PARP Inhibitor Drugs in the Treatment of Breast, Ovarian, Prostate and Pancreatic Cancers: An Update of Clinical Trials

Background: PARP inhibitors appear to offer a promising role in the accompaniment of many of the cytotoxic agents used in the present day to combat cancer proliferation in BRCA 1/2 deficient tumors. Current species of PARP inhibitors have yet to demonstrate a superior effect to that of existing therapies when administered as a single agent; however, they have appeared to amplify the effect of these existing chemotherapies when utilized together. This suggests that PARP inhibitors could play an effective maintenance role in current cancer-combating strategies. In the immediate future, PARP inhibitors may only be applicable to a select group of cancers (i.e., those caused by defective HR pathways), though research is emerging that could indicate an extension of applicability to HR proficient cancer types as well. For the time being, however, the current literature suggests that a viable PARP inhibitor-chemotherapy hybrid targeting HR deficient cancers could be well on its way very soon. Objective: In this manuscript we explores the ongoing and the completed clinical trials for different PARP inhibitors. Conclusion: Since the approval of Olaparib by both FDA and EMA, further clinical trials continue to investigate the use of Olaparib and other PARP inhibitors. The anticipating outcome of these trials may clarify the benefit of PARP inhibitors in management of various BRCA mutated solid tumors.