Merck & Co. (MSD) has secured $700 million in funding from Blackstone Life Sciences to accelerate the Phase III clinical development of its promising antibody-drug conjugate (ADC) sacituzumab tirumotecan (sac-TMT) — a TROP2-targeting therapy with potential across multiple tumour types.

The financing will support MSD’s pivotal development programs for sac-TMT through 2026, reinforcing the company’s commitment to expanding its oncology portfolio with cutting-edge ADC therapies. Under the agreement, Blackstone will receive low-to-mid single-digit royalties on future net sales of sac-TMT, contingent upon regulatory approval in the U.S. for first-line treatment of triple-negative breast cancer (TNBC).

Currently, sac-TMT is being evaluated in 15 global Phase III trials across six tumour types, including TNBC, endometrial, lung, and cervical cancers. The TroFuse-011 Phase III trial will play a critical role in supporting potential approval. Recent data from both global and China-based studies have shown encouraging results for sac-TMT.

Originally developed by Kelun-Biotech, sac-TMT was licensed to MSD in 2022 through a deal valued at up to $1.4 billion, granting MSD exclusive rights to develop, manufacture, and commercialize the drug outside Greater China. The National Medical Products Administration (NMPA) has already approved sac-TMT for TNBC, positioning it as a strong competitor to Gilead Sciences’ Trodelvy.

With sac-TMT and four additional ADCs in development, MSD continues to build a robust oncology pipeline. The company is also collaborating with Daiichi Sankyo on three ADC programs, while another candidate, ilovertamab vedotin, has shown promise in treating diffuse large B-cell lymphoma.

The ADC landscape remains dynamic, with pharmaceutical leaders investing heavily in next-generation therapies. MSD’s strategic partnership with Blackstone underscores its focus on advancing targeted cancer treatment and expanding patient access to innovative therapies worldwide.