RUBY / ENGOT-EN6 / GOG-3031
Adding immunotherapy to first chemotherapy for advanced endometrial cancer extended life by more than a year on average, most dramatically in tumours with a broken DNA spell-checker.
In dMMR/MSI-H tumours, 24-month PFS was 61.4% vs 15.7% (HR 0.28); in the overall population PFS HR 0.64 (NEJM 2023). Overall survival in the overall population was 44.6 vs 28.2 months (HR 0.69; Annals of Oncology 2024), with dMMR OS HR 0.32. FDA approval July 2023 (dMMR) and August 2024 (all comers).
Setting
Primary advanced (stage III-IV) or first recurrent endometrial cancer: dostarlimab + carboplatin-paclitaxel, then dostarlimab up to 3 years, vs chemotherapy
Phase
Phase 3
Sponsor
GSK
Registry
Headline result
OS 44.6 vs 28.2 months overall (HR 0.69); dMMR PFS HR 0.28.
Reported
2023
Enrolled
494
Replication
NRG-GY018/KEYNOTE-868 (pembrolizumab) and DUO-E (durvalumab) reproduced the dMMR effect; RUBY is the only one with a reported all-comers OS benefit so far.
In plain words
What these results mean for people, not percentages
Progression-free survival at 24 months (dMMR/MSI-H)primarysurrogate endpoint
- 61.4 vs 15.7 out of 100 alive without the cancer growing at 24 months with Dostarlimab + chemo compared with Placebo + chemo; 45.7 more per 100.
- Roughly one extra person helped for every 2 treated. That is a rough figure taken from the two percentages, not a guarantee for any one person.
- Put another way, the treated group had about 72 percent lower chance of the event at any given time (hazard ratio 0.28, likely range 0.16 to 0.5).
- 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 (overall population)primarysurvival endpoint
- Median 44.6 vs 28.2 months with Dostarlimab + chemo compared with Placebo + chemo; about 16.4 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 31 percent lower chance of the event at any given time (hazard ratio 0.69, likely range 0.54 to 0.89).
- 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: Primary advanced (stage III-IV) or first recurrent endometrial cancer: dostarlimab + carboplatin-paclitaxel, then dostarlimab up to 3 years, vs chemotherapy. 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.
494 participants enrolled.
Progression-free survival at 24 months (dMMR/MSI-H)primary
HR 0.28 (0.16–0.5)
Dostarlimab + chemo61.4 of 100
Placebo + chemo15.7 of 100
Overall survival (overall population)primary
HR 0.69 (0.54–0.89)
Dostarlimab + chemo
44.6 mo
Placebo + chemo
28.2 mo
| Endpoint | Arm | n | Value | HR (95% CI) | p | Source |
|---|---|---|---|---|---|---|
| Progression-free survival at 24 months (dMMR/MSI-H)primary | Dostarlimab + chemo | — | 61.4% | 0.28 (0.16–0.5) | — | link |
| Placebo + chemo | — | 15.7% | ||||
| Overall survival (overall population)primary | Dostarlimab + chemo | 245 | 44.6 months | 0.69 (0.54–0.89) | — | link |
| Placebo + chemo | 249 | 28.2 months |
Replication
NRG-GY018/KEYNOTE-868 (pembrolizumab) and DUO-E (durvalumab) reproduced the dMMR effect; RUBY is the only one with a reported all-comers OS benefit so far.