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.

Predictors of long-term progression-free survival in patients with ovarian cancer treated with niraparib in the PRIMA/ENGOT-OV26/GOG-3012 study.

OBJECTIVE: To identify characteristics associated with long-term progression-free survival (≥2 years) in patients with advanced ovarian cancer treated with niraparib first-line maintenance therapy in the phase III PRIMA/ENGOT-OV26/GOG-3012 study. METHODS: In this post hoc analysis of PRIMA, patients randomized to niraparib were grouped based on investigator-assessed progression-free survival (progressive disease/censoring <2 years or ≥2 years after randomization). Variables assessed for predictive value were Eastern Cooperative Oncology Group performance status, International Federation of Gynecology and Obstetrics (FIGO) stage at diagnosis, clinical response to platinum-based chemotherapy, number of prior chemotherapy cycles, primary tumor location, body mass index, categorical age, debulking surgery type, number of baseline target lesions, number of baseline non-target lesions, BRCA/homologous recombination-deficiency status, residual disease status, and duration from end of chemotherapy to randomization. Logistic regression modeling using backward elimination (significance level=0.15) identified covariates associated with long-term progression-free survival (clinical cut-off date November 17, 2021). RESULTS: Of 487 patients randomized to niraparib, 152 (31%) had progressive disease/censoring ≥2 years after randomization. Multivariable logistic regression modeling using backward elimination identified BRCA1/2 mutation/homologous recombination deficiency status (p<0.0001), FIGO stage (p=0.041), primary tumor location (p=0.095), and number of baseline non-target lesions (p=0.0001) to be associated with long-term progression-free survival. Patients significantly more likely to achieve progression-free survival of ≥2 years in the final model were those with BRCA1- and BRCA2-mutated/homologous recombination-deficient tumors or BRCA wild-type/not determined/homologous recombination-deficient tumors (vs BRCA wild-type/homologous recombination-proficient/not determined tumors), FIGO stage III (vs IV), and 0 or 1 baseline non-target lesions (vs ≥2 baseline non-target lesions). CONCLUSIONS: The hypothesis-generating results of this analysis suggest that BRCA1/2 mutation/homologous recombination-deficiency status, FIGO stage, and number of baseline non-target lesions may predict progression-free survival of ≥2 years in patients with advanced ovarian cancer receiving niraparib first-line maintenance therapy. TRIAL REGISTRATION NUMBER: NCT02655016.