Similar response rates and survival with PARPi treatments for patients harboring somatic versus germline BRCA mutations: A meta-analysis and systematic review.

Abstract

e16802 Background: PARP inhibitor (PARPi) has recently been approved for various cancers. However, trials have mostly recruited pts with germline BRCA (gBRCA) mutations, and it is unclear whether PARPi have similar efficacy in pts with somatic BRCA (sBRCA) mutations. We aimed to determine the efficacy of PARPi in pts with sBRCA mutations. Methods: Per PRISMA guidelines, systematic review of PubMed, Embase, Cochrane RCT, and Web of Science Collection was performed from inception thru Jan 2020 to identify studies. Our inclusion criteria were clinical trials and retrospective studies that reported use of PARPi in pts with both s and g BRCA mutations. We performed a meta-analysis comparing overall response rate and PFS with PARPi in pts with s versus g BRCA mutations. Results: After screening, 18 studies met our criteria for including both s and g BRCA mutations. Only 8 studies reported response rates for both s and g BRCA mutations (Table). In those studies, 24 out of 43 pts with sBRCA mutations (55.8%), and 69 out of 157 (43.9%) pts with gBRCA had a response to PARPi (pooled OR 1.13, p value = 0.399, I2 = 0). In all five studies that reported PFS, there was no obvious difference in outcomes between sBRCA (HR in these studies ranged 0.23 to 0.27) versus gBRCA (HR ranged 0.17 to 0.27), however a precise statistical analysis could not be done. Conclusions: Our meta-analysis and systematic review of the literature indicates similar outcomes of PARPi therapy in pts with s and g BRCA mutations. Investigation of use of PARPi therapy in a broader patient population, and the inclusion of sBRCA mutations in future clinical trials is essential. [Table: see text]