Merck, known as MSD outside the United States and Canada, has entered into an agreement with Blackstone Life Sciences to advance the development of sacituzumab tirumotecan (sac-TMT), an investigational antibody-drug conjugate (ADC) that targets trophoblast cell-surface antigen 2 (TROP2), a protein commonly found on various cancer cells. Merck is currently evaluating sac-TMT in 15 global phase 3 clinical trials across six tumour types, including breast, endometrial, and lung cancers.

Under the agreement, Blackstone will provide Merck with USD 700 million in non-refundable funding to support a portion of the development costs expected through 2026. In return, Blackstone will be eligible for low-to-mid single-digit royalties on future net sales of sac-TMT, contingent on regulatory approval in the United States for first-line treatment of triple-negative breast cancer based on the results of the TroFuse-011 trial.

Merck will retain full authority over the development, manufacturing, and commercialisation of sac-TMT, which remains under an exclusive licence and collaboration with Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. The agreement underscores Merck’s commitment to expanding its oncology pipeline and developing innovative therapies to address unmet cancer care needs.