Over the last decade, a new class of drugs called “PARP Inhibitors” has been evaluated as a form of targeted treatment among BRCA carriers. Results were recently reported from a Phase 3 clinical trial among BRCA carriers with HER2-negative metastatic breast cancer who received two or less prior chemotherapy regimens for their metastatic disease. Study participants received either the PARP inhibitor (olaparib) or standard treatment, and the primary outcome measured was progression-free survival (i.e. the length of time during and after the treatment where the cancer does not get worse). Of the 302 women who participated in this study, progression-free survival was ~3 months longer among those who received olaparib compared to standard treatment. Side effects from treatment and treatment discontinuation were also lower in the olaparib group. Furthermore, progression of disease or death was 42% lower among those given olaparib. Although no PARP inhibitor is yet FDA-approved for breast cancer, these results demonstrate the type of evidence needed to move a drug from the clinical trials setting to an FDA-approved treatment and highlight the expansion of personalized treatments among BRCA carriers.
Robson et al. Olaparib for Metastatic Breast Cancer in Patients with a Germline BRCA Mutation. N Engl J Med. 2017 Jun 4. PMID: 28578601.