NEW YORK – Merck said on Friday that it has begun three Phase III clinical trials of the TROP2-directed antibody-drug conjugate, MK-2870, in certain patients with non-small cell lung cancer and endometrial cancer.
Merck has licensed the antibody-drug conjugate from Kelun Pharmaceutical subsidiary Kelun-Biotech. Under the terms of the deal, Kelun-Biotech granted Merck the exclusive rights to develop, manufacture, and commercialize MK-2870 globally, excluding in Greater China.
In the first Phase III trial, dubbed MK-2870-004, the drugmaker is evaluating MK-2870 versus chemotherapy in patients with previously treated NSCLC whose cancers harbor EGFR mutations or other genomic alterations. The trial, which Merck expects will include 556 patients, is designed to assess patients' progression-free survival and overall survival, among other outcomes.
In another Phase III trial of the antibody-drug conjugate, dubbed MK-2870-007, Merck has begun studying MK-2870 combined with the immune checkpoint inhibitor Keytruda (pembrolizumab) versus Keytruda alone in advanced NSCLC patients whose tumors express PD-L1 with a tumor proportion score of at least 50 percent. MK-2870-007 will enroll an expected 614 patients, and the primary endpoint will be overall survival.
Finally, Merck has started a Phase III trial dubbed MK-2870-005 to evaluate MK-2870 versus chemotherapy in advanced, previously treated endometrial cancer patients. The drugmaker also plans to develop the antibody-drug conjugate as both a monotherapy and combined with Keytruda in solid tumors beyond NSCLC and endometrial cancer.
Separately on Friday, Merck said that, in partnership with Orion Corporation, it has started evaluating the CYP11A1 enzyme inhibitor MK-5684 in two pivotal Phase III trials, OMAHA1 and OMAHA2a.
The firms are studying the drug, which is also known as ODM-208, in certain patients with previously treated metastatic castration-resistant prostate cancer. In OMAHA1, Merck and Orion are studying CYP11A1 combined with hormone replacement therapy versus either Janssen's Zytiga (abiraterone acetate) plus prednisone or Pfizer and Astellas Oncology's Xtandi (enzalutamide) in mCRPC patients who've received both a prior hormone therapy and chemo. In OMAHA2a, the firms are studying CYP11A1 plus hormone replacement therapy versus the same choice of Zytiga-prednisone or Xtandi in mCRPC patients who've received one prior hormone therapy but no prior chemo. In both studies, Merck and Orion are studying overall survival and progression-free survival according to patients' androgen receptor ligand-binding domain mutation status.