Blackstone Life Sciences agreed to purchase a stake in Merck’s Trop‑2 antibody‑drug conjugate program, paying roughly $700 million to underwrite development and share future royalty streams. Simultaneously, Merck made an upfront $150 million payment to regain full control of an early‑phase asset, moves that reallocate risk and capital across partners. The Blackstone transaction shifts development economics and provides Merck with near‑term funding to accelerate pivotal studies while retaining operational control. The deal is part of a broader trend where private investment firms buy royalties or co‑development rights to finance late‑stage oncology portfolios. For biopharma execs, the transaction highlights alternative financing routes—royalty monetizations and life‑science private equity—that can de‑risk expensive oncology pivots while preserving upside for the originator company.