PCN7 - A TIME WITHOUT SYMPTOMS OR TOXICITY ANALYSIS OF NIRAPARIB COMPARED WITH ROUTINE SURVEILLANCE IN THE MAINTENANCE TREATMENT OF PATIENTS WITH RECURRENT OVARIAN CANCER

To estimate the time without symptoms and toxicity (TWiST) of niraparib, a poly (ADP-ribose) polymerase inhibitor, compared with routine surveillance (RS) in the maintenance treatment of patients with recurrent ovarian cancer. Mean progression-free survival (PFS) was estimated for niraparib and RS using parametric survival curves based on 553 patients enrolled in the ENGOT-OV16/NOVA Phase 3 trial. A restricted mean time with toxicity (TOX) was estimated based on Kaplan-Meier curves for adverse events (AEs) using patient level data. Symptomatic AEs included were grade ≥2 fatigue, nausea, and vomiting. TOX time was calculated as the number of days a patient experienced an AE after randomisation and prior to disease progression. TWiST was then estimated as the difference between mean PFS and mean TOX between niraparib and RS. Treatment with niraparib resulted in a mean PFS benefit of 3.23 years and a greater mean TOX of 0.28 years compared with RS in the gBRCAmut cohort. Treatment with niraparib resulted in a mean PFS benefit of 1.44 years and a greater mean TOX of 0.10 years compared with RS in the non-gBRCAmut cohort. Hence, treatment with niraparib resulted in a mean TWiST benefit of 2.95 and 1.34 years compared with RS in the gBRCAmut and non-gBRCAmut cohorts, respectively. These results indicate that patients treated with niraparib experienced increased mean TWiST compared with RS. Thus, patients treated with niraparib in the ENGOT-OV16/NOVA trial experienced more time without symptoms or toxicities compared to control.