Predictors of long-term progression-free survival in patients with ovarian cancer treated with niraparib in the PRIMA/ENGOT-OV26/GOG-3012 study.

OBJECTIVE: To identify characteristics associated with long-term progression-free survival (≥2 years) in patients with advanced ovarian cancer treated with niraparib first-line maintenance therapy in the phase III PRIMA/ENGOT-OV26/GOG-3012 study. METHODS: In this post hoc analysis of PRIMA, patients randomized to niraparib were grouped based on investigator-assessed progression-free survival (progressive disease/censoring <2 years or ≥2 years after randomization). Variables assessed for predictive value were Eastern Cooperative Oncology Group performance status, International Federation of Gynecology and Obstetrics (FIGO) stage at diagnosis, clinical response to platinum-based chemotherapy, number of prior chemotherapy cycles, primary tumor location, body mass index, categorical age, debulking surgery type, number of baseline target lesions, number of baseline non-target lesions, BRCA/homologous recombination-deficiency status, residual disease status, and duration from end of chemotherapy to randomization. Logistic regression modeling using backward elimination (significance level=0.15) identified covariates associated with long-term progression-free survival (clinical cut-off date November 17, 2021). RESULTS: Of 487 patients randomized to niraparib, 152 (31%) had progressive disease/censoring ≥2 years after randomization. Multivariable logistic regression modeling using backward elimination identified BRCA1/2 mutation/homologous recombination deficiency status (p<0.0001), FIGO stage (p=0.041), primary tumor location (p=0.095), and number of baseline non-target lesions (p=0.0001) to be associated with long-term progression-free survival. Patients significantly more likely to achieve progression-free survival of ≥2 years in the final model were those with BRCA1- and BRCA2-mutated/homologous recombination-deficient tumors or BRCA wild-type/not determined/homologous recombination-deficient tumors (vs BRCA wild-type/homologous recombination-proficient/not determined tumors), FIGO stage III (vs IV), and 0 or 1 baseline non-target lesions (vs ≥2 baseline non-target lesions). CONCLUSIONS: The hypothesis-generating results of this analysis suggest that BRCA1/2 mutation/homologous recombination-deficiency status, FIGO stage, and number of baseline non-target lesions may predict progression-free survival of ≥2 years in patients with advanced ovarian cancer receiving niraparib first-line maintenance therapy. TRIAL REGISTRATION NUMBER: NCT02655016.

A Plain Language Summary of "Dostarlimab for primary advanced or recurrent endometrial cancer".

What is this summary about? Dostarlimab, also known by the brand name JEMPERLI, is a medicine that uses a patient's own immune system to treat endometrial cancer. Dostarlimab is a type of medicine called an immunotherapy. Immunotherapies help the immune system find and attack cancer cells. Dostarlimab stops cancer cells from being able to hide from the immune system, which allows the patient to have a boosted immune response against their cancer.The RUBY study is a phase 3 clinical study of primary advanced (cancer that has spread outside the uterus) or recurrent (cancer that has come back) endometrial cancer. A phase 3 clinical study looks at how well a new treatment works compared to the standard, or usual, treatment in a large patient population. The RUBY study is testing how well dostarlimab given with chemotherapy, followed by dostarlimab alone, works at delaying primary advanced or recurrent endometrial cancer from getting worse and preventing patients from dying, compared to chemotherapy given alone (the current standard treatment for primary advanced or recurrent endometrial cancer).What were the results? When dostarlimab was given with chemotherapy, this combination was found to delay primary advanced or recurrent endometrial cancer from getting worse and to prevent patients from dying, compared with chemotherapy given alone (without dostarlimab). Patients in the study who received dostarlimab with chemotherapy had a 36% lower risk of dying or having their cancer get worse.What do the results mean? The results from this study contributed to the approval of dostarlimab with chemotherapy as a new treatment option for patients with mismatch repair deficient/microsatellite instability-high primary advanced or recurrent endometrial cancer. As of the publication of this plain language summary of publication (PLSP), this combination of dostarlimab with chemotherapy has been approved in the United States of America, the United Kingdom, the European Union and Hong Kong.Clinical Trial Registration: NCT03981796 (RUBY).

Efficacy and safety of niraparib in patients aged 65 years and older with advanced ovarian cancer: Results from the PRIMA/ENGOT-OV26/GOG-3012 trial.

OBJECTIVE: To evaluate the impact of age on the efficacy and safety of niraparib first-line maintenance therapy in patients with newly diagnosed advanced ovarian cancer with a complete/partial response to first-line platinum-based chemotherapy. METHODS: Post hoc analysis of the phase 3 PRIMA/ENGOT-OV26/GOG-3012 study (NCT02655016). Patients in the intent-to-treat population were categorized according to age at baseline (<65 years vs ≥65 years), and progression-free survival (PFS), safety, and health-related quality of life (HRQOL) were evaluated for each age subgroup (clinical cutoff date, May 17, 2019). Safety findings were also evaluated according to a fixed starting dose (FSD) or an individualized starting dose (ISD). RESULTS: Of 733 randomized patients, 289 (39.4%) were ≥65 years (190 niraparib, 99 placebo) at baseline. Median PFS (niraparib vs placebo) and hazard ratios (95% CI) were similar in patients aged <65 years (13.9 vs 8.2 months; HR, 0.61 [0.47-0.81]) and ≥65 years (13.7 vs 8.1 months; HR, 0.53 [0.39-0.74]). The incidences of any-grade and grade ≥3 treatment-emergent adverse events (TEAEs) were similar across age subgroups; in the niraparib arm, TEAEs leading to dose discontinuation occurred in 7.8% of patients <65 years and 18.4% of patients ≥65 years. ISD use lowered the incidence of grade ≥3 thrombocytopenia events in niraparib-treated patients compared with the FSD (<65 years: 42.8% vs 18.0%; ≥65 years 57.0% vs 26.1%). HRQOL was comparable across age subgroups. CONCLUSION: Niraparib efficacy, safety, and HRQOL were generally comparable across age subgroups, although patients ≥65 years had a higher rate of discontinuations due to TEAEs. ISD use reduced grade ≥3 thrombocytopenia events regardless of age.

ENGOT-EN20/GOG-3083/XPORT-EC-042 - A phase III, randomized, placebo-controlled, double-blind, multicenter trial of selinexor in maintenance therapy after systemic therapy for patients with p53 wild-type, advanced, or recurrent endometrial carcinoma: rationale, methods, and trial design.

BACKGROUND: Patients with advanced/recurrent endometrial cancer have a poor prognosis and limited treatment options. Biomarkers such as tumor protein 53 (TP53) in endometrial cancer can integrate novel strategies for improved and individualized treatment that could impact patient outcomes. In an exploratory analysis of the phase III ENGOT-EN5/GOG-3055/SIENDO study of selinexor maintenance monotherapy 80 mg in advanced/recurrent endometrial cancer, a pre-specified subgroup of patients with TP53 wild type (wt) endometrial cancer showed preliminary activity at long-term follow-up with a generally manageable safety profile (median progression-free survival 27.4 months vs 5.2 months placebo, HR=0.41). PRIMARY OBJECTIVE: To evaluate the efficacy of selinexor compared with placebo as maintenance therapy in patients with advanced or recurrent TP53wt endometrial cancer. STUDY HYPOTHESIS: Selinexor administered at 60 mg weekly as maintenance therapy will show manageable safety and maintain efficacy in patients with TP53wt advanced/recurrent endometrial cancer after systemic therapy versus placebo. TRIAL DESIGN: This is a prospective, multicenter, double-blind, placebo-controlled, randomized phase III study designed to evaluate the efficacy and safety of selinexor as a maintenance therapy in patients with advanced or recurrent TP53wt endometrial cancer. MAJOR INCLUSION/EXCLUSION CRITERIA: Eligible patients must have histologically confirmed endometrial cancer, TP53wt confirmed by next-generation sequencing, completed at least 12 weeks of platinum-based therapy with or without immunotherapy, with confirmed partial response or complete response, and primary Stage IV disease or at first relapse. PRIMARY ENDPOINT: The primary endpoint is investigator-assessed progression-free survival per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 in the intent-to-treat population. SAMPLE SIZE: A total of 220 patients will be enrolled. ESTIMATED DATES FOR COMPLETING ACCRUAL AND PRESENTING RESULTS: Accrual is expected to be completed in 2024 with presentation of results in 2025. TRIAL REGISTRATION: NCT05611931.

Progression-free survival and safety at 3.5 years of follow-up: results from the randomized phase 3 PRIMA/ENGOT-OV26/GOG-3012 trial of niraparib maintenance treatment in patients with newly diagnosed ovarian cancer - a plain language summary.

What is this summary about? This PLSP provides a short summary of an original scientific article that presented results from the PRIMA study after 3.5 years of follow-up time. The original article was published in the European Journal of Cancer in 2023.The PRIMA study included adult patients with newly diagnosed advanced high-risk ovarian cancer whose tumors shrunk or became undetectable after treatment with chemotherapy with or without surgery. The PRIMA study evaluated how well the drug niraparib, also known as Zejula, worked at delaying or preventing ovarian cancer from coming back (recurring) or getting worse (progressing) compared with placebo (a substance with no effects that a doctor gives to a patient instead of a drug). The first results from the PRIMA study were published in 2019, when patients had participated in the PRIMA study for about 1.2 years.The article this PLSP is based on reports longer-term data from the PRIMA study, when patients had participated in the PRIMA study for about 3.5 years. Patients were monitored (or followed) for a longer time to understand how well niraparib continued to work and to evaluate whether the safety of niraparib changed with additional time being monitored.What were the results? Patients who took niraparib had more time before their cancer came back or got worse than patients who took placebo. In terms of safety, no new types of side effects with niraparib treatment were observed with additional time being monitored as part of the PRIMA study.What do the results mean? These results support that niraparib remains an important treatment option to help delay the cancer from coming back or getting worse in patients with newly diagnosed advanced ovarian cancer that responded to initial treatment.Clinical Trial Registration: NCT02655016 (PRIMA study) (ClinicalTrials.gov).

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.

Guideline concordant care for patients with locally advanced cervical cancer by disaggregated Asian American and Native Hawaiian/Pacific Islander groups: A National Cancer Database Analysis.

OBJECTIVE: Despite the within-group heterogeneity, Asian American (AA) and Native Hawaiian and Pacific Islander (NH/PI) patients are often grouped together. We compared the patterns of guideline-concordant care for locally advanced cervical cancer for disaggregated AA and NH/PI patients. METHODS: Patients with stage II-IVA cervical cancer between 2004 and 2020 were identified from the National Cancer Database. AA patients were disaggregated as East Asian (EA), South Asian (SA), and Southeast Asian (SEA). NH/PI patients were classified as a distinct racial subgroup. The primary outcome was the proportion undergoing guideline-concordant care, defined by radiation therapy with concurrent chemotherapy, brachytherapy, and completion of treatment within eight weeks. RESULTS: Of 48,116 patients, 2107 (4%) were AA and 171 (<1%) were NH/PI. Of the AA patients, 36% were SEA, 31% were EA, 12% were SA, and 21% could not be further disaggregated due to missing or unknown data. NH/PI patients were more likely to be diagnosed at an early age (53% NH/PI vs. 30% AA, p < 0.001) and have higher rates of comorbidities (18% NH/PI vs. 14% AA, p < 0.001). Within the AA subgroups, only 82% of SEA patients received concurrent chemotherapy compared to 91% of SA patients (p = 0.026). SA patients had the longest median OS (158 months) within the AA subgroups compared to SEA patients (113 months, p < 0.001). CONCLUSION: Disparities exist in the receipt of standard of care treatment for cervical cancer by racial and ethnic subgroups. It is imperative to disaggregate race and ethnicity data to understand potential differences in care and tailor interventions to achieve health equity.

Demographic reporting and language exclusion in gynecologic oncology clinical trials.

BACKGROUND: Participation in clinical trials may help mitigate disparate cancer outcomes. Thus, ensuring equitable access to clinical trials is a major priority for national cancer organizations. OBJECTIVE: This study aimed to examine clinical trial eligibility criteria that may adversely affect the enrollment of underrepresented groups and assess the availability of demographic information in published gynecologic oncology studies. STUDY DESIGN: ClinicalTrials.gov was searched for gynecologic oncology studies conducted between 1997 and 2021. Each study's inclusion and exclusion criteria were reviewed to determine whether demographic factors were used for enrollment screening. For published studies, demographic variables that were reported were identified. The expected clinical trial enrollment based on disease incidence and mortality was compared with the observed trial enrollment based on race. RESULTS: There were 1597 gynecologic oncology studies: 883 (55%) from ovarian cancer studies, 336 (21%) from cervical cancer studies, 262 (17%) from uterine cancer studies, and 116 (7%) from multisite gynecologic oncology studies. Of the 581 published studies, 554 (95%) reported age, 363 (63%) reported race, and 171 (29%) reported ethnicities. Cervical cancer studies were most likely to report demographic information, including race (P=.026) and ethnicity (P<.001). During the study period, 189 studies (12%) excluded patients based on the language spoken. Industry-sponsored trials (odds ratio, 0.07; 95% confidence interval, 0.02-0.30) and organization-sponsored trials (odds ratio, 0.40; 95% confidence interval, 0.22-0.73) were less likely to exclude patients because of language than investigator-initiated trials. A minority of patients (37%) in cervical cancer trials were of White race, compared with 85% of patients in uterine cancer trials and 82% of patients in ovarian cancer trials. CONCLUSION: Over the last 3 decades, 1 in 10 gynecologic oncology trials excluded patients because of language. Race and ethnicity were reported in more than half of the available studies. Initiatives to increase transparency in recruiting underrepresented patients and reporting demographic data are urgently needed.

Optimizing disease progression assessment using blinded central independent review and comparing it with investigator assessment in the PRIMA/ENGOT-ov26/GOG-3012 trial: challenges and solutions.

OBJECTIVE: Progression-free survival is an established clinically meaningful endpoint in ovarian cancer trials, but it may be susceptible to bias; therefore, blinded independent centralized radiological review is often included in trial designs. We compared blinded independent centralized review and investigator-assessed progressive disease performance in the PRIMA/ENGOT-ov26/GOG-3012 trial examining niraparib monotherapy. METHODS: PRIMA/ENGOT-ov26/GOG-3012 was a randomized, double-blind phase 3 trial; patients with newly diagnosed stage III/IV ovarian cancer received niraparib or placebo. The primary endpoint was progression-free survival (per Response Evaluation Criteria in Solid Tumors [RECIST] v1.1), determined by two independent radiologists, an arbiter if required, and by blinded central clinician review. Discordance rates between blinded independent centralized review and investigator assessment of progressive disease and non-progressive disease were routinely assessed. To optimize disease assessment, a training intervention was developed for blinded independent centralized radiological reviewers, and RECIST refresher training was provided for investigators. Discordance rates were determined post-intervention. RESULTS: There was a 39% discordance rate between blinded independent centralized review and investigator-assessed progressive disease/non-progressive disease in an initial patient subset (n=80); peritoneal carcinomatosis was the most common source of discordance. All reviewers underwent training, and as a result, changes were implemented, including removal of two original reviewers and identification of 10 best practices for reading imaging data. Post-hoc analysis indicated final discordance rates between blinded independent centralized review and investigator improved to 12% in the overall population. Median progression-free survival and hazard ratios were similar between blinded independent centralized review and investigators in the overall population and across subgroups. CONCLUSION: PRIMA/ENGOT-ov26/GOG-3012 highlights the need to optimize blinded independent centralized review and investigator concordance using early, specialized, ovarian-cancer-specific radiology training to maximize validity of outcome data.

Concurrent uterine surgery and uptake of hormone therapy in patients undergoing bilateral salpingo-oophorectomy for risk-reducing or therapeutic indications.

OBJECTIVE: This study aimed to analyze factors associated with concurrent uterine surgery in patients undergoing bilateral salpingo-oophorectomy (BSO) for risk reducing or therapeutic purposes. Additionally, trends in surgical choice and uptake of post-operative hormone therapy (HT) were examined. METHODS: A 10-year retrospective study was conducted on patients who underwent risk-reducing or therapeutic BSO at one institution. Multinomial regression analysis of patient and case characteristics was performed evaluating associations with surgery type (BSO, BSO and hysterectomy, or BSO and endometrial sampling). Trends in surgery type and uptake of HT post operatively are described. RESULTS: Among the study sample of 643 patients, 140 (22%) patients underwent therapeutic BSO for a history of hormone receptor (HR) positive breast cancer, while the remainder underwent risk-reducing BSO due to a pathogenic variant and/or family history. Pathogenic variants included BRCA1 (141, 40%) BRCA2 (173, 49%), and Lynch syndrome genes (15, 4%). Regression analysis revealed significant associations between concurrent hysterectomy and Black race (RR = 3.55, CI = 1.51-8.38, p = 0.004), history of HR positive breast cancer (RR = 1.88, CI = 1.03-3.42, p = 0.04), and surgeon (Surgeon 1, RR = 2.43, CI = 1.36-4.35, p = 0.003). Among eligible patients under age 51, 36% initiated HT. Over the study period, concurrent hysterectomy rates declined while endometrial sampling increased. CONCLUSIONS: Rates of hysterectomy declined over the study period and slightly more than one-third of eligible patients utilized post-operative HT. Further research on concurrent uterine surgery is needed to establish standardized treatment recommendations in the risk-reducing and therapeutic BSO population. Additionally, education regarding the benefits of postoperative HT in eligible patients is warranted.

Oral Selinexor as Maintenance Therapy After First-Line Chemotherapy for Advanced or Recurrent Endometrial Cancer.

PURPOSE: Selinexor inhibits exportin-1 (XPO1) resulting in nuclear accumulation of tumor suppressor proteins including p53 and has clinical activity in endometrial cancer (EC). The primary end point was to assess progression-free survival (PFS) with once-weekly oral selinexor in patients with advanced or recurrent EC. PATIENTS AND METHODS: ENGOT-EN5/GOG-3055/SIENDO was a randomized, prospective, multicenter, double-blind, placebo-controlled, phase III study at 107 sites in 10 countries. Patients 18 years or older with histologically confirmed EC were enrolled. All had completed a single line of at least 12 weeks of taxane-platinum combination chemotherapy and achieved partial or complete response. Patients were assigned to receive 80 mg oral selinexor once weekly or placebo with 2:1 random assignment (ClinicalTrials.gov identifier: NCT03555422). RESULTS: Between January 2018 and December 2021, 263 patients were randomly assigned, with 174 allocated to selinexor and 89 to placebo. The median PFS was 5.7 months (95% CI, 3.81 to 9.20) with selinexor versus 3.8 months (95% CI, 3.68 to 7.39) with placebo (hazard ratio [HR], 0.76 [95% CI, 0.54 to 1.08]; two-sided P = .126), which did not meet the criteria for statistical significance in the intent-to-treat population. Incorrect chemotherapy response stratification data for 7 (2.7%) patients were identified. In a prespecified exploratory analysis of PFS in audited stratification data, PFS for selinexor met the threshold for statistical significance (HR, 0.71; 95% CI, 0.499 to 0.996; two-sided P = .049). Furthermore, patients with the TP53 wild-type (wt) EC had a median PFS of 13.7 and 3.7 months with selinexor and placebo. The most common grade 3 treatment-related adverse events were nausea (9%), neutropenia (9%), and thrombocytopenia (7%). CONCLUSION: The significance level for PFS was only met in the audited analysis. However, a preliminary analysis of a prespecified exploratory subgroup of patients with TP53wt EC showed promising results with selinexor maintenance therapy.

TP53 mutation and abnormal p53 expression in endometrial cancer: Associations with race and outcomes.

OBJECTIVE: This multi-center cohort study assessed associations between race, TP53 mutations, p53 expression, and histology to investigate racial survival disparities in endometrial cancer (EC). METHODS: Black and White patients with advanced or recurrent EC with Next Generation Sequencing data in the Endometrial Cancer Molecularly Targeted Therapy Consortium database were identified. Clinicopathologic and treatment variables were summarized by race and compared. Overall survival (OS) and progression-free survival (PFS) among all patients were estimated by the Kaplan-Meier method. Cox proportional hazards models estimated the association between race, TP53 status, p53 expression, histology, and survival outcomes. RESULTS: Black patients were more likely than White patients to have TP53-mutated (N = 727, 71.7% vs 49.7%, p < 0.001) and p53-abnormal (N = 362, 71.1% vs 53.2%, p = 0.003) EC. Patients with TP53-mutated EC had worse PFS (HR 2.73 (95% CI 1.88-3.97)) and OS (HR 2.20 (95% CI 1.77-2.74)) compared to those with TP53-wildtype EC. Patients with p53-abnormal EC had worse PFS (HR 2.01 (95% CI 1.22-3.32)) and OS (HR 1.61 (95% CI 1.18-2.19)) compared to those with p53-wildtype EC. After adjusting for TP53 mutation and p53 expression, race was not associated with survival outcomes. The most frequent TP53 variants were at nucleotide positions R273 (n = 54), R248 (n = 38), and R175 (n = 23), rates of which did not differ by race. CONCLUSIONS: Black patients are more likely to have TP53-mutated and p53-abnormal EC, which are associated with worse survival outcomes than TP53- and p53-wildtype EC. The higher frequency of these subtypes among Black patients may contribute to survival disparities.

A plain language summary of results from the GARNET study of dostarlimab in patients with endometrial cancer.

WHAT IS THIS SUMMARY ABOUT?: Dostarlimab, also known by the brand name JEMPERLI, is a medicine that can be used to treat certain types of endometrial cancer. GARNET is an ongoing phase 1 clinical study that is testing the safety and side effects of dostarlimab and the best way to administer it to patients. The results presented in this summary are from a time point in the middle of the study. WHAT WERE THE RESULTS?: The results from the GARNET study published in 2022 showed how well dostarlimab worked for people participating in the study. Dostarlimab was found to reduce the size of tumors in patients with certain types of endometrial cancer. The patients treated with dostarlimab had side effects that could be managed and few severe side effects. WHAT DO THE RESULTS MEAN?: The results of the GARNET study led to dostarlimab being approved to treat patients with certain types of endometrial cancer. For patients with advanced-stage endometrial cancer, or endometrial cancer that has come back after chemotherapy (recurrent), there are few treatment options. The results suggest that dostarlimab may provide long-term benefits for these patients.

Improving genetic testing following abnormal mismatch repair immunohistochemistry results in endometrial cancer.

OBJECTIVES: Although universal mismatch repair (MMR) immunohistochemistry (IHC) in endometrial cancer began at our institution in July 2015, not all eligible patients were referred for genetic testing (GT). In April 2017, genetic counselors obtained IHC data and contacted physicians to approve genetic counseling referrals (GCRs) for Lynch Syndrome (LS) in eligible patients. We assessed if this protocol increased frequency of GCRs and GT in patients with abnormal MMR IHC. METHODS: We retrospectively (7/2015-5/2022) identified patients with abnormal MMR IHC at a large urban hospital. GCRs and GT were compared between cases from 7/2015-4/2017 (pre-protocol) and 5/2017-5/2022 (post-protocol) with chi-square and Fisher's exact tests. RESULTS: Of 794 patients with IHC testing, 177 (22.3%) had abnormal MMR results with 46 (26.0%) meeting criteria for LS screening with GT. Of 46 patients, 16 (34.8%) were identified prior to and 30 (65.2%) after the protocol initiation. GCRs significantly increased from 11/16 (68.8%) to 29/30 (96.7%) in the pre-protocol versus post-protocol groups, p = 0.02. There was no statistically significant difference in GT between groups (10/16, 62.5% vs 26/30, 86.7%, p = 0.07). Of 36 patients who underwent GT, 16 (44.4%) had LS: MSH6, 9; MSH2, 4; PMS2, 2; MLH1, 1. CONCLUSIONS: Increased frequency of GCRs was observed following the change in protocol, which is important as LS screening has clinical implications for patients and their families. Despite this additional effort, approximately 15% who met criteria did not undergo GT; further efforts such as universal germline testing in patients with endometrial cancer should be considered.

Progression-free survival and safety at 3.5years of follow-up: results from the randomised phase 3 PRIMA/ENGOT-OV26/GOG-3012 trial of niraparib maintenance treatment in patients with newly diagnosed ovarian cancer.

PURPOSE: To report updated long-term efficacy and safety from the double-blind, placebo-controlled, phase 3 PRIMA/ENGOT-OV26/GOG-3012 study (NCT02655016). METHODS: Patients with newly diagnosed advanced ovarian cancer with complete or partial response (CR or PR) to first-line platinum-based chemotherapy received niraparib or placebo once daily (2:1 ratio). Stratification factors were best response to first-line chemotherapy regimen (CR/PR), receipt of neoadjuvant chemotherapy (yes/no), and homologous recombination deficiency (HRD) status (deficient [HRd]/proficient [HRp] or not determined). Updated (ad hoc) progression-free survival (PFS) data (as of November 17, 2021) by investigator assessment (INV) are reported. RESULTS: In 733 randomised patients (niraparib, 487; placebo, 246), median PFS follow-up was 3.5years. Median INV-PFS was 24.5 versus 11.2months (hazard ratio, 0.52; 95% confidence interval [CI], 0.40-0.68) in the HRd population and 13.8 versus 8.2months (hazard ratio, 0.66; 95% CI, 0.56-0.79) in the overall population for niraparib and placebo, respectively. In the HRp population, median INV-PFS was 8.4 versus 5.4months (hazard ratio, 0.65; 95% CI, 0.49-0.87), respectively. Results were concordant with the primary analysis. Niraparib-treated patients were more likely to be free of progression or death at 4years than placebo-treated patients (HRd, 38% versus 17%; overall, 24% versus 14%). The most common grade ≥ 3 treatment-emergent adverse events in niraparib patients were thrombocytopenia (39.7%), anaemia (31.6%), and neutropenia (21.3%). Myelodysplastic syndromes/acute myeloid leukaemia incidence rate (1.2%) was the same for niraparib- and placebo-treated patients. Overall survival remained immature. CONCLUSIONS: Niraparib maintained clinically significant improvements in PFS with 3.5years of follow-up in patients with newly diagnosed advanced ovarian cancer at high risk of progression irrespective of HRD status. No new safety signals were identified.

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.

Antibody-Drug Conjugates in Gynecologic Cancer.

The present article reviews the current evidence for antibody-drug conjugates (ADCs) in gynecologic cancer. ADCs consist of a highly selective monoclonal antibody for a tumor-associated antigen and a potent cytotoxic payload conjugated through a linker. Overall, the toxicity profiles of ADCs are manageable. Ocular toxicity is a known class effect of some ADCs and is managed with prophylactic corticosteroid and vasoconstrictor eye drops as well as dose interruptions/holds and dose modifications. In ovarian cancer, mirvetuximab soravtansine, an ADC targeting alpha-folate receptor (FRα), received US Food and Drug Administration (FDA) accelerated approval in November 2022 after data from the single-arm phase III SORAYA trial. A second ADC targeting FRα, STRO-002, received FDA fast track designation in August 2021. Multiple studies with upifitamab rilsodotin, an ADC comprising a NaPi2B-binding antibody, are underway. In cervical cancer, tisotumab vedotin, an ADC-targeting tissue factor, received FDA accelerated approval in September 2021 after the phase II innovaTV 204 trial. Tisotumab vedotin in combination with chemotherapy and other targeted agents is currently being evaluated. Although there are no currently approved ADCs for endometrial cancer, there are many under active evaluation, including mirvetuximab soravtansine. Trastuzumab-deruxtecan (T-DXd), an ADC targeting human epidermal growth factor receptor 2 (HER2), is currently approved for HER2-positive and HER2-low breast cancer and shows promise in endometrial cancer. Like all anticancer treatments, the decision for a patient to undergo therapy with an ADC is a personal choice that balances the potential benefits with the side effects and requires thorough and compassionate support of their physician and care team and shared decision making.

Biomarker-driven therapy in endometrial cancer.

This article reviews treatments and targets of interest in endometrial cancer by molecular subtype. The Cancer Genome Atlas (TCGA) classifies four molecular subtypes-mismatch repair deficient (dMMR)/microsatellite instability-high (MSI-H); copy number high (CNH)/p53abn; copy number low (CNL)/no specific molecular profile (NSMP); and POLEmut-which are validated and highly prognostic. Treatment consideration by subtype is now recommended. In March and April 2022, respectively, the US Food and Drug Administration (FDA) fully approved and the European Medicines Agency adopted a positive opinion recommending the anti-programmed cell death protein-1 (PD-1) antibody pembrolizumab for advanced/recurrent dMMR/MSI-H endometrial cancer which has progressed on or following a platinum-containing therapy. A second anti-PD-1, dostarlimab, received accelerated approval by the FDA and conditional marketing authorization by the European Medicines Agency in this group. The combination of pembrolizumab/lenvatinib for mismatch repair proficient/microsatellite stable endometrial cancer, including p53abn/CNH and NSMP/CNL, received accelerated FDA approval in conjunction with Australia's Therapeutic Goods Administration and Health Canada in September 2019. The FDA and European Medicines Agency made full recommendations in July 2021 and October 2021. Trastuzumab is National Comprehensive Cancer Network (NCCN) compendium listed for human epidermal growth factor receptor-2-positive serous endometrial cancer, which is primarily within the p53abn/CNH subtype. In addition to hormonal therapy, maintenance therapy with selinexor (exportin-1 inhibitor) showed potential benefit in p53-wildtype cases in a subset analysis and is being investigated prospectively. Other treatment regimens being evaluated in NSMP/CNL are hormonal combinations with cyclin-dependent kinase 4/6 inhibitors and letrozole. Ongoing trials are evaluating immunotherapy in combination with frontline chemotherapy and other targeted agents. Treatment de-escalation is being evaluated in POLEmut cases given its favorable prognosis with or without adjuvant therapy. Molecular subtyping has important prognostic and therapeutic implications, and should guide patient management and clinical trial design in endometrial cancer, which is a molecularly driven disease.