AstraZeneca and Merck (referred to as MSD outside the U.S. and Canada) have presented promising long-term results from the OlympiA Phase 3 trial at the 2024 San Antonio Breast Cancer Symposium. The study shows that Lynparza (olaparib) continues to work well for people with gBRCA mutations (gBRCAm) and HER2-negative high-risk early breast cancer.

At a median follow-up of 6.1 years, Lynparza showed significant enhancements in overall survival (OS), invasive disease-free survival (IDFS), and distant disease-free survival (DDFS) when compared to placebo. The findings expand upon the primary results of the trial, previously published in The New England Journal of Medicine.

Patients receiving Lynparza demonstrated a 28% decrease in mortality risk (hazard ratio [HR] 0.72; 95% confidence interval [CI] 0.56-0.93). At six years, overall survival rates were 87.5% for recipients of Lynparza, in contrast to 83.2% for the placebo group. Lynparza also cut the risk of invasive breast cancer coming back, getting other cancers, or dying by 35% (HR 0.65; 95% CI 0.53-0.78). It also cut the risk of distant disease coming back or dying by the same amount (HR 0.65; 95% CI 0.53-0.81).

Dr. Judy E. Garber, co-principal investigator of the trial and Chief of the Division of Cancer Genetics and Prevention at Dana-Farber Cancer Institute, stated, “These long-term data from OlympiA confirm that one year of adjuvant treatment with olaparib provides a clinically meaningful survival benefit.” She highlighted the significance of conducting germline BRCA testing at the time of diagnosis to facilitate the early identification of eligible patients.

The advantages encompassed all major subgroups, including individuals with high-risk, hormone-receptor-positive conditions. The trial reaffirmed the drug's safety profile, indicating no new safety signals or heightened risks of myelodysplastic syndrome or acute myeloid leukaemia.

Lynparza, a PARP inhibitor, has proven to be a significant advancement in the treatment of breast cancer. “The continuation of this benefit after six years of follow-up is significant for patients and underscores Lynparza's role in transforming the treatment of BRCA-mutated early-stage breast cancer,” stated Susan Galbraith, Executive Vice President of Oncology R&D at AstraZeneca.

Dr. Eliav Barr, Chief Medical Officer of Merck Research Laboratories, emphasized the aggressive characteristics of the type of cancer addressed in the OlympiA trial.  The long-term efficacy demonstrated in the OlympiA study underscores Lynparza's significance as a treatment option for individuals diagnosed with this aggressive form of breast cancer.

Breast cancer is the second most frequently diagnosed cancer globally, with around 2.3 million new cases reported in 2022. Sixty-three percent of patients receive early stage diagnoses, and approximately 5-10% have BRCA mutations, frequently associated with increased recurrence risks and more aggressive disease.

The Breast International Group (BIG) and various institutions lead the OlympiA trial, which underscores the importance of targeted therapies in oncology. Lynparza has received approval in multiple countries for gBRCAm, HER2-negative breast cancers, encompassing both early-stage and metastatic forms.

The trial results indicate a transition toward precision medicine, providing renewed optimism for patients with high-risk breast cancer. Lynparza's sustained benefits and strong safety profile reinforce its role as an essential instrument in cancer treatment.