Merck (NYSE: MRK) uterine cancer drug met late-stage goals, boosting investor focus on ADC pipeline

Merck & Co. said its experimental cancer therapy sacituzumab tirumotecan (sac-TMT) improved survival and delayed disease progression in patients with advanced or recurrent endometrial cancer in a late-stage trial.

The Phase 3 study enrolled 776 patients previously treated with platinum-based chemotherapy and immunotherapy. Patients received either sac-TMT or chemotherapy treatments doxorubicin or paclitaxel.

Merck said the antibody-drug conjugate met the trial’s primary endpoints by demonstrating statistically significant and clinically meaningful improvements in both overall survival and progression-free survival compared with chemotherapy, although detailed efficacy data were not disclosed.

The therapy, which targets the TROP2 protein, is being developed alongside Kelun-Biotech.

Investor attention around sac-TMT has increased in recent months as Merck continues expanding its oncology pipeline beyond blockbuster immunotherapy Keytruda. Analysts at RBC Capital Markets previously estimated potential risk-adjusted sales of $7.2 billion by 2034, assuming a launch in 2027.

The drug was also previously selected for the FDA’s Commissioner’s National Priority Voucher programme, which could accelerate regulatory review timelines if a filing is submitted later this year.

The positive trial outcome may further strengthen investor sentiment around antibody-drug conjugates, a fast-growing area of oncology drug development attracting increasing pharmaceutical investment globally.