MONALEESA-2
The first CDK4/6 inhibitor trial to show that adding the pill to hormone therapy makes women live longer, by about a year.
PFS 25.3 vs 16.0 months (HR 0.57); final OS 63.9 vs 51.4 months (HR 0.76, P=0.004), the first OS benefit for a CDK4/6 inhibitor in first-line postmenopausal disease and the longest median OS reported in this setting at the time. With MONALEESA-3 and -7 it established ribociclib as the CDK4/6 inhibitor with the most consistent survival data.
Setting
First-line postmenopausal HR+/HER2- advanced breast cancer: ribociclib + letrozole vs placebo + letrozole
Phase
Phase 3
Sponsor
Novartis
Registry
Headline result
OS 63.9 vs 51.4 months, HR 0.76.
Reported
2016
Enrolled
668
Replication
OS benefit replicated in MONALEESA-7 (premenopausal) and MONALEESA-3 (fulvestrant partner); the class effect on OS was not seen with palbociclib (PALOMA-2).
In plain words
What these results mean for people, not percentages
Progression-free survivalprimarysurrogate endpoint
- Median 25.3 vs 16 months with Ribociclib + letrozole compared with Placebo + letrozole; about 9.3 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 43 percent lower chance of the event at any given time (hazard ratio 0.57, likely range 0.46 to 0.7).
- 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 survivalsurvival endpoint
- Median 63.9 vs 51.4 months with Ribociclib + letrozole compared with Placebo + letrozole; about 12.5 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 0.63 to 0.93).
- 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: First-line postmenopausal HR+/HER2- advanced breast cancer: ribociclib + letrozole vs placebo + letrozole. People in a different situation may not see the same effect.
- The trial selected people by a biomarker (HER2); the result should not be assumed for people whose cancer does not have it.
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.
668 participants enrolled.
Progression-free survivalprimary
HR 0.57 (0.46–0.7)
Ribociclib + letrozole
25.3 mo
Placebo + letrozole
16 mo
Overall survival
HR 0.76 (0.63–0.93) · p = 0.004
Ribociclib + letrozole
63.9 mo
Placebo + letrozole
51.4 mo
| Endpoint | Arm | n | Value | HR (95% CI) | p | Source |
|---|---|---|---|---|---|---|
| Progression-free survivalprimary | Ribociclib + letrozole | 334 | 25.3 months | 0.57 (0.46–0.7) | — | link |
| Placebo + letrozole | 334 | 16 months | ||||
| Overall survival | Ribociclib + letrozole | 334 | 63.9 months | 0.76 (0.63–0.93) | 0.004 | link |
| Placebo + letrozole | 334 | 51.4 months |
Replication
OS benefit replicated in MONALEESA-7 (premenopausal) and MONALEESA-3 (fulvestrant partner); the class effect on OS was not seen with palbociclib (PALOMA-2).