Overtreatment and excessive cost associated with primary versus secondary PARP inhibitor (PARPi) maintenance therapy for ovarian/peritoneal/fallopian tube cancer (EOC)

Abstract

Objectives: To determine the efficacy and cost of primary olaparib or niraparib maintenance versus secondary olaparib or niraparib maintenance in platinum sensitive EOC. Methods: An institutional review board (IRB) approved single institution retrospective cohort study was performed in women with EOC to determine the efficacy and cost of primary or secondary maintenance PARPi therapy. We determined the costs of olaparib and niraparib therapy based on previously published costs of therapy and duration of therapy based on the Solo 1/ Solo 2 and Prima and Nova trials, respectively. Results: Among 40 patients treated with PARPi after 1 or 2 platinum chemotherapy there was no difference in overall survival (p=0.97) Among 166 women with stage III/IV germ-line BRCA mutated EOC who were followed >3 years following chemotherapy without PARPi therapy, 28.8% were disease free for more than 3 years (18.6% never recurred and 10.2% recurred >3 years after chemotherapy). Among 193 patients without a BRCA mutation 20.2% did not recur and 12 (6.2%) recurred more than 3 years after their chemotherapy. Primary olaparib maintenance therapy was significantly more expensive than secondary olaparib maintenance therapy by 260%. Primary niraparib maintenance therapy was slightly more expensive than secondary niraparib maintenance therapy by 4%, 51%, and 15% for BRCA mutated, HR deficient, and HR proficient patients, respectively. Notably, by eliminating the overtreatment of patients with primary PARPi therapy, the cost of delayed maintenance treatment for 100 women with EOC with BRCA mutations would be associated with a cost savings of $37,335,360 for olaparib and $7,335,360 for niraparib. Download : Download high-res image (89KB) Download : Download full-size image Conclusions: In this retrospective cohort of women with EOC, up to 29% percent of BRCA mutated patients may be over treated with primary PARPi maintenance therapy with significantly increased treatment costs.