Pharmacokinetic drug evaluation of niraparib for the treatment of ovarian cancer

An Updated Comprehensive Pharmacovigilance Study of Drug-Induced Thrombocytopenia Based on FDA Adverse Event Reporting System Data

Drug-induced thrombocytopenia (DIT) deserves both clinical and research attention for the serious clinical consequences and high prevalence of the condition. The current study aimed to perform a comprehensive pharmacovigilance analysis of DIT reported in the US Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) database, with a particular focus on drugs associated with thrombocytopenia events. A disproportionality analysis of DIT was conducted using reports submitted to FARES from January 2004 to December 2022. Both the information component (IC) and reporting odds ratio (ROR) algorithms were applied to identify an association between target drugs and DIT events. A total of 15,940,383 cases were gathered in FAERS, 168,657 of which were related to DIT events. The top 50 drugs ranked by number of cases and ranked by signal strength were documented. The top 5 drugs ranked by number of cases were lenalidomide (10,601 cases), niraparib (3726 cases), ruxolitinib (3624 cases), eltrombopag (3483 cases), and heparin (3478 cases). The top 5 drugs ranked by signal strength were danaparoid (ROR 37.61, 95%CI 30.46-46.45), eptifibatide (ROR 34.75, 95%CI 30.65-39.4), inotersen (ROR 34.00, 95%CI 29.47-39.23), niraparib (ROR 30.53, 95%CI 29.42-31.69), and heparin (ROR 28.84, 95%CI 27.76-29.97). The top 3 involved drug groups were protein kinase inhibitors, antimetabolites, and monoclonal antibodies and antibody-drug conjugates. The current comprehensive pharmacovigilance study identified more drugs associated with thrombocytopenia. Although the mechanisms of DIT have been elucidated for some drugs, others still require further investigation.

Niraparib and Advanced Ovarian Cancer: A Beacon in the Non-BRCA Mutated Setting

Ovarian cancer (OC) is the eighth most common cancer among the female population and the most lethal of all the female reproductive system malignancies. Poly (ADP-ribose) polymerase inhibitors (PARPis) have reshaped the treatment scenario of metastatic OC in the maintenance setting post platinum-based chemotherapy. Niraparib is the first Food and Drug Administration (FDA)- and European Medical Agency (EMA)-approved PARPi as maintenance therapy for platinum-sensitive OC, regardless of BReast CAncer gene (BRCA) status, in first-line patients, with a recent restriction to germline BRCA mutations in second-line patients. In this review, we comprehensively summarized the pharmacological properties of niraparib, alongside the efficacy and safety data of the main trials leading to the current approvals, and discussed the future development of this agent.

Proteomic Analysis Reveals Low-Dose PARP Inhibitor-Induced Differential Protein Expression in BRCA1-Mutated High-Grade Serous Ovarian Cancer Cells

High-grade serous ovarian cancer (HGSOC) is the most common form of ovarian cancer diagnosed in patients worldwide. Patients with BRCA1/2-mutated HGSOC have benefited from targeted treatments such as poly(ADP-ribose) polymerase inhibitors (PARPi). Despite the initial success of PARPi-based ovarian cancer treatment regimens, approximately 70% of patients with ovarian cancer relapse and the 5-year survival rate remains at 30%. PARPi exhibit variable treatment efficacy and toxicity profiles. Furthermore, the off-target effects of PARP inhibition have not yet been fully elucidated, warranting further study of these classes of molecules in the context of HGSOC treatment. Highly reproducible quantitative mass spectrometry-based proteomic workflows have been developed for the analysis of tumor tissues and cell lines. To detect the off-target effects of PARP inhibition, we conducted a quantitative mass spectrometry-based proteomic analysis of a BRCA1-mutated HGSOC cell line treated with low doses of two PARPi, niraparib and rucaparib. Our goal was to identify PARPi-induced protein signaling pathway alterations toward a more comprehensive elucidation of the mechanism of action of PARPi beyond the DNA damage response pathway. A significant enrichment of nuclear and nucleoplasm proteins that are involved in protein binding was observed in the rucaparib-treated cells. Shared upregulated proteins between niraparib and rucaparib treatment demonstrated RNA II pol promoter-associated pathway enrichment in transcription regulation. Pathway enrichment analyses also revealed off-target effects in the Golgi apparatus and the ER. The results from our mass spectrometry-based proteomic analysis highlights notable off-target effects produced by low-dose treatment of BRCA1-mutated HGSOC cells treated with rucaparib or niraparib.

Poly (ADP-ribose) polymerase-1 as a promising drug target for neurodegenerative diseases

AIMS

Poly (ADP-ribose) polymerase- (PARP)-1 is predominantly triggered by DNA damage. Overexpression of PARP-1 is known for its association with the pathogenesis of several CNS disorders, such as Stroke, Parkinson's disease (PD), Alzheimer's disease (AD), Huntington (HD) and Amyotrophic lateral sclerosis (ALS). NAD+ depletion resulted PARP related cell death only happened when the trial used extreme high oxidization treatment. Inhibition of PARP1/2 may induce replication related cell death due to un-repaired DNA damage. This review has discussed PARP-1 modulated downstream pathways in neurodegeneration and various FDA approved PARP-1 inhibitors.

MATERIALS AND METHODS

A systematic literature review of PubMed, Medline, Bentham, Scopus and EMBASE (Elsevier) databases was carried out to understand the nature of the extensive work done on mechanistic role of Poly (ADP-ribose) polymerase and its inhibition in Neurodegenerative diseases.

KEY FINDINGS

Several researchers have put forward number of potential treatments, of which PARP-1 enzyme has been regarded as a potent target intended for the handling of neurodegenerative ailments. Targeting PARP using its chemical inhibitors in various neurodegenerative may have therapeutic outcomes by reducing neuronal death mediated by PARPi. Numerous PARP-1 inhibitors have been studied in neurodegenerative diseases but they haven't been clinically evaluated.

SIGNIFICANCE

In this review, the pathological role of PARP-1 in various neurodegenerative diseases has been discussed along with the therapeutic role of PARP-1 inhibitors in various neurodegenerative diseases.

USP39 promotes ovarian cancer malignant phenotypes and carboplatin chemoresistance

Ubiquitin‑specific protease 39 (USP39), as one of the deubiquitinating enzymes (DUBs), exhibits aberrant an expression and has oncogenic functions in several types of cancer. However, the function and underlying molecular mechanisms of action of USP39 in ovarian cancer remain largely undetermined. The present study thus aimed to investigate whether USP39 is a promising tumor‑associated gene and whether it could be a viable target for overcoming chemotherapeutic resistance in ovarian cancer. The present study identified that USP39 was highly expressed in ovarian cancer samples with carboplatin resistance. A series of functional assays revealed that the knockdown of USP39 in ES2 and SKOV3 cells significantly decreased cell proliferation, induced cell cycle arrest at the G2/M phase and impaired the cell colony formation ability. USP39 deficiency enhanced the carboplatin‑induced apoptosis of the SKOV3 cells via the activation of poly‑ADP ribose polymerase and caspase‑3. USP39 knockdown led to the inhibition of cell migration and invasion. The opposite effects were observed when USP39 was overexpressed in the ES2 and SKOV3 cells. In vivo animal models revealed that the subcutaneous transplantation and intraperitoneal injection of USP39‑overexpressing ES2 cells increased tumor burden with or without treatment with carboplatin. However, the knockdown of USP39 suppressed SKOV3 cell growth in vivo. Mechanistic analyses also demonstrated that USP39 induced the phosphorylation of extracellular signal‑regulated kinase and AKT and increased the expression of epidermal growth factor receptor and cyclin B1. Collectively, the findings of this study suggest that USP39 may paly a vital role in regulating ovarian cancer malignant phenotypes and carboplatin resistance. Therefore, USP39 may prove to be a promising therapeutic target for patients with ovarian cancer.

Identifying the need to refine the potential patient risk factors for niraparib-induced thrombocytopenia

OBJECTIVE

Niraparib is a poly (ADP-ribose) polymerase inhibitor (PARP) approved for use in maintenance therapy for ovarian cancer that is associated with the unpredictable grade 3/4 thrombocytopenia. This study was conducted to refine patient dosing recommendations for niraparib based upon clinical practice observations of grade 3/4 thrombocytopenia.

METHODS AND MATERIALS

Six patient cases were reviewed to identify similarities in patient factors. An in vitro study was conducted using healthy volunteer blood spiked with Niraparib concentrations ranging from 0 ng/mL to 5000 ng/mL. Manual platelet counts were evaluated at different time intervals for each concentration and compared to untreated controls. Data was then analyzed based on percent change in platelet count versus untreated control for each concentration/time point.

RESULTS

In three patients with body weight > 80 kg and platelet count >200 × 10⁹/L, decreased creatinine clearance (CrCl) <60 mL/min was identified as potential signal. An additional three patients with weights below 77 kg and/or baseline platelet counts <150 × 10⁹/L were re-evaluated, and it was observed that all had decreased CrCl of <60 mL/min. Albumin <3.5 g/dL was also observed in some patients with thrombocytopenia. The in vitro study, observed a direct concentration-dependent relationship between niraparib and thrombocytopenia.

CONCLUSION

The data suggests that renal insufficiency and hypoalbuminemia may be associated with the development of niraparib-induced thrombocytopenia. Moreover, the preliminary in vitro studies also demonstrated a concentration-dependent relationship between niraparib and direct toxicity to platelets.