Evaluation of the occurrence and management of PARP inhibitor toxicities.
e18073 Background: Poly-adenosine diphosphate ribose polymerase inhibitors (PARPi) have become a major cornerstone of therapy in the management of patients with ovarian cancer and other cancer types. The most common adverse events with PARPi therapy include bone marrow suppression, gastrointestinal (GI) toxicity, and fatigue. Currently, information is scarce regarding the management of some of these adverse events. Methods: A retrospective, descriptive observational study of adult patients with gynecologic malignancy, who received at least 2 weeks of PARPi therapy, was conducted at the University of Pennsylvania Health System. Data was collected on patients prescribed a PARPi between December 2014 and October 2019, from initiation of therapy through one-year post-initiation or last follow-up. The primary endpoint was the status of PARPi therapy at the end of the study period. Secondary endpoints included time to toxicity, progression free survival (PFS), and overall survival (OS). Descriptive statistics were used to analyze all endpoints. Results: Of the 85 patients included in the study, 45 (53%) received olaparib, 24 (28%) niraparib, and 16 (19%) rucaparib. Twenty-nine patients (34%) continued on PARPi therapy, 16 (19%) discontinued the due toxicity, and 40 (47%) discontinued due to progression. Of 147 unique toxicities, 67 (46%) were GI-related, 48 (33%) were hematologic, and 32 (22%) were other toxicities, including fatigue, elevated serum creatinine, hypertension, and rash. Twenty-three percent of all toxicities were categorized as grade 3 or 4 per the Common Terminology Criteria for Adverse Events v5.0. The median number of management strategies required for GI toxicities was 1 (range 1-7), hematologic toxicities was 2 (1-8), and fatigue was 1.5 (1-4). Primary management strategies included pharmacologic therapy (96%) for GI toxicities; transfusion support (65%), holding PARPi therapy (67%), and dose reduction (52%) for hematologic toxicities; and dose reduction (78%) for fatigue. Hospital admission due to PARPi toxicity occurred in 12% of patients. The median time to toxicity was 29 days (1-330) and the median time to discontinuation due to toxicity was 72.5 days (9-353). Fifty-four patients (64%) had progression of disease and 18 (21%) died within one-year of initiation. Median PFS was 181 days and median OS was 338 days, censored for time to last follow-up. Conclusions: This observational study outlines the incidence of PARPi toxicity and some of the management strategies within an academic health system, further guiding practitioners in an area with limited information.