At a Glance
- Pembrolizumab plus paclitaxel, with or without bevacizumab, for PD-L1 positive platinum-resistant ovarian cancer
- 28% reduction in disease progression or death risk
- 24% reduction in risk of death
- Includes newly approved subcutaneous KEYTRUDA QLEX
Written By: Nikita Jha, BPharm
Reviewed By: Pharmacally Editorial Team
Merck announced that the U.S. Food and Drug Administration approved KEYTRUDA (pembrolizumab) and KEYTRUDA QLEX (pembrolizumab with berahyaluronidase alfa) in combination with paclitaxel, with or without bevacizumab, for adults with PD-L1 positive platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal carcinoma. Eligible patients must have received one or two prior systemic treatment regimens, with PD-L1 expression defined as a Combined Positive Score (CPS) ≥1 using an FDA-authorized test.
The approvals are supported by findings from the Phase 3 KEYNOTE-B96 trial (ENGOT-ov65) (NCT05116189) presented at the European Society for Medical Oncology Congress. In patients with PD-L1 expressing tumors, pembrolizumab plus paclitaxel, with or without bevacizumab, reduced the risk of disease progression or death by 28% compared with chemotherapy alone (HR 0.72; p=0.0014). The regimen also demonstrated a 24% reduction in the risk of death (HR 0.76; p=0.0053).
Median progression-free survival reached 8.3 months with the pembrolizumab regimen versus 7.2 months in the control arm. Median overall survival improved to 18.2 months compared with 14.0 months for patients receiving placebo plus chemotherapy.
KEYTRUDA QLEX, a subcutaneous formulation, received approval based on established clinical evidence from KEYTRUDA studies and additional comparative data showing similar pharmacokinetic, efficacy, and safety profiles between the two formulations.
Safety findings remained consistent with the known profile of pembrolizumab. Serious adverse reactions occurred in 54% of patients receiving pembrolizumab-based therapy. The most frequently reported serious events included pneumonia, urinary tract infection, adrenal insufficiency, hyponatremia, and pulmonary embolism. Fatal adverse reactions were reported in 3.9% of patients. Treatment discontinuation due to adverse reactions occurred in 16% of cases.
KEYNOTE-B96 enrolled 643 patients regardless of PD-L1 status. Among participants, 72% had PD-L1 positive tumors, 73% received bevacizumab, and nearly half had a platinum-free interval shorter than three months, reflecting a high-risk population with limited treatment options.
Pembrolizumab is an anti–PD-1 immunotherapy designed to enhance immune system recognition of tumor cells by blocking PD-1 interactions with PD-L1 and PD-L2. The newly approved subcutaneous formulation combines pembrolizumab with berahyaluronidase alfa to enable faster administration.
Platinum-resistant ovarian cancer remains associated with poor outcomes and limited therapeutic choices. Most patients experience disease progression following platinum-based chemotherapy, with resistance developing within six months in approximately one-quarter of cases.
These approvals introduce the first PD-1 inhibitor-based treatment options specifically indicated for platinum-resistant ovarian cancer, expanding available strategies for a patient population with historically limited alternatives.
References
KEYTRUDA® (pembrolizumab) and KEYTRUDA QLEX™ (pembrolizumab and berahyaluronidase alfa-pmph), Plus Paclitaxel ± Bevacizumab, Approved for Certain Adults with PD-L1+ (CPS ≥1) Platinum-Resistant Ovarian Carcinoma as Second or Third Line Treatment, 11 February 2026, KEYTRUDA® (pembrolizumab) and KEYTRUDA QLEX™ (pembrolizumab and berahyaluronidase alfa-pmph), Plus Paclitaxel ± Bevacizumab, Approved for Certain Adults with PD-L1+ (CPS ≥1) Platinum-Resistant Ovarian Carcinoma as Second or Third Line Treatment – Merck.com
Pembrolizumab/Placebo Plus Paclitaxel with or Without Bevacizumab for Platinum-resistant Recurrent Ovarian Cancer (MK-3475-B96/KEYNOTE-B96/ENGOT-ov65), ClinicalTrials.gov ID NCT05116189, https://clinicaltrials.gov/study/NCT05116189
Colombo, N. et al., LBA3 Pembrolizumab vs placebo plus weekly paclitaxel ± bevacizumab in platinum-resistant recurrent ovarian cancer: Results from the randomized double-blind phase III ENGOT-ov65/KEYNOTE-B96 study, Annals of Oncology, Volume 36, S1582, https://doi.org/10.1016/j.annonc.2025.09.049