The success of cancer immunotherapies like Merck & Co.’s Keytruda and Bristol Myers’ Opdivo kicked off a broad search by biopharmaceutical companies for other ways to turn the immune system against cancer. One strategy that drew interest was targeting a protein called CD47, which tumors use to protect themselves.
In recent years, companies developing CD47 drugs became hot commodities. Gilead acquired magrolimab three years ago in a $5 billion deal for biotech Forty Seven. One year later, Pfizer bought Trillium Therapeutics for $2.3 billion.