# SOLAR-1

Source: https://onco.cc/trials/solar-1/  
OnCo record `solar-1` (Trial). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

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.

## Summary

SOLAR-1, trial NCT02437318 sponsored by Novartis and reported in 2018, was the first trial to show that a PI3K inhibitor helps in breast cancers carrying a PIK3CA mutation, at the cost of high blood sugar and rash. It randomised 572 women with HR-positive, HER2-negative advanced breast cancer after an aromatase inhibitor to alpelisib or placebo with fulvestrant, met its primary progression-free survival endpoint in the 341 patients with the mutation and showed no benefit without it, while severe hyperglycaemia in about 37 percent limited uptake. OnCo links it to PIK3CA and PI3K-alpha as a target, alpelisib, fulvestrant and Fabrice André. Whether alpelisib keeps a role as selective inhibitors arrive is the open question.

## Fields

- Kind: Trial
- Status: positive
- Last checked: 2026-09-07
- Registry id: NCT02437318
- Phase: 3
- Setting: HR+/HER2- advanced breast cancer after aromatase inhibitor: alpelisib + fulvestrant vs placebo + fulvestrant, by PIK3CA status
- Sponsor: Novartis
- Enrolled: 572
- Result: PFS 11.0 vs 5.7 months, HR 0.65 (PIK3CA-mutant).
- Outcomes: Progression-free survival (PIK3CA-mutant): Alpelisib + fulvestrant 11 months vs Placebo + fulvestrant 5.7 months, HR 0.65
- Replication: Activity after CDK4/6 inhibitors confirmed in the single-arm BYLieve study; the mutant-selective successor inavolisib (INAVO120) showed a larger effect with less hyperglycaemia.

## Sources

- ClinicalTrials.gov NCT02437318: https://clinicaltrials.gov/study/NCT02437318

## Connected records

- cancers: [HR-positive / HER2-negative breast cancer](https://onco.cc/cancers/breast-hr-positive/), [HR-positive metastatic breast cancer after CDK4/6 inhibitors](https://onco.cc/cancers/hr-positive-metastatic-post-cdk46/)
- technologies: [PI3K, AKT and mTOR inhibitors](https://onco.cc/technologies/pi3k-akt-mtor-inhibitors/), [Small-molecule kinase inhibitors](https://onco.cc/technologies/kinase-inhibitors/)
- targets: [PIK3CA / PI3K-alpha](https://onco.cc/targets/pik3ca/)
- drugs: [Alpelisib](https://onco.cc/drugs/alpelisib/), [Fulvestrant](https://onco.cc/drugs/fulvestrant/)
- companies: [Novartis](https://onco.cc/companies/novartis/)
- people: [Fabrice André](https://onco.cc/people/fabrice-andre/)
- key papers: [Alpelisib plus fulvestrant for PIK3CA-mutated, hormone receptor-positive, human epidermal growth factor receptor-2-negative advanced breast cancer: final overall survival results from SOLAR-1](https://onco.cc/key-papers/paper-solar-1-ann-oncol-2021-update/), [SOLAR-1: alpelisib plus fulvestrant for PIK3CA-mutated hormone receptor-positive advanced breast cancer](https://onco.cc/key-papers/paper-solar-1-alpelisib-nejm-2019/)
- roadmaps: [Hormonal therapy roadmap: removing the ovaries → tamoxifen → oral degraders switched by a blood test](https://onco.cc/roadmaps/hormonal-therapy-roadmap/)

---
JSON: https://onco.cc/api/v1/entities/solar-1.json