More frequently, cancer drugs are being developed to treat tumors based on their molecular make-up. PARP inhibitors are the first class of drugs specifically developed to treat BRCA-related tumors through targeting the DNA repair pathway. The PARP Inhibitors target this pathway and cause cancer cells to die while healthy cells are spared.
Although PARP inhibitors were developed almost a decade ago, they were only recently approved for clinical use through the U.S. Food and Drug Administration (FDA) after extensive evaluation through clinical trials. Specifically, the PARP inhibitor called Olaparib (Lynparza) was approved for use in BRCA carriers with advanced ovarian cancer treated with three or more prior lines of chemotherapy.
The effectiveness of this PARP inhibitor, Olaparib, was examined in a study of 137 women with BRCA mutations and advanced ovarian cancer. Results showed that about a third of patients had partial shrinkage or complete disappearance of their ovarian tumor for an average of 8 months. These findings led the FDA to grant accelerated approval of this drug to treat life-threatening disease (because results of the clinical trial showed likely clinical benefit to patients).
Olaparib constitutes the first of a new class of drugs (i.e., PARP inhibitors) for treating ovarian cancer. This drug serves as an example of how the understanding of the underlying molecular mechanisms by which cancer develops can lead to more personalized and effective treatments.
There are many open clinical trials that continue to evaluate PARP inhibitors to determine: 1) when to start treatment with these agents in ovarian cancer patients; 2) whether they work in other BRCA-associated cancers such as breast cancer, pancreatic cancer and prostate cancer (among others); and 3) whether they may also be of benefit to individuals without germline BRCA mutations. Thus it is important to continue evaluating these drugs through clinical trials to determine how they may be best used to treat and perhaps prevent cancer.