The role of PARP inhibitors in germline BRCA-associated pancreatic ductal adenocarcinoma.

Moffat, Gordon T; O'Reilly, Eileen M

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy that remains a challenge to treat. In pursuit of personalized medicine, researchers continue active exploration of the genetic and molecular framework of PDAC to apply novel therapeutics and enhance outcomes. In patients who have PDAC, germline mutations-such as those in the BRCA1/2 and PALB2 genes-are predominantly associated with the DNA damage response and repair pathway. On the basis of studies completed in patients with BRCA-mutated advanced breast and ovarian cancer, the poly(ADP-ribose) polymerase (PARP) inhibitors have been evaluated for safety, tolerability, and efficacy in patients with advanced PDAC who are carrying germline BRCA gene mutations. Results have demonstrated meaningful activity and identified BRCA as a predictive and targetable biomarker in PDAC, and have also identified the role of olaparib as a maintenance therapy in PDAC. On the basis of the principle of synthetic lethality, and to avert resistance to PARP inhibitors, clinical trials of combination therapy with PARP inhibitors and platinum-based chemotherapy have been conducted with an early signal. As we continue to explore the role of PARP inhibitors in the management of PDAC, recent clinical trials are studying the effectiveness of PARP inhibitors in combination with immunotherapy, targeted inhibitors, and angiogenesis inhibitors. The next steps are to understand the role of PARP inhibitors beyond germline BRCA in other homologous recombination repair gene mutations and in other subgroups of patients with PDAC.