Treatment With Niraparib Maintenance Therapy in Patients With Newly Diagnosed Advanced Ovarian Cancer: A Phase 3 Randomized Clinical Trial

Updates in the Use of Targeted Therapies for Gynecologic Cancers

Targeted therapies have changed the treatment landscape in gynecologic cancer. Studies released over the past year have led to the incorporation of immunotherapy (IO) into the treatment for all patients with endometrial and cervical cancers at some point during their disease course. Poly(ADP-ribose) polymerase (PARP) inhibitors continue to play a role in women with ovarian carcinoma, particularly in homologous repair deficient tumors. Furthermore, the benefit of PARP inhibitors in challenging subgroups continues to be elucidated. Biomarker identification has led to the approval or compendium listing of several antibody-drug conjugates (ADCs). This review will update on IO, ADCs, and PARP inhibition for the treatment of gynecologic cancers.

Niraparib maintenance therapy using an individualised starting dose in patients with platinum-sensitive recurrent ovarian cancer (NORA): final overall survival analysis of a phase 3 randomised, placebo-controlled trial

Background

Niraparib significantly prolonged progression-free survival versus placebo in patients with platinum-sensitive, recurrent ovarian cancer (PSROC), regardless of germline BRCA mutation (gBRCAm) status, in NORA. This analysis reports final data on overall survival (OS).

Methods

This randomised, double-blind, placebo-controlled, phase 3 trial enrolled patients across 30 centres in China between 26 September 2017 and 2 February 2019 (clinicaltrials.gov, NCT03705156). Eligible patients had histologically confirmed, recurrent, (predominantly) high-grade serous epithelial ovarian cancer, fallopian tube carcinoma, or primary peritoneal carcinoma (no histological restrictions for those with gBRCAm) and had received ≥2 prior lines of platinum-based chemotherapy. Patients were randomised (2:1) to receive niraparib or placebo, with stratification by gBRCAm status, time to recurrence following penultimate platinum-based chemotherapy, and response to last platinum-based chemotherapy. Following a protocol amendment, the starting dose was individualised: 200 mg/day for patients with bodyweight <77 kg and/or platelet count <150 × 103/μL at baseline and 300 mg/day otherwise. OS was a secondary endpoint.

Findings

Totally, 265 patients were randomised to receive niraparib (n = 177) or placebo (n = 88), and 249 (94.0%) received an individualised starting dose. As of 14 August 2023, median follow-up for OS was 57.9 months (IQR, 54.8-61.6). Median OS (95% CI) with niraparib versus placebo was 51.5 (41.4-58.9) versus 47.6 (33.3-not evaluable [NE]) months, with hazard ratio [HR] of 0.86 (95% CI, 0.60-1.23), in the overall population; 56.0 (36.1-NE) versus 47.6 (31.6-NE) months, with HR of 0.86 (95% CI, 0.46-1.58), in patients with gBRCAm; and 46.5 (41.0-NE) versus 46.9 (31.8-NE) months, with HR of 0.87 (95% CI, 0.56-1.35), in those without. No new safety signals were identified, and myelodysplastic syndromes/acute myeloid leukaemia occurred in three (1.7%) niraparib-treated patients.

Interpretation

Niraparib maintenance therapy with an individualised starting dose demonstrated a favourable OS trend versus placebo in PSROC patients, regardless of gBRCAm status.

Funding

Zai Lab (Shanghai) Co., Ltd; National Major Scientific and Technological Special Project for "Significant New Drugs Development" in 2018, China [grant number 2018ZX09736019].

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.

Progesterone Enhances Niraparib Efficacy in Ovarian Cancer by Promoting Palmitoleic-Acid-Mediated Ferroptosis

Poly (adenosine 5'-diphosphate-ribose) polymerase inhibitors (PARPi) are increasingly important in the treatment of ovarian cancer. However, more than 40% of BRCA1/2-deficient patients do not respond to PARPi, and BRCA wild-type cases do not show obvious benefit. In this study, we demonstrated that progesterone acted synergistically with niraparib in ovarian cancer cells by enhancing niraparib-mediated DNA damage and death regardless of BRCA status. This synergy was validated in an ovarian cancer organoid model and in vivo experiments. Furthermore, we found that progesterone enhances the activity of niraparib in ovarian cancer through inducing ferroptosis by up-regulating palmitoleic acid and causing mitochondrial damage. In clinical cohort, it was observed that progesterone prolonged the survival of patients with ovarian cancer receiving PARPi as second-line maintenance therapy, and high progesterone receptor expression combined with low glutathione peroxidase 4 (GPX4) expression predicted better efficacy of PARPi in patients with ovarian cancer. These findings not only offer new therapeutic strategies for PARPi poor response ovarian cancer but also provide potential molecular markers for predicting the PARPi efficacy.

Safety and hematological toxicities of PARP inhibitors in patients with cancer: a systematic review of randomized controlled trials and a pharmacovigilance analysis

INTRODUCTION

This study aimed to estimate the toxicities of PARP inhibitors (PARPis), based on randomized controlled trials (RCTs) and the FDA Adverse Event Reporting System (FAERS) database.

METHODS

Four electronic databases were searched from inception to 16 April 2024, for RCTs of approved PARPis. The primary and secondary outcomes were grade 3-5 adverse events (AEs) and grade 3-5 hematological AE, respectively. We conducted network meta-analyses to calculate the relative risks (RRs) and 95% confidence intervals (CIs) of outcomes. A disproportionality analysis was conducted to estimate the signals of hematological AEs associated with PARPis from the FAERS database.

RESULTS

Overall, 27 RCTs involving 11,067 patients with cancer were included. Olaparib had the best safety profile for any grade 3-5 AEs and hematological AEs among four approved PARPis. Olaparib did not increase the risk of thrombocytopenia (RR: 1.48; 95%CI: 0.64-3.39), but other PARPis did. Furthermore 14,780 hematological AE reports associated with PARPis were identified in the FAERS database, and all PARPis were associated with strong hematological AE signals. Hematological AEs mainly occurred within the first 3 months (80.84%) after PARPi initiation.

CONCLUSION

Olaparib had the best safety profile among five PARPis. PARPi-associated hematological AEs mainly occurred within the first 3 months.

REGISTRATION

PROSPERO (CRD42022385274).

Heterogeneous treatment effect of dose-dense paclitaxel plus carboplatin therapy for advanced ovarian cancer

A Japanese clinical trial (JGOG3016) showed that dose-dense weekly paclitaxel in combination with carboplatin extensively prolonged overall survival (OS) in patients with advanced ovarian cancer. However, in other clinical trials, dose-dense paclitaxel regimens were not superior to triweekly paclitaxel regimens. In this study, causal tree analysis was applied to explore subpopulations with different treatment effects of dose-dense paclitaxel in a data-driven approach. The 587 participants with stage II-IV ovarian cancer in the JGOG3016 trial were used for model development. The primary endpoint was treatment effect in terms of 3-year OS in patients receiving dose-dense vs. conventional paclitaxel therapies. In patients <50 years, the 3-year OS was similar in both groups; however, it was higher in the dose-dense group in patients ≥50 years. Dose-dense paclitaxel showed strong positive treatment effects in patients ≥50 years with stage II/III disease, BMI <23 kg/m2, non-CC/MC, and residual tumor ≥1 cm. In contrast, although there was no significant difference in OS; the 3-year OS rate was 23% lower in dose-dense paclitaxel than conventional paclitaxel in patients ≥60 years with stage IV cancer. Patients in this group had a particularly lower performance status than other groups. Our causal tree analysis suggested that poor prognosis groups represented by residual tumor tissue ≥1 cm benefit from dose-dense paclitaxel, whereas elderly patients with advanced disease and low-performance status are negatively impacted by dose-dense paclitaxel. These subpopulations will be of interest to future validation studies. Personalized treatments based on clinical features are expected to improve advanced ovarian cancer prognosis.

Outcomes of secondary cytoreductive surgery in patients with platinum-sensitive recurrent ovarian cancer progressed after prior poly (adenosine diphosphate-ribose) polymerase inhibitors: A retrospective cohort study

OBJECTIVE

To evaluate the impact of previous poly (adenosine diphosphate-ribose) polymerase (PARP) inhibitor therapy on the effectiveness of secondary cytoreductive surgery (SCS) in patients with platinum-sensitive recurrent ovarian cancer (PSROC).

METHODS

We identified patients with PSROC who underwent SCS at the Cancer Hospital, Chinese Academy of Medical Science, between January 2010 and December 2022. Postoperative complications within 30 days were categorized using the Accordion Severity Grading System. The Kaplan‒Meier method was used to estimate both overall survival (OS) and progression-free survival (PFS), and multivariate analysis was used to identify independent prognostic factors.

RESULTS

Of the 265 patients included, 39 received prior PARP inhibitor therapy (Group A), and 226 did not (Group B). The rates of complete resection after SCS did not significantly differ between the two groups (79.5 % for Group A vs. 81.0 % for Group B; p = 0.766). As of December 2023, Group A exhibited a significantly shorter median PFS (14.2 months) than Group B (22.5 months; p = 0.002). Furthermore, the 3-year OS rate was lower in Group A (72.5 %) than in Group B (82.7 %; p = 0.015). The incidence of severe postoperative complications was comparable between Groups A and B (7.7 % vs. 1.8 %; p = 0.061). Multivariate analysis revealed that prior PARP inhibitor therapy significantly reduced the median PFS (hazard ratio (HR) = 4.434; p = 0.021) and OS (HR = 2.076; p = 0.010).

CONCLUSIONS

SCS for PSROC demonstrated reduced efficacy in patients previously treated with PARP inhibitors compared to those without prior PARP inhibitor treatment.

Olaparib and niraparib as maintenance therapy in patients with newly diagnosed and platinum-sensitive recurrent ovarian cancer: A single-center study in China

BACKGROUND

Poly adenosine-diphosphate-ribose polymerase (PARP) inhibitors (PARPi) have been approved to act as first-line maintenance (FL-M) therapy and as platinum-sensitive recurrent maintenance (PSR-M) therapy for ovarian cancer in China for >5 years. Herein, we have analyzed the clinical-application characteristics of olaparib and niraparib in ovarian cancer-maintenance therapy in a real-world setting to strengthen our understanding and promote their rational usage.

METHODS

A retrospective chart review identified patients with newly diagnosed or platinum-sensitive recurrent ovarian cancer, who received olaparib or niraparib as maintenance therapy at Sichuan Cancer Hospital between August 1, 2018, and December 31, 2021. Patient medical records were reviewed. We grouped and analyzed patients based on the type of PARPi they used (the olaparib group and the niraparib group) and the line of PARPi maintenance therapy (the FL-M setting and the PSR-M setting). The primary endpoint was the 24-month progression-free survival (PFS) rate.

RESULTS

In total, 131 patients (olaparib: n = 67, 51.1%; niraparib: n = 64, 48.9%) were enrolled. Breast cancer susceptibility genes (BRCA) mutations (BRCAm) were significantly less common in the niraparib group than in the olaparib group [9.4% (6/64) vs. 62.7% (42/67), P <0.001], especially in the FL-M setting [10.4% (5/48) vs. 91.4% (32/35), P <0.001]. The 24-month PFS rates in the FL-M and PSR-M settings were 60.4% and 45.7%, respectively. In patients with BRCAm, the 24-month PFS rates in the FL-M and PSR-M settings were 62.2% and 72.7%, respectively.

CONCLUSIONS

Olaparib and niraparib were effective in patients with ovarian cancer without any new safety signals except for skin pigmentation. In patients with BRCAm, the 24-month PFS of the PARPi used in the PSR-M setting was even higher than that used in the FL-M setting.

Immunotherapy and the ovarian cancer microenvironment: Exploring potential strategies for enhanced treatment efficacy

Despite progress in cancer immunotherapy, ovarian cancer (OC) prognosis continues to be disappointing. Recent studies have shed light on how not just tumour cells, but also the complex tumour microenvironment, contribute to this unfavourable outcome of OC immunotherapy. The complexities of the immune microenvironment categorize OC as a 'cold tumour'. Nonetheless, understanding the precise mechanisms through which the microenvironment influences the effectiveness of OC immunotherapy remains an ongoing scientific endeavour. This review primarily aims to dissect the inherent characteristics and behaviours of diverse cells within the immune microenvironment, along with an exploration into its reprogramming and metabolic changes. It is expected that these insights will elucidate the operational dynamics of the immune microenvironment in OC and lay a theoretical groundwork for improving the efficacy of immunotherapy in OC management.

Functional analysis and validation of oncodrive gene AP3S1 in ovarian cancer through filtering of mutation data from whole-exome sequencing

BACKGROUND

High-grade serous ovarian carcinoma (HGSOC) is the most aggressive and prevalent subtype of ovarian cancer and accounts for a significant portion of ovarian cancer-related deaths worldwide. Despite advancements in cancer treatment, the overall survival rate for HGSOC patients remains low, thus highlighting the urgent need for a deeper understanding of the molecular mechanisms driving tumorigenesis and for identifying potential therapeutic targets. Whole-exome sequencing (WES) has emerged as a powerful tool for identifying somatic mutations and alterations across the entire exome, thus providing valuable insights into the genetic drivers and molecular pathways underlying cancer development and progression.

METHODS

Via the analysis of whole-exome sequencing results of tumor samples from 90 ovarian cancer patients, we compared the mutational landscape of ovarian cancer patients with that of TCGA patients to identify similarities and differences. The sequencing data were subjected to bioinformatics analysis to explore tumor driver genes and their functional roles. Furthermore, we conducted basic medical experiments to validate the results obtained from the bioinformatics analysis.

RESULTS

Whole-exome sequencing revealed the mutational profile of HGSOC, including BRCA1, BRCA2 and TP53 mutations. AP3S1 emerged as the most weighted tumor driver gene. Further analysis of AP3S1 mutations and expression demonstrated their associations with patient survival and the tumor immune response. AP3S1 knockdown experiments in ovarian cancer cells demonstrated its regulatory role in tumor cell migration and invasion through the TGF-β/SMAD pathway.

CONCLUSION

This comprehensive analysis of somatic mutations in HGSOC provides insight into potential therapeutic targets and molecular pathways for targeted interventions. AP3S1 was identified as being a key player in tumor immunity and prognosis, thus providing new perspectives for personalized treatment strategies. The findings of this study contribute to the understanding of HGSOC pathogenesis and provide a foundation for improved outcomes in patients with this aggressive disease.

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.

Subsequent management and outcomes after first-line PARP inhibitors progression in ovarian cancer patients

OBJECTIVES

This retrospective study aims to evaluating the subsequent management and outcomes after first-line PARPi progression in Chinese ovarian cancer population.

METHODS

Clinical and pathologic variables, treatment modalities, and outcomes were assessed. We investigated the subsequent management and outcomes after first-line PARPi progression. The objective response rate (ORR) and disease control rate (DCR) parameters were evaluated to determine the response to subsequent chemotherapy. For the survival analyses, progression-free survival 1 (PFS1), PFS2, overall survival (OS) and PFS2 - PFS1 were analysed.

RESULTS

A total of 124 patients received PARPi maintenance treatment after first-line chemotherapy during the study period in our center. 44 of them (35.5%) experienced a recurrence. The median duration of PARPi in these patients was 11.1 months (range: 1.2-75.1 months). A total of 40 patients (40/44, 90.9%) received subsequent chemotherapy with 35 (35/44, 79.5%) and 5 (5/44, 11.4%) patients received platinum-based and non-platinum-based chemotherapy in our center. 2 patients (4.5%) received target therapy and other 2 patients (4.5%) received best supportive care. 27.3% (12/44) patients received secondary cytoreduction surgery (SCS). After subsequent chemotherapy, 14 patients received PARPi retreatment as maintenance therapy. In patients who received platinum-based regimens (n = 35), 23 of 35 patients (65.7%) had complete/partial response (CR/PR), 8 of 35 (22.9%) had stable disease (SD), and 4 of 35 (12.1%) had progressive disease (PD). The ORR and DCR of patients who received subsequent chemotherapy was 65.7% and 88.6%, respectively. 15 patients (57.7%, 15/26) were reported to be platinum resistant with a platinum-free interval (PFI)  of < 6 months in patients whose platinum sensitivity of the second line platinum-based regimens was evaluable. Patients who received SCS after PARPi resistant associated with a borderline better PFS2 (median PFS2: 41.9 vs. 29.2 months, P = 0.051) and a non-significantly increased PFS2-PFS1 (median PFS2-PFS1: 12.2 vs. 9.8 months, P = 0.551). Patients with a PFI ≥ 12 months had a significantly better PFS2 (median PFS2: 37.0 vs. 25.3 months, P < 0.001) and a tendency towards a better PFS2-PFS1 than those with a PFI < 12 months (median PFS2-PFS1: 11.2 vs. 8.5 months, P = 0.334). A better PFS2 was observed in patients who received second PARPi maintenance therapy (median PFS2 of 35.4 vs. 28.8 months); however, the difference was not statistically significant (P = 0.200). A better PFS2-PFS1 was observed in patients who received second PARPi maintenance therapy (median PFS2-PFS1: 13.6 vs. 8.9 months, P = 0.002) than those without.

CONCLUSIONS

In summary, some degree of resistance to standard subsequent platinum and non-platinum chemotherapy is noted in the entire cohort. A trend towards higher benefit from subsequent chemotherapy after first-line PARP inhibitors progression was observed in the PFI ≥ 12 months subgroup than those with PFI < 12 months. PARPi retreatment as maintenance therapy and SCS can be offered to some patients with PARPi resistance.

Hypertension associated with niraparib in cancer patients: A pharmacovigilance analysis based on the FAERS database and meta-analysis of randomized controlled trials

BACKGROUND

Niraparib plays a crucial role in the treatment of ovarian cancer. A comprehensive understanding of the incidence and risk of hypertension associated with niraparib would be of vital importance to healthcare practitioners.

METHODS

In this study, an observational, retrospective, pharmacovigilance study was conducted based on the FDA Adverse Event Reporting System (FAERS) database. Cases of hypertension related to niraparib were extracted for disproportionality analysis from the first quarter (Q1) of 2017 to Q1 of 2023. Moreover, a separate meta-analysis was performed using the randomized controlled trials (RCTs) on niraparib for cancer treatment published in PubMed, Embase, and Web of Science from inception to May 31st, 2023. The primary outcomes were the incidence and risk of hypertension associated with niraparib.

RESULTS

In the FAERS, 1196 hypertension cases were found to be related to niraparib treatment. Notably, niraparib exhibited the highest level of disproportionality, as indicated by a reporting odds ratio (ROR) of 2.85 (95% CI, 2.69-3.01), suggesting a greater likelihood of causing hypertension compared to other poly-ADP-ribose polymerase (PARP) inhibitors (P < 0.01). Our safety meta-analysis included five pivotal RCTs of niraparib that reported hypertension. In comparison to placebo treatment, the meta-analysis demonstrated a significant increase in the risk of hypertension with niraparib (OR 2.84 [95% CI, 2.17-3.72], P < 0.01), with no heterogeneity observed among the studies (I2 = 0%, χ2 = 2.02, P = 0.73). The incidence of niraparib-induced hypertension was determined to be 16.9% (95% CI, 14.9-18.9; I2 = 34%).

CONCLUSIONS

These findings suggest that hypertension is a distinctive adverse event associated with niraparib compared to other PARP inhibitors. Niraparib significantly increases the risk of hypertension that needs early recognition and management in clinical medication.

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

OBJECTIVE

To assess patient-reported health-related quality of life (HRQoL) in patients with ovarian cancer (OC) who received niraparib as first-line maintenance therapy.

METHODS

PRIMA/ENGOT-OV26/GOG-3012 (NCT02655016) enrolled patients with newly diagnosed advanced OC who responded to first-line platinum-based chemotherapy. Patients were randomized (2:1) to niraparib or placebo once daily in 28-day cycles until disease progression, intolerable toxicity, or death. HRQoL was assessed as a prespecified secondary end point using patient-reported responses to the European Organisation for Research and Treatment of Cancer QOL Questionnaire (EORTC QLQ-C30), the EORTC QLQ Ovarian Cancer Module (EORTC QLQ-OV28), the Functional Assessment of Cancer Therapy-Ovarian Symptom Index (FOSI), and EQ-5D-5L questionnaires. Assessments were collected at baseline and every 8 weeks (±7 days) for 56 weeks, beginning on cycle 1/day 1, then every 12 weeks (±7 days) thereafter while the patient received study treatment.

RESULTS

Among trial participants (niraparib, n = 487; placebo, n = 246), PRO adherence exceeded 80% for all instruments across all cycles. Patients reported no decline over time in HRQoL measured via EORTC QLQ-C30 Global Health Status/QoL and FOSI overall scores. Scores for abdominal/gastrointestinal symptoms (EORTC QLQ-OV28) and nausea and vomiting, appetite loss, and constipation (EORTC QLQ-C30) were higher (worse symptoms) in niraparib-treated patients than placebo-treated patients; except for constipation, these differences resolved over time. Patients did not self-report any worsening from baseline of fatigue, headache, insomnia, or abdominal pain on questionnaires.

CONCLUSIONS

Despite some early, largely transient increases in gastrointestinal symptoms, patients with OC treated with niraparib first-line maintenance therapy reported no worsening in overall HRQoL.

PARP inhibitor maintenance treatment for newly diagnosed ovarian cancer patients: a real-world study from China

Purpose

This study evaluated the efficacy and safety in a real-world population of epithelial ovarian cancer (EOC) treated with poly (ADP-ribose) polymerase inhibitor (PARPi) as first-line maintenance therapy in the largest gynecologic oncology center in Western China.

Methods

This study included patients newly diagnosed EOC who received PARPi as first-line maintenance therapy in West China Second University Hospital from August 1, 2018 to September 31, 2022. The primary endpoints were progression-free survival (PFS) and safety evaluated by Common Terminology Criteria for Adverse Events Version 5.0(CTCAE 5.0). The secondary endpoints were overall survival (OS) and prognostic factors influencing the PFS of patients in real world.

Results

Among the eligible 164 patients, 104 patients received olaparib and 60 patients received niraparib. 100 patients (61.0%) had mutations in breast cancer susceptibility gene (BRCA). 87 patients (53.0%) received primary debulking surgery (PDS) while 77 patients (47.0%) received interval debulking surgery (IDS). 94 patients (94/164, 57.3%) achieved R0 and 39 patients (23.8%) achieved R1 after PDS/IDS. 112 (68.3%) achieved complete response (CR) after first-line chemotherapy, while 49 (29.9%) achieved partial response (PR). The median follow-up time was 17.0 months (95% CI 15.6-18.4), and the median PFS has not been reached yet. Multivariate analysis demonstrated that BRCA mutations and CR/PR after platinum-based chemotherapy were independent factors associated with prolonged PFS. Hematologic toxicity was the most common grade≥3 AE. There were no incidence of myelodysplastic syndromes/acute myelogenous leukemia (MDS/AML).

Conclusion

Focusing on PARPi as first-line maintenance therapy for patients with EOC, this study represented the largest single-center real-world study in China to date. Two independent factors were identified to prolong the PFS of patients: BRCA mutated type and CR/PR after primary treatment, which should be further confirmed with long-term follow-up and large sample sizes.

Case report: Minimally invasive primary debulking surgery for advanced stage epithelial ovarian cancer

The surgical management of advanced ovarian cancer has historically emphasized an open technique, but advances in minimally invasive surgery (MIS) have led to its increasing use in ovarian cancer. Most research has focused on the utility of MIS in the interval debulking setting. Here, we present a case of a 38-year-old patient with incidentally diagnosed advanced stage ovarian cancer. We describe the robotic surgery techniques used to achieve complete primary cytoreduction, including resection of disease on the diaphragm. The patient has completed standard adjuvant chemotherapy and maintenance treatment and remains without evidence of disease for more than 2 years. This case details the techniques utilized to achieve complete cytoreduction including trocar placement, robotic instrument preference, and rotation of the robotic boom. This patient has had successful perioperative and oncologic outcomes, and her case highlights the role for minimally invasive primary debulking surgery for select patients with advanced ovarian cancer.

m6A methylation-mediated regulation of LncRNA MEG3 suppresses ovarian cancer progression through miR-885-5p and the VASH1 pathway

BACKGROUND

Ovarian cancer poses a serious threat to women's health. Due to the difficulty of early detection, most patients are diagnosed with advanced-stage disease or peritoneal metastasis. We found that LncRNA MEG3 is a novel tumor suppressor, but its role in tumor occurrence and development is still unclear.

METHODS

We investigated the expression level of MEG3 in pan-cancer through bioinformatics analysis, especially in gynecological tumors. Function assays were used to detect the effect of MEG3 on the malignant phenotype of ovarian cancer. RIP, RNA pull-down, MeRIP-qPCR, actinomycin D test were carried out to explore the m6A methylation-mediated regulation on MEG3. Luciferase reporter gene assay, PCR and Western blot were implemented to reveal the potential mechanism of MEG3. We further confirmed the influence of MEG3 on tumor growth in vivo by orthotopic xenograft models and IHC assay.

RESULTS

In this study, we discovered that MEG3 was downregulated in various cancers, with the most apparent downregulation in ovarian cancer. MEG3 inhibited the proliferation, migration, and invasion of ovarian cancer cells. Overexpression of MEG3 suppressed the degradation of VASH1 by negatively regulating miR-885-5p, inhibiting the ovarian cancer malignant phenotype. Furthermore, we demonstrated that MEG3 was regulated at the posttranscriptional level. YTHDF2 facilitated MEG3 decay by recognizing METTL3‑mediated m6A modification. Compared with those injected with vector control cells, mice injected with MEG3 knockdown cells showed larger tumor volumes and faster growth rates.

CONCLUSION

We demonstrated that MEG3 is influenced by METTL3/YTHDF2 methylation and restrains ovarian cancer proliferation and metastasis by binding miR-885-5p to increase VASH1 expression. MEG3 is expected to become a therapeutic target for ovarian cancer.

Real world data of niraparib in platinum sensitive relapsed ovarian cancer: A multicenter experience of the MITO group

OBJECTIVE

PARP (poly adenosine diphosphate [ADP]-ribose polymerase) inhibitors are approved as maintenance therapy in platinum sensitive ovarian cancer (OC), in first line and in the recurrent setting, regardless of BRCA mutational status. Real-world data after the introduction of these agents are needed to evaluate whether the benefit observed in phase III randomized clinical trials can be translated into clinical practice. The aim of our study was to provide real-life data on efficacy and safety of niraparib administered as maintenance in platinum sensitive relapsed OC patients (PSROC).

METHODS

This retrospective/prospective observational study included relapsed OC patients that received niraparib as maintenance, at the time of platinum sensitive recurrence within the Italian expanded-access program. Clinical data at the time of diagnosis and at the time of recurrence were collected and analyzed. Median progression free survival (PFS) and overall survival (OS) were calculated as the time from start of niraparib treatment to subsequent radiologically confirmed relapse and death or last contact, respectively.

RESULTS

Among 304 eligible patients, 260 (85%) had BRCA wild-type tumor and 36. (11.9%) were BRCA mutated. Median PFS was 9.1 months (95% CI: 6.9-11.2) and 10.3 months (95% CI: 7.0-13.5) in the BRCAwt and BRCAmut cohorts, respectively. Furthermore, median OS was 41.7 months (95% CI: 31.6-41.9) and 34.6 months (95% CI: N.E.) in the BRCAwt and BRCAmut cohorts, respectively.

CONCLUSION

Data from this large real-life dataset suggested that maintenance with niraparib in the real-life setting of platinum sensitive OC recurrence is effective and well tolerated.

PARPis response and outcome of ovarian cancer patients with BRCA1/2 germline mutation and a history of breast cancer

OBJECTIVE

The aim of this study was to determine the poly (ADP-ribose) polymerase inhibitors (PARPis) response and outcome of ovarian cancer (OC) patients with BRCA1/2 germline mutation and a history of breast cancer (BC).

METHODS

Thirty-nine OC patients with BRCA1/2 germline mutation and a history of BC were included. The clinicopathological characteristics, PARPis response and prognosis were analyzed.

RESULTS

The median interval from BC to OC diagnosis was 115.3 months (range=6.4-310.1). A total of 38 patients (38/39, 97.4%) received platinum-based chemotherapy after surgical removal. The majority of these patients were reported to be platinum sensitive (92.1%, 35/38). 21 patients (53.8%) received PARPis treatment with 16 patients (76.2%) for maintenance treatment and 5 patients (5/21, 23.8%) for salvage treatment. The median duration for PARPis maintenance and salvage treatment was 14.9 months (range=2.0-56.9) and 8.2 months (range=5.2-20.7), respectively. In the entire cohort, 5-year progression-free survival (PFS) and overall survival (OS) rate was 33.1% and 78.9%, respectively. Patients with BRCA1 mutation had a non-significantly worse 5-year PFS (28.6% vs. 45.8%, p=0.346) and 5-year OS (76.9% vs. 83.3%, p=0.426) than those with BRCA2 mutation. In patients with stage III-IV (n=31), first line PARPis maintenance treatment associated with a non-significantly better PFS (median PFS: NR vs. 22.4 months; 5-year PFS: 64.3% vs. 21.9%, p=0.096).

CONCLUSION

The current study shows that these patients may have a good response to platinum-based chemotherapy and a favorable survival. And these patients can benefit from PARPis treatment and will likely be suitable candidates for PARPis.

A real-world study of PARP inhibitors in 75 patients with platinum-sensitive recurrent ovarian cancer from China

Objective

The aim of this study is to assess the efficacy and safety of poly (ADP-ribose) polymerase inhibitor (PARPi) as a maintenance therapy for patients with platinum-sensitive recurrent epithelial ovarian cancer (PSROC) at the largest center of gynecologic oncology in Western China.

Patients and methods

The efficacy of PARPi was evaluated by progression-free survival (PFS) and overall survival (OS) in this real-world single-center retrospective cohort study conducted at West China Second University Hospital. The safety of PARPi was assessed using Common Terminology Criteria for Adverse Events Version 5.0.

Results

In this study, we included a total of 75 eligible patients, of which 54 (72.0%) received olaparib and 21 (28.0%) received niraparib. Among these patients, 24 (32.0%) had breast cancer susceptibility gene (BRCA) mutations, 27 (36.0%) achieved complete response after their last platinum-based therapy, and 22 (29.3%) had previously received ≥3rd-line chemotherapy. The median progression-free survival (mPFS) was 19.1 months (95% CI 8.5-29.7), and the median overall survival (mOS) had not been reached. Log-rank analysis revealed that age (<65 years old V.S. ≥65 years old) and previous lines of chemotherapy (2nd-line V.S. 3rd-line V.S. ≥4th-line) were associated with prolonged PFS (P <0.05). However, multivariate COX regression analysis did not identify any independent factors associated with prognosis (P >0.05). The most common grade≥3 adverse events in the olaparib group were anemia, thrombocytopenia, and leukopenia, while in the niraparib group, they were anemia and thrombocytopenia.

Conclusion

This study confirmed that olaparib and niraparib are effective and tolerate for PSROC in real-world settings. At the follow-up endpoint, no independent prognostic factor associated with prolonged PFS was identified.

Front-line chemoimmunotherapy for treating epithelial ovarian cancer: Part II promising results of phase 2 study of paclitaxel-carboplatin-oregovomab regimen

In the Part I, we have discussed the background of CA125 and the development of anti-CA125 monoclonal antibody (MAb) to highlight the potential role of CA125 and anti-CA125 MAb in the management of women with advanced stage epithelial ovarian cancer (EOC). Glycosylation change either by N-link or by O-link of CA125 is supposed to play a role in the modification of immunity. Anti-CA125 MAb, which can be classified as OC 125-like Abs, M11-like Abs, and OV197-like Abs, is often used for diagnosing, screening, monitoring and detecting the mesothelin-related diseases of the abdominal cavity, particular for those women with EOC. Additionally, anti-CA125 MAb also plays a therapeutic role, named as OvaRex MAb-B43.13 (oregovomab), which has also been extensively reviewed in the Part I review article. The main mechanisms include (a) forming CA125 immune complexes to activate the antigen-presenting cells; (b) triggering induction of CA125-specific immune responses, including anti-CA125 Abs against various epitopes and CA125-specific B and T cell responses; and (c) triggering CD4 and CD8 T-cell responses specific for B43.13 to produce specific and non-specific immune response. With success in vitro, in vivo and in primitive studies, phase II study was conducted to test the effectiveness of chemoimmunotherapy (CIT) for the management of EOC patients. In the 97 EOC patients after optimal debulking surgery (residual tumor <1 cm or no gross residual tumor), patients treated with CIT had a dramatical and statistically significant improvement of both progression-free survival (PFS) and overall survival (OS) compared to those treated with chemotherapy alone with a median PFS of 41.8 months versus 12.2 months (hazard ratio [HR] 0.46, 95 % confidence interval [CI] 0.28-0.7) and OS not yet been reached (NE) versus 42.3 months (HR 0.35, 95 % CI 0.16-0.74), respectively. The current review as Part II will explore the possibility of using CIT as front-line therapy in the management of advanced-stage EOC patients after maximal cytoreductive surgery based on the evidence by many phase 2 studies.

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.

Identifying Explainable Machine Learning Models and a Novel SFRP2+ Fibroblast Signature as Predictors for Precision Medicine in Ovarian Cancer

Ovarian cancer (OC) is a type of malignant tumor with a consistently high mortality rate. The diagnosis of early-stage OC and identification of functional subsets in the tumor microenvironment are essential to the development of patient management strategies. However, the development of robust models remains unsatisfactory. We aimed to utilize artificial intelligence and single-cell analysis to address this issue. Two independent datasets were screened from the Gene Expression Omnibus (GEO) database and processed to obtain overlapping differentially expressed genes (DEGs) in stage II-IV vs. stage I diseases. Three explainable machine learning algorithms were integrated to construct models that could determine the tumor stage and extract important characteristic genes as diagnostic biomarkers. Correlations between cancer-associated fibroblast (CAF) infiltration and characteristic gene expression were analyzed using TIMER2.0 and their relationship with survival rates was comprehensively explored via the Kaplan-Meier plotter (KM-plotter) online database. The specific expression of characteristic genes in fibroblast subsets was investigated through single-cell analysis. A novel fibroblast subset signature was explored to predict immune checkpoint inhibitor (ICI) response and oncogene mutation through Tumor Immune Dysfunction and Exclusion (TIDE) and artificial neural network algorithms, respectively. We found that Support Vector Machine-Shapley Additive Explanations (SVM-SHAP), Extreme Gradient Boosting (XGBoost), and Random Forest (RF) successfully diagnosed early-stage OC (stage I). The area under the receiver operating characteristic curves (AUCs) of these models exceeded 0.990. Their overlapping characteristic gene, secreted frizzled-related protein 2 (SFRP2), was a risk factor that affected the overall survival of OC patients with stage II-IV disease (log-rank test: p < 0.01) and was specifically expressed in a fibroblast subset. Finally, the SFRP2+ fibroblast signature served as a novel predictor in evaluating ICI response and exploring pan-cancer tumor protein P53 (TP53) mutation (AUC = 0.853, 95% confidence interval [CI]: 0.829-0.877). In conclusion, the models based on SVM-SHAP, XGBoost, and RF enabled the early detection of OC for clinical decision making, and SFRP2+ fibroblast signature used in diagnostic models can inform OC treatment selection and offer pan-cancer TP53 mutation detection.

Front-line chemo-immunotherapy for treating epithelial ovarian cancer: Part I CA125 and anti-CA125

The current standard therapy of epithelial ovarian cancer (EOC) is the combination of surgery (primary cytoreductive surgery or interval cytoreductive surgery) and platinum-based chemotherapy (mainly using paclitaxel and carboplatin either by neoadjuvant chemotherapy and/or by postoperative adjuvant chemotherapy) with/without adding targeted therapy (mainly using anti-angiogenesis agent- bevacizumab). After front-line chemotherapy, the advanced-stage EOC can be successfully controlled and three-quarters of patients can achieve a complete clinical remission. Unfortunately, nearly all patients will recur and progression-free survival (PFS) of these patients is seldom more than 3 years with a dismal median PFS of 12-18 months. With each recurrence, patients finally develop resistance to standard chemotherapy regimen, contributing to fewer than half of women who survive for more than 5 years after diagnosis with a median overall survival (OS) of 40.7 months. Due to the lower PFS and OS, particularly for those advanced-stage patients, novel therapeutic options during the front-line therapy are desperately needed to decrease the occurrence of recurrence, and the majority of them are still under investigation. It is well-known that overexpression of CA125 has been associated with attenuated cellular apoptosis, platinum chemotherapy resistance, tumor proliferation and disease progression, suggesting that anti-CA125 may play a role in the management of patients with EOC. The current review is a Part I which will focus on development of anti-CA125 monoclonal antibody, hoping that alternation of the front-line therapy by chemo-immunotherapy will be beneficial for prolonged survival of patients with EOC.

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.

Selection of maintenance therapy during first-line treatment of advanced ovarian cancer based on pharmacologic characteristics

INTRODUCTION

Maintenance therapy with bevacizumab and the poly (ADP-ribose) polymerase (PARP) inhibitors olaparib and niraparib after first-line treatment of advanced ovarian cancer has been approved. However, it is not clear which one should be used for which patients.

AREAS COVERED

This paper presents a detailed analysis of data from phase 3 trials in ovarian cancer evaluating bevacizumab (ICON7, GOG-0218), olaparib (SOLO1, PAOLA-1), and niraparib (PRIMA, PRIME). We will discuss how the results of these trials relate to the 'rebound effect,' in which the risk of progression increases after discontinuation of bevacizumab in patients receiving bevacizumab, and to the significant difference in tissue permeability between olaparib and niraparib.

EXPERT OPINION

In patients with homologous recombination deficiency and no macroscopic residual disease (R0) after primary debulking surgery (PDS), the combination of bevacizumab plus olaparib seems to be the best regimen. Olaparib monotherapy is suitable for patients with BRCA mutations other than PDS R0. Bevacizumab is most useful in cases with a short duration of the rebound effect, i.e. short survival. Niraparib is useful in others but may be more useful in Asians.