Abstract PS10-32: Patient reported outcomes (PROs) with poly(ADP-ribose) polymerase inhibitors (PARPi) versus chemotherapy (CTX) in patients (pts) with germlineBRCA1/2mutated (gBRCA1/2mut) HER2- advanced breast cancer (ABC): Results from a multi-country real-world (RW) study

Background: In ABC, where treatment is palliative, an important goal is the maintenance or improvement of quality of life (QoL). In the past 3 years, PARPi have demonstrated improved progression-free survival and favorable PROs compared with CTX in randomized clinical trials (RCTs) in pts with ABC and a gBRCA1/2mut. These agents are now available in multiple countries for the treatment of gBRCA1/2mut HER2- locally advanced and/or metastatic breast cancer. Limited information is available on the PRO benefit of these agents in the RW setting. We assessed RW cancer-related and breast-cancer specific PROs among adult pts with gBRCA1/2mut HER2- ABC in Germany, France, Italy, Spain (EU4), US, and Israel. Methods: Oncologists were recruited to abstract data from medical records (2019/2020) for pts with gBRCA1/2mut HER2- ABC. A subset of pts completed the European Organisation for Research and Treatment of Cancer Quality of Life Core 30 (EORTC QLQ-C30) and the breast cancer module QLQ-BR23. PROs were compared between CTX and PARPi monotherapy utilizing inverse probability weighted regression adjustment (IPWRA) controlling for age at therapy initiation, Charlson Comorbidity Index at time of data collection, baseline symptoms, hormone receptor (HR) status, ECOG score at therapy initiation, stage of therapy initiation (locally advanced breast cancer or metastatic breast cancer) and number of lines of ABC treatment. Results: Overall 96 female pts participated; mean age was 51 years. Tumor characteristics were: 34.4% HR+/HER2-, 65.6% triple negative breast cancer. CTX (n=58) was received among 60.4% of pts [n=29 (50.0%) platinum based, n=29 (50.0%) non-platinum based], and PARPi monotherapy (n=38) was received among 39.6% of pts. Compared to pts receiving CTX, pts receiving PARPi reported significantly better scores in physical and social functioning (Table 1). Pts receiving PARPi reported significantly better symptoms scores vs. CTX in constipation, breast symptoms, arm symptoms and systemic therapy side effects (Table 1). Pts receiving PARPi reported significantly worse scores vs. CTX in nausea/vomiting (Table 1). Global health status (GHS)/QoL scores were numerically better among pts receiving PARPi vs. CTX (Table 1). Conclusions: PARPi have demonstrated superior efficacy and favorable PROs vs. CTX in RCTs in pts with gBRCA1/2mut HER2- ABC. In this RW study, the PRO benefits reported with PARPi were consistent with what has been observed in RCTs, further supporting the value of PARPi. Additional studies to validate these findings are planned. Funding: Pfizer EORTC QLQ-BR23 categories sexual enjoyment and upset by hair loss were excluded from the analysis due to low sample size Citation Format: Reshma Mahtani, Alexander Niyazov, Katie Lewis, James Pike, Alex Rider, Bhakti Arondekar, Michael Patrick Lux. Patient reported outcomes (PROs) with poly(ADP-ribose) polymerase inhibitors (PARPi) versus chemotherapy (CTX) in patients (pts) with germline BRCA1/2 mutated (gBRCA1/2mut) HER2- advanced breast cancer (ABC): Results from a multi-country real-world (RW) study [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS10-32.