09:18 AM EST, 11/04/2025 (MT Newswires) -- Merck ( MRK ) said Tuesday that it has signed a $700 million funding agreement with Blackstone (BX) unit Blackstone Life Sciences to support the development of sacituzumab tirumotecan, an experimental cancer drug.

Merck ( MRK ) said the funds from Blackstone are expected to cover part of the development costs through next year. Merck ( MRK ) said that in exchange, Blackstone may earn low- to mid-single-digit royalties on future global sales of the drug if it gains US approval for first-line treatment of triple-negative breast cancer.

The biopharmaceutical company said it is testing sacituzumab tirumotecan in 15 late-stage trials across six cancer types. The drug is being developed under an existing license and collaboration with Sichuan Kelun-Biotech, and Merck ( MRK ) will keep full control over its development, production, and commercialization, the company added.