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.

Patterns of initial ovarian cancer recurrence on niraparib maintenance monotherapy in patients with no baseline evidence of disease after first-line chemotherapy: An ad hoc subgroup analysis of PRIMA/ENGOT-OV26/GOG-3012.

OBJECTIVES: Patterns of disease recurrence on poly(ADP-ribose) polymerase inhibitor maintenance therapy are unclear and may affect subsequent treatment. This ad hoc subgroup analysis of the phase 3 PRIMA/ENGOT-OV26/GOG-3012 study evaluated patterns of initial recurrence in patients with advanced ovarian cancer (AOC). METHODS: PRIMA included participants at high risk for disease progression. This ad hoc analysis only evaluated participants randomized to niraparib maintenance without evidence of disease at baseline. The number and site(s) of initial recurrent lesions at investigator-assessed progressive disease (PD) were evaluated. RESULTS: Of the 314 niraparib-treated patients analyzed, 190 developed ≥1 new lesion (median number of new lesions, 1.0; interquartile range, 1-2). In total, 93.2% (177/190) of patients developed 1-3 lesions at first disease progression. The most common sites of recurrence were the peritoneum (30.0% [57/190]), lymph nodes (26.3% [50/190]), and liver (20.5% [39/190]). Similar results were observed when patients with PD were stratified by biomarker status, disease stage at diagnosis, and type of debulking surgery. Patients with homologous recombination-proficient tumors, stage III disease, or a history of primary debulking developed a median of 2.0 new lesions at first progression; patients with homologous recombination-deficient tumors, stage IV disease, or a history of interval debulking developed a median of 1.0 new lesion. CONCLUSIONS: Many patients with AOC without lesions at first-line maintenance treatment initiation develop oligometastatic disease at first recurrence. Prospective evaluation is required to determine whether these patients have improved outcomes when local therapies are combined with continuous, systemic, targeted maintenance therapy.

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.

Progression-free survival and safety at 3.5 years of follow-up: results from the randomized phase 3 PRIMA/ENGOT-OV26/GOG-3012 trial of niraparib maintenance treatment in patients with newly diagnosed ovarian cancer - a plain language summary.

What is this summary about? This PLSP provides a short summary of an original scientific article that presented results from the PRIMA study after 3.5 years of follow-up time. The original article was published in the European Journal of Cancer in 2023.The PRIMA study included adult patients with newly diagnosed advanced high-risk ovarian cancer whose tumors shrunk or became undetectable after treatment with chemotherapy with or without surgery. The PRIMA study evaluated how well the drug niraparib, also known as Zejula, worked at delaying or preventing ovarian cancer from coming back (recurring) or getting worse (progressing) compared with placebo (a substance with no effects that a doctor gives to a patient instead of a drug). The first results from the PRIMA study were published in 2019, when patients had participated in the PRIMA study for about 1.2 years.The article this PLSP is based on reports longer-term data from the PRIMA study, when patients had participated in the PRIMA study for about 3.5 years. Patients were monitored (or followed) for a longer time to understand how well niraparib continued to work and to evaluate whether the safety of niraparib changed with additional time being monitored.What were the results? Patients who took niraparib had more time before their cancer came back or got worse than patients who took placebo. In terms of safety, no new types of side effects with niraparib treatment were observed with additional time being monitored as part of the PRIMA study.What do the results mean? These results support that niraparib remains an important treatment option to help delay the cancer from coming back or getting worse in patients with newly diagnosed advanced ovarian cancer that responded to initial treatment.Clinical Trial Registration: NCT02655016 (PRIMA study) (ClinicalTrials.gov).