Clinical trialPhase 3Breast cancer

Sustained benefit of adjuvant olaparib in women with germline BRCA1- and BRCA2-associated high-risk HER2-negative early breast cancer: updated results from the OlympiA phase III trial

Ann Oncol · 20261836 patients

Garber JE, Cameron D, Campbell C, Yothers G, Taboada M, El-Abed S, et al. Ann Oncol. 2026

Study type: Clinical trial
Study name: OlympiA
Phase: Phase 3
Design: Randomised placebo-controlled trial — third prespecified interim analysis (median follow-up 6.1 years)
Sample size: 1836 patients
Source: Ann Oncol · 2026
Trial registration: NCT02032823

In plain words

This study looked at women with an inherited BRCA1 or BRCA2 mutation and HER2-negative breast cancer with a high risk of coming back. After finishing chemotherapy, they were given one year of olaparib tablets or a placebo (dummy tablet). After about six years, the cancer came back less often in the olaparib group and more patients were alive (87.5% vs 83.2%), with no increase in serious blood-related side effects. Decisions about treatment should be made with your treating doctor.

Key results

0.65 (95% CI: 0.53 to 0.78)

Invasive disease-free survival (HR)

Median follow-up 6.1 years

0.65 (0.53 to 0.81)

Distant disease-free survival (HR)

0.72 (0.56 to 0.93)

Overall survival (HR)

87.5% vs 83.2%

6-year overall survival

Difference 4.4% (95% CI: 0.9% to 6.7%)

0.4% vs 0.7%

MDS/AML

Olaparib vs placebo

Drugs in this study:Olaparib (Lynparza)

Dose and schedule cards

Adjuvant olaparib (OlympiA)

Germline BRCA1/2 mutation, HER2-negative, high risk, after completion of neoadjuvant or adjuvant chemotherapy and local treatmentCycle length: ContinuousOn the page “Breast cancer” · Early HER2-negative disease: chemotherapy, immunotherapy and adjuvant therapy

Germline BRCA1/2 mutation, HER2-negative, high risk, after completion of neoadjuvant or adjuvant chemotherapy and local treatment

Drug	Dose	Route	Schedule
Olaparib	300 mg twice daily	Oral	Continuous

Cycle length: Continuous
Duration: 1 year (or until recurrence or unacceptable toxicity); in HR-positive disease, together with hormone therapy

Start only after haematologic toxicity from prior chemotherapy has recovered to grade 1 or lower.

On the page “Breast cancer” · Early HER2-negative disease: chemotherapy, immunotherapy and adjuvant therapy

Adjuvant treatment of high-risk early HER2-negative breast cancer with a germline BRCA mutation (OlympiA)

After neoadjuvant or adjuvant chemotherapyCycle length: ContinuousOn the page “Olaparib (Lynparza)” · Standard dosing (FDA label)

After neoadjuvant or adjuvant chemotherapy

Drug	Dose	Route	Schedule
Continuous
Olaparib	300 mg	Oral (with or without food)	Twice daily (about every 12 hours)

Cycle length: Continuous
Duration: 1 year in total, or until recurrence or unacceptable toxicity

In hormone receptor-positive disease, continue concurrent endocrine therapy as per guidelines.

On the page “Olaparib (Lynparza)” · Standard dosing (FDA label)

Doses follow the trial protocol, guideline or official drug label (source given in the notes of each regimen). Before prescribing, check blood counts, renal and hepatic function, drug interactions and the patient’s condition, and adjust the dose according to the drug label.

Treatment arms and regimens

1Olaparib

Olaparib tablets 300 mg (two 150 mg tablets) orally twice daily about 12 hours apart, for 1 year; in HR-positive tumours concurrent endocrine therapy was continued.

2Placebo

Matching placebo tablets twice daily for 1 year.

Source of the regimen details: ClinicalTrials.gov NCT02032823 (300 mg twice daily) and the FDA label for Lynparza (duration 1 year; continued endocrine therapy in HR-positive disease)

Doses are given for the information of specialists, as in this study’s protocol, and are not a prescription. Every drug must be prescribed by the treating physician for the individual patient.

Study population

Patients with a germline pathogenic/likely pathogenic BRCA1 or BRCA2 variant and high-risk HER2-negative early breast cancer who had completed neoadjuvant or adjuvant chemotherapy.

Endpoints

Primary endpoint: invasive disease-free survival (IDFS); key secondary endpoints: distant disease-free survival (DDFS) and overall survival (OS). The analyses in this report are descriptive.

Safety and side effects

The risk of adverse events of special interest did not increase (6.3% vs 9.3%), including myelodysplastic syndrome/acute myeloid leukaemia (0.4% vs 0.7%).

Clinical significance and place in guidelines

This update confirms the durable benefit of adjuvant olaparib in disease-free survival and overall survival, and highlights the importance of germline BRCA testing in high-risk HER2-negative patients, including HR-positive disease, before decisions on adjuvant treatment.

Limitations

The analyses in this report are descriptive. Dose and adverse event details are in the full text of the paper.

Original article (DOI)PubMed ClinicalTrials.gov

This summary was prepared by the editorial team from the published paper; the original paper is the final reference. Read the original abstract on PubMed.