postMONARCH
Continuing CDK4/6 blockade with a different drug after the first one fails gives a small but real benefit.
PFS 6.0 vs 5.3 months (HR 0.73; P=0.017 nominal); the first placebo-controlled phase 3 showing benefit of CDK4/6 inhibition beyond progression. Absolute gain is modest; biomarker-defined subgroups (no ESR1 or PIK3CA mutation) did better.
- Median 6 vs 5.3 months with Abemaciclib + fulvestrant compared with Placebo + fulvestrant; about 0.7 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 27 percent lower chance of the event at any given time (hazard ratio 0.73, likely range 0.57 to 0.95).
- 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.
- These results apply to the people the trial enrolled: HR+/HER2- advanced breast cancer after progression on CDK4/6 + endocrine therapy: abemaciclib + fulvestrant vs placebo + fulvestrant. 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.
368 participants enrolled.
| Endpoint | Arm | n | Value | HR (95% CI) | p | Source |
|---|---|---|---|---|---|---|
| Progression-free survivalprimary | Abemaciclib + fulvestrant | 182 | 6 months | 0.73 (0.57–0.95) | 0.017 | link |
| Placebo + fulvestrant | 186 | 5.3 months |
Pages like this
not linked directly; found by shared links- TrialINAVO120
Shares Fulvestrant, CDK4/6, HR-positive / HER2-negative breast cancer.
- PersonMatthew P. Goetz
Shares Abemaciclib, CDK4/6, HR-positive / HER2-negative breast cancer.
- TrialMONARCH 3
Shares Abemaciclib, CDK4/6, HR-positive / HER2-negative breast cancer.
- IdeaCDK4-selective inhibitors as the new first-line backbone
Shares Abemaciclib, CDK4/6, HR-positive / HER2-negative breast cancer.
- TrialVERITAC-2
Shares Fulvestrant, HR-positive / HER2-negative breast cancer.
- TrialEMBER-3
Shares Abemaciclib, CDK4/6, HR-positive / HER2-negative breast cancer.
- TrialPALOMA-2
- TrialSOLAR-1
Shares Fulvestrant, HR-positive / HER2-negative breast cancer.