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

The deal is a follow-up to Gilead’s statement of intent regarding acquisitions to build on its presence in immuno-oncology.

“This mechanism not covered in our current portfolio,” Merdad Parsey, Gilead’s chief medical officer, said on Monday morning’s investor call. “We will continue to pursue deals like this.”

SVB Leerink analyst Geoffrey Porges said the deal represents “a reasonable late-stage oncology asset for Gilead to acquire,” but his firm does not “see it as a foundational oncology platform for Gilead.”

While the deal is a large one, it does not rank in the top 20 for either biopharma or biotech M&As. It is Gilead’s third biggest acquisition, behind Pharmasset Inc., acquired in 2012 for $11.4 billion, and Kite Pharma Inc., acquired in August 2017 for $11.9 billion, according to Cortellis.

The deal has swollen Forty Seven’s stock (NASDAQ:FTSV) as it rose 18.8% on Friday, then rose a dramatic 62%, to $93.87 per share, when the market opened today. Menlo Park, Calif.-based Forty Seven, which moved the needle big time last year, with its shares vaulting a whopping 150%, carried the momentum into 2020, with the share value up 14%. The immuno-oncology-focused company said its expected milestones for this year include advancing magrolimab in registration-enabling programs for the treatment of patients with untreated, higher-risk MDS and heavily pretreated, relapsed or refractory DLBCL. In MDS, it planned to initiate in the second quarter a phase III ENHANCE trial evaluating the combination of magrolimab and azacitidine compared to azacitidine alone in patients with untreated, higher risk-MDS.

Meanwhile, Gilead’s (NASDAQ:GILD) stock stayed steady, rising a modest 2.75% at the open.

Forty Seven presented promising phase Ib data on magrolimab for treating MDS and AML at December’s American Society of Hematology meeting. The updated data from its phase Ib trial evaluating magrolimab, its monoclonal anti-CD47 antibody that is designed to interfere with recognition of CD47 by the SIRPα receptor on macrophages, thus blocking the "don't eat me" signal used by cancer cells to avoid being ingested by macrophages, combined with azacitidine to treat MDS and AML. The data showed the combination regimen is active and well-tolerated in patients with MDS and AML. In higher-risk MDS, the overall response rate was 92%, as 12 patients achieved a complete response (CR) rate, with 33% achieving a marrow CR and 8% achieving hematologic improvement. 

Magrolimab was granted fast track designation by the FDA for treating MDS and AML, and for the treatment of relapsed or refractory DLBCL and follicular lymphoma, two forms of B-cell NHL. Magrolimab has also been granted orphan drug designation by the FDA to treat of MDS and AML and by the EMA to treat AML.

The deal is expected to close in the second quarter of 2020.