Short answer: OlympiAD was an open-label phase 3 trial of 302 patients with germline BRCA-mutated, HER2-negative metastatic breast cancer. Olaparib 300 mg twice daily improved median progression-free survival over physician's choice single-agent chemotherapy (7.0 vs 4.2 months, HR 0.58) and roughly doubled the response rate (59.9% vs 28.8%), with fewer grade 3 or higher adverse events overall (about 37% vs 51%). The final analysis showed no statistically significant overall survival benefit (19.3 vs 17.1 months, HR 0.90), although a small, non alpha-controlled subgroup treated in the first-line metastatic setting had a longer median OS. This guide is for trainees who need the design, the numbers, and the board-relevant toxicities.
Author and disclosure: Roupen Odabashian, MD, FRCPC, Oncologist and founder of MeDucation AI. I am the founder of MeDucation AI, which sells hematology and oncology board preparation. I have no other financial relationships relevant to the studies discussed here. This article is educational and is not a substitute for individualized clinical judgment or tumor board discussion.
What was the OlympiAD trial design?
OlympiAD (NCT02000622) randomized 302 patients 2:1 between April 2014 and November 2015 to olaparib 300 mg twice daily (n = 205) or single-agent chemotherapy of physician's choice (n = 97). The chemotherapy options were capecitabine, eribulin or vinorelbine in 21-day cycles; in the control arm 41 patients received capecitabine, 34 eribulin and 16 vinorelbine. Eligible patients had a germline BRCA1 or BRCA2 mutation, HER2-negative metastatic breast cancer, and no more than two prior chemotherapy regimens for metastatic disease. Baseline composition was about half hormone receptor positive and half triple negative. The primary endpoint was progression-free survival by blinded independent central review. The trial was funded by AstraZeneca and published by Robson and colleagues in the New England Journal of Medicine in 2017.
What were the primary and secondary endpoint results?
Outcome | Olaparib (n = 205) | Chemotherapy of physician's choice (n = 97) |
|---|---|---|
Median progression-free survival | 7.0 months | 4.2 months (HR 0.58, P < 0.001) |
Objective response rate (measurable disease) | 59.9% | 28.8% |
Grade 3 or higher adverse events | About 37% | About 51% |
Grade 3 or higher anemia | 16% | 4% |
Grade 3 or higher neutropenia | 9% | 26% |
Discontinuation for adverse events | 4.9% | 7.7% |
The pattern to remember is that olaparib traded neutropenia and alopecia for anemia. In the final analysis, alopecia was less frequent with olaparib (3.4% vs 13.2%), and the authors reported no evidence of cumulative toxicity with longer exposure.
Did olaparib improve overall survival?
No, not in the prespecified final analysis. At 64% data maturity (192 deaths), median overall survival was 19.3 months with olaparib and 17.1 months with chemotherapy (HR 0.90, 95% CI 0.66 to 1.23, P = 0.513). In an exploratory subgroup of patients who had not received prior chemotherapy for metastatic disease, median OS was 22.6 vs 14.7 months (HR 0.51, 95% CI 0.29 to 0.90). The authors described this as a possible meaningful benefit, but the subgroup was small and not alpha-controlled, so treat it as hypothesis generating. This distinction between a positive PFS result and a negative OS result is a classic board question.
How does OlympiAD compare with the EMBRACA talazoparib trial?
Feature | OlympiAD | EMBRACA |
|---|---|---|
PARP inhibitor and dose | Olaparib 300 mg twice daily | Talazoparib 1 mg daily |
Patients | 302 (2:1) | 431 (2:1) |
Control arm | Capecitabine, eribulin or vinorelbine | Capecitabine, eribulin, gemcitabine or vinorelbine |
Median PFS | 7.0 vs 4.2 months (HR 0.58) | 8.6 vs 5.6 months (HR 0.54) |
Objective response rate | 59.9% vs 28.8% | 62.6% vs 27.2% |
Overall survival | No significant benefit in the final analysis | No significant benefit in the final analysis |
Hematologic toxicity signal | Grade 3 or higher anemia 16% | Grade 3 or 4 anemia 39% vs 5% |
Patient-reported outcomes | Not a reported strength in the final OS paper | Global health status improved with talazoparib and deteriorated with chemotherapy |
The two trials look similar, and cross-trial comparisons are unreliable because the populations, control arms and designs differ. Both PARP inhibitors are accepted options for gBRCA-mutated, HER2-negative metastatic breast cancer.
Where does OlympiA fit?
OlympiA moved olaparib into the curative setting. It randomized 1,836 patients with germline BRCA-mutated, high-risk, HER2-negative early breast cancer who had completed definitive local therapy and neoadjuvant or adjuvant chemotherapy to olaparib or placebo for one year. At a median follow-up of 2.5 years, invasive disease-free survival favored olaparib (HR 0.58, 99.5% CI 0.41 to 0.82), with 3-year rates of 85.9% vs 77.1%. Distant disease-free survival also favored olaparib (HR 0.57). Do not confuse the adjuvant trial with OlympiAD: OlympiA treats for one year, whereas metastatic therapy continues until progression or unacceptable toxicity.
Who should be tested for germline BRCA mutations?
Testing eligibility has broadened over time, and recommendations are updated regularly, so check the current NCCN and ASCO guidance rather than relying on a memorized age cutoff. The practical point is that OlympiAD and EMBRACA only apply once a deleterious germline BRCA1 or BRCA2 variant is confirmed, and the label requires selection with an FDA-approved companion diagnostic. In hormone receptor positive disease, patients should have had prior endocrine therapy or be considered unsuitable for it.
What PARP inhibitor toxicities should you know?
Anemia is the most frequent significant toxicity: in OlympiAD, all-grade anemia was 40% with olaparib vs 26% with chemotherapy (16% vs 4% grade 3 or higher).
Myelodysplastic syndrome and acute myeloid leukemia are listed in the label warnings: the cumulative incidence across olaparib trials was about 1.2%, and more than half of those cases were fatal.
Pneumonitis occurred in about 1% of patients and requires interruption and workup of new respiratory symptoms.
Venous thromboembolism is uncommon in the breast trials (about 0.5% to 1%).
Dose reductions step down to 250 mg and then 200 mg twice daily.
To practice this kind of question, see Oncology Board Review Question Banks Compared or the broader plan in How to Pass the ABIM Medical Oncology Boards. For the full exam approach, read Oncology Board Review 2026.
Frequently asked questions
What did the OlympiAD trial show?
Olaparib improved progression-free survival over single-agent chemotherapy in germline BRCA-mutated, HER2-negative metastatic breast cancer (7.0 vs 4.2 months, HR 0.58) with a higher response rate and fewer serious adverse events overall.
Did olaparib improve overall survival in OlympiAD?
The final analysis showed no statistically significant benefit (19.3 vs 17.1 months, HR 0.90). An exploratory first-line metastatic subgroup had a longer median survival, but it was small and not alpha-controlled.
What is the difference between OlympiAD and OlympiA?
OlympiAD tested olaparib in the metastatic setting. OlympiA tested one year of adjuvant olaparib in high-risk early breast cancer and improved invasive disease-free survival.
Is olaparib better than talazoparib?
There is no head-to-head trial. The pivotal trials showed similar progression-free survival benefits versus chemotherapy, and neither showed a significant overall survival advantage, so choice depends on toxicity profile, access and patient factors.
Does olaparib cause leukemia?
Myelodysplastic syndrome and acute myeloid leukemia are recognized risks. The prescribing information reports a cumulative incidence of about 1.2% across trials, so persistent cytopenias should prompt evaluation.
References
Robson M, Im SA, Senkus E, et al. Olaparib for metastatic breast cancer in patients with a germline BRCA mutation. N Engl J Med. 2017. doi:10.1056/NEJMoa1706450
The ASCO Post. OlympiAD results presented at the 2017 ASCO Annual Meeting. ascopost.com
Robson ME, Tung N, Conte P, et al. OlympiAD final overall survival and tolerability results: olaparib versus chemotherapy treatment of physician's choice in patients with a germline BRCA mutation and HER2-negative metastatic breast cancer. Ann Oncol. 2019;30(4):558 to 566. doi:10.1093/annonc/mdz012
Litton JK, Rugo HS, Ettl J, et al. Talazoparib in patients with advanced breast cancer and a germline BRCA mutation. N Engl J Med. 2018;379:753 to 763. ASCO Post summary
The ASCO Post. Final overall survival results from the phase III EMBRACA trial. April 2020. ascopost.com
Merck. Lynparza reduced the risk of invasive disease recurrence or death by 42% versus placebo in adjuvant treatment of patients with germline BRCA mutations and high-risk HER2-negative early breast cancer (OlympiA). June 2021. merck.com
Lynparza (olaparib) prescribing information. Drugs.com professional monograph
ClinicalTrials.gov. OlympiAD, NCT02000622. clinicaltrials.gov
ClinicalTrials.gov. OlympiA, NCT02032823. clinicaltrials.gov
