Gilead Sciences Inc. will acquire Forty Seven Inc. for $4.9 billion, or $95.50 per share in cash, bringing Gilead magrolimab, an anti-CD47 monoclonal antibody being developed to treat several cancers, including myelodysplastic syndrome (MDS), acute myeloid leukemia (AML) and diffuse large B-cell lymphoma (DLBCL).