Real-world adverse events with niraparib 200 mg/day maintenance therapy in ovarian cancer: a retrospective study

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.

Niraparib as maintenance therapy in Japan: a retrospective observational study using a Japanese claims database

OBJECTIVE

Epithelial ovarian cancer (EOC) is the leading cause of female mortality in gynecologic malignancies, with a rising incidence in Japan. This study aimed to validate the treatment patterns and safety of niraparib as maintenance therapy for EOC following initial chemotherapy in clinical practice in Japan.

METHODS

Leveraging claims data between April 2008 and December 2022, this descriptive study comprised EOC-diagnosed patients receiving initial platinum-based chemotherapy, debulking surgery, and niraparib as maintenance therapy. Patient characteristics, prescription status, transfusion details, and laboratory data were assessed and reported as summary statistics and frequencies.

RESULTS

Among 291 patients, the median age was 64.0 years and 94.5% received a 200-mg daily dose of niraparib. At week 12, 78.7% (229/291) continued niraparib treatment, 21.3% (62/291) discontinued, and 52.2% (152/291) required treatment interruptions. Of the 62 patients who discontinued treatment, 27 patients initiated subsequent EOC treatment within 12 weeks following niraparib discontinuation. Blood transfusions were needed in 10.3% (30/291), and of 55 patients with available laboratory data, 61.8% (34/55) had decreased platelet count <100,000/µL, 25.5% (14/55) had decreased hemoglobin level <8 g/dL, and 22.7% (5/22) had decreased neutrophil count <1,000/µL, meeting the criteria for treatment interruption. Among those with thrombocytopenia, 88.2% (30/34) were able to either resume or continue treatment.

CONCLUSION

Niraparib demonstrated favorable tolerability in Japanese patients with advanced EOC, with effective management of thrombocytopenia through dose adjustments and supportive care, supporting its viability as post-chemotherapy maintenance therapy.

Safety assessments and clinical features of PARP inhibitors from real-world data of Japanese patients with ovarian cancer

Poly (ADP-ribose) polymerase inhibitors have been increasingly used in ovarian cancer treatment. However, the real-world safety data of these drugs in Japanese patients are limited. This retrospective study included 181 patients with ovarian cancer who received olaparib or niraparib at two independent hospitals in Japan between May 2018 and December 2022. Clinical information and blood sampling data were collected. Regarding patient backgrounds, the olaparib group had higher proportions of patients with serous carcinoma, BRCA positivity, homologous recombination deficiency, and those receiving maintenance therapy after recurrence treatment than the niraparib group. Regarding toxicity properties, the most common reasons for discontinuation in the olaparib group were anemia, fatigue, and nausea, while the reason in the niraparib was thrombocytopenia. Thrombocytopenia caused by niraparib treatment occurred earlier than anemia caused by olaparib treatment. Patients with a low body mass index or who had undergone several previous treatment regimens were more likely to discontinue treatment within the first 3 months. Although we analyzed blood collection data, predicting treatment interruptions due to blood toxicity was challenging. In this study, we revealed the characteristics of patients and the timing of interruptions for each drug, highlighting the importance of carefully managing adverse effects.

Efficacy and safety of niraparib in platinum-sensitive recurrent ovarian cancer: retrospective observational study in a tertiary hospital

BACKGROUND

Niraparib has been authorized for maintenance treatment of epithelial ovarian cancer after first-line treatment with platinum, in partial or complete response.

OBJECTIVES

To evaluate the effectiveness and safety of maintenance niraparib in platinum-sensitive recurrent ovarian cancer (PSROC) patients in a tertiary hospital.

MATERIALS AND METHODS

This retrospective observational unicentre study included women diagnosed with ovarian adenocarcinoma who received niraparib. Eligibility criteria encompassed women with PSROC, in response to platinum chemotherapy, and not previously treated with other PARPis. Data on demographics, comorbidities, BRCA mutation status, disease stage, treatment history and adverse events were recorded. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method.

RESULTS

A total of 33 patients were included, with a median age of 63.5 years. The majority of patients received niraparib at 200 mg/day based on Research on Adverse Drug Events and Report criteria. Median OS was 30 months (95% CI: 16.76-43.23), and median PFS was 8 months (95% CI: 2.48-13.52). Adverse effects were more frequent during the initial months of treatment, with most classified as CTCAE v5 grade 1-2. Dose reductions, interruption of treatment and discontinuations were observed due to haematologic toxicities primarily.

CONCLUSION

This real-world study showed that maintenance niraparib in PSROC patients had effectiveness and safety profiles consistent with clinical trials and other observational studies. Median PFS and OS were comparable to previous reports, and most adverse events were manageable with dose modifications. The results support the use of niraparib as a maintenance therapy option in this patient population.

Peripheral Neuropathy Potentially Associated to Poly (ADP-Ribose) Polymerase Inhibitors: An Analysis of the Eudravigilance Database

Poly (ADP-Ribose) polymerase inhibitors (PARPi) have emerged as a targeted therapy in cancer treatment with promising results in various types of cancer. This work aims to investigate the profile of adverse drug reactions (ADRs) associated with PARPi through the reports provided by the Eudravigilance (EV) database. We also intend to analyze the potential association of peripheral neuropathy to PARPi. Data on individual case safety reports (ICSRs) were obtained by accessing the European spontaneous reporting system via the EV website. A total of 12,762 ICSRs were collected from the EV database. Serious cases of nervous system disorders were analyzed providing strong evidence that peripheral neuropathy was reported in a higher frequency in patients treated with niraparib. Most cases reported a not recovered/not resolved outcome and involved drug withdrawal. However, several studies suggest that PARPi attenuate chemotherapy-induced painful neuropathy. Unexpected ADRs such as peripheral neuropathy may also occur, mostly in patients taking niraparib. Further pharmacovigilance studies should be conducted in this area to clarify with more precision the toxicity profile of these drugs.

Safety and management of niraparib monotherapy in ovarian cancer clinical trials

Niraparib is a poly (ADP-ribose) polymerase inhibitor that has shown a significant improvement in progression-free survival irrespective of biomarker status in patients with advanced epithelial ovarian cancer. This review focuses on the adverse events associated with niraparib and their management to maintain efficacy of niraparib treatment and improve quality of life for patients. In five trials assessing efficacy of niraparib in patients with advanced epithelial ovarian cancer (PRIMA, NOVA, NORA, QUADRA, and PRIME), treatment-emergent adverse events of any grade were reported in nearly all patients (≥99%) receiving niraparib; the events were grade ≥3 in 51-74% of patients. Across all lines of therapy, treatment-emergent adverse events led to dose interruptions in 62-80% of patients receiving niraparib and dose reductions in 47-71%. Hematologic events were most frequently reported, including thrombocytopenia, anemia, and neutropenia. Common non-hematologic events included gastrointestinal events, which were generally low grade (<5% were grade ≥3). Clinical strategies to manage these and other events, such as fatigue and insomnia, cognitive behavioral therapy and pharmacologic agents, are summarized. Once-daily niraparib dosing may be advantageous for some patients for many reasons, including night-time dosing which may help alleviate gastrointestinal symptoms. An individualized starting dose (determined by baseline body weight and platelet count) of niraparib demonstrated an improved safety profile while maintaining efficacy. Patients receiving the niraparib individualized starting dose had fewer grade ≥3 adverse events, dose interruptions, and dose reductions than patients receiving a fixed starting dose. The safety profile of niraparib across five pivotal studies in advanced epithelial ovarian cancer was consistent across multiple lines of treatment, including as maintenance therapy in first-line and recurrent settings and as treatment in heavily pre-treated patients. Long-term safety data from the NOVA trial confirmed that, with appropriate and early dose modifications, niraparib is well tolerated.

Real-world safety and effectiveness of maintenance niraparib for platinum-sensitive recurrent ovarian cancer: A GEICO retrospective observational study within the Spanish expanded-access programme

AIM

To describe patient characteristics, effectiveness and safety in a real-world population treated with niraparib in the Spanish expanded-access programme.

PATIENTS AND METHODS

This retrospective observational study included women with platinum-sensitive recurrent high-grade serous ovarian cancer who received maintenance niraparib within the Spanish niraparib expanded-access programme. Eligible patients had received ≥2 previous lines of platinum-containing therapy, remained platinum-sensitive after the penultimate line of platinum and had responded to the most recent platinum-containing therapy. Niraparib dosing was at the treating physician's discretion (300 mg/day fixed starting dose or individualised starting dose [ISD] according to baseline body weight and platelet count). Safety, impact of dose adjustments, patient characteristics and effectiveness were analysed using data extracted from medical records.

RESULTS

Among 316 eligible patients, 80% had BRCA wild-type tumours and 66% received an ISD. Median niraparib duration was 7.8 months. The most common adverse events typically occurred within 3 months of starting niraparib. Median progression-free survival was 8.6 (95% confidence interval [CI] 7.6-10.0) months. One- and 2-year overall survival rates were 86% (95% CI 81-89%) and 65% (95% CI 59-70%), respectively. Dose interruptions, dose reductions, haematological toxicities and asthenia/fatigue were less common with ISD than fixed starting dose niraparib, but progression-free survival was similar irrespective of dosing strategy. Subsequent therapy included platinum in 71% of patients who received further treatment.

CONCLUSION

Outcomes in this large real-world dataset of niraparib-treated patients are consistent with phase III trials, providing reassuring evidence of the tolerability and activity of niraparib maintenance therapy for platinum-sensitive recurrent ovarian cancer.

CLINICALTRIALS

GOV REGISTRATION

NCT04546373.

Pharmacokinetics and Pharmacodynamics of PARP Inhibitors in Oncology

Olaparib, niraparib, rucaparib, and talazoparib are poly (ADP-ribose) polymerase (PARP) inhibitors approved for the treatment of ovarian, breast, pancreatic, and/or prostate cancer. Poly (ADP-ribose) polymerase inhibitors are potent inhibitors of the PARP enzymes with comparable half-maximal inhibitory concentrations in the nanomolar range. Olaparib and rucaparib are orally dosed twice a day, extensively metabolized by cytochrome P450 enzymes, and inhibitors of several enzymes and drug transporters with a high risk for drug-drug interactions. Niraparib and talazoparib are orally dosed once a day with a lower risk for niraparib and a minimal risk for talazoparib to cause drug-drug interactions. All four PARP inhibitors show moderate-to-high interindividual variability in plasma exposure. Higher exposure is associated with an increase in toxicity, mostly hematological toxicity. For talazoparib, exposure-efficacy relationships have been described, but for olaparib, niraparib, and rucaparib this relationship remains inconclusive. Further studies are required to investigate exposure-response relationships to improve dosing of PARP inhibitors, in which therapeutic drug monitoring could play an important role. In this review, we give an overview of the pharmacokinetic properties of the four PARP inhibitors, including considerations for patients with renal dysfunction or hepatic impairment, the effect of food, and drug-drug interactions. Furthermore, we focus on the pharmacodynamics and summarize the available exposure-efficacy and exposure-toxicity relationships.

Rucaparib in recurrent ovarian cancer: real-world experience from the rucaparib early access programme in Spain – A GEICO study

Background:

Rucaparib is a poly(ADP-ribose) polymerase inhibitor approved in Europe as maintenance therapy for recurrent platinum-sensitive (Pt-S) ovarian cancer (OC). The Rucaparib Access Programme (RAP) was designed to provide early access to rucaparib for the above-mentioned indication, as well as for patients with BRCA-mutated Pt-S or platinum-resistant (Pt-R) OC and no therapeutic alternatives.

Methods:

In this observational, retrospective study we analysed the efficacy and safety of rucaparib within the RAP in Spain. Hospitals associated with the Spanish Ovarian Cancer Research Group (GEICO) recruited patients with high-grade epithelial ovarian, fallopian tube, or primary peritoneal cancer treated with rucaparib 600 mg twice daily as maintenance or treatment (Pt-S/Pt-R) in the RAP. Baseline characteristics, efficacy, and safety data were collected.

Results:

Between July 2020 and February 2021, 51 patients treated in 22 hospitals in the RAP were included in the study. Eighteen patients with a median of 3 (range, 1–6) prior treatment lines received rucaparib as maintenance; median progression-free survival (PFS) for this group was 9.1 months (95% confidence interval [CI], 4.2–11.6 months). Among 33 patients (median 5 [range, 1–9] prior treatment lines) who received rucaparib as treatment, 7 and 26 patients had Pt-S and Pt-R disease, respectively. Median PFS was 10.6 months (95% CI, 2.5 months-not reached) in the Pt-S group and 2.2 months (95% CI, 1.1–3.2 months) in the Pt-R group. Grade ≥ 3 treatment-emergent adverse events were reported in 39% of all patients, the most common being anaemia (12% and 15% in the maintenance and treatment groups, respectively). At data cut-off, 5 patients remained on treatment.

Conclusion

Efficacy results in these heavily pre-treated patients were similar to those from previous trials. The safety profile of rucaparib in real life was predictable and manageable.

Comprehensive Analysis of Adverse Events Induced by PARP Inhibitors Using JADER and Time to Onset

Poly (ADP-ribose) polymerase (PARP) inhibitors are effective against breast cancer susceptibility gene (BRCA) mutations. Clinical trials have reported hematologic toxicity and gastrointestinal symptoms as class effects of PARP inhibitors. However, information on adverse events (AEs) in a Japanese clinical cohort is currently lacking. In this study, we conducted a comprehensive survey of the AEs of two PARP inhibitors, olaparib and niraparib, using the Japanese Adverse Reaction Reporting (JADER) database provided by the Pharmaceuticals and Medical Devices Agency (PMDA). Moreover, we also analyzed the course and time to the onset of AEs. Signals were detected for 15 and 11 AEs for olaparib and niraparib, respectively. Most occurred within the first month of treatment with either agent. These results may indicate the importance of early response and monitoring after beginning PARP inhibitor therapy. The results of this study may be useful for managing side effects and suggesting supportive care for patients using PARP inhibitors in the future.

Impact of disease progression on health-related quality of life of advanced ovarian cancer patients - Pooled analysis from the PRIMA trial

OBJECTIVE

Progression-free survival (PFS) is an important early efficacy endpoint in ovarian cancer (OC) and its relevance to patients should be assessed. PRIMA, a phase III trial, assessed niraparib in patients with OC; this post hoc analysis examined the relationship between disease progression in OC and health-related quality of life (HRQoL).

METHODS

The PRIMA trial randomized patients with advanced OC responsive to first-line platinum-based chemotherapy to once daily maintenance oral niraparib or placebo. This post hoc analysis evaluated the impact of disease progression on HRQoL by comparing HRQoL at the last visit pre-progression to end of treatment (EoT), and after 4, 8, 12, and 24 weeks. Assessments included the Functional Assessment of Cancer Therapy-Ovarian Symptom Index (FOSI), the European Quality of Life Five Dimension Five Level questionnaire (EQ-5D-5L) and EQ Visual Analogue Scale (EQ-VAS), the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (EORTC-QLQ-C30), and the EORTC Quality of Life Questionnaire Ovarian Cancer module (EORTC-QLQ-OV28).

RESULTS

This post hoc analysis included 733 patients. Mean FOSI, EQ-5D-5L, and EQ-VAS scores deteriorated from last visit pre-progression to EoT and remained low up to 24-week follow-up. Least squares mean changes from last visit pre-progression to EoT were -2.1 (95% confidence interval -2.4, -1.7) for FOSI, -4.6 (-5.6, -3.5) for the EQ-5D-5L index, and -7.9 (-9.6, -6.3) for EQ-VAS.

CONCLUSIONS

Disease progression negatively impacted HRQoL in patients with OC. PFS is clinically relevant, and prolonging PFS may preserve HRQoL.

A Pan-Canadian Consensus Statement on First-Line PARP Inhibitor Maintenance for Advanced, High-Grade Serous and Endometrioid Tubal, Ovarian, and Primary Peritoneal Cancers

The majority of patients with advanced, high-grade epithelial-tubo ovarian cancer (EOC) respond well to initial treatment with platinum-based chemotherapy; however, up to 80% of patients will experience a recurrence. Poly(ADP-ribose) Polymerase (PARP) inhibitors have been established as a standard of care maintenance therapy to prolong remission and prevent relapse following a response to first-line platinum-chemotherapy. Olaparib and niraparib are the PARP inhibitors currently approved for use in the first-line maintenance setting in Canada. Selection of maintenance therapy requires consideration of patient and tumour factors, presence of germline and somatic mutations, expected drug toxicity profile, and treatment access. This paper discusses the current clinical evidence for first-line PARP inhibitor maintenance therapy in patients with advanced, high-grade EOC and presents consensus statements and a treatment algorithm to aid Canadian oncologists on the selection and use of PARP inhibitors within the Canadian EOC treatment landscape.

Cost comparison of adverse event management among breast and ovarian cancer patients treated with poly (ADP-ribose) polymerase inhibitors: analysis based on phase 3 clinical trials

BACKGROUND

The economic impact of adverse events (AEs) for poly (ADP-ribose) polymerase inhibitors (PARPis) in ovarian or breast cancer has not been widely evaluated.

OBJECTIVE

Compare PARPi-related AE management costs from a US payer perspective.

METHODS

The frequency of treatment-related grade 3-4 AEs was obtained from published clinical trials of PARPis for the treatment of advanced ovarian cancer (AOC), platinum-sensitive recurrent ovarian cancer (PSROC), and metastatic breast cancer (MBC). AE management costs per patient (2020 USD) per treatment course were calculated by multiplying the AE unit costs by the frequency of AEs for each arm of each trial. Sensitivity analyses were conducted according to the lower and upper limits of the 95% confidence interval for AE rates and unit costs, respectively. Scenarios were also performed to explore the uncertainty of outcomes.

RESULTS

Total AE management costs in AOC were: $3,904, olaparib; $5,595, olaparib plus bevacizumab; and $12,215, niraparib. In PSROC, total costs were: $3,894, olaparib; $6,001, rucaparib; and $11,492, niraparib, and in MBC: $3,574, olaparib; and $9,489, talazoparib. Hematological toxicities were the key drivers of AE management costs for PARPis.

CONCLUSIONS

The main AEs among PARPis were hematological. Olaparib was associated with lower AE costs compared to other PARPis.

Safety Profile of Niraparib as Maintenance Therapy for Ovarian Cancer: A Systematic Review and Meta-Analysis

Background: Patients with epithelial ovarian cancer (EOC), treated with niraparib maintenance, present with haematological and gastrointestinal toxicities. Limited data exist on niraparib safety assessment. Objective: To evaluate niraparib safety profile, as maintenance therapy, in women with platinum-sensitive EOC. Methods: PubMed and Cochrane searches were carried out up to April 2021 for randomised controlled trials (RCTs) evaluating niraparib versus placebo in EOC patients with a response to platinum-based chemotherapy. Regarding the meta-analysis, for dichotomous data, the pooled risk ratio (RR) was calculated. Results: A total of 1539 patients from three RCTs revealed that niraparib-treated patients are associated with a significantly higher risk of any grade of nausea (RR, 2.15; 95% CI, 1.86 to 2.48), fatigue (RR, 1.26; 95% CI, 1.05 to 1.52, p < 0.00001), anemia (RR, 6.86; 95% CI, 2.54 to 18.52, p = 0.0001), thrombocytopenia (RR, 7.02; 95% CI, 1.68 to 29.38, p < 0.00001), vomiting (RR, 2.51; 95% CI, 1.50 to 4.19, p = 0.0005), neutropenia (RR, 2.96; 95% CI, 1.13 to 7.73, p < 0.00001), headache (RR, 2.08; 95% CI, 1.57 to 2.74, p < 0.00001), constipation (RR, 2.10; 95% CI, 1.72 to 2.57, p < 0.00001) and insomnia (RR, 2.48; 95% CI, 1.52 to 2.89, p = 0.0003) when compared with placebo. For grade 3 or 4 adverse effects, significantly higher risk was only noted for fatigue (RR,6.25; 95% CI, 1.70 to 23.05, p = 0.006), anemia (RR, 16.23; 95% CI, 4.86 to 54.17, p < 0.00001), thrombocytopenia (RR, 35.12; 95% CI, 12.23 to 100.82, p < 0.00001) and neutropenia episodes (RR, 6.35; 95% CI, 2.08 to 19.39, p = 0.001) for those taking niraparib. Notably, incidents of adverse effects and discontinuation rates were substantially lower among patients treated with an individualised niraparib dose than those treated with the standard one. Efficacy was not reduced, and no treatment-related deaths occurred during the included trials. Conclusion: Niraparib is considered an effective and well-tolerated choice, with an improved safety profile, for the maintenance treatment of EOC patients.

PARP inhibitors: clinical relevance and the role of multidisciplinary cancer teams on drug safety

INTRODUCTION

Cancer is considered one of the most devastating causes of death for humanity. Innovative and targeted therapies have become urgent in the treatment of this large subset of diseases. Over the last decade, the development of PARP (poly (ADP-Ribose) polymerase) inhibitors has emerged as a new target in cancer therapy.

AREAS COVERED

The authors conducted a review focusing on the clinic relevance and adverse effects of the four drugs already approved by drug regulatory agencies, namely: olaparib, rucaparib, niraparib and talazoparib. Despite the targeted action of this drug class, the adverse effects should be carefully monitored for the adequate safety of cancer patients taking them. The role of multidisciplinary cancer teams is crucial to help more and more patients to benefit from these revolutionary agents.

EXPERT OPINION

PARP (poly (ADP-Ribose) polymerase) inhibitors are drugs with great potential in the treatment of several types of cancer. However, their toxicity profiles often lead to treatment interruption or early discontinuation. The daily monitoring of these cancer patients by multidisciplinary cancer teams is essential for the success of therapy and for the promotion of a better quality of life.

Identification of different side effects between PARP inhibitors and their polypharmacological multi-target rationale

AIMS

The aim of this study was to determine the differences and potential mechanistic rationale for observed adverse drug reactions (ADRs) between four approved PARP inhibitors (PARPi).

METHODS

The Medicines and Healthcare products Regulatory Authority (MHRA) Yellow Card drug analysis profiles and NHS secondary care medicines database enabled the identification of suspected ADRs associated with the PARPi in the UK from launch to 2020. The polypharmacology of the PARPi were data-mined from several public data sources.

RESULTS

The overall ADRs per 100 000 R_x identified across the four PARPi are statistically significant (χ² test, P < .001). Rucaparib has the greatest relative suspected ADRs, which can be explained by its least clean kinome and physicochemical properties. The suspected gastrointestinal ADRs of rucaparib and niraparib can be ascribed to their kinase polypharmacology. Suspected blood and lymphatic system ADRs of PARPi can be linked to their high volume of distribution (V_d ). The thrombocytopenia rate of niraparib > rucaparib > olaparib tracked with the V_d trend. Hypertension is only associated with niraparib and could be explained by the therapeutically achievable inhibition of DYRK1A and/or transporters. Arrhythmia cases are potentially linked to the structural features of hERG ion-channel inhibition found in rucaparib and niraparib. Enhanced psychiatric/nervous disorders associated with niraparib can be interpreted from the diverse neurotransporter off-targets reported.

CONCLUSIONS

Despite their similar mode of action, the differential polypharmacology of PARP inhibitors influences their ADR profile.

The efficacy and safety of niraparib for ovarian cancer: a single-center observational study from China

BACKGROUND

Niraparib, a poly (ADP-ribose) polymerase (PARP) inhibitor, is approved for first/second-line maintenance treatment of ovarian cancer patients with complete or partial response to platinum-based chemotherapy, and multi-line monotherapy in BRCAmt patients or platinum-sensitive recurrence patients with homologous recombination deficiency (HRD). We present real-world experience from a single center of China.

METHODS

Patients treated with niraparib in Jiangsu Cancer Hospital between June 2019 to July 2020 were recruited. The initial dose was given according to individualization. Response and adverse events (AEs) were analyzed by Response Evaluation Criteria in Solid Tumors v1.1. and National Cancer Institute Common Terminology Criteria for Adverse Events v5.0, respectively. HRD testing (AmoyDx®) was detected in most patients. Treatment was given until unequivocal progression or intolerable toxicity.

RESULTS

Twenty-two patients all received niraparib at a bolus of 200 mg/d. Fifty percent of patients with high-grade serous ovarian cancer are HRD-positive. Six patients underwent first-line maintenance therapy. Sixteen patients received exploratory therapy. Ultimately image evaluation revealed that two patients achieved partial response (PR) and one patient achieved stable disease (SD), yielding objective response rate (ORR) of 33.3% (95%CI = 0.060-0.759) and disease control rate (DCR) of 50% (95%CI = 0.140-0.861) in the exploratory multi-line monotherapy group. The most common AEs were nausea, thrombocytopenia, and anemia. Grade 3-4 thrombocytopenia were managed by dose reduction and interruption. Leg swelling was observed as a new adverse event.

CONCLUSION

It is feasible that patients receiving a bolus of 200 mg/d in patients from Chinese population can acquire promising efficacy and tolerance. This is the first real-world data about niraparib in ovarian cancer patients with available HRD status from China.

Real-world hematological adverse events in Chinese patients with advanced ovarian cancer treated with an individualized starting dose of niraparib

Background

This work set out to examine the hematological adverse events (AEs) of an individualized starting dose (ISD) of niraparib in Chinese patients with ovarian cancer (OC).

Methods

The medical records of 43 patients with OC who were treated with an ISD of niraparib at the Cancer Hospital of The University of Chinese Academy of Sciences between February 2019 and January 2020 were retrospectively reviewed. Treatment-emergent hematological AEs were analyzed.

Results

Of the 43 patients with OC, 28 (65.1%) had hematological AEs of ≥ grade 1, including thrombocytopenia (39.5%), leukopenia (37.2%), and anemia (34.9%). Ten (23.3%) patients developed grade 3/4 hematological AEs, including thrombocytopenia (11.6%), leukopenia (9.3%), and anemia (7.0%). Among the individuals who developed AEs during treatment, 9 (32.1%) patients had their treatment interrupted, with treatment being restarted in 8 (28.6%) cases, and 4 (14.3%) patients had the drug dose decreased. No deaths were reported. The median times to the occurrence of any-grade leukopenia, anemia, and thrombocytopenia were 30 (range, 7 to 162), 34 (range, 7 to 108), and 20 (range, 13 to 180) days, respectively. Most AEs occurred within the first 3 months of treatment (93.8% leukopenia, 80.0% anemia, and 76.5% thrombocytopenia). Treatments for AEs included supplementation of recombinant human granulocyte colony-stimulating factor (n=5, 17.9%), erythrocytes (n=2, 7.1%), and recombinant human thrombopoietin (n=5, 17.9%).

Conclusions

The incidence of adverse hematological reactions to an ISD of niraparib in Chinese patients with advanced OC is relatively lower in the real world than in the phase III clinical trials PRIMA (also an ISD) and NOVA. These hematological AEs can be managed through dose adjustment and symptomatic therapy.

Differences in PARP Inhibitors for the Treatment of Ovarian Cancer: Mechanisms of Action, Pharmacology, Safety, and Efficacy

Poly(ADP-ribose) polymerases (PARP) are proteins responsible for DNA damage detection and signal transduction. PARP inhibitors (PARPi) are able to interact with the binding site for PARP cofactor (NAD+) and trapping PARP on the DNA. In this way, they inhibit single-strand DNA damage repair. These drugs have been approved in recent years for the treatment of ovarian cancer. Although they share some similarities, from the point of view of the chemical structure and pharmacodynamic, pharmacokinetic properties, these drugs also have some substantial differences. These differences may underlie the different safety profiles and activity of PARPi.