SERB buys Y-mAbs for $412M to expand rare cancer pipeline

SERB Pharmaceuticals is acquiring Y-mAbs Therapeutics in a $412 million deal, paying $8.60 per share, a 105% premium over Y-mAbs' previous closing price.

Why it matters: The acquisition gives SERB control of Danyelza, the first FDA-approved treatment for relapsed or refractory high-risk neuroblastoma, a rare pediatric cancer, and marks a dramatic pivot for Y-mAbs after years of setbacks.

Backstory: Y-mAbs gained FDA approval for Danyelza in 2020. The company intended to become a leader in pediatric oncology but faced major hurdles, including FDA rejection of a second therapy and deep staff cuts. As a result, its stock plummeted from ~$48 in 2020 to ~$3 in 2023.

Zoom in: Danyelza generated $88M in 2024 and competes with United Therapeutics’ Unituxin and Apeiron Biologics’ Qarziba.

Big picture: This acquisition reflects continued consolidation in rare disease pharma, as larger companies look to acquire specialized treatments rather than develop them in-house. SERB, which markets 70+ drugs globally, including several in rare diseases, sees Danyelza as a potential growth engine.