PARP (1 and 2) inhibitor, MK-4827, shows anti-tumor activity in first trial in humans (mutation/non mutation carriers)

"He gave a possible explanation as to why patients with cancers that were not caused by BRCA1/2 mutations also responded to the PARP inhibition. "BRCA is a tumour suppressor gene that assists in repairing double stranded DNA breaks. In BRCA-mutation related cancers, loss of both copies of the gene results in a non-functional protein and thus BRCA deficiency. Because BRCA works with other proteins, BRCA-pathway related deficiency can be seen in the absence of two mutated copies of the BRCA genes. This may explain why responses have been reported for this class of drugs in non-BRCA mutant cancers."