OBJECTIVES : The PARP inhibitors (PARPi) niraparib, olaparib, and rucaparib are approved for maintenance treatment of platinum sensitive recurrent ovarian cancer (PSROC). Modifications to the recommended doses may occur due to adverse reactions, co-morbidities, and the use of concomitant medication. The objective of this study was to determine the real-world average doses of PARPi therapies used in the PSROC maintenance setting.

METHODS : This retrospective, real-world study utilized Flatiron Health EHR-derived de-identified oncology database representing over 2.2 million US patients nationwide. The dataset comprised patients diagnosed with ovarian cancer from 1 January 2011 to 31 August 2019 who received PARPi maintenance therapy in the second or later line after completing a platinum-based regimen.

RESULTS : Recommended daily doses for niraparib, olaparib, and rucaparib are 300 mg, 600 mg, and 1200 mg respectively. These represent “standard” recommended doses. Results of this analysis are reported for 2L, 2L and beyond (2L+), and 3L and beyond (3L+). 142 patients were included, 75 received niraparib, 38 received olaparib, and 29 received rucaparib.

Average daily starting doses were: niraparib – 253 mg (2L), 248 mg (2L+), 242 mg (3L+); olaparib – 524 mg (2L), 514 mg (2L+), 492 mg (3L+); and rucaparib – 1171 mg (2L), 1133 mg (2L+), 1092 mg (3L+). The average daily doses over the course of treatment were: niraparib – 218 mg (2L), 204 mg (2L+), 186 mg (3L+); olaparib – 536 mg (2L), 513 mg (2L+), 460 mg (3L+); and rucaparib – 912 mg (2L), 973 mg (2L+), 1039 mg (3L+).

CONCLUSIONS : The data presented show the real world average starting dose for the 3 PARPi and the average dose during maintenance treatment. For each drug, the average dose during maintenance treatment is lower than the average starting dose.