PARP Inhibitors in Ovarian Cancer: A Review

The efficacy and safety of mirvetuximab soravtansine in FRα-positive, third-line and later, recurrent platinum-sensitive ovarian cancer: the single-arm phase II PICCOLO trial

BACKGROUND

Mirvetuximab soravtansine-gynx (MIRV) is a first-in-class, folate receptor alpha (FRα)-targeting antibody-drug conjugate with United States Food and Drug Administration approval for FRα-positive platinum-resistant ovarian cancer. PICCOLO is a phase II, global, open-label, single-arm trial of MIRV as third-line or greater (≥3L) treatment in patients with FRα-positive (≥75% of cells with ≥2+ staining intensity) recurrent platinum-sensitive ovarian cancer (PSOC).

PATIENTS AND METHODS

Participants received MIRV (6 mg/kg adjusted ideal body weight every 3 weeks) until progressive disease (PD), unacceptable toxicity, withdrawal of consent, or death. Primary endpoint was investigator-assessed objective response rate (ORR). Key secondary endpoint was investigator-assessed duration of response (DOR). Additional endpoints included investigator-assessed progression-free survival (PFS), overall survival (OS), and safety. Analyses of subgroups by disease characteristics (e.g. platinum-free interval) and treatment history [e.g. prior bevacizumab and poly (adenosine diphosphate [ADP]-ribose) polymerase inhibitor (PARPi) treatment] were exploratory.

RESULTS

Seventy-nine participants were enrolled and efficacy assessable. The primary endpoint was met; ORR was 51.9% [95% confidence interval (CI) 40.4% to 63.3%]. Median DOR was 8.25 months (95% CI 5.55-10.78 months) and median PFS was 6.93 months (95% CI 5.85-9.59 months). OS was not mature at data cut-off. ORR was 45.8% (95% CI 32.7% to 59.2%) in participants with PD while on/within 30 days of prior PARPi (n = 59) and 60.0% (95% CI 14.7% to 94.7%) in those without PD with prior PARPi (n = 5). No new safety signals occurred; most common treatment-emergent adverse events (TEAEs) were gastrointestinal, neurosensory, and resolvable ocular events. TEAEs led to discontinuation in 13 participants (16%) and death in 2 participants (3%).

CONCLUSIONS

MIRV as ≥3L treatment in heavily pretreated recurrent FRα-positive PSOC demonstrated notable efficacy and tolerable safety, including among those with prior PD on or within 30 days of PARPi (NCT05041257).

Real-world duration of first-line maintenance niraparib monotherapy in patients with epithelial ovarian cancer in the United States: the CHAR1ZMA study

OBJECTIVE

The CHAR1ZMA study described real-world duration of first-line maintenance niraparib monotherapy among patients with epithelial ovarian cancer.

METHODS

This retrospective study used a US nationwide, electronic-health-record-derived, de-identified database. Eligible patients were aged ≥18 years with epithelial ovarian cancer who initiated first-line maintenance niraparib monotherapy (January 2017-December 2022 [inclusive]) following first-line platinum-based chemotherapy. Niraparib monotherapy duration was measured as the time to treatment discontinuation, estimated using Kaplan-Meier methodology, overall and stratified by treatment duration (early discontinuers [≤90 days]; non-early discontinuers [>90 days or did not discontinue]). Analyses were repeated in a sub-group of patients with homologous recombination-deficient tumors.

RESULTS

Toxicity was the most common reason for niraparib discontinuation among early discontinuers (67.7%) and was less frequent among non-early discontinuers (18.1%). Dose modifications were less frequent among early discontinuers (29.8%) than non-early discontinuers (53.6%). Disease progression was the most common reason for niraparib discontinuation among non-early discontinuers (74.8%) and was less frequent among early discontinuers (30.4%). The observed median treatment duration was 7.2 months (95% CI 6.0 to 8.1) overall (N = 560) and was 4.5 months longer among non-early discontinuers (11.7 months [95% CI 9.8 to 14.7]; n = 399). In the homologous recombination-deficient sub-group (n = 144), the observed median treatment duration was 11.6 months (95% CI 7.8. to 16.1) and was 5.1 months longer among non-early discontinuers (16.7 months [95% CI 12.0 to 22.8]; n = 114).

CONCLUSION

In this real-world study of patients with epithelial ovarian cancer receiving first-line maintenance niraparib monotherapy, drug toxicity was the most common reason for treatment discontinuation in early discontinuers. Effective and early clinical management of drug toxicity may help mitigate these adverse events, allowing patients to remain on niraparib maintenance treatment longer and experience the potential full therapeutic benefit.

Unlocking the future: mitochondrial genes and neural networks in predicting ovarian cancer prognosis and immunotherapy response

Background

Mitochondrial genes are involved in the tumor metabolism of ovarian cancer (OC), affecting immune cell infiltration and treatment response. We aimed to utilize mitochondrial genes to predict OC prognosis and immunotherapy response.

Methods

The prognosis data, immunotherapy efficacy and next generation sequencing data of OC patients were downloaded from The Cancer Genome Atlas Program (TCGA) and Gene Expression Omnibus (GEO). Mitochondrial genes were sourced from the MitoCarta3.0 database. Seventy percent of the patients were randomly selected as the discovery cohort for model construction, while the remaining 30% constituted the validation cohort for model assessment. Using the expression of mitochondrial genes as the predictor variable and based on the neural network algorithm, the overall survival (OS) time and immunotherapy efficacy (complete or partial response) of the included patients were predicted.

Results

There were 375 OC patients included to construct the prognostic model, and 26 patients were included to construct the immune efficacy model. The average area under the receiver operating characteristic curve (AUC) of the prognostic model was: 0.7268 [95% confidence interval (CI), 0.7258-0.7278] in the discovery cohort and 0.6475 (95% CI: 0.6466-0.6484) in the validation cohort. The average AUC of the immunotherapy efficacy model was: 0.9444 (95% CI: 0.8333-1.0000) in the discovery cohort and 0.9167 (95% CI: 0.6667-1.0000) in the validation cohort.

Conclusions

The application of mitochondrial genes and neural networks shows potential in predicting the prognosis and immunotherapy response in OC patients. And this approach could provide valuable insights for personalized treatment strategies.

A comprehensive comparison of PARP inhibitors as maintenance therapy in platinum-sensitive recurrent ovarian cancer: a systematic review and network meta-analysis

BACKGROUND

PARP inhibitors (PARPis) have shown promising effectiveness for ovarian cancer. This network meta-analysis (PROSPERO registration number CRD42024503390) comprehensively evaluated the effectiveness and safety of PARPis in platinum-sensitive recurrent ovarian cancer (PSROC).

METHODS

Articles published before January 6, 2024 were obtained from electronic databases. The study assessed and compared survival outcomes including overall survival (OS), progression-free survival (PFS), second progression-free survival (PFS2), time to first subsequent treatment (TFST), time to second subsequent treatment (TSST), and chemotherapy-free interval (CFI). Additionally, safety outcomes were investigated, specifically focusing on grade 3-4 treatment-emergent adverse effects (TEAEs). The evaluation of OS and PFS was also conducted based on the BRCA and HRD (homologous recombination deficiency) statuses.

RESULTS

Six randomized controlled trials were examined and the four PARPis (olaparib, niraparib, rucaparib and fuluzolparib) have been found to significantly increase the PFS in entire population as well as in subgroups of HRD and BRCAm (BRCA mutation). Only olaparib demonstrated a substantial improvement in OS compared to placebo in entire population (hazard ratio [HR] 0.73; 95% confidence interval [CI] 0.60-0.90), as well as in the subgroup of BRCAm. All analyzed PARPis had significant efficacy in prolonging PFS2, TFST, TSST and CFI. For safety concerns, PARPis could significantly increase incidence of TEAEs (grade3-4), while olaparib had least haematological TEAEs (grade3-4) events compared to other PARPis.

CONCLUSION

All included PARPis showed various degrees of benefit in survival outcomes and safety profile was acceptable for PSROC patients. Among them olaparib had the best performance in both efficacy and safety.

Niraparib Maintenance Therapy in Patients with Platinum-Sensitive Recurrent Ovarian Cancer: Real-World Experience at Hospitals in Spain

BACKGROUND

The reported benefit of poly (ADP-ribose) polymerase inhibitor (PARPi) maintenance in patients with newly diagnosed and platinum (Pt)-sensitive recurrent ovarian cancer (OC) included in randomized clinical trials needs to be corroborated in a less selected population.

OBJECTIVE

The aim is to increase the evidence on niraparib in a real-world setting.

METHODS

This is a retrospective observational study including women with platinum-sensitive relapsed high-grade serous OC who started niraparib maintenance between August 2019 (marketing data, Spain) and May 2022. Patients received ≥ 2 previous lines of therapy with complete or partial response to prior chemotherapy. Patient characteristics, niraparib dose, adequacy of dose individualization, effectiveness (progression-free survival [PFS] and overall survival), safety, and economic savings with an individualized starting dose (ISD) strategy were assessed.

RESULTS

The study included 217 patients with a median of 8.9 months of niraparib duration: breast cancer gene (BRCA) wild-type OC, 70%; two prior treatment lines, 49%; Research on Adverse Drug Events and Reports (RADAR) criteria, 82% (receiving mainly 200 mg of niraparib, 79%). Median PFS was 10.8 months (95% confidence interval [CI], 8.4-14.8) without statistically significant differences based on starting dose strategy, contrary to what was observed on the basis of prior lines, response to prior chemotherapy, BRCA mutational status, and International Federation of Gynecology and Obstetrics (FIGO) stage at diagnosis. The last three variables also showed a statistically significant predictive prognostic value for effectiveness. Dose interruptions due to toxicity were required in 7% of patients, and dose adjustments in 56% were mainly due to hematologic toxicities. The actual dose of niraparib reveals economic savings versus the theoretical cost.

CONCLUSION

This large real-world analysis corroborates the tolerability and activity of niraparib maintenance for platinum-sensitive recurrent OC and economic savings.

Unlocking the future: Mitochondrial genes and neural networks in predicting ovarian cancer prognosis and immunotherapy response

BACKGROUND

Mitochondrial genes are involved in tumor metabolism in ovarian cancer (OC) and affect immune cell infiltration and treatment responses.

AIM

To predict prognosis and immunotherapy response in patients diagnosed with OC using mitochondrial genes and neural networks.

METHODS

Prognosis, immunotherapy efficacy, and next-generation sequencing data of patients with OC were downloaded from The Cancer Genome Atlas and Gene Expression Omnibus. Mitochondrial genes were sourced from the MitoCarta3.0 database. The discovery cohort for model construction was created from 70% of the patients, whereas the remaining 30% constituted the validation cohort. Using the expression of mitochondrial genes as the predictor variable and based on neural network algorithm, the overall survival time and immunotherapy efficacy (complete or partial response) of patients were predicted.

RESULTS

In total, 375 patients with OC were included to construct the prognostic model, and 26 patients were included to construct the immune efficacy model. The average area under the receiver operating characteristic curve of the prognostic model was 0.7268 [95% confidence interval (CI): 0.7258-0.7278] in the discovery cohort and 0.6475 (95%CI: 0.6466-0.6484) in the validation cohort. The average area under the receiver operating characteristic curve of the immunotherapy efficacy model was 0.9444 (95%CI: 0.8333-1.0000) in the discovery cohort and 0.9167 (95%CI: 0.6667-1.0000) in the validation cohort.

CONCLUSION

The application of mitochondrial genes and neural networks has the potential to predict prognosis and immunotherapy response in patients with OC, providing valuable insights into personalized treatment strategies.

Promising new drugs and therapeutic approaches for treatment of ovarian cancer-targeting the hallmarks of cancer

Ovarian cancer remains the most lethal gynecological malignancy. Despite the approval of promising targeted therapy such as bevacizumab and PARP inhibitors, 5-year survival has not improved significantly. Thus, there is an urgent need for new therapeutics. New advancements in therapeutic strategies target the pivotal hallmarks of cancer. This review is giving an updated overview of innovative and upcoming therapies for the treatment of ovarian cancer that focuses specific on the hallmarks of cancer. The hallmarks of cancer constitute a broad concept to reenact complexity of malignancies and furthermore identify possible targets for new treatment strategies. For this purpose, we analyzed approvals and current clinical phase III studies (registered at ClinicalTrials.gov (National Library of Medicine, National Institutes of Health; U.S. Department of Health and Human Services, 2024)) for new drugs on the basis of their mechanisms of action and identified new target approaches. A broad spectrum of new promising drugs is currently under investigation in clinical phase III studies targeting mainly the hallmarks "self-sufficiency in growth signals," "genomic instability," and "angiogenesis." The benefit of immune checkpoint inhibitors in ovarian cancer has been demonstrated for the first time. Besides, targeting the tumor microenvironment is of growing interest. Replicative immortality, energy metabolism, tumor promoting inflammation, and the microbiome of ovarian cancer are still barely targeted by drugs. Nevertheless, precision medicine, which focuses on specific disease characteristics, is becoming increasingly important in cancer treatment.

The association of the chemotherapy response score and homologous recombination deficiency in patients undergoing interval tumor reductive surgery following neoadjuvant chemotherapy

OBJECTIVES

In patients undergoing interval tumor reductive surgery, a good response to neoadjuvant chemotherapy may limit available tumor for homologous recombination deficiency testing. The objective of this study was to assess whether the chemotherapy response score predicts homologous recombination status.

METHODS

We identified patients with advanced epithelial ovarian cancer (diagnosed January 2019 to 20 June 2023) who received neoadjuvant chemotherapy, underwent interval surgery, and for whom a chemotherapy response score was reported (1=no or minimal tumor response, 2=appreciable tumor response, 3=complete or near complete response with no residual tumor). Comparisons were made using ANOVAs or Kruskal-Wallis test for continuous variables and χ2 or Fisher's exact test for categorical variables.

RESULTS

The cohort consisted of 234 patients with advanced ovarian cancer who underwent interval surgery following neoadjuvant chemotherapy. Of those who underwent germline genetic testing, 22% (51/232) had a pathogenic BRCA1 or BRCA2 mutation and of those with tumors sent for testing, 65% were found to have homologous recombination deficiency (66/146). With increasing chemotherapy response scores, a higher likelihood of a complete gross resection was observed (50% (chemotherapy response score, CRS 1) vs 77% (CRS 2) vs 88% (CRS 3), p<0.001). On multivariable analysis, CRS 2 (adjusted odds ratio=3.28, 95% CI 1.12 to 9.60, p=0.03) and CRS 3 (5.83, 1.79 to 18.93, p=0.003) were independently associated with homologous recombination deficiency compared with CRS 1.

CONCLUSION

A positive response to chemotherapy at the time of interval tumor reductive surgery defined by the chemotherapy response score was associated with homologous recombination status and the likelihood of achieving a complete gross resection.

Genomic scarring score predicts the response to PARP inhibitors in non-small cell lung cancer

PARP inhibitors (PARPi) have shown efficacy in tumours harbouring mutations in homologous recombination repair (HRR) genes. Somatic HRR mutations have been described in patients with Non-Small Cell Lung Cancer (NSCLC), but PARP inhibitors (PARPi) are not yet a therapeutic option. Here we assessed the homologous recombination status of early-stage NSCLC and explored the therapeutic benefit of PARPi in preclinical models. The Genomic Scarring Score GSS (GSS) and HRR mutation profile of 136 patients were assessed. High GSS (h-GSS) was observed in 39 (28.7%) patients half of which carried pathogenic/likely pathogenic somatic HRR mutations. TP53 mutations were significantly enriched in h-GSS tumours (p < 0.001). Olaparib significantly delayed tumour growth in h-GSS but not l-GSS Patient-derived Xenografts (PDXs), while patients with h-GSS/TP53mut tumours respond favourably to adjuvant platinum-based chemotherapy. Our functional data clearly support the idea that the use of GSS rather than the mutational status of HRR genes could select patients for administration of PARPi.

Pharmacoproteomics reveals energy metabolism pathways as therapeutic targets of ivermectin in ovarian cancer toward 3P medical approaches

Objective

Ovarian cancer is the malignant tumor with the highest mortality rate in the female reproductive system, enormous socio-economic burden, and limited effective drug therapy. There is an urgent need to find novel effective drugs for ovarian cancer therapy. Our previous in vitro studies demonstrate that ivermectin effectively inhibits ovarian cancer cells and affects energy metabolism pathways. This study aims to clarify in vivo mechanisms and therapeutic targets of ivermectin in the treatment of ovarian cancer to establish predictive biomarkers, guide personalized treatments, and improve preventive strategies in the framework of 3P medicine.

Methods

A TOV-21G tumor-bearing mouse model was constructed based on histopathological data and biochemical parameters. TMT-based proteomic analysis was performed on tumor tissues from the different treatment groups. All significantly differentially abundant proteins were characterized by hierarchical clustering, Gene Ontology (GO) enrichment analyses, and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. In addition, the data were integrated and analyzed with the proteomic data of clinical ovarian cancer tissues from our previous study and the proteomic data of ivermectin intervention in ovarian cancer cells to identify key regulators of ivermectin.

Results

Ivermectin (10 mg/kg) had a significant anti-ovarian cancer effect in mice, with a tumor inhibitory rate of 61.5%. Molecular changes in tumor tissue of ivermectin-treated mice were established, and protein-protein interaction (PPI) analysis showed that the main differential pathway networks included the TCA cycle, propanoate metabolism, 2-0xocarboxyacid metabolism, and other pathways. Integrating our previous clinical ovarian cancer tissue and cell experimental data, this study found that ivermectin significantly interfered with the energy metabolic pathways of ovarian cancer, including glycolysis, TCA cycle, oxidative phosphorylation, and other related pathways.

Conclusions

This study evaluated the anti-ovarian cancer effect in vitro and in vivo, and its specific regulatory effect on energy metabolism. The expressions of drug target molecules in the energy metabolism pathway of ovarian cancer will be used to guide the diagnosis and prevention of ovarian cancer. The significant efficacy of ivermectin will be applied to the treatment of ovarian cancer and personalized medication. This has guiding significance for the clinical diagnosis, treatment, personalized medication, and prognosis evaluation of ovarian cancer.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13167-024-00385-1.

Differential Receipt of Genetic Services Among Patients With Gynecologic Cancer and Their Relatives: A Review of Challenges to Health Equity

Up to 14% of endometrial cancers and 23% of epithelial ovarian cancers are associated with genetic predispositions. Referral for genetic testing and counseling can significantly impact a patient's oncologic outcomes. However, significant disparities in genetic referral and testing exist within medically underserved and minority populations in the United States. These disparities in care and access to care are multifactorial, often involving patient-level, health care-level, and system-level factors. In this review, we focus on disparities in genetic testing among patients with ovarian and uterine cancer, and the missed opportunities for primary cancer prevention among their relatives.

PARG inhibitor sensitivity correlates with accumulation of single-stranded DNA gaps in preclinical models of ovarian cancer

Poly (ADP-ribose) glycohydrolase (PARG) is a dePARylating enzyme which promotes DNA repair by removal of poly (ADP-ribose) (PAR) from PARylated proteins. Loss or inhibition of PARG results in replication stress and sensitizes cancer cells to DNA-damaging agents. PARG inhibitors are now undergoing clinical development for patients having tumors with homologous recombination deficiency (HRD), such as cancer patients with germline or somatic BRCA1/2-mutations. PARP inhibitors kill BRCA-deficient cancer cells by increasing single-stranded DNA gaps (ssGAPs) during replication. Here, we report that, like PARP inhibitor (PARPi), PARG inhibitor (PARGi) treatment also causes an accumulation of ssGAPs in sensitive cells. PARGi exposure increased accumulation of S-phase-specific PAR, a marker for Okazaki fragment processing (OFP) defects on lagging strands and induced ssGAPs, in sensitive cells but not in resistant cells. PARGi also caused accumulation of PAR at the replication forks and at the ssDNA sites in sensitive cells. Additionally, PARGi exhibited monotherapy activity in specific HR-deficient, as well as HR-proficient, patient-derived, or patient-derived xenograft (PDX)-derived organoids of ovarian cancer, and drug sensitivity directly correlated with the accumulation of ssGAPs. Taken together, PARGi treatment results in toxic accumulation of PAR at replication forks resulting in ssGAPs due to OFP defects during replication. Regardless of the BRCA/HRD-status, the induction of ssGAPs in preclinical models of ovarian cancer cells correlates with PARGi sensitivity. Patient-derived organoids (PDOs) may be a useful model system for testing PARGi sensitivity and functional biomarkers.

Efficacy and safety of angiogenesis inhibitors combined with poly ADP ribose polymerase inhibitors in the maintenance treatment of advanced ovarian cancer: a meta-analysis

INTRODUCTION

This meta-analysis was performed to evaluate the efficacy and safety of angiogenesis inhibitors (Ais) combined with poly ADP ribose polymerase inhibitors (PARPi) in the maintenance treatment of advanced ovarian cancer (OC).

MATERIALS AND METHODS

A systematic search was conducted in four databases (Pubmed, Embase, Web of Science, and Cochrane) for articles published from the inception of the databases until January 15, 2024. The focus of the search was on articles investigating the combination of Ais with PARPi in the maintenance treatment of ovarian cancer. Meta-analyses were conducted to assess the objective response rate (ORR), progression-free survival (PFS), overall survival (OS), and the risk of Grade ≥ 3 adverse events (Grade≥ 3 AEs).

RESULTS

Totally nine studies were included for meta-analysis. The overall pooled ORR of Ais combined with PARPi was 57% (95% CI, 35% to 77%). Subgroup analyses showed that the ORR for patients with platinum-resistant recurrent ovarian cancer, platinum-sensitive recurrent ovarian cancer and newly diagnosed advanced ovarian cancer were 30% (95% CI, 12% to 52%), 70% (95% CI, 61% to 78%) and 59% (95% CI, 55% to 63%), respectively. The median PFS was 5.8 months (95% CI, 5.3 to 7.1), 12.4 months (95% CI, 10.6 to 13.2) and 22.4 months (95% CI, 21.5 to 24.2), respectively. The median OS was 15.5 months (95% CI, 12.3 to 24.8), 40.8 months (95% CI, 33.4 to 45.2) and 56.3 months (95% CI, 49.0 to 62.0), respectively. The rate Grade≥ 3 TRAEs rate was found to be 0.22 (95% CI, 0.13 to 0.33).

CONCLUSIONS

Our results confirmed that PARPi plus Ais was a feasible and safe option for the maintenance treatment of advanced ovarian cancer. The combination therapy should be recommended as the first-line maintenance treatment for patients with advanced ovarian cancer. PARPi plus Ais yielded more favorable oncological prognosis for patients with platinum-sensitive recurrent ovarian cancer, compared to patients with platinum-resistant recurrent ovarian cancer.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42024543590, identifier CRD42024543590.

Long-read sequencing of an advanced cancer cohort resolves rearrangements, unravels haplotypes, and reveals methylation landscapes

The Long-Read Personalized OncoGenomics (POG) dataset comprises a cohort of 189 patient tumors and 41 matched normal samples sequenced using the Oxford Nanopore Technologies PromethION platform. This dataset from the POG program and the Marathon of Hope Cancer Centres Network includes DNA and RNA short-read sequence data, analytics, and clinical information. We show the potential of long-read sequencing for resolving complex cancer-related structural variants, viral integrations, and extrachromosomal circular DNA. Long-range phasing facilitates the discovery of allelically differentially methylated regions (aDMRs) and allele-specific expression, including recurrent aDMRs in the cancer genes RET and CDKN2A. Germline promoter methylation in MLH1 can be directly observed in Lynch syndrome. Promoter methylation in BRCA1 and RAD51C is a likely driver behind homologous recombination deficiency where no coding driver mutation was found. This dataset demonstrates applications for long-read sequencing in precision medicine and is available as a resource for developing analytical approaches using this technology.

Case report: High grade serous fallopian tube carcinoma with rare NRG1 gene fusion presenting as widespread peritoneal carcinomatosis

The discovery of gene fusions involving Neuregulin-1 (NRG1) within solid tumors has important therapeutic implications, as they are being actively explored as targets for emerging ERBB/ERBB2/ERBB3-directed anti-cancer agents. NRG1 fusions are very uncommon across all tumor types and are infrequently documented in the medical literature. We report a female patient presenting with widespread peritoneal carcinomatosis diagnosed as high grade serous fallopian tube carcinoma, which harbored a previously undescribed MYH10::NRG1 fusion. Moreover, we queried the whole transcriptome sequencing results of neoplasms analyzed by a commercial laboratory (Caris Life Sciences) to determine the overall incidence of NRG1 fusions in carcinomas of the ovary, fallopian tube, and peritoneum (0.18%). Twenty-five additional tumors were found to demonstrate NRG1 fusions, including 20 new genes partners that had not been previously identified in gynecologic carcinomas. Overall, NRG1 fusion events are rare in ovarian, fallopian tube, and primary peritoneal carcinomas, but they may carry diagnostic significance in the context of borderline/low grade serous tumors, which demonstrated exclusively CLU::NRG1 fusions, and could have important predictive implications for response to ERBB/ERBB2/ERBB3-directed therapies.

PARP inhibitors in ovarian cancer: Mechanisms, resistance, and the promise of combination therapy

Current approaches to treating ovarian cancer focus mainly on surgical cytoreduction and chemotherapy using platinum-based drugs, while newer methods such as immunotherapy are being investigated to enhance treatment outcomes. Treating ovarian cancer is complicated by challenges such as late-stage detection, tumor diversity, and limited treatment choices. Therefore, innovative strategies such as precision medicine and targeted therapies like PARPi (Poly ADP-Ribose Polymerase inhibitors) are increasingly necessary. The article highlights the significance of an innovative therapeutic approach focusing on PARPi in revolutionizing ovarian cancer treatment and improving patient outcomes. It covers the basic knowledge of PARP, its structure, and its function in DNA repair. It further emphasizes how inhibiting PARP can help in treating ovarian cancer. It elaborates on the mechanism of action of PARPi. It covers the clinical trials governing PARPi and the combination of drugs used with PARPi. It mentions how the resistance is developed to PARPi and the strategies to overcome the resistance developed.

Role of Fyn expression in predicting the sensitivity to platinum‑based chemotherapy in patients with ovarian serous carcinoma

Ovarian serous carcinoma is a gynecological malignancy associated with a high mortality rate, which is commonly diagnosed in the first instance at a late stage and has a propensity to develop resistance to platinum-based chemotherapy. Identifying reliable biomarkers for platinum sensitivity is critical for improving patient outcomes. The present retrospective study included 64 patients with high-grade serous ovarian carcinoma (Federation of Gynecology and Obstetrics stages III or IV). Patients were classified as platinum-sensitive (no relapse within 6 months of the last platinum administration) or platinum-resistant (relapse within 6 months). Immunohistochemical analysis was performed to evaluate Fyn expression in tumor tissues, and Fyn knockdown experiments were performed using the OVSAHO ovarian cancer cell line to assess carboplatin sensitivity. Fyn expression was significantly higher in platinum-resistant patients compared with in platinum-sensitive patients (P<0.01). A weighted Fyn expression score was developed and a cutoff score of 6 was determined to predict platinum sensitivity with a specificity of 65.5% and a sensitivity of 62.9%. Patients with low Fyn expression (score ≤6) exhibited higher platinum sensitivity and longer overall survival (P<0.05). Multivariate analysis identified Fyn expression and postoperative residual tumor size as independent predictors of platinum sensitivity (P=0.033 and P=0.023, respectively). In vitro, Fyn knockdown significantly increased carboplatin sensitivity in ovarian cancer cells (P<0.05). Fyn, a member of the Src family of kinases, serves a crucial role in various cellular functions and has been implicated in chemotherapy resistance. The results demonstrated a notable association between Fyn expression and platinum sensitivity in ovarian serous carcinoma. The findings suggested that Fyn may serve as a predictive biomarker for response to platinum-based chemotherapy, offering the potential for more personalized treatment strategies. To the best of our knowledge, the present study is the first to establish an association between Fyn expression and platinum sensitivity in advanced ovarian serous carcinoma. Prospective studies with larger, multi-center cohorts and comprehensive biomarker analyses are recommended to validate and extend these results, ultimately improving therapeutic strategies and patient prognosis.

PARP inhibitor-related acute renal failure: a real-world study based on the FDA adverse event reporting system database

BACKGROUND

Current clinical trial data on PARP inhibitors (PARPis)-related acute renal failure (ARF) are not entirely representative of real-world situations. Therefore, in this study, the US Food and Drug Administration Adverse Event Reporting System (FAERS) was used to evaluate PARPis-related ARF.

RESEARCH DESIGN AND METHODS

Data were obtained from 1 January 2015, to 30 September 2023. ARF event reports were analyzed based on four algorithms. The time-to-onset (TTO) and clinical outcomes of PARPis-associated ARF were assessed.

RESULTS

The total included cases were 2726. Significant signals were observed for olaparib, niraparib, and rucaparib (reporting odds ratio (ROR): 1.62, 95% confidence interval (CI): 1.49-1.78, 1.25, 95% CI: 1.19-1.32 and 1.59, 95% CI: 1.47-1.72 respectively). The median TTO of ARF onset was 57, 36, and 85 days for olaparib, niraparib, and rucaparib, respectively. The proportion of deaths with olaparib (9.88%) was significantly higher than for niraparib (2.52%) and rucaparib (2.94%) (p < 0.005). The proportion of life-threatening adverse events associated with niraparib (4.89%) was significantly higher than for rucaparib (0.98%) (p < 0.005).

CONCLUSIONS

ARF and PARPi were related, with the exception of talazoparib. More emphasis should be given to PARPis-related ARF due to the high proportion of serious AEs and delayed adverse reactions.

Impact of PARP inhibitors on progression-free survival in platinum-sensitive recurrent epithelial ovarian cancer: a retrospective analysis

OBJECTIVE

Poly (ADP-ribose) polymerase (PARP) inhibitors such as olaparib and niraparib have shown promise in extending progression-free survival (PFS) in patients with platinum-sensitive recurrent (PSR) epithelial ovarian cancer. In this retrospective study, we aimed to present our own data on the effect of PARP inhibitors on PFS in recurrent epithelial ovarian cancer.

METHODS

82 patients diagnosed with PSR epithelial ovarian, tubal, or primary peritoneal cancer between May 2017 and September 2023 were initially enrolled from our hospital. However, 16 patients had prior exposure to PARP inhibitors during primary treatment, and 11 were lost to follow-up. Consequently, the study focused on 55 eligible patients. PFS was compared between patients receiving PARP inhibitor maintenance therapy and those who did not.

RESULTS

Among the 55 patients with PSR epithelial ovarian cancer, 18 received olaparib as maintenance therapy, 19 received niraparib, and 18 opted for observation. PARP inhibitor therapy significantly extended PFS (mean 24.0 months) compared to observation (mean 9.0 months, p = 0.0005), regardless of BRCA mutation status (HR = 0.20, 95% CI: 0.08-0.50). Subgroup analysis showed no statistical difference between olaparib and niraparib. Additionally, there was no PFS difference based on BRCA mutation status within both PARP inhibitor groups.

CONCLUSION

Our retrospective study demonstrates that PARP inhibitor maintenance therapy, including olaparib and niraparib, significantly prolongs PFS in patients with PSR epithelial ovarian, tubal, or primary peritoneal cancer, These findings support the broad utilization of PARP inhibitors as a standard maintenance therapy for PSR epithelial ovarian cancer irrespective of BRCA mutation status.

Cabozantinib inhibits tumor growth in mice with ovarian cancer

Ovarian cancer is usually detected in the advanced stages. Existing treatments for high grade serous ovarian cancer (HGSOC) are not adequate and approximately fifty percent of patients succumb to this disease and die within five years after diagnosis. We conducted pre-clinical studies in a mouse model of ovarian cancer to evaluate disease outcome in response to treatment with the multi-kinase inhibitor cabozantinib. Cabozantinib is a receptor tyrosine kinase inhibitor with multiple targets including vascular endothelial growth factor receptor-2 (VEGFR-2), associated with immune suppression in ovarian cancer. Mice (C57BL/6) were injected with ID8-RFP ovarian tumor cells and treated with cabozantinib. Studies investigated ascites development, tumor burden and regulation of anti-tumor immunity with treatment. Mice treated with cabozantinib had significantly decreased solid tumor burden and decreased malignant ascites as compared to untreated controls. Improved outcome in cabozantinib treated mice was associated with a significantly higher percentage of CD69 early activated T cells, a higher percentage of granzyme B secreting CD8 T cells, the enhanced release of cytokines and chemokines known to recruit CD8 T cells and amplify T cell function, as well as reduced VEGFR-2. Findings suggest that cabozantinib is an important clinical agent capable of improving ovarian cancer in mice potentially in part by priming the autologous immune system to promote anti-tumor immunity.

Synthesis of 5-hydroxyisatin thiosemicarbazones, spectroscopic investigation, protein-ligand docking, and in vitro anticancer activity

A series of novel modifications were performed at the N(4) position of 5-hydroxyisatin thiosemicarbazone (TSC). The structure-activity approach is applied to design and synthesize derivatives by condensing thiosemicarbazides with 5-hydroxy isatin. The TSCs were characterized by various spectroscopic techniques viz. FTIR, 1H NMR, 13C NMR, UV-Vis, HRMS data, CHN elemental analysis, and single crystal X-ray diffraction. Biological evaluation of the synthesized compounds revealed the anticancer potency of the TSC analogues against breast cancer (MD-AMD-231, MCF-7), lung cancer (A549, NCI-H460), prostate cancer (PC3), and skin cancer (A431). The molecules, L2, L3, and L6 showed activity in the micromolar range (IC50; 0.19-2.19 μM). L6 exhibited the highest potency against skin cancer A431 cell line, with an IC50 of 0.19 μM compared to 1.8 μM with triapine and showed low toxicity against PNT-2 cells with an SI index of >100 μM. The mechanistic study revealed that L6 inhibited cancer cell proliferation, colony formation, and 3-dimensional spheroid formation by targeting the Ras/MAPK axis. It induced DNA damage and impaired DNA damage repair machinery, which led to the accumulation of DSB. Also, it lowered the ERK1/2 expression, which affected the caspase 3 activity and showed higher binding affinity compared to the FDA-approved drug Lenalidomide in molecular docking studies. Our findings demonstrated the possible future anticancer drug potency of L6 in the skin cancer A431 cells.

Poly(ADP-Ribose) Polymerase (PARP) Inhibitors for Cancer Therapy: Advances, Challenges, and Future Directions

Poly(ADP-ribose) polymerases (PARPs) are crucial nuclear proteins that play important roles in various cellular processes, including DNA repair, gene transcription, and cell death. Among the 17 identified PARP family members, PARP1 is the most abundant enzyme, with approximately 1-2 million molecules per cell, acting primarily as a DNA damage sensor. It has become a promising biological target for anticancer drug studies. Enhanced PARP expression is present in several types of tumors, such as melanomas, lung cancers, and breast tumors, correlating with low survival outcomes and resistance to treatment. PARP inhibitors, especially newly developed third-generation inhibitors currently undergoing Phase II clinical trials, have shown efficacy as anticancer agents both as single drugs and as sensitizers for chemo- and radiotherapy. This review explores the properties, characteristics, and challenges of PARP inhibitors, discussing their development from first-generation to third-generation compounds, more sustainable synthesis methods for discovery of new anti-cancer agents, their mechanisms of therapeutic action, and their potential for targeting additional biological targets beyond the catalytic active site of PARP proteins. Perspectives on green chemistry methods in the synthesis of new anticancer agents are also discussed.

Design, synthesis and antitumor activities of phthalazinone derivatives as PARP-1 inhibitors and PARP-1/HDAC-1 inhibitors

In recent years, poly(ADP-ribose)polymerase-1 (PARP-1) and histone deacetylase (HDAC) have emerged as significant targets in tumor therapy, garnering widespread attention. In this study, we designed and synthesized two novel phthalazinone PARP-1 inhibitors and dual PARP-1/HDAC-1 inhibitors, named DLC-1-46 containing dithiocarboxylate fragments and DLC-47-63 containing hydroxamic acid fragments, and evaluated their inhibitory activities on enzymes and cells. Among the PARP-1 inhibitors, most compounds exhibited high inhibitory activity against the PARP-1 enzyme, with DLC-1-6 being particularly notable, showing IC50 values <0.2 nM. Notably, DLC-1 demonstrated significant anti-proliferative activity, with IC50 values for inhibiting the proliferation of MDA-MB-436, MDA-MB-231, and MCF-7 cells reaching 0.08, 26.39, and 1.01 μM, respectively. Further investigation revealed that DLC-1 arrested MDA-MB-231 cells in the G1 phase and induced apoptosis in a dose-dependent manner. Among the designed dual PARP-1/HDAC-1 inhibitors, several compounds exhibited potent dual-target inhibitory activity, with DLC-49 displaying IC50 values of 0.53 nM and 17 nM for PARP-1 and HDAC-1, respectively. DLC-50 demonstrated the most potent anti-proliferative activity, with IC50 values for inhibiting the proliferation of MDA-MB-436, MDA-MB-231, and MCF-7 cells at 0.30, 2.70, and 2.41 μM, respectively. Cell cycle arrest and apoptosis assays indicated that DLC-50 arrested the cell cycle in the G2 phase and induced apoptosis in HCT-116 cells. Our findings present a novel avenue for further exploration of PARP-1 inhibitors and dual PARP-1/HDAC-1 inhibitors.

A comprehensive review on the potential of coumarin and related derivatives as multi-target therapeutic agents in the management of gynecological cancers

Current treatments for gynecological cancers include surgery, radiotherapy, and chemotherapy. However, these treatments often have significant side effects. Phytochemicals, natural compounds derived from plants, offer promising anticancer properties. Coumarins, a class of benzopyrone compounds found in various plants like tonka beans, exhibit notable antitumor effects. These compounds induce cell apoptosis, target PI3K/Akt/mTOR signaling pathways, inhibit carbonic anhydrase, and disrupt microtubules. Additionally, they inhibit tumor multidrug resistance and angiogenesis and regulate reactive oxygen species. Specific coumarin derivatives, such as auraptene, praeruptorin, osthole, and scopoletin, show anti-invasive, anti-migratory, and antiproliferative activities by arresting the cell cycle and inducing apoptosis. They also inhibit metalloproteinases-2 and -9, reducing tumor cell migration, invasion, and metastasis. These compounds can sensitize tumor cells to radiotherapy and chemotherapy. Synthetic coumarin derivatives also demonstrate potent antitumor and anticancer activities with minimal side effects. Given their diverse mechanisms of action and minimal side effects, coumarin-class phytochemicals hold significant potential as therapeutic agents in gynecological cancers, potentially improving treatment outcomes and reducing side effects. This review will aid in the synthesis and development of novel coumarin-based drugs for these cancers.

Genetic landscape of homologous recombination repair and practical outcomes of PARPi therapy in ovarian cancer management

Background

Genetic studies of ovarian cancer (OC) have historically focused on BRCA1/2 mutations, lacking other studies of homologous recombination repair (HRR). Poly (ADP-ribose) polymerase inhibitors (PARPi) exploit synthetic lethality to significantly improve OC treatment outcomes, especially in BRCA1/2 deficiency patients.

Objectives

Our study aims to construct a mutation map of HRR genes in OC and identify factors influencing the efficacy of PARPi.

Design

A retrospective observational analysis of HRR gene variation data from 695 OC patients from March 2019 to February 2022 was performed.

Methods

The HRR gene variation data of 695 OC patients who underwent next-generation sequencing (NGS) in the First Affiliated Hospital of Zhengzhou University were retrospectively collected. Clinical data on the use of PARPi in these patients were also gathered to identify factors that may interfere with the efficacy of PARPi.

Results

Out of 127 pathogenic variants in the BRCA1/2 genes, 104 (81.9%) were BRCA1 mutations, and 23 (18.1%) were BRCA2 mutations. Among the 59 variants of uncertain significance (VUS), 20 (33.9%) were BRCA1, while 39 (66.1%) were BRCA2 mutations. In addition to BRCA1/2, HRR gene results showed that 9 (69%) of 13 were HRR pathway pathogenic variants; and 16 (1.7%) of 116 VUS were Food and Drug Administration (FDA)-approved mutated HRR genes. Notably, the treatment regimen significantly influenced the effectiveness of PARPi, especially when using first-line maintenance therapy, leading to enhanced progression-free survival (PFS) compared to alternative protocols.

Conclusion

Focusing on HRR gene mutations and supporting clinical research about PARPi in OC patients is crucial for developing precision treatment strategies and enhancing prognosis.

Association of PARP1 Expression Levels and Clinical Parameters in Different Leukemic Subtypes With BCR::ABL1 p190+ Translocation

Background/Aim

Although the reciprocal translocation t(9;22)(q34;q11) is a hallmark of chronic myeloid leukemia (CML), it is also present in acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). Depending on the gene's breakpoint, it is possible to obtain three isoforms, among which p190 stands out for the poor prognosis it induces whenever it appears. Due to the genomic instability induced by BCR::ABL1, it is proposed to expand the applicability of poly-ADP-ribose polymerase-1 (PARP1) and its inhibitors in hematological neoplasms.

Materials and Methods

We measured the expression levels of PARP1 by quantitative real-time PCR (qPCR) using TaqMan®, correlating its expression with BCR::ABL1 p190+, to evaluate its influence in the clinic of adult patients.

Results

We found that PARP1 is expressed differently in ALL, AML and CML and that p190 transcripts do not follow a linear pattern in these populations. We also found that PARP1 expression is not correlated with age, white blood cell and the amount of p190 transcripts.

Conclusion

Despite the lack of statistical correlation between the variables analyzed, the role of PARP1 in BCR::ABL1 leukemia cannot be ruled out, given the instability profile promoted by this translocation. Finally, further studies involving a larger sample of patients are needed, as well as investigations into other molecular pathways that may impact on the pathogenesis of different BCR::ABL1 leukemic subtypes.

Guidelines of the Brazilian Society of Surgical Oncology for anatomopathological, immunohistochemical, and molecular testing in female tumors

INTRODUCTION

Precision medicine has revolutionized oncology, providing more personalized diagnosis, treatment, and monitoring for patients with cancer. In the context of female-specific tumors, such as breast, ovarian, endometrial, and cervical cancer, proper tissue collection and handling are essential for obtaining tissue, immunohistochemical (IHC), and molecular data to guide therapeutic decisions.

OBJECTIVES

To establish guidelines for the collection and handling of tumor tissue, to enhance the quality of samples for histopathological, IHC, genomic, and molecular analyses. These guidelines are fundamental in informing therapeutic decisions in cancer treatment.

METHOD

The guidelines were developed by a multidisciplinary panel of renowned specialists between June 12, 2013 and February 12, 2024. Initially, the panel deliberated on critical and controversial topics related to conducting precision medicine studies focusing on female tumors. Subsequently, 22 pivotal topics were identified within the framework and assigned to groups. These groups reviewed relevant literature and drafted preliminary recommendations. Following this, the recommendations were reviewed by the coordinators and received unanimous approval. Finally, the groups made the final adjustments, classified the level of evidence, and ranked the recommendations.

CONCLUSION

The collection of surgical samples requires minimum quality standards to enable histopathological, IHC, genomic, and molecular analyses. These analyses provide crucial data for informing therapeutic decisions, significantly impacting potential survival gains for patients with female tumors.

Overview of BH3 mimetics in ovarian cancer

Ovarian carcinoma is the leading cause of gynecological cancer-related death, still with a dismal five-year prognosis, mainly due to late diagnosis and the emergence of resistance to cytotoxic and targeted agents. Bcl-2 family proteins have a key role in apoptosis and are associated with tumor development/progression and response to therapy in different cancer types, including ovarian carcinoma. In tumors, evasion of apoptosis is a possible mechanism of resistance to therapy. BH3 mimetics are small molecules that occupy the hydrophobic pocket on pro-survival proteins, allowing the induction of apoptosis, and are currently under study as single agents and/or in combination with cytotoxic and targeted agents in solid tumors. Here, we discuss recent advances in targeting anti-apoptotic proteins of the Bcl-2 family for the treatment of ovarian cancer, focusing on BH3 mimetics, and how these approaches could potentially offer an alternative/complementary way to treat patients and overcome or delay resistance to current treatments.

Leveraging PARP-1/2 to Target Distant Metastasis

Poly (ADP-Ribose) Polymerase (PARP) inhibitors have changed the outcomes and therapeutic strategy for several cancer types. As a targeted therapeutic mainly for patients with BRCA1/2 mutations, PARP inhibitors have commonly been exploited for their capacity to prevent DNA repair. In this review, we discuss the multifaceted roles of PARP-1 and PARP-2 beyond DNA repair, including the impact of PARP-1 on chemokine signalling, immune modulation, and transcriptional regulation of gene expression, particularly in the contexts of angiogenesis and epithelial-to-mesenchymal transition (EMT). We evaluate the pre-clinical role of PARP inhibitors, either as single-agent or combination therapies, to block the metastatic process. Efficacy of PARP inhibitors was demonstrated via DNA repair-dependent and independent mechanisms, including DNA damage, cell migration, invasion, initial colonization at the metastatic site, osteoclastogenesis, and micrometastasis formation. Finally, we summarize the recent clinical advancements of PARP inhibitors in the prevention and progression of distant metastases, with a particular focus on specific metastatic sites and PARP-1 selective inhibitors. Overall, PARP inhibitors have demonstrated great potential in inhibiting the metastatic process, pointing the way for greater use in early cancer settings.

Prescribers and patients drive maintenance therapy patterns in a community oncology practice: National guidelines versus the real-world experience

Objective

Previous studies have shown that first-line (1L) maintenance therapy (MT) with poly(ADP-ribose) polymerase inhibitors and/or bevacizumab improves outcomes among patients with advanced ovarian cancer (OC); however, these treatments are underutilized. This study aimed to provide a real-world understanding of MTs among patients with advanced OC who received 1L platinum-based chemotherapy (PBC).

Methods

A retrospective chart review using iKnowMed electronic health records to identify patients aged ≥18 years with advanced OC who initiated 1L PBC between January 1, 2018-December 31, 2020. Following 1L PBC, patients could have received MT or active surveillance (AS). Kaplan-Meier methods were used to estimate time to treatment discontinuation (TTD), real-world progression-free survival (rwPFS), and overall survival (OS).

Results

Of the 600 chart-reviewed patients included, 239 (39.8 %) received MT and 315 (52.5 %) received AS. Patients who were <65 years of age, or those with higher-stage disease or those who had received neoadjuvant treatment, were more likely to initiate MT than AS. Genetic testing rates were low across both cohorts. Median (95 % confidence interval [CI]) TTD for the MT cohort was 13.6 months (11.0, 21.2). Median (95 % CI) rwPFS was 26.9 months (21.3, not reached) and 11.3 months (9.5, 13.0) for the 1L MT and AS cohorts, respectively (p < 0.0001). OS at 36 months was 82.4 % in the 1L MT cohort and 58.0 % in the 1L AS cohort.

Conclusions

This study reinforces clinical trial findings that 1L MT improves outcomes in patients with advanced OC; however, genetic testing rates and 1L MT remained low.

FLT1 activation in cancer cells promotes PARP-inhibitor resistance in breast cancer

Acquired resistance to PARP inhibitors (PARPi) remains a treatment challenge for BRCA1/2-mutant breast cancer that drastically shortens patient survival. Although several resistance mechanisms have been identified, none have been successfully targeted in the clinic. Using new PARPi-resistance models of Brca1- and Bard1-mutant breast cancer generated in-vivo, we identified FLT1 (VEGFR1) as a driver of resistance. Unlike the known role of VEGF signaling in angiogenesis, we demonstrate a novel, non-canonical role for FLT1 signaling that protects cancer cells from PARPi in-vivo through a combination of cell-intrinsic and cell-extrinsic pathways. We demonstrate that FLT1 blockade suppresses AKT activation, increases tumor infiltration of CD8+ T cells, and causes dramatic regression of PARPi-resistant breast tumors in a T-cell-dependent manner. Moreover, PARPi-resistant tumor cells can be readily re-sensitized to PARPi by targeting Flt1 either genetically (Flt1-suppression) or pharmacologically (axitinib). Importantly, a retrospective series of breast cancer patients treated with PARPi demonstrated shorter progression-free survival in cases with FLT1 activation at pre-treatment. Our study therefore identifies FLT1 as a potential therapeutic target in PARPi-resistant, BRCA1/2-mutant breast cancer.

Trends in estimated PARP inhibitor eligibility and benefit among US epithelial ovarian cancer patients

OBJECTIVE

To estimate the annual percentage of patients with epithelial ovarian cancer (EOC) who could be eligible for and benefit from PARP inhibitor therapy amidst changing US Food and Drug Administration (FDA)-approved indications.

METHODS

This is a simulated retrospective observational study using publicly available data on patients with advanced-stage EOC. PARPi eligibility is based on FDA approvals and withdrawals from 2014 through 2023, along with published demographic and genomic data. Clinical trial data is used to estimate treatment benefit. PARPi including olaparib, niraparib, and rucaparib are analyzed in aggregate with sub-analyses by molecular classification and treatment timing. Results are reported as the percentage of EOC patients appropriate for any cancer-directed therapy.

RESULTS

PARPi were approved for 9 different indications in EOC between 2014 and 2021; reduced to 6 indications by 2023. Eligibility increased from 2.0% (95% CI,1.3%-1.6%) in 2014 to a maximum of 93.4% (95% CI,90.1%-94.6%) in 2021. The maximum percentage of patients with 2-year PFS benefit was 22.0% (95% CI, 17.2%-26.8%) in 2021, projected to decrease to 13.0% (95% CI, 9.9%-15.9%) in 2024. Most of this decrease was seen in the homologous recombination deficient, BRCA wild-type population (8.4% to 4.0%).

CONCLUSIONS

PARPi eligibility increased at a greater rate than benefit resulting in a low population-level benefit-to-eligibility ratio until 2021. Recent FDA withdrawals improved this ratio with an accompanied decrease in the absolute number of patients benefiting. To further optimize population-level benefit-to-eligibility ratio of targeted therapies in ovarian cancer, we need to identify better biomarkers, treatment combinations, and novel therapeutic targets.

Targeted Nanocarrier-Based Drug Delivery Strategies for Improving the Therapeutic Efficacy of PARP Inhibitors against Ovarian Cancer

The current focus of ovarian cancer (OC) research is the improvement of treatment options through maximising drug effectiveness. OC remains the fifth leading cause of cancer-induced mortality in women worldwide. In recent years, nanotechnology has revolutionised drug delivery systems. Nanoparticles may be utilised as carriers in gene therapy or to overcome the problem of drug resistance in tumours by limiting the number of free drugs in circulation and thereby minimising undesired adverse effects. Cell surface receptors, such as human epidermal growth factor 2 (HER2), folic acid (FA) receptors, CD44 (also referred to as homing cell adhesion molecule, HCAM), and vascular endothelial growth factor (VEGF) are highly expressed in ovarian cancer cells. Generation of active targeting nanoparticles involves modification with ligands that recognise cell surface receptors and thereby promote internalisation by cancer cells. Several poly(ADP-ribose) polymerase (PARP) inhibitors (PARPi) are currently used for the treatment of high-grade serous ovarian carcinomas (HGSOC) or platinum-sensitive relapsed OC. However, PARP resistance and poor drug bioavailability are common challenges, highlighting the urgent need to develop novel, effective strategies for ovarian cancer treatment. This review evaluates the utility of nanoparticles in ovarian cancer therapy, with a specific focus on targeted approaches and the use of PARPi nanocarriers to optimise treatment outcomes.

Unveiling G-protein coupled receptors as potential targets for ovarian cancer nanomedicines: from RNA sequencing data analysis to in vitro validation

Genetic heterogeneity in ovarian cancer indicates the need for personalised treatment approaches. Currently, very few G-protein coupled receptors (GPCRs) have been investigated for active targeting with nanomedicines such as antibody-conjugated drugs and drug-loaded nanoparticles, highlighting a neglected potential to develop personalised treatment. To address the genetic heterogeneity of ovarian cancer, a future personalised approach could include the identification of unique GPCRs expressed in cancer biopsies, matched with personalised GPCR-targeted nanomedicines, for the delivery of lethal drugs to tumour tissue before, during and after surgery. Here we report on the systematic analysis of public ribonucleic acid-sequencing (RNA-seq) gene expression data, which led to prioritisation of 13 GPCRs as candidates with frequent overexpression in ovarian cancer tissues. Subsequently, primary ovarian cancer cells derived from ascites and ovarian cancer cell lines were used to confirm frequent gene expression for the selected GPCRs. However, the expression levels showed high variability within our selection of samples, therefore, supporting and emphasising the need for the future development of case-to-case personalised targeting approaches.

PARP Inhibitors in Brain Metastases from Epithelial Ovarian Cancer through a Multimodal Patient Journey: Case Reports and Literature Review

Epithelial ovarian cancer (EOC) is the deadliest gynecological malignancy worldwide. Brain metastasis (BM) is quite an uncommon presentation. However, the likelihood of central nervous system (CNS) metastasization should be considered in the context of disseminated disease. The therapeutic management of BMs is an unmet clinical need, to date. We identified, across different cancer centers, six cases of both BRCA wild-type and BRCA-mutated EOCs spreading to the CNS. They presented either with a single brain lesion or with multiple lesions and most of them had intracranial-only disease. All cases received Poly-ADP ribose polymerase inhibitor (PARPi) maintenance, as per clinical practice, for a long time within a multimodal treatment approach. We also provide an insight into the available body of work regarding the management of this intriguing disease setting, with a glimpse of future therapeutic challenges. Despite the lack of unanimous guidelines, multimodal care pathways should be encouraged for the optimal disease control of this unfortunate patient subset. Albeit not being directly investigated in BM patients, PARPi maintenance is deemed to have a valuable role in this setting. Prospective research, aimed to implement worthwhile strategies in the multimodal patient journey of BMs from EOC, is eagerly awaited.

Structure and Functions of HMGB3 Protein

HMGB3 protein belongs to the group of HMGB proteins from the superfamily of nuclear proteins with high electrophoretic mobility. HMGB proteins play an active part in almost all cellular processes associated with DNA-repair, replication, recombination, and transcription-and, additionally, can act as cytokines during infectious processes, inflammatory responses, and injuries. Although the structure and functions of HMGB1 and HMGB2 proteins have been intensively studied for decades, very little attention has been paid to HMGB3 until recently. In this review, we summarize the currently available data on the molecular structure, post-translational modifications, and biological functions of HMGB3, as well as the possible role of the ubiquitin-proteasome system-dependent HMGB3 degradation in tumor development.

New hopes and promises in the treatment of ovarian cancer focusing on targeted treatment-a narrative review

Unfortunately, ovarian cancer is still diagnosed most often only in an advanced stage and is also the most lethal gynecological cancer. Another problem is the fact that treated patients have a high risk of disease recurrence. Moreover, ovarian cancer is very diverse in terms of molecular, histological features and mutations. Many patients may also develop platinum resistance, resulting in poor response to subsequent lines of treatment. To improve the prognosis of patients with ovarian cancer, it is expected to make better existing and implement new, promising treatment methods. Targeted therapies seem very promising. Currently, bevacizumab - a VEGF inhibitor and therapy with olaparib - a polyADP-ribose polymerase inhibitor are approved. Other methods worth considering in the future include: folate receptor α, immune checkpoints or other immunotherapy methods. To improve the treatment of ovarian cancer, it is also important to ameliorate the determination of molecular features to describe and understand which group of patients will benefit most from a given treatment method. This is important because a larger group of patients treated for ovarian cancer can have a greater chance of surviving longer without recurrence.

Senaparib as first-line maintenance therapy in advanced ovarian cancer: a randomized phase 3 trial

Poly(adenosine diphosphate-ribose) polymerase (PARP) inhibitors as maintenance therapy after first-line chemotherapy have improved progression-free survival in women with advanced ovarian cancer; however, not all PARP inhibitors can provide benefit for a biomarker-unselected population. Senaparib is a PARP inhibitor that demonstrated antitumor activity in patients with solid tumors, including ovarian cancer, in phase 1 studies. The multicenter, double-blind, phase 3 trial FLAMES randomized (2:1) 404 females with advanced ovarian cancer (International Federation of Gynecology and Obstetrics stage III-IV) and response to first-line platinum-based chemotherapy to senaparib 100 mg (n = 271) or placebo (n = 133) orally once daily for up to 2 years. The primary endpoint was progression-free survival assessed by blinded independent central review. At the prespecified interim analysis, the median progression-free survival was not reached with senaparib and was 13.6 months with placebo (hazard ratio 0.43, 95% confidence interval 0.32-0.58; P < 0.0001). The benefit with senaparib over placebo was consistent in the subgroups defined by BRCA1 and BRCA2 mutation or homologous recombination status. Grade ≥3 treatment-emergent adverse events occurred in 179 (66%) and 27 (20%) patients, respectively. Senaparib significantly improved progression-free survival versus placebo in patients with advanced ovarian cancer after response to first-line platinum-based chemotherapy, irrespective of BRCA1 and BRCA2 mutation status and with consistent benefits observed between homologous recombination subgroups, and was well tolerated. These results support senaparib as a maintenance treatment for patients with advanced ovarian cancer after a response to first-line chemotherapy. ClinicalTrials.gov identifier: NCT04169997 .

Poly(ADP-Ribose) Polymerase Inhibitor Development: Promising Strategies to Move Beyond Approved Indications

Biomarker-based patient selection and rational combinations show promise in expanding the use of PARP inhibitors.

Enhanced amphiregulin exposure promotes modulation of the high grade serous ovarian cancer tumor immune microenvironment

High grade serous ovarian cancer (HGSOC) is a lethal gynecologic malignancy in which chemoresistant recurrence rates remain high. Furthermore, HGSOC patients have demonstrated overall low response rates to clinically available immunotherapies. Amphiregulin (AREG), a low affinity epidermal growth factor receptor ligand is known to be significantly upregulated in HGSOC patient tumors following neoadjuvant chemotherapy exposure. While much is known about AREG's role in oncogenesis and classical immunity, it is function in tumor immunology has been comparatively understudied. Therefore, the objective of this present study was to elucidate how increased AREG exposure impacts the ovarian tumor immune microenvironment (OTIME). Using NanoString IO 360 and protein analysis, it was revealed that treatment with recombinant AREG led to prominent upregulation of genes associated with ovarian pathogenesis and immune evasion (CXCL8, CXCL1, CXCL2) along with increased STAT3 activation in HGSOC cells. In vitro co-culture assays consisting of HGSOC cells and peripheral blood mononuclear cells (PBMCs) stimulated with recombinant AREG (rAREG) led to significantly enhanced tumor cell viability. Moreover, PBMCs stimulated with rAREG exhibited significantly lower levels of IFNy and IL-2. In vivo rAREG treatment promoted significant reductions in circulating levels of IL-2 and IL-5. Intratumoral analysis of rAREG treated mice revealed a significant reduction in CD8+ T cells coupled with an upregulation of PD-L1. Finally, combinatorial treatment with an AREG neutralizing antibody and carboplatin led to a synergistic reduction of cell viability in HGSOC cell lines OVCAR8 and PEA2. Overall, this study demonstrates AREG's ability to modulate cytotoxic responses within the OTIME and highlights its role as a novel HGSOC immune target.

Oncogenic Pathways and Targeted Therapies in Ovarian Cancer

Epithelial ovarian cancer (EOC) is one of the most aggressive forms of gynaecological malignancies. Survival rates for women diagnosed with OC remain poor as most patients are diagnosed with advanced disease. Debulking surgery and platinum-based therapies are the current mainstay for OC treatment. However, and despite achieving initial remission, a significant portion of patients will relapse because of innate and acquired resistance, at which point the disease is considered incurable. In view of this, novel detection strategies and therapeutic approaches are needed to improve outcomes and survival of OC patients. In this review, we summarize our current knowledge of the genetic landscape and molecular pathways underpinning OC and its many subtypes. By examining therapeutic strategies explored in preclinical and clinical settings, we highlight the importance of decoding how single and convergent genetic alterations co-exist and drive OC progression and resistance to current treatments. We also propose that core signalling pathways such as the PI3K and MAPK pathways play critical roles in the origin of diverse OC subtypes and can become new targets in combination with known DNA damage repair pathways for the development of tailored and more effective anti-cancer treatments.

New horizons for platinum-resistant ovarian cancer: insights from the 2023 American Society of Clinical Oncology (ASCO) and European Society for Medical Oncology (ESMO) Annual Meetings

Platinum-resistant ovarian cancer is difficult to treat and has a poor prognosis. Patients with platinum-resistant ovarian cancer have limited treatment options and often have a limited benefit from existing chemotherapeutic agents. There is a lack of contemporary effective anticancer drugs and reliable predictive biomarkers for this aggressive cancer. Recent cutting-edge research presented at the 2023 American Society of Clinical Oncology (ASCO) and the European Society for Medical Oncology (ESMO) Annual Meetings has provided insights into several potential therapeutic targets, such as DNA damage repair proteins, cell-cycle regulators, and immune-modulating agents. In addition, antibody-drug conjugates have provided new practice-changing results in platinum-resistant ovarian cancer. Here, we review the results of research presented at this annual event, with a focus on clinical trials investigating novel treatment approaches for platinum-resistant ovarian cancer, in addition to predictive and prognostic biomarkers for optimal patient selection, and other topics, such as real-world evidence.

Spotlight on New Hallmarks of Drug-Resistance towards Personalized Care for Epithelial Ovarian Cancer

Epithelial ovarian cancer (EOC) is the deadliest gynecological malignancy worldwide. Despite the latest advances, a major clinical issue in EOC is the disappointing prognosis related to chemoresistance in almost one-third of cases. Drug resistance relies on heterogeneous cancer stem cells (CSCs), endowed with tumor-initiating potential, leading to relapse. No biomarkers of chemoresistance have been validated yet. Recently, major signaling pathways, micro ribonucleic acids (miRNAs), and circulating tumor cells (CTCs) have been advocated as putative biomarkers and potential therapeutic targets for drug resistance. However, further investigation is mandatory before their routine implementation. In accordance with the increasing rate of therapeutic efforts in EOC, the need for biomarker-driven personalized therapies is growing. This review aims to discuss the emerging hallmarks of drug resistance with an in-depth insight into the underlying molecular mechanisms lacking so far. Finally, a glimpse of novel therapeutic avenues and future challenges will be provided.

Complexity of the Genetic Background of Oncogenesis in Ovarian Cancer-Genetic Instability and Clinical Implications

Ovarian cancer is a leading cause of death among women with gynecological cancers, and is often diagnosed at advanced stages, leading to poor outcomes. This review explores genetic aspects of high-grade serous, endometrioid, and clear-cell ovarian carcinomas, emphasizing personalized treatment approaches. Specific mutations such as TP53 in high-grade serous and BRAF/KRAS in low-grade serous carcinomas highlight the need for tailored therapies. Varying mutation prevalence across subtypes, including BRCA1/2, PTEN, PIK3CA, CTNNB1, and c-myc amplification, offers potential therapeutic targets. This review underscores TP53's pivotal role and advocates p53 immunohistochemical staining for mutational analysis. BRCA1/2 mutations' significance as genetic risk factors and their relevance in PARP inhibitor therapy are discussed, emphasizing the importance of genetic testing. This review also addresses the paradoxical better prognosis linked to KRAS and BRAF mutations in ovarian cancer. ARID1A, PIK3CA, and PTEN alterations in platinum resistance contribute to the genetic landscape. Therapeutic strategies, like restoring WT p53 function and exploring PI3K/AKT/mTOR inhibitors, are considered. The evolving understanding of genetic factors in ovarian carcinomas supports tailored therapeutic approaches based on individual tumor genetic profiles. Ongoing research shows promise for advancing personalized treatments and refining genetic testing in neoplastic diseases, including ovarian cancer. Clinical genetic screening tests can identify women at increased risk, guiding predictive cancer risk-reducing surgery.

Low-dose Olaparib improves septic cardiac function by reducing ferroptosis via accelerated mitophagy flux

Sepsis is a dysregulated response to infection that can result in life-threatening organ failure, and septic cardiomyopathy is a serious complication involving ferroptosis. Olaparib, a classic targeted drug used in oncology, has demonstrated potential protective effects against sepsis. However, the exact mechanisms underlying its action remain to be elucidated. In our study, we meticulously screened ferroptosis genes associated with sepsis, and conducted comprehensive functional enrichment analyses to delineate the relationship between ferroptosis and mitochondrial damage. Eight sepsis-characterized ferroptosis genes were identified in sepsis patients, including DPP4, LPIN1, PGD, HP, MAPK14, POR, GCLM, and SLC38A1, which were significantly correlated with mitochondrial quality imbalance. Utilizing DrugBank and molecular docking, we demonstrated a robust interaction of Olaparib with these genes. Lipopolysaccharide (LPS)-stimulated HL-1 cells and monocytes were used to establish an in vitro sepsis model. Additionally, an in vivo model was developed using mice subjected to cecal ligation and perforation (CLP). Intriguingly, low-dose Olaparib (5 mg/kg) effectively targeted and mitigated markers associated with ferroptosis, concurrently improving mitochondrial quality. This led to a marked enhancement in cardiac function and a significant increase in survival rates in septic mice (p < 0.05). The mechanism through which Olaparib ameliorates ferroptosis in cardiac and leukocyte cells post-sepsis is attributed to its facilitation of mitophagy, thus favoring mitochondrial integrity. In conclusion, our findings suggest that low-dose Olaparib can improve mitochondrial quality by accelerating mitophagy flux, consequently inhibiting ferroptosis and preserving cardiac function after sepsis.

Evaluation of Homologous Recombination Deficiency in Ovarian Cancer

OPINION STATEMENT

Homologous recombination deficiency (HRD) is an important biomarker guiding selection of ovarian cancer patients who will derive the most benefit from poly(ADP-ribose) polymerase inhibitors (PARPi). HRD prevents cells from repairing double-stranded DNA damage with high fidelity, PARPis limit single-stranded repair, and together these deficits induce synthetic lethality. Germline or somatic BRCA mutations represent the narrowest definition of HRD, but do not reflect all patients who will have a durable PARPi response. HRD can also be defined by its downstream consequences, which are measured by different metrics depending on the test used. Ideally, all patients will undergo genetic counseling and germline testing shortly after diagnosis and have somatic testing sent once an adequate tumor sample is available. Should barriers to one test be higher, pursuing germline testing with reflex to somatic testing for BRCA wildtype patients or somatic testing first strategies are both evidence-based. Ultimately both tests offer complementary information, germline testing should be pursued for any patient with a history of ovarian cancer, and somatic testing is valuable at recurrence if not performed in the upfront setting. There is a paucity of data to suggest superiority of one germline or somatic assay; therefore, selection should optimize turnaround time, cost to patients, preferred result format, and logistical burden. Each clinic should implement a standard testing strategy for all ovarian cancer patients that ensures HRD status is known at the time of upfront chemotherapy completion to facilitate comprehensive counseling about anticipated maintenance PARPi benefit.

Assessing the Phenotype of a Homologous Recombination Deficiency Using High Resolution Array-Based Comparative Genome Hybridization in Ovarian Cancer

Ovarian cancer (OC) cells with homologous recombination deficiency (HRD) accumulate genomic scars (LST, TAI, and LOH) over a value of 42 in sum. PARP inhibitors can treat OC with HRD. The detection of HRD can be done directly by imaging these genomic scars, or indirectly by detecting mutations in the genes involved in HR. We show that HRD detection is also possible using high-resolution aCGH. A total of 30 OCs were analyzed retrospectively with high-resolution arrays as a test set and 19 OCs prospectively as a validation set. Mutation analysis was performed by HBOC TruRisk V2 panel to detect HR-relevant mutations. CNVs were clustered with respect to the involved HR genes versus the OC cases. In prospective validation, the HRD status determined by aCGH was compared with external HRD assessments. Two BRCA mutation carriers did not have HRD. OC could approximately differentiate into two groups with characteristic CNV patterns with different survival rates. Mutation frequencies have a linear regression on the HRD score. Mutations in individual HR-relevant genes do not always indicate HRD. This may depend on the mutation frequency in tumor cells. The aCGH shows the genomic scars of an HRD inexpensively and directly.

Novel PARP7 Inhibitors for Treating Cancer

Provided herein are novel PARP7 inhibitors, pharmaceutical compositions, use of such compounds in treating cancer, and processes for preparing such compounds.