RAHWAY, N.J. — Merck’s cancer therapy portfolio received an expanded U.S. regulatory approval after the Food and Drug Administration authorized Keytruda (pembrolizumab) and Keytruda Qlex, used with Gilead Sciences’ Trodelvy (sacituzumab govitecan-hziy), as a first-line treatment option for certain patients with advanced triple-negative breast cancer, the companies said.
The FDA approval covers adults with unresectable locally advanced or metastatic triple-negative breast cancer whose tumors express PD-L1 with a Combined Positive Score of 10 or higher, as determined by an FDA-authorized test. The decision makes the combination of a PD-1 inhibitor with a Trop-2-directed antibody-drug conjugate available as an initial treatment option for this patient group.
Merck said the approval was supported by results from the Phase 3 ASCENT-04/KEYNOTE-D19 study, which evaluated pembrolizumab combined with sacituzumab govitecan compared with pembrolizumab plus chemotherapy in patients with PD-L1-positive advanced triple-negative breast cancer. The company said the combination demonstrated a reduction in disease progression or death compared with the chemotherapy-based regimen.
The FDA also approved Trodelvy as a single-agent first-line treatment for adults with unresectable locally advanced or metastatic triple-negative breast cancer who are not candidates for PD-1 or PD-L1 inhibitor-based therapy, based on results from the ASCENT-03 study, according to the agency.
Triple-negative breast cancer accounts for a smaller but aggressive subset of breast cancer cases and lacks three common treatment targets: estrogen receptors, progesterone receptors and HER2. Because of the absence of those targets, treatment options have historically relied on chemotherapy, immunotherapy and newer targeted approaches.
Merck’s Keytruda, a PD-1 immune checkpoint inhibitor, was previously approved for other triple-negative breast cancer settings, including certain high-risk early-stage cases and PD-L1-positive advanced disease in combination with chemotherapy.
“Patients with PD-L1+ unresectable locally advanced or metastatic TNBC have limited treatment options in the first-line setting,” Merck executive Gursel Aktan said in the company’s announcement, adding that the new approvals provide additional treatment options for eligible patients.
As with other immunotherapies, Keytruda and Keytruda Qlex carry warnings for potentially serious immune-related side effects, including inflammation affecting organs such as the lungs, liver and colon, according to prescribing information cited by Merck.
The FDA’s decision adds another treatment pathway for advanced triple-negative breast cancer patients and expands the role of Merck’s oncology franchise in combination-based cancer therapies.
