The impact of inter-cycle treatment delays on overall survival in patients with advanced-stage ovarian cancer.

INTRODUCTION: Chemotherapy forms the cornerstone of systemic treatment for advanced ovarian cancer, extending overall survival; however, drug-related toxicity can lead to treatment delays, potentially diminishing treatment efficacy. This study evaluated the impact of treatment delays on all-cause mortality of patients with ovarian cancer, to better inform decisions on patient management. METHODS: This retrospective, population-based cohort study included 1517 women with advanced-stage ovarian cancer, receiving first-line adjuvant or neoadjuvant chemotherapy in 2014 and 2015. The frequency of inter-cycle delays >7 days was calculated using drug administration dates. Kaplan-Meier estimates were used to compare 2-year overall survival (OS) between patients who were delayed and those treated to schedule. Cox proportional hazards regression was used to investigate the impact of treatment delay on all-cause mortality. Inverse probability of treatment weighting propensity scores were used to adjust for confounding variables. RESULTS: Delays >7 days occurred in 35.3% of patients. Two-year OS probability was 62.7% in patients who experienced treatment delays >7 days (95% CI, 58.7-66.9) compared to 69.1% in those treated to schedule (95% CI, 66.2-72.0). Delays were not significantly associated with all-cause mortality when adjusted for confounders (HR 1.00 95% CI, 0.83-1.20, P = .9). CONCLUSIONS: Delays to chemotherapy treatment were not significantly associated with worsened survival in patients with advanced-stage ovarian cancer. These results can inform clinical decision making that prioritize toxicity management and quality of life for those treated with chemotherapy.

A multicenter retrospective study to assess feasibility, safety and efficacy of first-line carboplatin-paclitaxel versus carboplatin monotherapy in a frail, elderly epithelial ovarian cancer population.

OBJECTIVE: Underrepresentation of elderly ovarian cancer patients in clinical trials has led to lack of clarity regarding optimal first-line chemotherapy in this cohort. The Elderly Women with Ovarian Cancer (EWOC)-1 trial demonstrated that 3-weekly carboplatin (3wC) resulted in worse survival and feasibility compared with standard 3-weekly carboplatin-paclitaxel (3wCP) in frail, elderly ovarian cancer patients. Our retrospective study compares feasibility, safety, and efficacy of first-line 3wCP and 3wC in a frail ovarian cancer cohort. METHODS: Clinical data were retrospectively analyzed for newly-diagnosed, International Federation of Gynecology and Obstetrics (FIGO) stage III/IV, ≥70-year-old epithelial ovarian cancer patients, treated by clinician choice with 3wC or 3wCP at two London cancer centers over a 2 year period. Charlson Comorbidity Index (CCI) and Eastern Cooperative Oncology Group (ECOG) performance status provided surrogate markers of frailty. Common Terminology Criteria for Adverse Events v5.0 graded toxicity. RESULTS: A total of 107 patients were treated with 3wC (n=30) and 3wCP (n=77). Age, performance status, and CCI were significantly different between cohorts, with 3wC patients older (84 vs 75 years, p<0.001), with more comorbidities (median CCI 4 vs 3, p<0.001) and worse performance status (47% vs 17% PS ≥2, p=0.015). Surgical outcomes differed significantly between cohorts, with 20 (67%) 3wC patients not undergoing surgery, compared with 22 (29%) 3wCP patients (p<0.001). Median follow-up was 45.8 months (IQR 38.7-56.3 months). While we observed improved progression-free (HR 0.55, 95% CI 0.33 to 0.90, p=0.017) and overall survival (HR 0.44, 95% CI 0.27 to 0.73, p=0.001, log-rank test) in a univariate cox proportional hazards comparison between 3wCP and 3wC, this was not significant on multivariate analysis. Completion of six planned chemotherapy cycles was achieved by the majority, with similar discontinuation rates between groups (13% 3wC vs 8% 3wCP, p>0.05). Overall grade ≥3 hematological toxicity rates were similar between regimens (33% 3wC vs 44% 3wCP, p=0.37) with grade ≥3 neutropenia (p=0.019) and grade ≥3 thrombocytopenia (p=0.006) more common with 3wCP and 3wC, respectively. No treatment-related deaths occurred. CONCLUSION: Our data demonstrates that standard 3wCP is a well-tolerated, feasible first-line treatment for frail, elderly ovarian cancer patients. Improved survival with 3wCP was not significant when corrected for established clinical prognostic factors.

The impact of inter-cycle treatment delays on 5-year all-cause mortality in early-stage breast cancer: A retrospective cohort study.

BACKGROUND: Inter-cycle delays to chemotherapy are often required to manage drug toxicity. The impact of delays on mortality is poorly characterised. This retrospective cohort study examined the association of treatment delay with all-cause mortality in early-stage breast cancer. METHODS: This real-world analytical study included adult women with stage 2 or 3 breast cancer receiving first-line (neo-)adjuvant chemotherapy between 01/01/2014 and 31/12/2015 in England. Inter-cycle delays > 7 days during the treatment period were calculated, and the association of treatment delay with 5-year all-cause mortality was investigated. Survival was compared between patients experiencing treatment delay and those completing treatment to schedule using landmark methodology and Kaplan-Meier (KM) estimator. Cox proportional hazards regression was used to investigate the impact of delay on survival, using inverse probability of treatment weighting to adjust for confounding variables. RESULTS: 8567 patients were included. 17 % (1448) experienced inter-cycle delay > 7 days during the treatment period. 1120 (13 %) women had died at the end of the 5-year follow up period. Median follow-up time was 5.5 years. Survival probability was significantly lower in patients experiencing treatment delay by KM estimator analysis (p < 0.0001). Cox proportional hazards regression demonstrated a significant positive association between delay and 5-year all-cause mortality (HR 1.33 95 % CI 1.12-1.61, p < 0.001). CONCLUSIONS: This is the largest study of its kind demonstrating an association between treatment delay and all-cause mortality. These findings support interventions to improve toxicity management allowing completion of chemotherapy to schedule where patients experience treatment delay due to treatment-related toxicity or hospital capacity pressures.

Cost-Effectiveness of Unselected Multigene Germline and Somatic Genetic Testing for Epithelial Ovarian Cancer.

BACKGROUND: Parallel panel germline and somatic genetic testing of all patients with ovarian cancer (OC) can identify more pathogenic variants (PVs) that would benefit from PARP inhibitor (PARPi) therapy, and allow for precision prevention in unaffected relatives with PVs. In this study, we estimate the cost-effectiveness and population impact of parallel panel germline and somatic BRCA testing of all patients with OC incorporating PARPi therapy in the United Kingdom and the United States compared with clinical criteria/family history (FH)-based germline BRCA testing. We also evaluate the cost-effectiveness of multigene panel germline testing alone. METHODS: Microsimulation cost-effectiveness modeling using data from 2,391 (UK: n=1,483; US: n=908) unselected, population-based patients with OC was used to compare lifetime costs and effects of panel germline and somatic BRCA testing of all OC cases (with PARPi therapy) (strategy A) versus clinical criteria/FH-based germline BRCA testing (strategy B). Unaffected relatives with germline BRCA1/BRCA2/RAD51C/RAD51D/BRIP1 PVs identified through cascade testing underwent appropriate OC and breast cancer (BC) risk-reduction interventions. We also compared the cost-effectiveness of multigene panel germline testing alone (without PARPi therapy) versus strategy B. Unaffected relatives with PVs could undergo risk-reducing interventions. Lifetime horizon with payer/societal perspectives, along with probabilistic/one-way sensitivity analyses, are presented. Incremental cost-effectiveness ratio (ICER) and incremental cost per quality-adjusted life year (QALY) gained were compared with £30,000/QALY (UK) and $100,000/QALY (US) thresholds. OC incidence, BC incidence, and prevented deaths were estimated. RESULTS: Compared with clinical criteria/FH-based BRCA testing, BRCA1/BRCA2/RAD51C/RAD51D/BRIP1 germline testing and BRCA1/BRCA2 somatic testing of all patients with OC incorporating PARPi therapy had a UK ICER of £51,175/QALY (payer perspective) and £50,202/QALY (societal perspective) and a US ICER of $175,232/QALY (payer perspective) and $174,667/QALY (societal perspective), above UK/NICE and US cost-effectiveness thresholds in the base case. However, strategy A becomes cost-effective if PARPi costs decrease by 45% to 46% or if overall survival with PARPi reaches a hazard ratio of 0.28. Unselected panel germline testing alone (without PARPi therapy) is cost-effective, with payer-perspective ICERs of £11,291/QALY or $68,808/QALY and societal-perspective ICERs of £6,923/QALY or $65,786/QALY. One year's testing could prevent 209 UK BC/OC cases and 192 deaths, and 560 US BC/OC cases and 460 deaths. CONCLUSIONS: Unselected panel germline and somatic BRCA testing can become cost-effective, with a 45% to 46% reduction in PARPi costs. Regarding germline testing, unselected panel germline testing is highly cost-effective and should replace BRCA testing alone.

Patient decision aids in mainstreaming genetic testing for women with ovarian cancer: A prospective cohort study.

OBJECTIVE: To evaluate patient preference for short (gist) or detailed/extensive decision aids (DA) for genetic testing at ovarian cancer (OC) diagnosis. DESIGN: Cohort study set within recruitment to the Systematic Genetic Testing for Personalised Ovarian Cancer Therapy (SIGNPOST) study (ISRCTN: 16988857). SETTING: North-East London Cancer Network (NELCN) population. POPULATION/SAMPLE: Women with high-grade non-mucinous epithelial OC. METHODS: A more detailed DA was developed using patient and stakeholder input following the principles/methodology of IPDAS (International Patients Decision Aids Standards). Unselected patients attending oncology clinics evaluated both a pre-existing short and a new long DA version and then underwent mainstreaming genetic testing by a cancer clinician. Appropriate inferential descriptive and regression analyses were undertaken. MAIN OUTCOME MEASURES: Satisfaction, readability, understanding, emotional well-being and preference for long/short DA. RESULTS: The mean age of patients was 66 years (interquartile range 11), and 85% were White British ethnicity. Of the participants, 74% found DAs helpful/useful in decision-making. Women reported higher levels of satisfaction (86% versus 58%, p < 0.001), right amount of information provided (76.79% versus49.12%, p < 0.001) and improved understanding (p < 0.001) with the long DA compared with the short DA. There was no statistically significant difference in emotional outcomes (feeling worried/concerned/reassured/upset) between 'short' and 'long' DA; 74% of patients preferred the long DA and 24% the short DA. Patients undergoing treatment (correlation coefficient (coef) = 0.603; 95% CI 0.165-1.041, p = 0.007), those with recurrence (coef = 0.493; 95% CI 0.065-0.92, p = 0.024) and older women (coef = 0.042; 95% CI 0.017-0.066, p = 0.001) preferred the short DA. Ethnicity did not affect outcomes or overall preference for long/short DA. CONCLUSIONS: A longer DA in OC patients has higher satisfaction without increasing emotional distress. Older women and those undergoing treatment/recurrence prefer less extensive information, whereas those in remission preferred a longer DA.

Antitumor Activity and Safety of Dostarlimab Monotherapy in Patients With Mismatch Repair Deficient Solid Tumors: A Nonrandomized Controlled Trial.

Importance: Mismatch repair deficiency (dMMR) occurs in various cancers, and these tumors are attractive candidates for anti-programmed cell death 1 therapies, such as dostarlimab, a recently approved immune checkpoint inhibitor. Objective: To assess the antitumor activity and safety of dostarlimab in patients with advanced or recurrent dMMR solid tumors. Design, Setting, And Participants: The GARNET trial was a phase 1, open-label, single-group, multicenter study that began enrolling May 8, 2017. Participants had advanced or recurrent dMMR and microsatellite instability-high (MSI-H) or polymerase epsilon (POLE)-altered solid tumors. The data cut for this interim analysis was from November 1, 2021, with median follow-up of 27.7 months. Interventions: Patients received 500 mg of dostarlimab intravenously every 3 weeks for 4 doses, then 1000 mg every 6 weeks until disease progression, discontinuation, or withdrawal. Main Outcomes and Measures: The primary objective was to evaluate objective response rate and duration of response in patients with dMMR solid tumors by blinded independent central review using Response Evaluation Criteria in Solid Tumors, version 1.1. Results: The efficacy population included 327 patients (median [range] age, 63 [24-85] years; 235 [71.9%] female; 7 [2.1%] Asian, 6 [1.8%] Black, and 206 [63.0%] White patients), with 141 patients (43.1%) with dMMR endometrial cancer, 105 patients (32.1%) with dMMR colorectal cancer, and 81 patients (24.8%) with other dMMR tumor types. All patients had at least 1 previous line of therapy. Objective response rate assessed per blinded independent central review for dMMR solid tumors was 44.0% (95% CI, 38.6% to 49.6%). Median duration of response was not reached (range, ≥1.18 to ≥47.21 months); 72.2% of responders (104 of 144) had a response lasting 12 or more months. Median progression-free survival was 6.9 months (95% CI, 4.2 to 13.6 months); probability of progression-free survival at 24 months was 40.6% (95% CI, 35.0% to 46.1%). Median overall survival was not reached (95% CI, 31.6 months to not reached). The most frequent immune-related adverse events were hypothyroidism (25 [6.9%]), alanine aminotransferase increase (21 [5.8%]), and arthralgia (17 [4.7%]). No new safety concerns were identified. Conclusions And Relevance: In this nonrandomized controlled trial, dostarlimab was a well-tolerated treatment option with rapid, robust, and durable antitumor activity in patients with diverse dMMR solid tumors. These findings suggest that dostarlimab provides meaningful long-term benefit in a population with high unmet need. Trial Registration: ClinicalTrials.gov Identifier: NCT02715284.

Seminoma and dysgerminoma: evidence for alignment of clinical trials and de-escalation of systemic chemotherapy.

Malignant germ cell tumours are a group of rare cancers whose incidence peaks in late adolescence and early adulthood. Dysgerminomas of the ovary and seminomas of the testis are analogous diseases, but seminomas have a 10-fold higher incidence. The two tumours are morphologically identical and are only differentiated by surrounding organ-specific tissue or testicular germ cell neoplasia in situ. They share genetic features including KIT and RAS mutations, amplification of chromosome 12p, and expression of pluripotency markers (NANOG (Nanog homeobox), OCT3/4 (Octamer-binding transcription factor 3/4), and SAL4 (Spalt-like trascription factor 4)). Both histologies are exquisitely sensitive to platinum chemotherapy, and the combination of bleomycin, etoposide, and cisplatin (BEP) yields survival rates greater than 90%. However, BEP causes significant, lifelong toxicity (cardiovascular, renal, respiratory, and neurological) in these young patients with an expectation of cure. Here, we comprehensively review the biological features of dysgerminoma and seminoma to demonstrate that they are biologically analogous diseases. We present available clinical trial data supporting de-escalation of chemotherapy treatment. Finally, we propose that future trials should enrol men, women, and children to benefit all patients regardless of age or sex.

The Landscape of Adoptive Cellular Therapies in Ovarian Cancer.

Ovarian cancers are typically poorly immunogenic and have demonstrated disappointing responses to immune checkpoint inhibitor (ICI) therapy. Adoptive cellular therapy (ACT) offers an alternative method of harnessing the immune system that has shown promise, especially with the success of chimeric antigen receptor T-cell (CAR-T) therapy in haematologic malignancies. So far, ACT has led to modest results in the treatment of solid organ malignancies. This review explores the possibility of ACT as an effective alternative or additional treatment to current standards of care in ovarian cancer. We will highlight the potential of ACTs, such as CAR-T, T-cell receptor therapy (TCR-T), tumour-infiltrating lymphocytes (TILs) and cell-based vaccines, whilst also discussing their challenges. We will present clinical studies for these approaches in the treatment of immunologically 'cold' ovarian cancer and consider the rationale for future research.

Safety and anti-tumour activity of the IgE antibody MOv18 in patients with advanced solid tumours expressing folate receptor-alpha: a phase I trial.

All antibodies approved for cancer therapy are monoclonal IgGs but the biology of IgE, supported by comparative preclinical data, offers the potential for enhanced effector cell potency. Here we report a Phase I dose escalation trial (NCT02546921) with the primary objective of exploring the safety and tolerability of MOv18 IgE, a chimeric first-in-class IgE antibody, in patients with tumours expressing the relevant antigen, folate receptor-alpha. The trial incorporated skin prick and basophil activation tests (BAT) to select patients at lowest risk of allergic toxicity. Secondary objectives were exploration of anti-tumour activity, recommended Phase II dose, and pharmacokinetics. Dose escalation ranged from 70 µg-12 mg. The most common toxicity of MOv18 IgE is transient urticaria. A single patient experienced anaphylaxis, likely explained by detection of circulating basophils at baseline that could be activated by MOv18 IgE. The BAT assay was used to avoid enrolling further patients with reactive basophils. The safety profile is tolerable and maximum tolerated dose has not been reached, with evidence of anti-tumour activity observed in a patient with ovarian cancer. These results demonstrate the potential of IgE therapy for cancer.

Safety, Efficacy, and Biomarker Analyses of Dostarlimab in Patients with Endometrial Cancer: Interim Results of the Phase I GARNET Study.

PURPOSE: This interim report of the GARNET phase I trial presents efficacy and safety of dostarlimab in patients with advanced or recurrent endometrial cancer (EC), with an analysis of tumor biomarkers as prognostic indicators. PATIENTS AND METHODS: A total of 153 patients with mismatch repair deficient (dMMR)/microsatellite instability-high (MSI-H) and 161 patients with mismatch repair proficient (MMRp)/microsatellite stable (MSS) EC were enrolled and dosed. Patients received 500 mg dostarlimab every 3 weeks for four cycles, then 1,000 mg every 6 weeks until progression. Primary endpoints were objective response rate (ORR) and duration of response (DOR). RESULTS: A total of 143 patients with dMMR/MSI-H EC and 156 patients with MMRp/MSS EC were evaluated for efficacy. ORR was 45.5% (n = 65) and 15.4% (n = 24) for dMMR/MSI-H EC and MMRp/MSS EC, respectively. Median DOR for dMMR/MSI-H EC was not met (median follow-up, 27.6 months); median DOR for MMRp/MSS EC was 19.4 months. The ORRs by combined positive score (CPS) ≥1 status were 54.9% and 21.7% for dMMR/MSI-H EC and MMRp/MSS EC, respectively. ORRs by high tumor mutational burden (≥10 mutations/Mb) were 47.8% (43/90) and 45.5% (5/11) for dMMR/MSI-H EC and MMRp/MSS EC, respectively. ORR in TP53mut or POLεmut molecular subgroups was 18.1% (17/94) and 40.0% (2/5), respectively. The safety profile of dostarlimab was consistent with previous reports. CONCLUSIONS: Dostarlimab demonstrated durable antitumor activity and safety in patients with dMMR/MSI-H EC. Biomarkers associated with EC may identify patients likely to respond to dostarlimab. See related commentary by Jangra and Dhani, p. 4521.

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.

Genomic testing in high-grade serous ovarian cancer: current options and future development.

Understanding the genomic complexity of high-grade serous ovarian cancer is now essential in guiding patient management, particularly in the first-line setting. Our knowledge in this area has expanded rapidly in recent years, with biomarkers developing in parallel to agents designed to exploit cancer-associated genetic aberrations. In this review we will take stock of the current landscape of genetic testing and look towards the future with developments that aim to refine personalized treatment paradigms and track treatment resistance in real time.

Disparity in the era of personalized medicine for epithelial ovarian cancer.

The treatment of high-grade serous ovarian cancer and high-grade endometrioid ovarian cancer has seen significant improvements in recent years, with BRCA1/2 and homologous recombination status guiding a personalized approach which has resulted in improved patient outcomes. However, for other epithelial ovarian cancer subtypes, first-line treatment remains unchanged from the platinum-paclitaxel trials of the early 2000s. In this review, we explore novel therapeutic approaches being adopted in the treatment of clear cell, mucinous, carcinosarcoma and low-grade serous ovarian cancer and the biological rational behind them. We discuss why such disparities exist, the challenges faced in conducting dedicated trials in these rarer histologies and look towards new approaches being adopted to overcome them.

A Phase 2 study of prexasertib (LY2606368) in platinum resistant or refractory recurrent ovarian cancer.

OBJECTIVE: High-grade serous ovarian cancer, the most frequent type of ovarian cancer, has a poor prognosis and novel treatments are needed for patients with platinum resistant/refractory disease. New therapeutic strategies targeting cell cycle checkpoints, including CHK1 inhibition with prexasertib, may help improve clinical response and overcome resistance. METHODS: Patients with ovarian cancer (N = 169) were assigned to 4 cohorts as part of the Phase 2 multicenter trial (NCT03414047): Cohort 1: platinum resistant, BRCA-wildtype with ≥3 lines prior therapy; Cohort 2: platinum resistant BRCA-wildtype with <3 lines prior therapy; Cohort 3: platinum resistant, BRCA-mutated with prior PARP inhibitor therapy; Cohort 4: platinum refractory, BRCA-mutated, or BRCA-wildtype with any number of prior therapy lines. The primary endpoint was objective response rate (ORR) and secondary endpoints included disease control rate (DCR), and safety. DNA from tumor biopsies was sequenced to identify biomarkers. RESULTS: The ORR in platinum resistant patients (Cohorts 1--3) was 12.1%, and 6.9% in platinum refractory patients. In platinum resistant patients, DCR was 37.1%, and consistent across cohorts. In platinum refractory patients, DCR was 31.0%. Consistent with the prexasertib mechanism of action, the most common treatment related adverse events of all grades included thrombocytopenia, neutropenia, fatigue, nausea, and anemia. CONCLUSIONS: Prexasertib demonstrated durable single agent activity in a subset of patients with recurrent ovarian cancer regardless of clinical characteristics, BRCA status, or prior therapies, including PARPi. There was no obvious correlation with genomic alterations in responders vs non-responders, emphasizing the need for alternative biomarker approaches for responder identification.

First-in-human phase I/II, open-label study of the anti-OX40 agonist INCAGN01949 in patients with advanced solid tumors.

BACKGROUND: OX40 is a costimulatory receptor upregulated on antigen-activated T cells and constitutively expressed on regulatory T cells (Tregs). INCAGN01949, a fully human immunoglobulin G1κ anti-OX40 agonist monoclonal antibody, was designed to promote tumor-specific immunity by effector T-cell activation and Fcγ receptor-mediated Treg depletion. This first-in-human study was conducted to determine the safety, tolerability, and preliminary efficacy of INCAGN01949. METHODS: Phase I/II, open-label, non-randomized, dose-escalation and dose-expansion study conducted in patients with advanced or metastatic solid tumors. Patients received INCAGN01949 monotherapy (7-1400 mg) in 14-day cycles while deriving benefit. Safety measures, clinical activity, pharmacokinetics, and pharmacodynamic effects were assessed and summarized with descriptive statistics. RESULTS: Eighty-seven patients were enrolled; most common tumor types were colorectal (17.2%), ovarian (8.0%), and non-small cell lung (6.9%) cancers. Patients received a median three (range 1-9) prior therapies, including immunotherapy in 24 patients (27.6%). Maximum tolerated dose was not reached; one patient (1.1%) receiving 350 mg dose reported dose-limiting toxicity of grade 3 colitis. Treatment-related adverse events were reported in 45 patients (51.7%), with fatigue (16 (18.4%)), rash (6 (6.9%)), and diarrhea (6 (6.9%)) being most frequent. One patient (1.1%) with metastatic gallbladder cancer achieved a partial response (duration of 6.3 months), and 23 patients (26.4%) achieved stable disease (lasting >6 months in one patient). OX40 receptor occupancy was maintained over 90% among all patients receiving doses of ≥200 mg, while no treatment-emergent antidrug antibodies were detected across all dose levels. Pharmacodynamic results demonstrated that treatment with INCAGN01949 did not enhance proliferation or activation of T cells in peripheral blood or reduce circulating Tregs, and analyses of tumor biopsies did not demonstrate any consistent increase in effector T-cell infiltration or function, or decrease in infiltrating Tregs. CONCLUSION: No safety concerns were observed with INCAGN01949 monotherapy in patients with metastatic or advanced solid tumors. However, tumor responses and pharmacodynamic effects on T cells in peripheral blood and post-therapy tumor biopsies were limited. Studies evaluating INCAGN01949 in combination with other therapies are needed to further evaluate the potential of OX40 agonism as a therapeutic approach in patients with advanced solid tumors. TRIAL REGISTRATION NUMBER: NCT02923349.

Ovarian Cancer Therapy: Homologous Recombination Deficiency as a Predictive Biomarker of Response to PARP Inhibitors.

Poly(adenosine diphosphate-ribose) polymerase (PARP) inhibitors have revolutionised the management of patients with high-grade serous and endometrioid ovarian cancer demonstrating significant improvements in progression-free survival. Whilst the greatest benefit is seen with BRCA1/2 mutant cancers, it is clear that the benefit extends beyond this group. This sensitivity is thought to be due to homologous recombination deficiency (HRD), which is present in up to 50% of the high-grade serous cancers. Several different HRD assays exist, which fall into one of three main categories: homologous recombination repair (HRR)-related gene analysis, genomic "scars" and/or mutational signatures, and real-time HRD functional assessment. We review the emerging data on HRD as a predictive biomarker for PARP inhibitors and discuss the merits and disadvantages of different HRD assays.

The Tumor Microenvironment of Clear-Cell Ovarian Cancer.

Some patients with advanced clear-cell ovarian cancer (CCOC) respond to immunotherapy; however, little is known about the tumor microenvironment (TME) of this relatively rare disease. Here, we describe a comprehensive quantitative and topographical analysis of biopsies from 45 patients, 9 with Federation Internationale des Gynaecologistes et Obstetristes (FIGO) stage I/II (early CCOC) and 36 with FIGO stage III/IV (advanced CCOC). We investigated 14 immune cell phenotype markers, PD-1 and ligands, and collagen structure and texture. We interrogated a microarray data set from a second cohort of 29 patients and compared the TMEs of ARID1A-wildtype (ARID1Awt) versus ARID1A-mutant (ARID1Amut) disease. We found significant variations in immune cell frequency and phenotype, checkpoint expression, and collagen matrix between the malignant cell area (MCA), leading edge (LE), and stroma. The MCA had the largest population of CD138+ plasma cells, the LE had more CD20+ B cells and T cells, whereas the stroma had more mast cells and αSMA+ fibroblasts. PD-L2 was expressed predominantly on malignant cells and was the dominant PD-1 ligand. Compared with early CCOC, advanced-stage disease had significantly more fibroblasts and a more complex collagen matrix, with microarray analysis indicating "TGFß remodeling of the extracellular matrix" as the most significantly enriched pathway. Data showed significant differences in immune cell populations, collagen matrix, and cytokine expression between ARID1Awt and ARID1Amut CCOC, which may reflect different paths of tumorigenesis and the relationship to endometriosis. Increased infiltration of CD8+ T cells within the MCA and CD4+ T cells at the LE and stroma significantly associated with decreased overall survival.

PARP inhibitors in ovarian cancer: overcoming resistance with combination strategies.

The use of PARP inhibitors (PARPi) in patients with epithelial ovarian cancer is expanding, with the transition from use in recurrent disease to the first-line setting. This is accompanied with an increasing population of patients who develop acquired PARPi resistance. Coupled with those patients with primary PARPi resistance, there is an urgent need to better understand mechanisms of resistance and identify means to overcome this resistance. Combination therapy offers the potential to overcome innate and acquired resistance, by either working synergistically with PARPi or by restoring homologous recombination deficiency, targeting the homologous recombination repair pathway through an alternate strategy. We discuss mechanisms of PARPi resistance and data on novel combinations which may restore PARPi sensitivity.

Surgical management and outcomes for stage 1 malignant ovarian germ cell tumours: A UK multicentre retrospective cohort study.

OBJECTIVE: To describe the current surgical management of stage 1 malignant ovarian germ cell tumours and correlated oncological outcomes. STUDY DESIGN: We undertook a retrospective study of all stage 1 primary ovarian germ cell tumours treated in four major UK gynaecology oncology centres over 12 years. We assessed route of surgery, fertility-sparing approaches, ovarian cystectomy alone, and surgical staging and correlated these with clinical outcomes. RESULTS: Eighty-six patients were followed-up for a median of 4.4 years (IQR 4.3). The median age was 26 (range 11-47). There were 24 (27.9%) dysgerminomas, 13 (15.1%) yolk sac tumours, 10 (11.3%) mixed germ cell tumours, and 39 (45.3%) immature teratomas. Overall survival was 96.6% (OS, 95% CI 91.9-100%), with event free survival of 81.8% (EFS, 95% CI 72.5-92.3) at 5 years. The majority had fertility-sparing surgery (93%, n = 80). In a subset of patients with immature teratoma, there was no significant difference in recurrence or survival if patients underwent unilateral cystectomy only or salpingo-oophorectomy. Laparotomy was the most common approach (n = 66, 76.7%), used more frequently for larger tumours > 10 cm. Surgical staging procedures were undertaken in 42 (48.6%) patients with no significant difference in rates of staging across histological subtypes. Peritoneal biopsies were taken in 11 (12.7%), omental assessment in 40 (46.5%) and lymphadenectomy in 10 (11.6%). There was no significant difference in EFS between patients who underwent staging procedures (83%, CI 71-98%) versus those that did not (84%, CI 72-98%). There was no significant difference in the rate of staging procedures in paediatric (42.1% 8/19) and adult (57.9% 34/67) populations. CONCLUSIONS: Across all histologies and ages, the absence of surgical staging did not impact upon disease free or overall survival in this cohort. This study also raises the possibility of a role for ovarian cystectomy in immature teratoma. These findings warrant investigation in larger prospective studies.