KEYNOTE-B96 / ENGOT-ov65
After a decade of failures, the first immunotherapy trial to extend survival in ovarian cancer, leading to the first checkpoint-inhibitor approval in the disease.
In PD-L1-positive tumours (CPS ≥1), PFS 8.3 vs 7.2 months (HR 0.72) and OS 18.2 vs 14.0 months (HR 0.76); in the overall population OS 17.7 vs 14.0 months (HR 0.82; Lancet 2026). FDA approval February 2026 for PD-L1-positive platinum-resistant disease, including the subcutaneous formulation.
Setting
Platinum-resistant recurrent ovarian cancer, 1-2 prior lines: pembrolizumab + weekly paclitaxel ± bevacizumab vs placebo + paclitaxel ± bevacizumab
Phase
Phase 3
Sponsor
Merck
Registry
Headline result
OS 18.2 vs 14.0 months in CPS ≥1 (HR 0.76); ITT OS HR 0.82.
Reported
2025
Replication
First positive phase 3; earlier trials (JAVELIN Ovarian 200, IMagyn050, DUO-O) were negative for OS.
In plain words
What these results mean for people, not percentages
Progression-free survival (CPS ≥1)primarysurrogate endpoint
- Median 8.3 vs 7.2 months with Pembrolizumab + paclitaxel ± bev compared with Placebo + paclitaxel ± bev; about 1.1 months longer for half the group.
- A median is a midpoint: half the people did better than this and half did worse, so it is not a prediction for any one person.
- Put another way, the treated group had about 28 percent lower chance of the event at any given time (hazard ratio 0.72, likely range 0.58 to 0.89).
- This is a surrogate endpoint: it measures the cancer being controlled or absent on scans and tests, which often, but not always, translates into living longer.
Overall survival (CPS ≥1)survival endpoint
- Median 18.2 vs 14 months with Pembrolizumab + paclitaxel ± bev compared with Placebo + paclitaxel ± bev; about 4.2 months longer for half the group.
- A median is a midpoint: half the people did better than this and half did worse, so it is not a prediction for any one person.
- Put another way, the treated group had about 24 percent lower chance of the event at any given time (hazard ratio 0.76, likely range 0.61 to 0.94).
- Overall survival counts deaths from any cause, so it is the most direct measure of whether a treatment helps people live longer.
Overall survival (all patients)survival endpoint
- Median 17.7 vs 14 months with Pembrolizumab + paclitaxel ± bev compared with Placebo + paclitaxel ± bev; about 3.7 months longer for half the group.
- A median is a midpoint: half the people did better than this and half did worse, so it is not a prediction for any one person.
- Put another way, the treated group had about 18 percent lower chance of the event at any given time (hazard ratio 0.82, likely range 0.69 to 0.97).
- Overall survival counts deaths from any cause, so it is the most direct measure of whether a treatment helps people live longer.
Be careful
- These results apply to the people the trial enrolled: Platinum-resistant recurrent ovarian cancer, 1-2 prior lines: pembrolizumab + weekly paclitaxel ± bevacizumab vs placebo + paclitaxel ± bevacizumab. People in a different situation may not see the same effect.
Numbers are from the trial as recorded here; see the source links in the table below. This is orientation, not medical advice: ask your team how closely the trial population matches you.
Progression-free survival (CPS ≥1)primary
HR 0.72 (0.58–0.89)
Pembrolizumab + paclitaxel ± bev
8.3 mo
Placebo + paclitaxel ± bev
7.2 mo
Overall survival (CPS ≥1)
HR 0.76 (0.61–0.94)
Pembrolizumab + paclitaxel ± bev
18.2 mo
Placebo + paclitaxel ± bev
14 mo
Overall survival (all patients)
HR 0.82 (0.69–0.97)
Pembrolizumab + paclitaxel ± bev
17.7 mo
Placebo + paclitaxel ± bev
14 mo
| Endpoint | Arm | n | Value | HR (95% CI) | p | Source |
|---|---|---|---|---|---|---|
| Progression-free survival (CPS ≥1)primary | Pembrolizumab + paclitaxel ± bev | — | 8.3 months | 0.72 (0.58–0.89) | — | link |
| Placebo + paclitaxel ± bev | — | 7.2 months | ||||
| Overall survival (CPS ≥1) | Pembrolizumab + paclitaxel ± bev | — | 18.2 months | 0.76 (0.61–0.94) | — | link |
| Placebo + paclitaxel ± bev | — | 14 months | ||||
| Overall survival (all patients) | Pembrolizumab + paclitaxel ± bev | — | 17.7 months | 0.82 (0.69–0.97) | — | link |
| Placebo + paclitaxel ± bev | — | 14 months |
Replication
First positive phase 3; earlier trials (JAVELIN Ovarian 200, IMagyn050, DUO-O) were negative for OS.