Evaluating olaparib for patients with BRCA1/2-positive breast cancer

This study looked at the use of olaparib (Lynparza) treatment for patients with high risk, BRCA1/2-positive, HER2-negative breast cancer (BC). The authors found that in patients with BRCA1/2-positive BC, olaparib after local treatment improved the outcomes of these patients.

BC is one of the most common cancers found in women. BRCA1 and BRCA2 gene mutations (abnormalities) can be found in many patients with BC. These mutations are often found in young patients and can be very resistant to current treatment options. These patients are also more likely to have a relapse after initial treatments, even in the early stages.

Olaparib is a PARP (proteins involved in DNA repair) inhibitor. BRCA1 and BRCA2 mutated cancers have been shown to be responsive to PARP-inhibitors. Olaparib has been approved for the treatment of patients with BRCA-positive BC, particularly when it has spread. However, the effectiveness of olaparib after previous treatments in early-stage BRCA1/2-positive BC was unknown. 

There were a total of 1836 patients with BRCA-positive, HER2-negative included in this study. Patients had previously been treated with local therapies such as surgery, radiotherapy, or chemotherapy. Some patients also had hormonal therapy. They were randomly assigned to receive either olaparib or a placebo for 1 year. The average follow-up was 2.5 years. 

After 3 years, 85.9% in the olaparib group and 77.1% in the placebo group were alive and without invasive disease. Olaparib treatment was associated with a 42% higher chance of not having invasive disease. It was also associated with a 43% higher chance of not having cancer spread.

25.9% of the patients in the olaparib group and 20.7% in the placebo group stopped treatment due to side effects. The most common side effects in the olaparib group were low white and red blood cell counts, and tiredness. 

The authors concluded that olaparib was more effective than a placebo in increasing patients' survival without invasive or metastatic disease in BRCA1/2-positive early-stage BC that has received local therapies.

This study was funded by AstraZeneca, the manufacturers of olaparib.