SOLAR-1
The first trial to show a PI3K inhibitor helps in breast cancers carrying a PIK3CA mutation, at the cost of high blood sugar and rash.
In the PIK3CA-mutant cohort (n=341), PFS 11.0 vs 5.7 months (HR 0.65). No benefit without the mutation. Hyperglycaemia (grade 3-4 in ~37%) and rash limited uptake; the trial preceded routine CDK4/6 use, so BYLieve later confirmed activity after CDK4/6 inhibitors.
- Median 11 vs 5.7 months with Alpelisib + fulvestrant compared with Placebo + fulvestrant; about 5.3 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 35 percent lower chance of the event at any given time (hazard ratio 0.65, likely range 0.5 to 0.85).
- 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 aromatase inhibitor: alpelisib + fulvestrant vs placebo + fulvestrant, by PIK3CA status. 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.
572 participants enrolled.
| Endpoint | Arm | n | Value | HR (95% CI) | p | Source |
|---|---|---|---|---|---|---|
| Progression-free survival (PIK3CA-mutant)primary | Alpelisib + fulvestrant | 169 | 11 months | 0.65 (0.5–0.85) | <0.001 | link |
| Placebo + fulvestrant | 172 | 5.7 months |
Pages like this
not linked directly; found by shared links- PairingPI3K/AKT-pathway inhibitor + endocrine therapy (± CDK4/6)
Shares Alpelisib, Fulvestrant, PIK3CA / PI3K-alpha, HR-positive / HER2-negative breast cancer.
- TrialINAVO120
Shares Fulvestrant, PIK3CA / PI3K-alpha, HR-positive / HER2-negative breast cancer.
- TrialCAPItello-291
Shares Fulvestrant, PIK3CA / PI3K-alpha, HR-positive / HER2-negative breast cancer.
- TrialpostMONARCH
Shares Fulvestrant, HR-positive / HER2-negative breast cancer.
- TrialVERITAC-2
Shares Fulvestrant, HR-positive / HER2-negative breast cancer.
- PersonFrançois-Clément Bidard
Shares Fulvestrant, HR-positive / HER2-negative breast cancer.
- PersonRamon E. Parsons
Shares PIK3CA / PI3K-alpha, HR-positive / HER2-negative breast cancer.
- ProductGedatolisib
Shares PIK3CA / PI3K-alpha, HR-positive / HER2-negative breast cancer.