Merck struck parallel transactions that shift financing risk and consolidate control of an ADC program: Blackstone Life Sciences will provide roughly $700 million to underwrite pivotal development of a Trop‑2–targeting antibody‑drug conjugate, while Merck paid $150 million to reacquire full rights to an early‑phase asset. The structure blends risk‑sharing with an upfront buy‑in and underscores private‑markets appetite to fund late‑stage oncology programs. Antibody‑drug conjugates (ADCs) combine a monoclonal antibody with a cytotoxic payload to deliver targeted cell killing; the Merck‑Blackstone arrangement illustrates how financiers are designing bespoke royalty and milestone deals to align incentives and accelerate large Phase III programs.