OBJECTIVES : PARPi therapies (olaparib, niraparib, rucaparib) have different adverse event (AE) profiles, which may lead to meaningful variation in the costs of AE management. The aim of this analysis was to estimate the total AE costs of monotherapy PARPi maintenance in women with newly diagnosed advanced ovarian cancer (NDOC) and women with platinum-sensitive relapsed ovarian cancer (PSROC) from a US healthcare perspective.

METHODS : Grade 3 or above AE data were sourced from phase III randomised studies of monotherapy PARPi maintenance in NDOC and PSROC. US AE unit costs were obtained from 2016 AHRQ HCUPnet, inflated to 2019. Total AE costs were estimated as the product of AE incidence and unit costs. Incremental AE costs for PARPi were calculated by comparing total AE costs across active and placebo control arms of each randomised study.

RESULTS : AE data were available from 2 studies of monotherapy PARPi in NDOC and 3 studies in PSROC. In NDOC, PARPi monotherapy had incremental AE costs of $2,384 for olaparib and $7,502 for niraparib versus placebo. In PSROC, incremental AE costs were $1,692 for olaparib, $7,802 for niraparib and $3,414 for rucaparib versus placebo. Total AE costs were consistent across NDOC and PSROC; $3,697 vs $3,008 for olaparib, $8,066 vs $8,488 for niraparib. Anaemia was the most prevalent and costly AE to treat for olaparib ($1,722 NDOC to $1,558 PSROC) and rucaparib ($1,504 PSROC), while thrombocytopenia was the most costly AE for niraparib ($3,374 NDOC to $3,325 PSROC) followed by anaemia ($2,478 NDOC to $2,026 PSROC).

CONCLUSIONS : AE costs for monotherapy PARPi maintenance appear to be limited and consistent across both NDOC and PSROC treatment settings. In both settings, olaparib was associated with a lower incremental AE cost than other PARPis. These results require confirmation in future studies of AE costs in clinical practice.