A recent study explores niraparib’s efficacy, safety, and effect on quality of life in compared age-groups.
In a study of patients with newly diagnosed advanced ovarian cancer who responded to first-line platinum-based chemotherapy (hazard ratio [HR], 0.62; 95% confidence interval [CI], 0.50-0.76), the PRIMA/ENGOT-OV26/GOG-3012 clinical trial demonstrated that niraparib (Zejula) significantly improves progression-free survival (PFS). At the European Society for Medical Oncology Virtual Congress 2020, Giorgio Valabrega, MD, Assistant Professor, University of Torino School of Medicine, Sanatorio San Luigi, Italy, and Researcher, Medical Oncology and Ovarian Cancer, Candiolo Cancer Institute, Istituto di Ricovero e cura a Carattere Scientifico, Italy, reviewed the latest findings to derive whether age affected the safety and efficacy of niraparib.
In this double-blind, placebo-controlled, phase 3 clinical trial, the efficacy, safety, and effect on quality of life of niraparib were assessed in patients with newly diagnosed, advanced, high-grade serous or endometrioid ovarian, fallopian tube, or primary peritoneal cancer who had a complete or partial response to first-line platinum-based chemotherapy.
Patients were randomly assigned in a 2:1 ratio to receive niraparib or placebo either as a fixed starting dose of 300 mg niraparib or placebo daily. As part of an introduced protocol amendment, platelet count and body weight were considered, incorporating an individualized starting dose of 200 mg once daily for patients with a baseline body weight of <77 kg or a platelet count of <150,000 µL.
To investigate efficacy and safety of niraparib versus placebo in older patients, an examination of patients by age-group (<65 years vs ≥65 years) was conducted. A blinded independent central review was used to assess the PFS, which was the primary end point. Of the 733 enrolled patients, 444 were aged <65 years (297 received niraparib, 147 received placebo), and 289 were aged ≥65 years (190 received niraparib, 99 received placebo).
This analysis of data from the phase 3 PRIMA/ENGOT-OV26/GOG-3012 trial suggests that age does not affect niraparib’s safety and efficacy profile when used as maintenance therapy for newly diagnosed advanced ovarian cancer in the platinum-responsive chemotherapy setting.
In both age-groups, patient-reported outcomes and quality of life were comparable as evaluated by the Functional Assessment of Cancer Therapy Ovarian Cancer Symptom Index (FOSI) and the European Quality of Life–5 Dimensions (EQ-5D-5L) instruments. Comparable efficacy was shown in patients in the 2 niraparib cohorts: age <65 years (HR, 0.61; 95% CI, 0.47-0.81) and age ≥65 years (HR, 0.53; 95% CI, 0.39-0.74). Across the age-groups, treatment-emergent adverse events (any grade and grade ≥3) were comparable and similar.
Most notably however, grade ≥3 thrombocytopenia events were reported in 43% of patients receiving a fixed starting dose and 18% of patients receiving an individualized starting dose in patients aged <65 years. Similarly, in patients aged ≥65 years, the values were 57% for fixed dose and 26% for individualized starting dose. While these findings demonstrate that the efficacy, safety, and quality of life of niraparib were similar in compared age-groups, it may be particularly important to consider the clinical implications of incorporating these overall data, suggesting that implementing an individualized starting-dose regimen based on study parameters can improve rates of grade ≥3 thrombocytopenia events in the appropriate patient populations. Older patients may benefit from the implementation of an individualized starting-dose regimen, in terms of reduced rate of grade ≥3 events such as thrombocytopenia.
Source: Valabrega G, et al. Ann Oncol. 2020;31(4_suppl). Abstract 819P.