On February 10, 2026, the U.S. FDA approved pembrolizumab in combination with paclitaxel, with or without bevacizumab, for adults with platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal carcinomawhose tumors express PD-L1 (CPS ≥ 1) and who have received one or two prior systemic regimens.
In parallel, the agency authorized the PD-L1 IHC 22C3 pharmDx assay as the companion diagnostic to identify eligible patients—firmly embedding biomarker-guided immunotherapy into a setting that has historically lacked effective targeted options.
This decision, reviewed under Project Orbis, reflects coordinated international regulatory collaboration and underscores the growing global urgency to improve outcomes in platinum-resistant disease.
KEYNOTE-B96: The Evidence Behind the Approval
The approval is based on the randomized, double-blind phase III KEYNOTE-B96 trial, which enrolled 643 patientswith platinum-resistant ovarian-type carcinomas progressing within six months after prior platinum therapy.
Among PD-L1–positive tumors (CPS ≥ 1):
- Median PFS:
8.3 months with pembrolizumab-based therapy
vs 7.2 months with chemotherapy backbone alone
(HR 0.72) - Median OS:
18.2 months vs 14.0 months
(HR 0.76)
Although the PFS gain appears modest, the overall survival improvement is clinically meaningful in a population where durable benefit has been rare.
Safety findings were consistent with known pembrolizumab toxicity, dominated by immune-mediated events rather than unexpected signals—supporting feasibility in routine practice.
Recommended Dosage and Administration
Pembrolizumab is administered at a fixed dose of 200 mg every 3 weeks or 400 mg every 6 weeks, continued until disease progression, unacceptable toxicity, or for a maximum treatment duration of 24 months.
The subcutaneous formulation combining pembrolizumab and berahyaluronidase alfa-pmph is given at 395 mg/4,800 units every 3 weeks or 790 mg/9,600 units every 6 weeks under the same treatment-duration principles.
When used in combination therapy, pembrolizumab (intravenous or subcutaneous) should be administered prior to paclitaxel, with or without bevacizumab, on treatment days when agents are given together. Dosing for accompanying cytotoxic or anti-angiogenic agents should follow their respective prescribing information.
Ovarian Cancer: Symptoms, Causes, Stages, Diagnosis and Treatment
How Platinum-Resistant Ovarian Cancer Has Traditionally Been Treated
Platinum-resistant disease (progression <6 months after platinum) has historically been a “control the tempo” setting—short-lived responses, frequent switching, and constant balancing of symptoms vs toxicity. In NCCN-based practice, the backbone has been sequential single-agent therapy, with optional anti-angiogenic intensification in selected patients.
Sequential single-agent chemotherapy
Most patients cycle through one drug at a time, aiming for symptom relief and temporary disease control:
- Weekly paclitaxel
- Pegylated liposomal doxorubicin (PLD)
- Topotecan
- Gemcitabine
Across trials and real-world series, these regimens tend to deliver low-to-moderate response rates and short PFS, which is exactly why platinum-resistant disease has remained one of the toughest “everyday oncology” problems in gynecologic cancer.
Adding bevacizumab: meaningful PFS/response lift, but not a “reset”
The key proof-of-principle came from AURELIA, which tested bevacizumab + chemotherapy (weekly paclitaxel orPLD or topotecan) vs the same chemotherapy alone in platinum-resistant disease. The consistent message from AURELIA and subsequent summaries: adding bevacizumab improves disease control (PFS/response), but it doesn’t fully overcome resistance, and benefits vary by regimen and patient biology.
Immunotherapy alone
Single-agent PD-1 therapy has repeatedly shown modest response rates in recurrent ovarian cancer—KEYNOTE-100 is the classic example. In the final analysis (pembrolizumab 200 mg Q3W):
Overall response rate (ORR): ~8–10%
- Cohort A: 8.1%
- Cohort B: 9.9%
Median PFS: 2.1 months (both cohorts)
Median OS: 18.7 months (cohort A) vs 17.6 months (cohort B)
PD-L1 mattered, but didn’t “solve it”: higher CPS enriched for better ORR (e.g., CPS ≥10 increased ORR into the ~12–18% range depending on cohort), yet responses still remained a minority overall.
| Trial | Study Setting | Treatment Strategy | Key Results |
| AURELIA | Platinum-resistant recurrent ovarian cancer | Single-agent chemotherapy ± bevacizumab | Bevacizumab improved PFS (~6.7 vs 3.4 months) and response rate, no clear OS benefit |
| KEYNOTE-100 | Recurrent ovarian cancer (multiple prior lines) | Pembrolizumab monotherapy | Low ORR (~8–10%) overall; higher responses in PD-L1 CPS ≥10 (~17%); modest durability |
| KEYNOTE-B96 | Platinum-resistant disease, PD-L1 CPS ≥1 | Pembrolizumab + paclitaxel ± bevacizumab vs placebo combo | Improved PFS (8.3 vs 7.2 mo; HR 0.72) and OS (18.2 vs 14.0 mo; HR 0.76) |
Key Takeaway
The FDA approval of pembrolizumab with paclitaxel ± bevacizumab marks a turning point in platinum-resistant ovarian cancer—introducing:
- First survival-improving immunotherapy regimen
- Mandatory PD-L1 biomarker selection
- A new combinational treatment paradigm
The next critical question is no longer whether immunotherapy works in ovarian cancer— but how far combination immunotherapy strategies can push survival in this historically lethal setting.
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