Harbour Biomed announced the spin‑out of Solstice Oncology and outlicensed its CTLA‑4 antibody porustobart (HBM‑4003) to the new company in a transaction structured with cash and equity valued at more than $1.2 billion. The move transfers development focus and rights to a dedicated oncology vehicle intended to accelerate clinical development. Porustobart, Harbour’s CTLA‑4 program, becomes a cornerstone asset for Solstice and the arrangement pairs Harbour’s discovery engine with the newco’s operational focus. The spinout and licensing approach is designed to unlock value for investors while allowing Harbour to concentrate discovery resources on earlier‑stage programs. The deal is emblematic of recent biotech strategies that use carve‑outs and newcos to derisk and finance mid‑stage oncology development outside the parent company’s balance sheet.