A Study of Niraparib (GSK3985771) Maintenance Treatment in Participants With Advanced Ovarian Cancer Following Response on Front-Line Platinum-Based Chemotherapy

Niraparib first-line maintenance therapy in patients with newly diagnosed advanced ovarian cancer: final overall survival results from the PRIMA/ENGOT-OV26/GOG-3012 trial

The phase III PRIMA/ENGOT-OV26/GOG-3012 trial met its primary endpoint. Niraparib first-line maintenance significantly prolonged progression-free survival (PFS) among patients with newly diagnosed advanced ovarian cancer that responded to first-line platinum-based chemotherapy, regardless of homologous recombination deficiency (HRD) status. Final overall survival (OS) results are reported. Patients were randomized 2:1 to niraparib or placebo, stratified by response to first-line treatment, receipt of neoadjuvant chemotherapy, and tumor HRD status. After reaching 60% target maturity, OS was evaluated via a stratified log-rank test using randomization stratification factors and summarized using Kaplan-Meier methodology. OS testing was hierarchical [overall population first, then the homologous recombination-deficient (HRd) population]. Other secondary outcomes and long-term safety were assessed; an updated, ad hoc analysis of investigator-assessed PFS was also conducted (cut-off date, 8 April 2024). The median follow-up was 73.9 months. In the overall population, the OS hazard ratio was 1.01 [95% confidence interval (CI) 0.84-1.23; P = 0.8834] for niraparib (n = 487) versus placebo (n = 246). In the HRd (n = 373) and homologous recombination-proficient (n = 249) populations, the OS hazard ratios were 0.95 (95% CI 0.70-1.29) and 0.93 (95% CI 0.69-1.26), respectively. Subsequent poly(ADP-ribose) polymerase inhibitor therapy was received by 11.7% and 15.8% of niraparib patients and 37.8% and 48.4% of placebo patients in the overall and HRd populations, respectively. The 5-year PFS rate numerically favored niraparib in the overall (niraparib, 22%; placebo, 12%) and HRd populations (niraparib, 35%; placebo, 16%). Myelodysplastic syndromes/acute myeloid leukemia incidence was <2.5% (niraparib, 2.3%; placebo, 1.6%). No new safety signals were observed. In patients with newly diagnosed advanced ovarian cancer at high risk of recurrence, there was no difference in OS between treatment arms. In the HRd population, patients alive at 5 years were two times as likely to be progression free with niraparib treatment than placebo. Long-term safety remained consistent with the established niraparib safety profile.

Niraparib Population Pharmacokinetics and Exposure-Response Relationships in Patients With Newly Diagnosed Advanced Ovarian Cancer

Niraparib is a poly(adenosine diphosphate [ADP]-ribose) polymerase inhibitor approved for the maintenance treatment of advanced ovarian cancer (OC). Niraparib was originally approved in recurrent OC at a fixed starting dose (FSD) of 300 mg once daily (QD). This analysis characterized the population pharmacokinetics (PK) of niraparib and evaluated the relationships between exposure, efficacy, and safety to support clinical use of an individualized dosing strategy, in which the starting dose of niraparib was adjusted based on patient characteristics to improve the benefit-risk profile. A population PK model was developed by pooling data from four niraparib clinical trials (PN001 [n = 104], QUADRA [n = 455], NOVA [n = 403], and PRIMA [n = 480]) in patients with solid tumors, including OC. Exposure-response analyses were conducted to explore the relationships of niraparib exposure with progression-free survival (PFS) and adverse events in the PRIMA study. A multivariate logistic regression model was also developed to estimate the probability of grade ≥3 thrombocytopenia, using data from patients enrolled in PRIMA and NOVA. The impact of an individualized starting dose (ISD) regimen (200 mg QD in patients with body weight [BW] <77 kg or platelet count [PLT] <150,000/µL, or 300 mg QD in patients with BW ≥77 kg and PLT ≥150,000/µL) on systemic exposure, efficacy, and safety was assessed. Niraparib disposition was best described by a 3-compartment model with linear elimination. Key covariates included baseline creatinine clearance, BW, albumin, and age, all of which had minor effects on niraparib exposure. Comparable model-predicted exposure up to the time of disease progression/death or censoring in the 300-mg FSD and 200-/300-mg ISD groups was consistent with the lower rate of dose reduction in the ISD groups. No consistent niraparib exposure-response relationship was observed for efficacy in all PRIMA patients (first-line OC), and no statistically significant difference was seen in PFS curves for patients receiving a niraparib dose of 200 mg versus 300 mg. In the multivariate regression model, performed using combined data from PRIMA and NOVA, higher niraparib exposure (area under the concentration-time curve at steady-state [AUC Population PK and exposure-response analyses support use of an ISD to improve the safety profile of niraparib, including reducing the rate of grade ≥3 thrombocytopenia, without compromising efficacy. ClinicalTrials.gov, NCT01847274 (NOVA), NCT00749502 (PN001), NCT02655016 (PRIMA), NCT02354586 (QUADRA), www. gov.

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

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. 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, Of 487 patients randomized to niraparib, 152 (31%) had progressive disease/censoring ≥2 years after randomization. Multivariable logistic regression modeling using backward elimination identified The hypothesis-generating results of this analysis suggest that NCT02655016.

Tolerability of the niraparib individualized starting dose in the PRIMA/ENGOT-OV26/GOG-3012 trial of niraparib first-line maintenance therapy

To explore safety and tolerability parameters for the niraparib individualized starting dose (ISD) in patients with newly diagnosed advanced ovarian cancer that responded to platinum-based chemotherapy who participated in the phase 3 PRIMA/ENGOT-OV26/GOG-3012 trial (NCT02655016). The PRIMA protocol was amended so newly enrolled patients received an ISD based on baseline body weight/platelet count. In this ad hoc analysis, the timing, duration, and resolution of the first occurrence of common any-grade hematologic (thrombocytopenia, anemia, neutropenia) and nonhematologic (nausea, asthenia/fatigue, constipation, insomnia, hypertension) treatment-emergent adverse events (TEAEs) were evaluated by treatment arm in the ISD safety population (data cutoff, November 17, 2021; median follow-up, 3.5 years). Of 733 randomized patients, 255 were enrolled after the ISD protocol amendment and received ≥ 1 dose of study treatment (niraparib, 169; placebo, 86). In the niraparib arm, median times to first events were 22.0-35.0 days for hematologic TEAEs and 7.0-56.0 days for nonhematologic TEAEs. First events resolved in ≥ 89.8% of patients for hematologic TEAEs; for nonhematologic TEAEs, resolution rates ranged from 55.3% (insomnia) to 86.0% (nausea). Median durations of first hematologic TEAEs were ≤ 16.0 days, but for first nonhematologic TEAEs ranged from 18.0 days (nausea) to 134.0 days (insomnia). The niraparib ISD was generally well tolerated and TEAEs were manageable. Common hematologic and nonhematologic TEAEs occurred early and first events of hematologic TEAEs had a short duration (≈ 2 weeks) and a high resolution rate. These findings support close monitoring immediately following niraparib initiation and may help inform patient expectations for niraparib safety.

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

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. 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). 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. 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

Health-related quality of life in patients with newly diagnosed advanced ovarian cancer treated with niraparib vs placebo: Results from the phase 3 randomized PRIMA/ENGOT-OV26/GOG-3012 trial

To assess patient-reported health-related quality of life (HRQoL) in patients with ovarian cancer (OC) who received niraparib as first-line maintenance therapy. PRIMA/ENGOT-OV26/GOG-3012 (NCT02655016) enrolled patients with newly diagnosed advanced OC who responded to first-line platinum-based chemotherapy. Patients were randomized (2:1) to niraparib or placebo once daily in 28-day cycles until disease progression, intolerable toxicity, or death. HRQoL was assessed as a prespecified secondary end point using patient-reported responses to the European Organisation for Research and Treatment of Cancer QOL Questionnaire (EORTC QLQ-C30), the EORTC QLQ Ovarian Cancer Module (EORTC QLQ-OV28), the Functional Assessment of Cancer Therapy-Ovarian Symptom Index (FOSI), and EQ-5D-5L questionnaires. Assessments were collected at baseline and every 8 weeks (±7 days) for 56 weeks, beginning on cycle 1/day 1, then every 12 weeks (±7 days) thereafter while the patient received study treatment. Among trial participants (niraparib, n = 487; placebo, n = 246), PRO adherence exceeded 80% for all instruments across all cycles. Patients reported no decline over time in HRQoL measured via EORTC QLQ-C30 Global Health Status/QoL and FOSI overall scores. Scores for abdominal/gastrointestinal symptoms (EORTC QLQ-OV28) and nausea and vomiting, appetite loss, and constipation (EORTC QLQ-C30) were higher (worse symptoms) in niraparib-treated patients than placebo-treated patients; except for constipation, these differences resolved over time. Patients did not self-report any worsening from baseline of fatigue, headache, insomnia, or abdominal pain on questionnaires. Despite some early, largely transient increases in gastrointestinal symptoms, patients with OC treated with niraparib first-line maintenance therapy reported no worsening in overall HRQoL.

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

To report updated long-term efficacy and safety from the double-blind, placebo-controlled, phase 3 PRIMA/ENGOT-OV26/GOG-3012 study (NCT02655016). Patients with newly diagnosed advanced ovarian cancer with complete or partial response (CR or PR) to first-line platinum-based chemotherapy received niraparib or placebo once daily (2:1 ratio). Stratification factors were best response to first-line chemotherapy regimen (CR/PR), receipt of neoadjuvant chemotherapy (yes/no), and homologous recombination deficiency (HRD) status (deficient [HRd]/proficient [HRp] or not determined). Updated (ad hoc) progression-free survival (PFS) data (as of November 17, 2021) by investigator assessment (INV) are reported. In 733 randomised patients (niraparib, 487; placebo, 246), median PFS follow-up was 3.5years. Median INV-PFS was 24.5 versus 11.2months (hazard ratio, 0.52; 95% confidence interval [CI], 0.40-0.68) in the HRd population and 13.8 versus 8.2months (hazard ratio, 0.66; 95% CI, 0.56-0.79) in the overall population for niraparib and placebo, respectively. In the HRp population, median INV-PFS was 8.4 versus 5.4months (hazard ratio, 0.65; 95% CI, 0.49-0.87), respectively. Results were concordant with the primary analysis. Niraparib-treated patients were more likely to be free of progression or death at 4years than placebo-treated patients (HRd, 38% versus 17%; overall, 24% versus 14%). The most common grade ≥ 3 treatment-emergent adverse events in niraparib patients were thrombocytopenia (39.7%), anaemia (31.6%), and neutropenia (21.3%). Myelodysplastic syndromes/acute myeloid leukaemia incidence rate (1.2%) was the same for niraparib- and placebo-treated patients. Overall survival remained immature. Niraparib maintained clinically significant improvements in PFS with 3.5years of follow-up in patients with newly diagnosed advanced ovarian cancer at high risk of progression irrespective of HRD status. No new safety signals were identified.

Efficacy of niraparib by time of surgery and postoperative residual disease status: A post hoc analysis of patients in the PRIMA/ENGOT-OV26/GOG-3012 study

To evaluate the association between surgical timing and postoperative residual disease status on the efficacy of niraparib first-line maintenance therapy in patients with newly diagnosed advanced ovarian cancer at high risk of recurrence. Post hoc analysis of the phase 3 PRIMA/ENGOT-OV26/GOG-3012 (NCT02655016) study of niraparib in patients with newly diagnosed primary advanced ovarian, primary peritoneal, or fallopian tube cancer with a complete/partial response to first-line platinum-based chemotherapy. Progression-free survival (PFS) was assessed by surgical status (primary debulking surgery [PDS] vs neoadjuvant chemotherapy/interval debulking surgery [NACT/IDS]) and postoperative residual disease status (no visible residual disease [NVRD] vs visible residual disease [VRD]) in the intent-to-treat population. In PRIMA (N = 733), 236 (32.2%) patients underwent PDS, and 481 (65.6%) received NACT/IDS before enrollment. Median PFS (niraparib vs placebo) and hazard ratios (95% CI) for progression were similar in PDS (13.7 vs 8.2 months; HR, 0.67 [0.47-0.96]) and NACT/IDS (14.2 vs 8.2 months; HR, 0.57 [0.44-0.73]) subgroups. In patients who received NACT/IDS and had NVRD (n = 304), the hazard ratio (95% CI) for progression was 0.65 (0.46-0.91). In patients with VRD following PDS (n = 183) or NACT/IDS (n = 149), the hazard ratios (95% CI) for progression were 0.58 (0.39-0.86) and 0.41 (0.27-0.62), respectively. PFS was not evaluable for patients with PDS and NVRD because of sample size (n = 37). In this post hoc analysis, niraparib efficacy was similar across PDS and NACT/IDS subgroups. Patients who had NACT/IDS and VRD had the highest reduction in the risk of progression with niraparib maintenance.

Antonio Gonzalez-Martin

Antonio González-Martín graduated in medicine at the University of Navarra in Pamplona (Spain) and subsequently trained in medical oncology at University Hospital Ramón y Cajal in Madrid (Spain) from 1994 to 1997. During part of 1997, he attended as an observer to The Mount Sinai School of Medicine in New York. He joined as a staff member of the Medical Oncology Service at University Hospital Ramón y Cajal in 1998. From January 2009 he gained the position of Head of Medical Oncology Department at MD Anderson Cancer Center Madrid·Spain, an affiliate institution of MD Anderson in Houston. Since September 2017 he joined Clínica Universidad de Navarra in Madrid as head of Medical Oncology and co-director of the Oncology Department. Since 2020 he was appointed as Director of Cancer Centre Universidad de Navarra. He is an Associate Professor at Medicine at Francisco de Vitoria University in Madrid (Spain), collaborator Professor at Universidad de Navarra and Adjunct Professor at the University of Texas (TX, USA). He got the PhD degree at Francisco de Vitoria University in April 2018. He specialises in the treatment of gynaecological and breast cancer and is the chairman of GEICO (Spanish group for investigation in ovarian and gynaecological cancer). He is also the representative of GEICO in ENGOT (European Network for Gynaecological Oncological Trials), and was the President of this Group for the period 2018-2020. In addition, he is one of the representatives of GEICO in Gynaecologic Cancer InterGroup (GCIG), and has served as chair of the ovarian cancer committee for the period 2014-2020. He is also a member of the board of the Spanish Society of Medical Oncology (SEOM), and a member of GEICAM and SOLTI breast cancer cooperative groups. He has several relevant publications in the field of gynaecological and breast cancer. He is considered an expert in gynaecological cancer and has lectured widely on these areas of interest.

Bradley J. Monk

Christof Vulsteke

Domenica Lorusso

Hannah C. Karpel

Whitney S Graybill