OVARIO phase II trial of combination niraparib plus bevacizumab maintenance therapy in advanced ovarian cancer following first-line platinum-based chemotherapy with bevacizumab

Micellar curcumol for maintenance therapy of ovarian cancer by activating the FOXO3a

Maintenance therapy (MT) for ovarian cancer (OC) is crucial for preventing disease relapse. Curcumol shows effective anti-OC ability and low-toxicity to the normal ovarian epithelial cells, however, its bioavailability is low. Herein, micellar loaded curcumol (MC) was prepared and the anti-tumor ability of MC were performed on OC cells. The results indicated that the IC50 values of MC in two kinds of OC cells were 37.69 ± 2.43 and 28.54 ± 1.58 μg/mL, respectively. Mechanistically, curcumol could interact with the AKTThr308 site, inhibiting the phosphorylation of FOXO3a, which promoted FOXO3a nuclear locating and recruited it to the PERK promoter, activating the ERS induced apoptosis pathway. Moreover, MC inhibited the growth of SKOV3 cells on tumor-bearing nude mice and the DiR-labeled MC could quickly accumulate in the tumor region. MC provides great feasibility to achieve efficient MT for OC based on the nanoplatforms of active ingredients from natural products.

Strategies for the prevention or reversal of PARP inhibitor resistance

INTRODUCTION

Advances in our understanding of tumor biology shed light on hallmarks of cancer development and progression that include dysregulated DNA damage repair (DDR) machinery. Leveraging the underlying tumor genomic instability and tumor-specific defects in DDR, Poly (ADP-ribose) polymerase (PARP) inhibitors (PARPi) induced DNA damage emerges as a novel non-chemotherapy therapeutic opportunity. PARPis are currently approved in multiple tumor types, with the largest benefit seen in tumors with homologous recombination repair (HRR) deficiency, including germline and somatic mutations in BRCA1/2 genes (BRCA) and other pathway members such as PALB2 and Rad51c.

AREAS COVERED

This review article summarizes the current approval landscape and known and proposed mechanisms of resistance to PARPi. Further, therapeutic strategies to overcome PARPi resistance are discussed, including ongoing clinical trials.

EXPERT OPINION

PARPi have proven to be a safe and effective therapy and represents a cornerstone treatment across multiple solid tumor types. Elucidating innate and acquired mechanisms of resistance, coupled with the emergence of novel therapeutic options to capitalize on the activity of PARPi and prevent or reverse the acquisition of resistance, provides an opportunity to further expand the role of PARPi in cancer therapy.

Characteristics and real-world outcomes of patients with epithelial ovarian cancer who received niraparib plus bevacizumab first-line maintenance therapy in the COMB1NE study

OBJECTIVE

In the phase 2 OVARIO trial (NCT03326193) investigating niraparib-bevacizumab first-line maintenance, median progression-free survival was 14.2 months (95% confidence interval (CI) 8.6 to 16.8) for patients with homologous recombination (HR)-proficient (HRp) epithelial ovarian cancer, and 12.1 months (95% CI8.0-not evaluated) for patients with undefined HR status. However, real-world data are limited for patients who receive niraparib-bevacizumab first-line maintenance therapy. The COMB1NE study describes real-world clinical outcomes (time to treatment discontinuation; time to next treatment) in patients with epithelial ovarian cancer who received niraparib-bevacizumab first-line maintenance, regardless of first-line bevacizumab use.

METHODS

This real-world, retrospective study used a US nationwide electronic health record-derived deidentified database. Eligible patients were 18 years or older at initial epithelial ovarian cancer diagnosis and initiated niraparib-bevacizumab first-line maintenance (January 1, 2017-September 2, 2022) following first-line treatment. The index date was the start of first-line maintenance. Patients were followed until death, last clinical activity, or end of study, whichever occurred first. Time to treatment discontinuation and time to next treatment, a proxy for real-world progression-free survival, were estimated using the Kaplan-Meier method.

RESULTS

Among 59 included patients, the median age was 67 years (interquartile range (IQR) 61-76), and 81.4% had stage III/IV epithelial ovarian cancer at diagnosis. Overall, 83.1% of patients had BRCA wild-type with either HRp or HR status unknown disease. Median time to treatment discontinuation of first-line maintenance was 11.8 months (95% CI 8.7 to 13.5). Median time to next treatment was 14.1 months (95% CI 11.3 to 16.6). At 6 months after index, 77.9% of patients had not initiated second-line treatment; at 12 months, 61.3% had not.

CONCLUSION

In this real-world study of patients receiving niraparib-bevacizumab first-line maintenance, the majority of whom had HRp/HR status unknown, the median time to next treatment was consistent with observed progression-free survival in patients with similar HR status in the OVARIO study.

Prognostic analysis of peritoneal washing cytology during interval debulking surgery in advanced ovarian cancer

BACKGROUND

Interval debulking surgery (IDS) following neoadjuvant chemotherapy is a treatment option for advanced ovarian cancer. Optimal surgery is required for better survival; however, while peritoneal washing cytology (PWC) has been identified as a prognostic factor, its comprehensive assessment during IDS remains unexplored. Therefore, we aimed to evaluate PWC efficacy during IDS, alongside other factors including residual disease and the modeled cancer antigen 125 (CA-125) ELIMination rate constant K (KELIM), by retrospectively reviewing the medical records of 25 patients with advanced ovarian cancer underwent neoadjuvant chemotherapy and IDS between January 2017 to June 2023.

RESULTS

Twelve (48.0%) patients were PWC-positive, and the remainder were PWC-negative. PWC was performed at laparotomy during IDS, after which five (41.7%) PWC-positive and four (30.8%) PWC-negative patients received bevacizumab, an anti-vascular endothelial growth factor monoclonal antibody, for maintenance treatment. Four (33.3%) PWC-positive and 10 (76.9%) PWC-negative patients received poly adenosine diphosphate (ADP)-ribose polymerase inhibitors. In patients who received bevacizumab and poly ADP-ribose polymerase inhibitors, overall survival and progression-free survival did not significantly differ between those who were PWC-positive and PWC-negative (p = 0.27 and 0.20, respectively). Progression-free survival significantly differed between those with favorable and unfavorable CA-125 KELIM (p = 0.02). Multivariate analysis indicated that optimal surgery and favorable CA-125 KELIM were associated with better progression-free survival (p < 0.01 and 0.02, respectively), with only optimal surgery associated with better overall survival (p = 0.04).

CONCLUSIONS

A positive PWC at IDS was not associated with survival in advanced ovarian cancer. Our findings indicate that although PWC status at IDS should be one of the factors determining survival in patients with advanced ovarian cancer, recent improvements in maintenance therapy may make the combination of CA-125 KELIM and PWC status a more useful prognostic factor in selecting treatment after IDS. Further studies are needed to validate these results, highlighting the potential importance of maintenance treatment after IDS and the need for further research to validate the clinical significance of a positive PWC.

Application of PARP inhibitors combined with immune checkpoint inhibitors in ovarian cancer

The advent of polyadenosine diphosphate ribose polymerase inhibitors (PARPi) has brought about significant changes in the field of ovarian cancer treatment. However, in 2022, Rucaparib, Olaparib, and Niraparib, had their marketing approval revoked for third-line and subsequent therapies due to an increased potential for adverse events. Consequently, the exploration of new treatment modalities remains imperative. Recently, the integration of PARPi with immune checkpoint inhibitors (ICIs) has emerged as a potential remedy option within the context of ovarian cancer. This article offers a comprehensive examination of the mechanisms and applications of PARPi and ICIs in the treatment of ovarian cancer. It synthesizes the existing evidence supporting their combined use and discusses key considerations that merit attention in ongoing development efforts.

Arterial hypertension associated with PARPi: A meta-analysis of 41 placebo randomized controlled trials combined with a World Health Organization's pharmacovigilance study

BACKGROUND

Arterial hypertension has been recently reported from randomized controlled trials (RCTs) assessing poly (ADP-ribose) polymerase inhibitor (PARPi).

OBJECTIVE

In a context of increasing use of PARPi, it is crucial to properly assess risk and incidence of this adverse event for clinical practice.

METHODS

We performed a systematic review and meta-analysis in MEDLINE, Cochrane CENTRAL and ClinicalTrials.gov up to January 4, 2023 with an ongoing surveillance up to June 7, 2023. RCTs comparing PARPi to placebo in adult patients with solid tumors were included if hypertension was reported. The primary outcome was the summary risk ratio (RR, with 95% CIs) of any hypertension of PARPi class in placebo RCTs. Secondary outcomes were the summary risk and incidence of hypertension of each individual PARPi. To provide clinical features of PARPi-associated hypertension, we independently queried the WHO's pharmacovigilance database, up to September 1, 2022.

RESULTS

In total, 41 placebo RCTs (n = 15 264 adult patients) were included. PARPi class was not associated with an increased risk of hypertension compared with placebo. In individual analyses, the risk of hypertension was lower with olaparib than placebo (RR 0.77 [95% CI: 0.68-0.86], P < 0.01; I2 = 19%, χ2 P = 0.26). Niraparib monotherapy increased the risk of any (RR 2.84 [95% CI: 1.76-4.57], P < 0.01; I2 = 66%, χ2 P = 0.01) hypertension with a summary incidence of 19.87% (95% CI: 15.23-25.50). In real-life setting, niraparib-associated hypertension occurs within 20 days and was serious in 66%. Co-prescription of at least one antihypertensive or therapy-induced hypertension was reported in 20.5% or 14.4% of cases, respectively.

CONCLUSIONS

In a context of extensive assessment of niraparib in combination, these data reinforce the need of a close monitoring of this adverse event to preserve its clinical benefit on patients' survival.

Trends and frontiers of maintenance therapy for ovarian cancer over the past 20 years: a bibliometric analysis

Aim: To summarize and analyze the research trends and frontiers in maintenance therapy for ovarian cancer over the past 20 years.Methods: Relevant articles were identified in Web of Science, and analyzed using CiteSpace and Excel.Results: 1204 articles from 61 countries led by the USA and England were included. 6821 authors, 2345 institutions and 292 journals have participated in the publication of papers, but the collaboration between them was not very close. The annual publication volume has increased significantly since 2015. Drug combination therapy, genetic testing, management of adverse reaction and prognostic factors are research trends and frontiers of this field.Conclusion: This is the first bibliometric research in this field, which can provide some references for researchers.

Endometriosis-Associated Ovarian Cancer: From Molecular Pathologies to Clinical Relevance

Endometriosis is a chronic condition affecting reproductive-aged women, characterized by the growth of ectopic endometrial tissue. Despite being benign, endometriosis is associated with an increased risk of certain cancers, including endometriosis-associated ovarian cancer (EAOC). Ovarian cancer is rare, but more common in women with endometriosis, particularly endometrioid and clear-cell carcinomas. Factors such as hormonal imbalance, reproductive history, environmental exposures, and genetic predisposition contribute to the malignant transformation of endometriosis. Thus, understanding potential risk factors causing malignancy is crucial. Over the past few decades, various genetic mutations, microRNAs, as well as tumor microenvironmental factors have been identified, impacting pathways like PI3K/AKT/mTOR, DNA repair mechanisms, oxidative stress, and inflammation. Thus, this review aims to summarize molecular studies involved in EAOC pathogenesis as potential therapeutic targets. However, further research is needed to better understand the molecular and environmental factors driving EAOC development, to target the susceptibility of endometriotic lesions to malignant progression, and to identify effective therapeutic strategies.

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.

Efficacy and Safety of Niraparib as First-Line Maintenance Treatment for Patients with Advanced Ovarian Cancer: Real-World Data from a Multicenter Study in China

BACKGROUND

Poly (ADP-ribose) polymerase (PARP) inhibitors are a new maintenance therapy option for patients with ovarian cancer (OC).

OBJECTIVE

To evaluate the efficacy and influencing factors of the novel PARP inhibitor niraparib for maintenance treatment of Chinese patients with advanced OC.

PATIENTS AND METHODS

In this retrospective multicenter real-world study patients with advanced OC from 15 hospitals throughout China were enrolled. The primary endpoint was progression-free survival (PFS) and the secondary endpoints included the time to treatment discontinuation and safety. Least Absolute Shrinkage and Selection Operator (LASSO) regression was used to identify possible risk factors for PFS, after which a prediction model was established to evaluate the likelihood of achieving an 18-month PFS. The relationship between the dose of niraparib and PFS was also evaluated.

RESULTS

The PFS rates of 199 patients at 6, 12, 18, 24, and 30 months were 87.4%, 75.9%, 63.6%, 56.1%, and 51.8%, respectively. LASSO regression model revealed that only age < 65 years (P = 0.011), BRCA mutations (P < 0.001), and R0 status after cytoreductive surgery (P = 0.01) were significant factors associated with prolonged PFS times. Based on the LASSO logistic regression analysis, a clinical prediction formula was developed: - 2.412 + 1.396Age≥65yr + 2.374BRCAwt + 1.387R1 + 0.793Interval≥12w + 0.178BMI>24kg/m2 which yielded a cut-off value of 0.091, an area under the curve (AUC) of 0.839 (0.763-0.916), a sensitivity of 94.3%, and an accuracy of 78.5%. A nomogram was then built to visualize the results. The major treatment-emergent adverse events of ≥ grade 3 included a platelet count decrease (19.1%), white blood cell count decrease (15.1%), neutrophil count decrease (13.1%), and anemia (18.6%). The 18-month PFS rates in patients treated with 200 mg niraparib were somewhat higher than in patients treated with 100 mg after 3-months of therapy.

CONCLUSIONS

For Chinese OC patients, niraparib, particularly at a 200 mg individual starting dose, was an effective therapy with easily manageable safety.

Vascular normalization: reshaping the tumor microenvironment and augmenting antitumor immunity for ovarian cancer

Ovarian cancer remains a challenging disease with limited treatment options and poor prognosis. The tumor microenvironment (TME) plays a crucial role in tumor growth, progression, and therapy response. One characteristic feature of the TME is the abnormal tumor vasculature, which is associated with inadequate blood perfusion, hypoxia, and immune evasion. Vascular normalization, a therapeutic strategy aiming to rectify the abnormal tumor vasculature, has emerged as a promising approach to reshape the TME, enhance antitumor immunity, and synergize with immunotherapy in ovarian cancer. This review paper provides a comprehensive overview of vascular normalization and its potential implications in ovarian cancer. In this review, we summarize the intricate interplay between anti-angiogenesis and immune modulation, as well as ICI combined with anti-angiogenesis therapy in ovarian cancer. The compelling evidence discussed in this review contributes to the growing body of knowledge supporting the utilization of combination therapy as a promising treatment paradigm for ovarian cancer, paving the way for further clinical development and optimization of this therapeutic approach.

PARP inhibitors: enhancing efficacy through rational combinations

Poly (ADP-ribose) polymerase inhibitors (PARPi) have significantly changed the treatment landscape for tumours harbouring defects in genes involved in homologous repair (HR) such as BRCA1 and BRCA2. Despite initial responsiveness to PARPi, tumours eventually develop resistance through a variety of mechanisms. Rational combination strategies involving PARPi have been explored and are in various stages of clinical development. PARPi combinations have the potential to enhance efficacy through synergistic activity, and also potentially sensitise innately PARPi-resistant tumours to PARPi. Initial combinations involving PARPi with chemotherapy were hindered by significant overlapping haematologic toxicity, but newer combinations with fewer toxicities and more targeted approaches are undergoing evaluation. In this review, we discuss the mechanisms of PARPi resistance and review the rationale and clinical evidence for various PARPi combinations including combinations with chemotherapy, immunotherapy, and targeted therapies. We also highlight emerging PARPi combinations with promising preclinical evidence.

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.

New insights for gynecological cancer therapies: from molecular mechanisms and clinical evidence to future directions

Advanced and recurrent gynecological cancers lack effective treatment and have poor prognosis. Besides, there is urgent need for conservative treatment for fertility protection of young patients. Therefore, continued efforts are needed to further define underlying therapeutic targets and explore novel targeted strategies. Considerable advancements have been made with new insights into molecular mechanisms on cancer progression and breakthroughs in novel treatment strategies. Herein, we review the research that holds unique novelty and potential translational power to alter the current landscape of gynecological cancers and improve effective treatments. We outline the advent of promising therapies with their targeted biomolecules, including hormone receptor-targeted agents, inhibitors targeting epigenetic regulators, antiangiogenic agents, inhibitors of abnormal signaling pathways, poly (ADP-ribose) polymerase (PARP) inhibitors, agents targeting immune-suppressive regulators, and repurposed existing drugs. We particularly highlight clinical evidence and trace the ongoing clinical trials to investigate the translational value. Taken together, we conduct a thorough review on emerging agents for gynecological cancer treatment and further discuss their potential challenges and future opportunities.

NIRVANA-1: maintenance therapy with niraparib versus niraparib-bevacizumab in patients with advanced ovarian cancer

Following the results of the PRIMA and PAOLA-1 trials, the most effective maintenance strategy for International Federation of Gynecology and Obstetrics stage III patients is still debated, raising the question which of those two maintenance strategies is the most effective: PARP inhibitors alone or PARP inhibitors in combination with bevacizumab. The ongoing NIRVANA-1 study will try to answer this question by assessing the efficacy and safety of niraparib + bevacizumab in comparison with niraparib alone after adjuvant chemotherapy for completely resected stage III patients. Stratification factors include tumor BRCA status, International Federation of Gynecology and Obstetrics stage (IIIA vs IIIB/IIIC) and the use of hyperthermic intraperitoneal chemotherapy during surgery - within the OVHIPEC-2 trial. The primary end point will be progression-free survival rate at 24 months. Safety, median progression-free survival and overall survival will also be studied.

Prognostic risk factors of serous ovarian carcinoma based on mesenchymal stem cell phenotype and guidance for therapeutic efficacy

BACKGROUND

Epithelial ovarian cancer is the leading cause of death from gynecologic cancer, in which serous ovarian carcinoma (SOC) is the most common histological subtype. Although PARP inhibitors (PARPi) and antiangiogenics have been accepted as maintenance treatment in SOC, response to immunotherapy of SOC patients is limited.

METHODS

The source of transcriptomic data of SOC was from the Cancer Genome Atlas database and Gene Expression Omnibus. The abundance scores of mesenchymal stem cells (MSC scores) were estimated for each sample by xCell. Weighted correlation network analysis is correlated the significant genes with MSC scores. Based on prognostic risk model construction with Cox regression analysis, patients with SOC were divided into low- and high-risk groups. And distribution of immune cells, immunosuppressors and pro-angiogenic factors in different risk groups was achieved by single-sample gene set enrichment analysis. The risk model of MSC scores was further validated in datasets of immune checkpoint blockade and antiangiogenic therapy. In the experiment, the mRNA expression of prognostic genes related to MSC scores was detected by real-time polymerase chain reaction, while the protein level was evaluated by immunohistochemistry.

RESULTS

Three prognostic genes (PER1, AKAP12 and MMP17) were the constituents of risk model. Patients classified as high-risk exhibited worse prognosis, presented with an immunosuppressive phenotype, and demonstrated high micro-vessel density. Additionally, these patients were insensitive to immunotherapy and would achieve a longer overall survival with antiangiogenesis treatment. The validation experiments showed that the mRNA of PER1, AKAP12, and MMP17 was highly expressed in normal ovarian epithelial cells compared to SOC cell lines and there was a positive correlation between protein levels of PER1, AKAP12 and MMP17 and metastasis in human ovarian serous tumors.

CONCLUSION

This prognostic model established on MSC scores can predict prognosis of patients and provide the guidance for patients receiving immunotherapy and molecular targeted therapy. Because the number of prognostic genes was fewer than other signatures of SOC, it will be easily accessible on clinic.

PARP Inhibitors in Ovarian Cancer: A Review

Poly(ADP-ribose) polymerase (PARP) inhibitors (PARPis) have transformed the ovarian cancer (OC) treatment landscape. This narrative review provides a comprehensive overview of data for the PARPis olaparib, niraparib, and rucaparib in patients with OC and discusses their role in disease management, with a focus on the use of PARPis as maintenance therapy in the United States (US). Olaparib was the first PARPi to be approved as first-line maintenance monotherapy in the US, with maintenance niraparib subsequently approved in the first-line setting. Data also support the efficacy of rucaparib as first-line maintenance monotherapy. PARPi maintenance combination therapy (olaparib plus bevacizumab) also provides benefit in patients with newly diagnosed advanced OC whose tumors tested positive for homologous recombination deficiency (HRD). Biomarker testing is critical in the newly diagnosed setting to identify patients most likely to benefit from PARPi maintenance therapy and guide treatment decisions. Clinical trial data support the use of PARPis (olaparib, niraparib, rucaparib) as second-line or later maintenance therapy in patients with platinum-sensitive relapsed OC. Although distinct differences in tolerability profile were observed between PARPis, they were generally well tolerated, with the majority of adverse events managed by dose modification. PARPis had no detrimental effect on patients' health-related quality of life. Real-world data support the use of PARPis in OC, although some differences between PARPis are apparent. Data from trials investigating novel combination strategies, such as PARPis plus immune checkpoint inhibitors, are awaited with interest; the optimal sequencing of novel therapies in OC remains to be established.

The role of PARP inhibitor combination therapy in ovarian cancer

The use of PARP inhibitors (PARPi) has transformed the care of advanced high-grade serous/endometrioid ovarian cancer. PARPi are now available to patients in both the first-line and recurrent platinum-sensitive disease settings; therefore, most patients will receive PARPi at some point in their treatment pathway. The majority of this expanding population of patients eventually acquire resistance to PARPi, in addition to those with primary PARPi resistance. We discuss the rationale behind developing combination therapies, to work synergistically with PARPi and overcome mechanisms of resistance to restore drug sensitivity, and clinical evidence of their efficacy to date.

The Current Status of DNA-Repair-Directed Precision Oncology Strategies in Epithelial Ovarian Cancers

Survival outcomes for patients with advanced ovarian cancer remain poor despite advances in chemotherapy and surgery. Platinum-based systemic chemotherapy can result in a response rate of up to 80%, but most patients will have recurrence and die from the disease. Recently, the DNA-repair-directed precision oncology strategy has generated hope for patients. The clinical use of poly(ADP-ribose) polymerase (PARP) inhibitors in BRCA germ-line-deficient and/or platinum-sensitive epithelial ovarian cancers has improved survival. However, the emergence of resistance is an ongoing clinical challenge. Here, we review the current clinical state of PARP inhibitors and other clinically viable targeted approaches in epithelial ovarian cancers.

Real-World Outcomes Following First-Line Treatment in Patients with Advanced Ovarian Cancer with Multiple Risk Factors for Disease Progression who Received Maintenance Therapy or Active Surveillance

INTRODUCTION

We evaluated real-world outcomes in patients with advanced ovarian cancer (AOC) based on their cumulative risk profile and maintenance therapy (MT) status following first-line (1L) treatment.

METHODS

This retrospective observational study of a nationwide electronic health record-derived de-identified database included adult patients diagnosed with stage III/IV OC from January 1, 2011 to February 28, 2021, who received 1L therapy and had ≥ 12 weeks of follow-up after the index date (end of 1L therapy). Patients were grouped according to whether they received MT or active surveillance (AS) following 1L treatment and by the cumulative number of risk factors (RF) present (stage IV disease; no surgery/treated with neoadjuvant therapy and interval debulking surgery; had postoperative visible residual disease; and had BRCA wild-type disease/unknown BRCA status). Time to next treatment (TTNT) and overall survival (OS) were assessed with a cloning and inverse probability of censoring (IPC)-weighted Kaplan-Meier method.

RESULTS

Among 1920 patients, 22.2% received MT and 77.8% received AS. Median IPC-weighted TTNT and OS were 13.3 months (95% CI 11.7-15.8) and 39.1 months (95% CI 32.5-48.6) in the MT cohort, respectively, and 8.6 months (95% CI 8.0-9.5) and 38.4 months (95% CI 36.4-41.0) in the AS cohort, respectively. Almost all patients had ≥ 1 RF (MT 95.3%; AS 96.7%). Median IPC-weighted TTNT was shorter among patients with more RF in both cohorts (MT: 1 RF, 19.3 months, 95% CI 13.5-37.8; 2 RF, 17.2 months, 95% CI 12.8-20.2; 3 RF, 11.0 months, 95% CI 8.2-13.8; 4 RF, 7.0 months, 95% CI 6.2-8.8; AS: 1 RF, 17.7 months, 95% CI 13.5-22.3; 2 RF, 10.2 months, 95% CI 9.1-11.5; 3 RF, 6.5 months, 95% CI 5.8-7.4; 4 RF, 4.1 months, 95% CI 3.5-4.5).

CONCLUSION

Regardless of RF number, MT was associated with longer TTNT in real-world patients with AOC.

Poly (ADP-ribose) polymerase inhibitors (PARPi) in ovarian cancer: lessons learned and future directions

Poly (ADP-ribose) polymerase inhibitors (PARPi) represent a new standard of care in the upfront treatment of advanced epithelial ovarian cancer to the point that the vast majority of patients now receive a PARPi, alone or in combination with the anti-angiogenic bevacizumab, as part of their first-line maintenance therapy. The clinical benefit of PARPi is well established; however, much has changed since their introduction and several relevant questions have been raised and remain unresolved in the post-PARPi era. The decision-making process regarding the most appropriate first-line maintenance therapy could be challenging in clinical practice, especially in the homologous recombination-proficient setting, and several other factors need to be considered apart from the mutational status. Concerns regarding post-PARPi progression treatment have emerged, highlighting an unmet need to define a valid algorithm strategy. PARPi may not only compromise the response to further platinum due to cross-resistance mechanisms but the impact on subsequent non-platinum chemotherapy and surgery also remains unclear. Definitive results on the role of PARPi rechallenge are awaited, especially in the case of oligoprogression managed with locoregional treatment. Moreover, the updated overall survival data from the recurrent setting warrant caution in using PARPi as single agents for unselected patients. Several PARPi combination regimens are emerging for overcoming PARPi resistance and may become our new therapeutic armamentarium. This review discusses a set of clinically relevant issues in the PARPi era and provides a glimpse of future challenges and opportunities in ovarian cancer treatment.

Major clinical research advances in gynecologic cancer in 2022: highlight on late-line PARP inhibitor withdrawal in ovarian cancer, the impact of ARIEL-4, and SOLO-3

In the 2022 series, we summarized the major clinical research advances in gynecologic oncology based on communications at the conference of Asian Society of Gynecologic Oncology Review Course. The review consisted of 1) Ovarian cancer: long-term follow-up data, new poly (ADP-ribose) polymerase (PARP) inhibitors, overall survival (OS) issues with PARP inhibitor monotherapy, hyperthermic intraperitoneal chemotherapy, immunotherapy, and antibody-drug conjugate; 2) Cervical cancer: surgery in early stage disease, therapy for locally advanced stage and advanced, metastatic, or recurrent setting; and 3) Corpus cancer: follow-up regimen, immune checkpoint inhibitor, WEE1 inhibitor, selective inhibitor of nuclear export. A special note was made on the withdrawal of PARP inhibitor from the market for heavily pretreated ovarian cancer patients based on the final OS results of ARIEL-4 and SOLO-3 due to concerns of increased risk of death.

DNA Damage Response Alterations in Ovarian Cancer: From Molecular Mechanisms to Therapeutic Opportunities

The DNA damage response (DDR), a set of signaling pathways for DNA damage detection and repair, maintains genomic stability when cells are exposed to endogenous or exogenous DNA-damaging agents. Alterations in these pathways are strongly associated with cancer development, including ovarian cancer (OC), the most lethal gynecologic malignancy. In OC, failures in the DDR have been related not only to the onset but also to progression and chemoresistance. It is known that approximately half of the most frequent subtype, high-grade serous carcinoma (HGSC), exhibit defects in DNA double-strand break (DSB) repair by homologous recombination (HR), and current evidence indicates that probably all HGSCs harbor a defect in at least one DDR pathway. These defects are not restricted to HGSCs; mutations in ARID1A, which are present in 30% of endometrioid OCs and 50% of clear cell (CC) carcinomas, have also been found to confer deficiencies in DNA repair. Moreover, DDR alterations have been described in a variable percentage of the different OC subtypes. Here, we overview the main DNA repair pathways involved in the maintenance of genome stability and their deregulation in OC. We also recapitulate the preclinical and clinical data supporting the potential of targeting the DDR to fight the disease.

Targeted therapy and immunotherapy: Diamonds in the rough in the treatment of epithelial ovarian cancer

Currently, for ovarian cancer, which has the highest mortality rate among all gynecological cancers, the standard treatment protocol is initial tumor cytoreductive surgery followed by platinum-based combination chemotherapy. Although the survival rate after standard treatment has improved, the therapeutic effect of traditional chemotherapy is very limited due to problems such as resistance to platinum-based drugs and recurrence. With the advent of the precision medicine era, molecular targeted therapy has gradually entered clinicians' view, and individualized precision therapy has been realized, surpassing the limitations of traditional therapy. The detection of genetic mutations affecting treatment, especially breast cancer susceptibility gene (BRCA) mutations and mutations of other homologous recombination repair defect (HRD) genes, can guide the targeted drug treatment of patients, effectively improve the treatment effect and achieve a better patient prognosis. This article reviews different sites and pathways of targeted therapy, including angiogenesis, cell cycle and DNA repair, and immune and metabolic pathways, and the latest research progress from preclinical and clinical trials related to ovarian cancer therapy.

Towards Personalized Management of Ovarian Cancer

Despite advances in surgery and chemotherapy, the overall outcomes for patients with advanced ovarian cancer remain poor. Although initial response rates to platinum-based chemotherapy is about 60-80%, most patients will have recurrence and succumb to the disease. However, a DNA repair-directed precision medicine strategy has recently generated real hope in improving survival. The clinical development of PARP inhibitors has transformed lives for many patients with BRCA germline-deficient and/or platinum-sensitive epithelial ovarian cancers. Antiangiogenic agents and intraperitoneal chemotherapy approaches may also improve outcomes in patients. Moreover, evolving immunotherapeutic opportunities could also positively impact patient outcomes. Here we review the current clinical state of PARP inhibitors and other clinically viable targeted approaches in ovarian cancer.

Targeting Tyrosine Kinases in Ovarian Cancer: Small Molecule Inhibitor and Monoclonal Antibody, Where Are We Now?

Ovarian cancer is one of the most lethal gynaecological malignancies worldwide. Despite high success rates following first time treatment, this heterogenous disease is prone to recurrence. Oncogenic activity of receptor tyrosine kinases is believed to drive the progression of ovarian cancer. Here we provide an update on the progress of the therapeutic targeting of receptor tyrosine kinases in ovarian cancer. Broadly, drug classes that inhibit tyrosine kinase/pathways can be classified as small molecule inhibitors, monoclonal antibodies, or immunotherapeutic vaccines. Small molecule inhibitors tested in clinical trials thus far include sorafenib, sunitinib, pazopanib, tivantinib, and erlotinib. Monoclonal antibodies include bevacizumab, cetuximab, pertuzumab, trastuzumab, and seribantumab. While numerous trials have been carried out, the results of monotherapeutic agents have not been satisfactory. For combination with chemotherapy, the monoclonal antibodies appear more effective, though the efficacy is limited by low frequency of target alteration and a lack of useful predictive markers for treatment stratification. There remain critical gaps for the treatment of platinum-resistant ovarian cancers; however, platinum-sensitive tumours may benefit from the combination of tyrosine kinase targeting drugs and PARP inhibitors. Immunotherapeutics such as a peptide B-cell epitope vaccine and plasmid-based DNA vaccine have shown some efficacy both as monotherapeutic agents and in combination therapy, but require further development to validate current findings. In conclusion, the tyrosine kinases remain attractive targets for treating ovarian cancers. Future development will need to consider effective drug combination, frequency of target, and developing predictive biomarker.

Maintenance therapy for newly diagnosed epithelial ovarian cancer- a review

Epithelial ovarian cancer (EOC) is the most lethal gynaecological cancer among women worldwide, with the 5-year survival rate ranging between 30 and 40%. Due to the asymptomatic nature of the condition, it is more likely to be diagnosed at an advanced stage, requiring an aggressive therapeutic approach. Cytoreductive surgery (CRS) along with systemic chemotherapy with paclitaxel and carboplatin has been the mainstay of the treatment in the frontline management of EOC. In recent years, neo-adjuvant chemotherapy, followed by interval CRS has become an important strategy for the management of advanced EOC. Due to the high rate of recurrence, the oncology community has begun to shift its focus to molecular-targeted agents and maintenance therapy in the frontline settings. The rationale for maintenance therapy is to delay the progression or relapse of the disease, as long as possible after first-line treatment, irrespective of the amount of residual disease. Tumours with homologous recombination deficiency (HRD) including BReast CAncer gene (BRCA) mutations are found to be sensitive to polyadenosine diphosphate-ribose polymerase (PARP) inhibitors and understanding of HRD status has become important in the frontline setting. PARP inhibitors are reported to provide a significant improvement in progression-free survival and have an acceptable safety profile. PARP inhibitors have also been found to act regardless of BRCA status. Recently, PARP inhibitors as maintenance therapy in the frontline settings showed encouraging results in EOC; however, the results from further trials and survival data from ongoing trials are awaited for understanding the role of this pathway in treatment of EOC. This review discusses an overview of maintenance strategies in newly diagnosed EOC along with considerations for maintenance therapy in EOC with a focus on PARP inhibitors.