GlaxoSmithKline agreed to acquire exclusive rights to Syndivia’s preclinical antibody‑drug conjugate (ADC) targeting metastatic castration‑resistant prostate cancer (mCRPC) in a deal that includes $357 million up front plus milestone payments. GSK will assume responsibility for development, manufacturing and global commercialization of the candidate derived from Syndivia’s GeminiMab site‑specific conjugation platform. Syndivia reported strong anti‑tumor activity and a favorable safety profile in animal models; its GeminiMab technology aims to control drug‑to‑antibody ratio and improve tolerability. GSK framed the deal as expanding its tumor‑targeting portfolio and cited growing unmet need in mCRPC. The agreement exposes GSK to ADC innovation while sidestepping earlier‑stage discovery risk through an external purchase. For Syndivia the deal validates its site‑specific conjugation approach and provides funding to advance its platform, while GSK leverages established ADC expertise to accelerate clinical translation.