# SOLO-1

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

## TL;DR

Two years of an olaparib pill after chemotherapy made a large share of women with BRCA-mutated ovarian cancer long-term survivors.

## Summary

PFS HR 0.30 at the primary analysis (NEJM 2018). At 7 years, 67.0% of olaparib patients were alive versus 46.5% on placebo (HR 0.55; JCO 2023), the first PARP inhibitor trial with a clinically meaningful overall survival gain in the first-line setting and the basis for the 2018 maintenance approval. Roughly half of olaparib patients remained progression-free at 5 years.

## Fields

- Kind: Trial
- Status: positive
- Last checked: 2026-09-07
- Registry id: NCT01844986
- Phase: 3
- Setting: Newly diagnosed advanced BRCA-mutated ovarian cancer in response to platinum chemotherapy: olaparib maintenance for 2 years vs placebo
- Sponsor: AstraZeneca / Merck
- Enrolled: 391
- Result: PFS HR 0.30; 7-year OS 67.0% vs 46.5% (HR 0.55).
- Outcomes: Progression-free survival: Olaparib vs Placebo, HR 0.3; Overall survival at 7 years: Olaparib 67% vs Placebo 46.5%, HR 0.55
- Replication: PRIMA (niraparib) and PAOLA-1 (olaparib + bevacizumab) reproduced the PFS effect in HRD-positive disease; only SOLO-1 has shown a clear OS gain.

## Sources

- ClinicalTrials.gov NCT01844986: https://clinicaltrials.gov/study/NCT01844986
- NEJM 2018: https://www.nejm.org/doi/full/10.1056/NEJMoa1810858
- 7-year OS, JCO 2023: https://ascopubs.org/doi/10.1200/JCO.22.01549

## Connected records

- cancers: [High-grade serous ovarian cancer](https://onco.cc/cancers/high-grade-serous-ovarian-cancer/), [Ovarian cancer](https://onco.cc/cancers/ovarian/), [Platinum-sensitive ovarian cancer](https://onco.cc/cancers/platinum-sensitive-ovarian-cancer/)
- technologies: [PARP inhibitors](https://onco.cc/technologies/parp-inhibitor/)
- targets: [BRCA1 / BRCA2 (HRD)](https://onco.cc/targets/brca/), [PARP](https://onco.cc/targets/parp/)
- drugs: [BRACAnalysis CDx](https://onco.cc/drugs/bracanalysis-cdx/), [Olaparib](https://onco.cc/drugs/olaparib/)
- companies: [AstraZeneca](https://onco.cc/companies/astrazeneca/)
- people: [Kathleen N. Moore](https://onco.cc/people/kathleen-moore/)
- ideas: [ctDNA-guided duration of PARP maintenance](https://onco.cc/ideas/idea-ctdna-guided-parp-duration/)
- roadmaps: [Targeted therapy roadmap: imatinib → designed for resistance → the undruggable drivers fall](https://onco.cc/roadmaps/targeted-therapy-roadmap/)

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