Prospective evaluation of the tolerability and efficacy of niraparib dosing based on baseline body weight and platelet count: Results from the PRIMA/ENGOT-OV26/GOG-3012 trial

Effects of niraparib dose reduction on short-term outcomes in ovarian cancer patients

OBJECTIVES

Despite the individualized starting dose for maintenance therapy in ovarian cancer, the niraparib dose reduction rate remains high. The aim of this study was to evaluate the impact of niraparib dose reduction on progression-free survival in newly diagnosed primary advanced ovarian cancer and recurrent ovarian cancer patients. We also aimed to compare the reduction rates and the safety of niraparib on primary and relapse groups, and identify which factors may predict dose reduction.

METHODS

Patients with primary or recurrent ovarian cancer in maintenance who received niraparib between 2019 and 2022 were retrospectively evaluated. Niraparib dosing was based on individualized starting dose of 300 or 200 mg/day. The impact of niraparib dose reductions was focused on patients treated with 200 or 100 mg in both groups. Reduction rates, adverse events and predictive factors of reduction were assessed in each study group. The primary endpoint was progression-free survival in primary and relapse groups; the secondary endpoints were the reduction rates, the safety and tolerability of niraparib in both groups.

RESULTS

Of 215 patients identified, 124 (57.7%) primary and 91 (42.3%) recurrent ovarian cancer patients were included. The majority of patients started niraparib at 200 mg/day (92.7% primary and 80.2% relapse group); dose reductions from 300 or 200 mg/day to 200 or 100 mg/day occurred more frequently within cycles 1-3 (67% primary and 45% relapse group, p=0.001). Grade≥3 adverse events were lower in the relapse group (54.8% primary and 35.1% relapse, p=0.001). In both groups, dose modifications over the treatment did not significantly impair median progression-free survival. Univariate and multivariate analysis demonstrated that weight and platinum-doublets were possible risk factors for dose reduction.

CONCLUSIONS

Niraparib dose reduction occurs in almost half of patients within cycles 1-3, although it is significantly more common in the first-line setting. Survival outcomes seem not to be impaired by dose reduction.

Efficacy and safety of niraparib in patients aged 65 years and older with advanced ovarian cancer: Results from the PRIMA/ENGOT-OV26/GOG-3012 trial

OBJECTIVE

To evaluate the impact of age on the efficacy and safety of niraparib first-line maintenance therapy in patients with newly diagnosed advanced ovarian cancer with a complete/partial response to first-line platinum-based chemotherapy.

METHODS

Post hoc analysis of the phase 3 PRIMA/ENGOT-OV26/GOG-3012 study (NCT02655016). Patients in the intent-to-treat population were categorized according to age at baseline (<65 years vs ≥65 years), and progression-free survival (PFS), safety, and health-related quality of life (HRQOL) were evaluated for each age subgroup (clinical cutoff date, May 17, 2019). Safety findings were also evaluated according to a fixed starting dose (FSD) or an individualized starting dose (ISD).

RESULTS

Of 733 randomized patients, 289 (39.4%) were ≥65 years (190 niraparib, 99 placebo) at baseline. Median PFS (niraparib vs placebo) and hazard ratios (95% CI) were similar in patients aged <65 years (13.9 vs 8.2 months; HR, 0.61 [0.47-0.81]) and ≥65 years (13.7 vs 8.1 months; HR, 0.53 [0.39-0.74]). The incidences of any-grade and grade ≥3 treatment-emergent adverse events (TEAEs) were similar across age subgroups; in the niraparib arm, TEAEs leading to dose discontinuation occurred in 7.8% of patients <65 years and 18.4% of patients ≥65 years. ISD use lowered the incidence of grade ≥3 thrombocytopenia events in niraparib-treated patients compared with the FSD (<65 years: 42.8% vs 18.0%; ≥65 years 57.0% vs 26.1%). HRQOL was comparable across age subgroups.

CONCLUSION

Niraparib efficacy, safety, and HRQOL were generally comparable across age subgroups, although patients ≥65 years had a higher rate of discontinuations due to TEAEs. ISD use reduced grade ≥3 thrombocytopenia events regardless of age.

Comparison of survival outcomes between olaparib and niraparib maintenance therapy in BRCA-mutated, newly diagnosed advanced ovarian cancer

INTRODUCTION

This multicenter retrospective cohort study aimed to compare survival outcomes and adverse events between maintenance therapy with two poly (ADP-ribose) polymerase (PARP) inhibitors, olaparib and niraparib, in patients with BRCA-mutated, newly diagnosed advanced epithelial ovarian cancer (EOC) who responded to platinum-based chemotherapy.

METHODS

We enrolled stage III-IV EOC patients with germline and/or somatic BRCA1/2 mutations that had received maintenance therapy with olaparib or niraparib. A 3:1 propensity score matching was conducted using two variables: residual disease size and the presence of germline variants. The primary outcome was progression-free survival (PFS), and the secondary outcomes were time to first subsequent therapy (TFST), overall survival (OS), and treatment-emergent adverse events (TEAEs).

RESULTS

In the propensity score-matched analysis, 80 patients who received olaparib and 31 patients who received niraparib were matched (3:1). In the propensity score-matched cohort, median PFS with olaparib vs. niraparib was not reached vs 31.5 months (HR, 1.08; 95% CI, 0.47-2.52; p = 0.854). The median TFST was not reached vs 31.8 months (HR, 1.20; 95% CI, 0.51-2.81; p = 0.682), and neither olaparib nor niraparib reached the median OS (HR, 0.42; 95% CI, 0.01-17.61; p = 0.649). In terms of the incidence rates of any-grade hematologic or non-hematologic TEAEs, higher rates of thrombocytopenia (p = 0.021) and neutropenia (p = 0.011) were observed in the niraparib group.

CONCLUSION

Advanced EOC patients with BRCA1/2 mutations exhibited no significant difference in OS between olaparib and niraparib, indicating the need to consider individualized strategies for selecting PARP inhibitors based on adverse event profiles.