Richard Pazdur, MD
The FDA approved the PARP inhibitor olaparib (Lynparza) for the treatment of patients with germline BRCA
-positive, HER2-negative metastatic breast cancer who have previously received chemotherapy. Additionally, HR-positive patients should have prior endocrine therapy or not be considered appropriate for such treatment.
Olaparib was well-tolerated overall, with less than 2.0% of patients discontinuing treatment due to toxicity, compared with 2.2% in the chemotherapy arm. The main adverse events (AEs) associated with the PARP inhibitor were nausea, anemia, and fatigue.
Notably, in the olaparib arm versus the chemotherapy arm, there were fewer grade ≥3 AEs (36.6% vs 50.5%, respectively) and fewer AE-related discontinuations (4.9% vs 7.7%). The PARP inhibitor also had less of a negative impact on white blood cells compared with chemotherapy.
There was 1 death in each treatment group, a case of sepsis in the olaparib group and a case of dyspnea in the standard-therapy group. No cases of myelodysplastic syndrome or acute myeloid leukemia were noted in either treatment group.
Robson M, Im SA, Senkus E, et al. Olaparib for metastatic breast cancer in patients with a germline BRCA mutation. 2017;377:523-33. N Engl J Med. doi: 10.1056/NEJMoa1706450.