Multinational retrospective study of long-term outcomes in patients with recurrent ovarian cancer and exceptional response to PARP inhibitors

A subset of patients with platinum-sensitive recurrent ovarian cancer (PS-ROC) treated with maintenance PARP inhibitors (PARPi) have exceptional response, defined as progression-free survival (PFS) of 5 years or longer from PARPi start. A retrospective cohort study at 41 centers in 14 countries evaluated long-term outcomes in these patients. The primary endpoint was PFS. A total of 320 patients (mean age 56.4 ± 9.4 years) were included, with a median follow-up of 6.8 years. The median PARPi duration was 75.0 months (IQR 64.0-91.0). The 10-year PFS rate among all patients was 78.7%. Among 85 patients (26.6%) who discontinued PARPi for reasons other than disease progression, the 10-year PFS rate was 90.1% (95% CI 80.6-100) versus 72.5% (60.3-87.2) among those who continued taking PARPi. Five patients (1.6%) were diagnosed with late-onset MDS/AML. The authors conclude that in this cohort study, most patients with exceptional response to PARPi remained progression-free, including those who discontinued PARPi without progression, raising questions regarding the optimal duration of PARPi and the possibility of functional cure.