Treatment Duration, Adherence, Interruptions, and Discontinuations Associated With Maintenance Regimens for Recurrent Ovarian Cancer

Clinical trials have shown that maintenance therapy for ovarian can­cer after response to platinum chemotherapy prolongs progression-free survival. We sought to examine the real-world use of various maintenance therapies for recurrent ovarian cancer. Methods. We conducted a retrospective cohort study of US patients ≥18 years old with recurrent ovarian cancer utilizing diagnoses from claims data. Patients were identified using a two-step algorithm and if they had ≥2 diagnoses ≥30 days apart between July 1, 2010, and December 31, 2019, a subsequent systemic chemotherapy, and a second-line maintenance thera­py with a poly (ADP-ribose) polymerase (PARP) inhibitor or bevacizumab. Prev­alence of use for all second-line maintenance therapies was calculated. Treat­ment duration, adherence to treatment, dose decreases, and the time without dose interruption or treatment discontinuation were analyzed between thera­py groups. Results. A total of 1,092 patients met the inclusion criteria. Among these, 446 (40.8%) subsequently received second-line maintenance treatment: 38 (8.5%) received rucaparib, 110 (24.7%) niraparib, 114 (25.6%) olaparib, and 184 (41.3%) bevacizumab. Average durations of maintenance treatment in days were as follows: olaparib, 187.6 (SD, 178.7); bevacizumab, 185.2 (SD, 149.2); ruca­parib, 147.2 (SD, 155.4); and niraparib, 124.2 (SD, 122.9). Treatment adherence was similar across all therapies (86%-88%). Dose decreases were numerically more common in the niraparib group (28.1%) than in the rucaparib (21.1%) or olapar­ib (20.2%) groups but were not statistically significant (both P > .10). Compared with rucaparib, niraparib was associated with a shorter time to dose interrup­tion or discontinuation (hazard ratio: 3.7; 95% confidence interval: 1.1%-12.6%; P = .03). Conclusions. In this cohort, less than half of patients with recurrent ovarian cancer received second-line maintenance therapy with a PARP inhibitor or bevacizumab. Adherence was similar in all PARP inhibitor regimens regardless of dosing schedule, with dose reductions and discontinuations varying between treatments. Niraparib was associated with the shortest time to dose interruption or discontinuation among the agents evaluated.