niraparib and Thrombocytopenia

Metastatic castration-resistant prostate cancers are enriched for DNA repair gene defects (DRDs) that can be susceptible to synthetic lethality through inhibition of PARP proteins. We evaluated the anti-tumour activity and safety of the PARP inhibitor niraparib in patients with metastatic castration-resistant prostate cancers and DRDs who progressed on previous treatment with an androgen signalling inhibitor and a taxane.. In this multicentre, open-label, single-arm, phase 2 study, patients aged at least 18 years with histologically confirmed metastatic castration-resistant prostate cancer (mixed histology accepted, with the exception of the small cell pure phenotype) and DRDs (assessed in blood, tumour tissue, or saliva), with progression on a previous next-generation androgen signalling inhibitor and a taxane per Response Evaluation Criteria in Solid Tumors 1.1 or Prostate Cancer Working Group 3 criteria and an Eastern Cooperative Oncology Group performance status of 0-2, were eligible. Enrolled patients received niraparib 300 mg orally once daily until treatment discontinuation, death, or study termination. For the final study analysis, all patients who received at least one dose of study drug were included in the safety analysis population; patients with germline pathogenic or somatic biallelic pathogenic alterations in BRCA1 or BRCA2 (BRCA cohort) or biallelic alterations in other prespecified DRDs (non-BRCA cohort) were included in the efficacy analysis population. The primary endpoint was objective response rate in patients with BRCA alterations and measurable disease (measurable BRCA cohort). This study is registered with ClinicalTrials.gov, NCT02854436.. Between Sept 28, 2016, and June 26, 2020, 289 patients were enrolled, of whom 182 (63%) had received three or more systemic therapies for prostate cancer. 223 (77%) of 289 patients were included in the overall efficacy analysis population, which included BRCA (n=142) and non-BRCA (n=81) cohorts. At final analysis, with a median follow-up of 10·0 months (IQR 6·6-13·3), the objective response rate in the measurable BRCA cohort (n=76) was 34·2% (95% CI 23·7-46·0). In the safety analysis population, the most common treatment-emergent adverse events of any grade were nausea (169 [58%] of 289), anaemia (156 [54%]), and vomiting (111 [38%]); the most common grade 3 or worse events were haematological (anaemia in 95 [33%] of 289; thrombocytopenia in 47 [16%]; and neutropenia in 28 [10%]). Of 134 (46%) of 289 patients with at least one serious treatment-emergent adverse event, the most common were also haematological (thrombocytopenia in 17 [6%] and anaemia in 13 [4%]). Two adverse events with fatal outcome (one patient with urosepsis in the BRCA cohort and one patient with sepsis in the non-BRCA cohort) were deemed possibly related to niraparib treatment.. Niraparib is tolerable and shows anti-tumour activity in heavily pretreated patients with metastatic castration-resistant prostate cancer and DRDs, particularly in those with BRCA alterations.. Janssen Research & Development.

Topics: Adolescent; Adult; Androgen Antagonists; Androgens; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; DNA Repair; Humans; Indazoles; Male; Piperidines; Prostatic Neoplasms, Castration-Resistant; Thrombocytopenia

Platinum-based chemotherapy is the foundation of treatment for platinum-sensitive recurrent ovarian cancer, but has substantial toxicity. Bevacizumab and maintenance poly(ADP-ribose) polymerase (PARP) inhibitors both significantly improve efficacy versus standard therapy, primarily in terms of progression-free survival, and offer the potential for chemotherapy-free treatment. AVANOVA2 compared niraparib and bevacizumab versus niraparib alone as definitive treatment for platinum-sensitive recurrent ovarian cancer.. This open-label, randomised, phase 2, superiority trial in 15 university hospitals in Denmark, Sweden, Finland, Norway, and the USA enrolled women aged 18 years or older with measurable or evaluable high-grade serous or endometrioid platinum-sensitive recurrent ovarian cancer. Patients had to have an Eastern Cooperative Oncology Group performance status of 0-2, and had to have previously received platinum-containing therapy for primary disease but ≤1 prior non-platinum-containing regimen for recurrent disease. Previous treatment with bevacizumab or first-line maintenance PARP inhibitors was permitted. Eligible patients were randomly assigned 1:1 (by random permuted blocks with block sizes of two and four, no masking), stratified by homologous recombination deficiency status and chemotherapy-free interval, to receive once-daily oral niraparib 300 mg alone or with intravenous bevacizumab 15 mg/kg once every 3 weeks until disease progression. The primary endpoint was progression-free survival, assessed by the investigators in the intention-to-treat population after events in at least 62 patients. Safety was analysed in all patients who received at least one dose of study drug. This ongoing trial is registered with ClinicalTrials.gov, number NCT02354131.. Between May 23, 2016, and March 6, 2017, 97 patients were enrolled and randomly assigned: 48 to niraparib plus bevacizumab and 49 to single-agent niraparib. Median follow-up was 16·9 months (IQR 15·4-20·9). Niraparib plus bevacizumab significantly improved progression-free survival compared with niraparib alone (median progression-free survival 11·9 months [95% CI 8·5-16·7] vs 5·5 months [3·8-6·3], respectively; adjusted hazard ratio [HR] 0·35 [95% CI 0·21-0·57], p<0·0001). Grade 3 or worse adverse events occurred in 31 (65%) of 48 patients who received niraparib plus bevacizumab and 22 (45%) of 49 who received single-agent niraparib. The most common grade 3 or worse adverse events in both groups were anaemia (7 [15%] of 48 vs 9 [18%] of 49) and thrombocytopenia (5 [10%] vs 6 [12%]), and hypertension in the combination group (10 [21%] vs 0). Niraparib plus bevacizumab was associated with increased incidences of any-grade proteinuria (10 [21%] of 48 patients vs 0) and hypertension (27 [56%] of 48 vs 11 [22%] of 49) compared with niraparib alone. No treatment-related deaths occurred.. The efficacy observed with this chemotherapy-free combination of approved agents in women with platinum-sensitive recurrent ovarian cancer warrants further evaluation. A randomised phase 3 trial investigating niraparib plus bevacizumab versus chemotherapy plus bevacizumab in platinum-sensitive recurrent ovarian cancer is planned.. Nordic Society of Gynaecological Oncology and Tesaro.

Topics: Aged; Anemia, Aplastic; Antineoplastic Combined Chemotherapy Protocols; Bevacizumab; Carcinoma, Endometrioid; Disease Progression; Female; Humans; Hypertension; Indazoles; Middle Aged; Neoplasm Grading; Neoplasm Recurrence, Local; Ovarian Neoplasms; Piperidines; Progression-Free Survival; Proteinuria; Thrombocytopenia

Niraparib is a poly(ADP-ribose) polymerase inhibitor approved in the USA and Europe for maintenance treatment of adult patients with recurrent epithelial ovarian, fallopian tube, or primary peritoneal cancer who are in complete or partial response to platinum-based chemotherapy. In the pivotal ENGOT-OV16/NOVA trial, the dose reduction rate due to treatment-emergent adverse event (TEAE) was 68.9%, and the discontinuation rate due to TEAE was 14.7%, including 3.3% due to thrombocytopenia. A retrospective analysis was carried out to identify clinical parameters that predict dose reductions.. All analyses were carried out on the safety population, comprising all patients who received at least one dose of study drug. Patients were analyzed according to the study drug consumed (i.e., as treated). A predictive modeling method (decision trees) was used to identify important variables for predicting the likelihood of developing grade ≥3 thrombocytopenia within 30 days after the first dose of niraparib and determine cut-off points for chosen variables.. Following dose modification, 200 mg was the most commonly administered dose in the ENGOT-OV16/NOVA trial. Baseline platelet count and baseline body weight were identified as risk factors for increased incidence of grade ≥3 thrombocytopenia. Patients with a baseline body weight <77 kg or a baseline platelet count <150 000/µl in effect received an average daily dose ∼200 mg (median = 207 mg) due to dose interruption and reduction. Progression-free survival in patients who were dose reduced to either 200 or 100 mg was consistent with that of patients who remained at the 300 mg starting dose.. The analysis presented suggests that patients with baseline body weight of <77 kg or baseline platelets of <150 000/µl may benefit from a starting dose of 200 mg/day.. NCT01847274.

Topics: Administration, Oral; Adult; Body Weight; Dose-Response Relationship, Drug; Female; Humans; Incidence; Indazoles; Maintenance Chemotherapy; Neoplasm Recurrence, Local; Ovarian Neoplasms; Piperidines; Platelet Count; Poly(ADP-ribose) Polymerase Inhibitors; Progression-Free Survival; Retrospective Studies; Risk Factors; Thrombocytopenia

Niraparib dosages can be individualized to reduce the starting dose based on body weight and baseline platelet count. However, even with individualized dosing, scattered cases of ≥Grade 3 hematologic toxicity occur. This study explored markers predictive of serious hematologic toxicity in niraparib therapy.. This retrospective observational study investigated patients who started niraparib therapy at the Cancer Institute Hospital of the Japanese Foundation for Cancer Research between December 2020 and March 2022. Associations between hematologic toxicities and serum creatinine ratio (percentage increase in serum creatinine between baseline and after niraparib initiation) were investigated.. Out of 50 ovarian cancer patients who initiated niraparib, 45 patients were included in the final analysis. Twenty-three patients (51.1%) developed ≥Grade 3 hematologic toxicity, with neutropenia in 17 (37.8%), anemia in 9 (20.0%), and thrombocytopenia in 4 (8.9%). Patients with Grade 4 hematologic toxicity showed higher serum creatinine ratios than those with ≤Grade 2. Thrombocytopenia ≥Grade 3 occurred only within 2 months of niraparib initiation and was preceded by an increase in serum creatinine in all affected patients.. Serum creatinine ratio offers a potential marker for predicting severe hematologic toxicity following niraparib therapy.

Topics: Anemia; Creatinine; Female; Humans; Indazoles; Neutropenia; Ovarian Neoplasms; Risk Factors; Thrombocytopenia

BACKGROUND Thrombocytopenia is a potentially treatment-limiting adverse event of particular interest with the PARP inhibitor niraparib. This adverse event may necessitate niraparib dose reduction or treatment discontinuation, resulting in suboptimal treatment outcomes. Here, we report on niraparib dose optimization in 2 patients with breast cancer and 4 patients with ovarian cancer through concurrent administration of the thrombopoietin receptor stimulating agent avatrombopag to mitigate thrombocytopenia, enabling niraparib reescalation and improved clinical response. CASE REPORT Three of 6 patients received niraparib 300 mg daily, the highest recommended dose, for a sustained period. Avatrombopag therapy enabled niraparib dose escalation that led to reductions in biomarkers associated with disease progression. Before initiation of avatrombopag, increases in CA-125 levels, a marker for ovarian cancer, were observed in association with niraparib dose interruption, and in 2 patients with ovarian cancer CA-125 levels fell in response to niraparib dose escalation enabled by concurrent avatrombopag therapy. Further, in 2 patients with metastatic breast cancer, intracranial response was observed in association with avatrombopag-enabled niraparib therapy. In 1 patient with metastatic breast cancer, niraparib induced an intracranial response, while previous use of talazoparib had not, confirming preclinical findings of superior blood-brain-barrier penetrance with niraparib. CONCLUSIONS Avatrombopag is currently approved for use in chronic immune thrombocytopenia and thrombocytopenia associated with chronic liver disease in patients undergoing a surgical procedure. A clinical trial of avatrombopag for chemotherapy-induced thrombocytopenia is ongoing. Preliminary results in these 6 patient cases demonstrate the need for a confirmatory trial of avatrombopag for optimizing the dose of niraparib.

Topics: Adenosine Diphosphate Ribose; Breast Neoplasms; Female; Humans; Indazoles; Ovarian Neoplasms; Piperidines; Poly(ADP-ribose) Polymerase Inhibitors; Poly(ADP-ribose) Polymerases; Thiazoles; Thiophenes; Thrombocytopenia

Poly(ADP-ribose) polymerase (PARP) proteins are used by cells in several DNA repair processes. PARP inhibition can result in preferential death of cancer cells when another mechanism for repairing DNA is defective. Two PARP inhibitors, olaparib and rucaparib, have been approved by the US Food and Drug Administration (FDA) for the treatment of recurrent, BRCA-associated ovarian cancer. More recently, these two and a third PARP inhibitor, niraparib, were approved by the FDA as maintenance therapy following platinum-based chemotherapy for recurrent ovarian cancer. This has caused a paradigm shift in disease management and a challenge for clinicians, who must decide how best to use these agents in individualized treatment. The oral formulation is attractive to patients, but adverse effects such as nausea and fatigue can impact quality of life. As clinicians become comfortable selecting PARP inhibitors and managing associated toxicities, future steps will be to investigate how to safely administer them in combination with other therapies.

Topics: Anemia; Creatinine; Drug Administration Schedule; Drug Interactions; Exanthema; Fatigue; Female; Genes, BRCA1; Genes, BRCA2; Heart Rate; Humans; Hypertension; Indazoles; Leukopenia; Mutation; Myelodysplastic Syndromes; Nasopharyngitis; Nausea; Ovarian Neoplasms; Piperidines; Pneumonia; Poly(ADP-ribose) Polymerase Inhibitors; Thrombocytopenia; Transaminases; Vomiting