Faculty Bibliography

PURPOSE/OBJECTIVE: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.

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.

BACKGROUND:Tumor next-generation sequencing can identify potential germline pathogenic variants associated with cancer susceptibility. OBJECTIVE:To describe the frequency of tumor sequencing results that met European Society of Medical Oncology (ESMO) recommendations for further germline genetic testing, and the frequency of germline variants among a cohort with gynecologic cancer. METHODS:Patients with gynecologic cancer who underwent tumor sequencing between September 2019 and February 2022 in a large healthcare system in New York City were retrospectively identified. Eligible patients with suspected germline pathogenic variants on tumor sequencing were identified based on ESMO guidelines. Logistic regression was used to explore variables associated with referral and completion of germline testing. RESULTS:Of 358 patients with gynecologic cancers who underwent tumor sequencing, 81 (22.6%) had ≥1 suspected germline variant according to ESMO guidelines. Of the 81 patients with qualifying tumor sequencing results, 56 (69.1%) received germline testing: 41/46 (89.1%) eligible patients with ovarian cancer and 15/33 (45.5%) with endometrial cancer. In the endometrial cancer cohort, 11/33 (33.3%) eligible patients were not referred for germline testing and the majority of these patients had tumor variants in genes commonly known to cause hereditary cancer. Of the 56 patients who underwent germline testing, 40 (71.4%) had pathogenic germline variants. In multivariable analysis, race/ethnicity other than non-Hispanic white was associated with lower odds of germline testing referral and completion (OR=0.1, 95% CI 0.01 to 0.5 and OR=0.2, 95% CI 0.04 to 0.6, respectively). CONCLUSION/CONCLUSIONS:Given the high rate of pathogenic germline variant detection and the importance of identifying such variants for both patients and their family, it is imperative that eligible patients undergo germline testing. Additional education for providers on multidisciplinary guidelines and development of clinical pathways to ensure germline testing of suspected pathogenic variants identified on tumor sequencing is warranted, especially in light of the racial/ethnic inequity observed.

BACKGROUND:Dostarlimab is an immune-checkpoint inhibitor that targets the programmed cell death 1 receptor. The combination of chemotherapy and immunotherapy may have synergistic effects in the treatment of endometrial cancer. METHODS:We conducted a phase 3, global, double-blind, randomized, placebo-controlled trial. Eligible patients with primary advanced stage III or IV or first recurrent endometrial cancer were randomly assigned in a 1:1 ratio to receive either dostarlimab (500 mg) or placebo, plus carboplatin (area under the concentration-time curve, 5 mg per milliliter per minute) and paclitaxel (175 mg per square meter of body-surface area), every 3 weeks (six cycles), followed by dostarlimab (1000 mg) or placebo every 6 weeks for up to 3 years. The primary end points were progression-free survival as assessed by the investigator according to Response Evaluation Criteria in Solid Tumors (RECIST), version 1.1, and overall survival. Safety was also assessed. RESULTS:Of the 494 patients who underwent randomization, 118 (23.9%) had mismatch repair-deficient (dMMR), microsatellite instability-high (MSI-H) tumors. In the dMMR-MSI-H population, estimated progression-free survival at 24 months was 61.4% (95% confidence interval [CI], 46.3 to 73.4) in the dostarlimab group and 15.7% (95% CI, 7.2 to 27.0) in the placebo group (hazard ratio for progression or death, 0.28; 95% CI, 0.16 to 0.50; P<0.001). In the overall population, progression-free survival at 24 months was 36.1% (95% CI, 29.3 to 42.9) in the dostarlimab group and 18.1% (95% CI, 13.0 to 23.9) in the placebo group (hazard ratio, 0.64; 95% CI, 0.51 to 0.80; P<0.001). Overall survival at 24 months was 71.3% (95% CI, 64.5 to 77.1) with dostarlimab and 56.0% (95% CI, 48.9 to 62.5) with placebo (hazard ratio for death, 0.64; 95% CI, 0.46 to 0.87). The most common adverse events that occurred or worsened during treatment were nausea (53.9% of the patients in the dostarlimab group and 45.9% of those in the placebo group), alopecia (53.5% and 50.0%), and fatigue (51.9% and 54.5%). Severe and serious adverse events were more frequent in the dostarlimab group than in the placebo group. CONCLUSIONS:Dostarlimab plus carboplatin-paclitaxel significantly increased progression-free survival among patients with primary advanced or recurrent endometrial cancer, with a substantial benefit in the dMMR-MSI-H population. (Funded by GSK; RUBY ClinicalTrials.gov number, NCT03981796.).

PURPOSE OF REVIEW:This article reviews treatment strategies in endometrial cancer by molecular subtype. RECENT FINDINGS:The Cancer Genome Atlas (TCGA) classifies four molecular subtypes of endometrial cancer - 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. FDA-approved immune checkpoint inhibitors (ICIs) include pembrolizumab and dostarlimab for previously treated dMMR/MSI-H EC, and pembrolizumab/lenvatinib for mismatch repair-proficient/microsatellite-stable endometrial cancer, including CNH/p53abn and CNL/NSMP. ICIs are being studied as first-line therapy in advanced/recurrent endometrial cancer by MMR status, as well as in combination with other targeted agents. Trastuzumab is NCCN compendium listed for HER2-positive serous endometrial cancer, which are primarily p53-abnormal. Antibody-drug conjugates targeting low and high HER2 levels show promise in breast cancer, and are beginning to be studied in endometrial cancer. In addition to hormonal therapy, maintenance therapy with selinexor (XPO1-inhibitor) showed potential benefit in p53 -wildtype endometrial cancer and is being investigated prospectively. Multiple prospective trials are evaluating de-escalation of care for POLEmut endometrial cancer given favorable survival regardless of adjuvant therapy. SUMMARY:Molecular subtyping has important prognostic and therapeutic implications and should be guiding patient management and clinical trial design in endometrial 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.

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.

OBJECTIVE:The real-world management of patients with non-BRCA, homologous recombination repair pathway variants with increased or uncertain risks of ovarian cancer is unknown. The objective was to determine the adoption of risk-reducing salpingo-oophorectomy (RRSO) for carriers of variants with increased or uncertain risks of ovarian cancer beyond BRCA. METHODS:This was a retrospective cohort study of patients at three hospitals with non-BRCA, homologous recombination repair pathway variants with increased risk (BRIP1, RAD51C, RAD51D) and uncertain risk (ATM, BARD1, NBN, PALB2) of ovarian cancer. Outcomes of interest were adoption of RRSO and factors associated with adoption of RRSO. Wilcoxon rank-sum, chi-square, and logistic regression were performed with p < 0.05. RESULTS:Of 318 patients, 76 (24%) had pathogenic variants with increased risks of ovarian cancer (BRIP1, 45; RAD51C, 20; RAD51D, 11), and 242 (76%) had variants with uncertain risks of ovarian cancer (ATM, 145; PALB2, 69; NBN, 23; BARD1, 5). Of 64 patients eligible for RRSO by National Comprehensive Cancer Network (NCCN) criteria or family history, 31 (48%) underwent RRSO. Among eligible patients who did not undergo RRSO, 24 (73%) were not referred for gynecologic oncology consultation. Older age at testing (adjusted odds ratio [aOR] 1.08, 95% confidence interval [CI] 1.03-1.13) and referral to gynecologic oncology (aOR 33.48, CI 8.10-138.39) were associated with increased adoption of RRSO when adjusting for personal and family history of breast and ovarian cancer. CONCLUSION/CONCLUSIONS:Half of RRSO-eligible patients by NCCN criteria beyond BRCA did not undergo RRSO. Opportunities exist for improving education to increase referrals to facilitate RRSO for these patients.