kritchanut, Getty Images
