The therapies are approved as second or third line treatment for adults with platinum-resistant ovarian, fallopian tube, or primary peritoneal carcinoma whose tumours express programmed death-ligand 1 (PD-L1) (Combined Positive Score [CPS] ≥1), as determined by an FDA-authorised test.
The approvals stem from the Phase III KEYNOTE-B96 trial (ENGOT-ov65) data, which was presented at the 2025 European Society for Medical Oncology (ESMO) Congress.
Results demonstrated statistically significant improvements in progression-free survival and overall survival compared to placebo plus paclitaxel with or without bevacizumab for patients whose tumours express PD-L1 (CPS ≥1).
The approval of Keytruda Qlex for its indications is supported by data from well-controlled studies of Keytruda and additional results from MK-3475A-D77, which compared the efficacy, safety, and pharmacokinetic profiles of Keytruda Qlex and Keytruda.
MSD research laboratories global clinical development vice-president Dr Gursel Aktan said: “Historically, the prognosis has been poor for patients living with platinum-resistant recurrent ovarian cancer who have limited treatment options that may reduce the risk of disease progression or death. These approvals mark an important moment for the ovarian cancer community, reflecting years of focused investment in Keytruda.
“Introducing the first PD-1 inhibitors for platinum-resistant ovarian cancer means we’re expanding what’s possible for patients facing this disease. It also reinforces our commitment to advancing innovative therapies and improved outcomes across women’s cancers, where the need is greatest.”
In June 2025, MSD received FDA approval for its anti-PD-1 therapy, Keytruda, for adults with resectable locally advanced head and neck squamous cell carcinoma (HNSCC).