Pharma BD Deal Intelligence
Pfizer acquired Arena Pharmaceuticals for $6.7 billion in cash ($100.00/share) via a tender offer plus second-step merger, announced December 13, 2021 and completed March 11, 2022. The strategic rationale was Arena's immuno-inflammatory pipeline, led by etrasimod, an oral, once-daily, selective sphingosine-1-phosphate (S1P) receptor modulator. Etrasimod won U.S. FDA approval as VELSIPITY for moderately-to-severely active ulcerative colitis on October 12, 2023, followed by EU approval in 2024 — validating the deal's core thesis. Pfizer subsequently pruned the broader etrasimod program, discontinuing Phase 2 studies in atopic dermatitis and alopecia areata in May 2024 as part of a cost-and-pipeline review, narrowing the asset toward its approved UC indication and adjacent GI development.