Rahway, New Jersey — February 11, 2026 — Leads & Copy — The U.S. Food and Drug Administration (FDA) has approved KEYTRUDA® (pembrolizumab) and KEYTRUDA QLEX™ (pembrolizumab and berahyaluronidase alfa-pmph) plus paclitaxel, with or without bevacizumab, for treating adults with PD-L1+ (Combined Positive Score [CPS] ≥1) platinum-resistant epithelial ovarian, fallopian tube or primary peritoneal carcinoma who have received one or two prior systemic treatment regimens, Merck (NYSE: MRK) announced.
The approvals are based on data from the Phase 3 KEYNOTE-B96 trial (ENGOT-ov65), presented at the 2025 European Society for Medical Oncology (ESMO) Congress. The trial showed KEYTRUDA plus paclitaxel, with or without bevacizumab, significantly improved progression-free survival (PFS), reducing the risk of disease progression or death by 28% (HR=0.72 [95% CI, 0.58-0.89]; p=0.0014) in patients with platinum-resistant recurrent ovarian cancer whose tumors express PD-L1 (CPS ≥1) compared to placebo plus paclitaxel with or without bevacizumab.
In the same population, the KEYTRUDA regimen also demonstrated a statistically significant improvement in overall survival (OS), reducing the risk of death by 24% (HR=0.76 [95% CI, 0.61-0.94]; p=0.0053) compared to placebo plus paclitaxel with or without bevacizumab. The effectiveness of KEYTRUDA QLEX for its approved indications has been established based upon evidence from the adequate and well-controlled studies conducted with KEYTRUDA and additional data from MK-3475A-D77 comparing the pharmacokinetic, efficacy, and safety profiles of KEYTRUDA QLEX and KEYTRUDA.
Dr. Bradley Monk, gynecologic oncologist and medical director at Florida Cancer Specialists and Research Institute, noted that for many patients with ovarian cancer, the disease can become platinum-resistant, limiting treatment options. He stated that the FDA approvals of these pembrolizumab-based regimens offer the possibility of more time for patients previously treated with standard platinum-based therapies.
KEYTRUDA QLEX is contraindicated in patients with known hypersensitivity to berahyaluronidase alfa, hyaluronidase or to any of its excipients. KEYTRUDA and KEYTRUDA QLEX are associated with the following Warnings and Precautions: severe and fatal immune-mediated adverse reactions in any or multiple organs, which can occur during or after treatment, including pneumonitis, colitis, hepatitis, endocrinopathies, nephritis, dermatologic reactions, solid organ transplant rejection, other transplant (including corneal graft) rejection; severe and life-threatening infusion or injection-related reactions; fatal and other serious complications in patients who receive allogeneic hematopoietic stem cell transplantation before or after beginning treatment; embryo-fetal toxicity; and increased mortality in patients with multiple myeloma when KEYTRUDA or KEYTRUDA QLEX is added to a thalidomide analogue plus dexamethasone, which is not recommended outside of controlled trials. Immune-mediated adverse reactions listed here may not include all such possible severe or fatal reactions.
Dr. Gursel Aktan, vice president, global clinical development, Merck Research Laboratories, said the approvals mark an important moment for the ovarian cancer community, reflecting years of focused investment in KEYTRUDA. He added that introducing the first PD-1 inhibitors for platinum-resistant ovarian cancer expands what’s possible for patients and reinforces the company’s commitment to advancing innovative therapies and improved outcomes across women’s cancers.
In patients whose tumors express PD-L1 (CPS ≥1), the median PFS was 8.3 months (95% CI, 7.0-9.4) for those receiving KEYTRUDA plus paclitaxel, with or without bevacizumab, versus 7.2 months (95% CI, 6.2-8.1) for those receiving placebo plus paclitaxel with or without bevacizumab. The median OS for these patients receiving the KEYTRUDA regimen was 18.2 months (95% CI, 15.3-21.0) versus 14.0 months (95% CI, 12.5-16.1) for those receiving the placebo regimen.
The safety of KEYTRUDA in combination with paclitaxel with or without bevacizumab was evaluated in 463 patients with epithelial ovarian, fallopian tube, or primary peritoneal carcinoma whose tumors express PD-L1 (CPS ≥1) enrolled in KEYNOTE-B96. The median duration of exposure to KEYTRUDA was 7.4 months (range 1 day to 35.9 months).
Serious adverse reactions occurred in 54% of patients receiving KEYTRUDA and paclitaxel with or without bevacizumab. Fatal adverse reactions occurred in 3.9% of patients receiving KEYTRUDA and paclitaxel with or without bevacizumab, including assisted suicide (0.9%), death (0.4%), intestinal perforation (0.4%), sepsis (0.4%), COVID-19 (0.4%), cardio-respiratory arrest (0.4%), colitis (0.4%), and embolic stroke (0.4%).
KEYTRUDA was permanently discontinued for adverse reactions in 16% of patients. Adverse reactions leading to the interruption of KEYTRUDA occurred in 44% of patients.
The most common (≥20%) adverse reactions for patients treated with KEYTRUDA in combination with paclitaxel with or without bevacizumab were: diarrhea (45%), fatigue (43%), nausea (41%), alopecia (38%), peripheral neuropathy (38%), epistaxis (31%), urinary tract infection (27%), constipation (25%), abdominal pain (24%), decreased appetite (24%), vomiting (24%), hypothyroidism (21%), cough (20%), hypertension (20%), and rash (20%).
Of the 643 enrolled patients, 72% of patients had tumors expressing PD-L1 (CPS ≥1), 73% received bevacizumab in the study, and 46% received prior bevacizumab. A total of 47% had a platinum-free interval of less than 3 months. Patients were enrolled regardless of PD-L1 tumor expression status.
KEYTRUDA is an anti-programmed death receptor-1 (PD-1) therapy that works by increasing the ability of the body’s immune system to help detect and fight tumor cells. KEYTRUDA is a humanized monoclonal antibody that blocks the interaction between PD-1 and its ligands, PD-L1 and PD-L2, thereby activating T lymphocytes which may affect both tumor cells and healthy cells.
KEYTRUDA QLEX is a fixed-combination drug product of pembrolizumab and berahyaluronidase alfa. Pembrolizumab is a programmed death receptor-1 (PD-1) blocking antibody and berahyaluronidase alfa enhances dispersion and permeability to enable subcutaneous administration of pembrolizumab. KEYTRUDA QLEX is administered as a subcutaneous injection into the thigh or abdomen, avoiding the 5 cm area around the navel, over one minute every three weeks (2.4 mL) or over two minutes every six weeks (4.8 mL).
Merck has one of the industry’s largest immuno-oncology clinical research programs with more than 1,600 trials studying KEYTRUDA across a wide variety of cancers and treatment settings.
At Merck, known as MSD outside of the United States and Canada, we are unified around our purpose: We use the power of leading-edge science to save and improve lives around the world. For more than 130 years, we have brought hope to humanity through the development of important medicines and vaccines. We aspire to be the premier research-intensive biopharmaceutical company in the world – and today, we are at the forefront of research to deliver innovative health solutions that advance the prevention and treatment of diseases in people and animals. We foster a diverse and inclusive global workforce and operate responsibly every day to enable a safe, sustainable and healthy future for all people and communities.
Additional information about KEYTRUDA and KEYTRUDA QLEX, including selected safety information and indications, is available in the full press release.
Source: Merck
