Lenvatinib plus Pembrolizumab for Advanced Endometrial Cancer.

BACKGROUND: Standard therapy for advanced endometrial cancer after failure of platinum-based chemotherapy remains unclear. METHODS: In this phase 3 trial, we randomly assigned, in a 1:1 ratio, patients with advanced endometrial cancer who had previously received at least one platinum-based chemotherapy regimen to receive either lenvatinib (20 mg, administered orally once daily) plus pembrolizumab (200 mg, administered intravenously every 3 weeks) or chemotherapy of the treating physician's choice (doxorubicin at 60 mg per square meter of body-surface area, administered intravenously every 3 weeks, or paclitaxel at 80 mg per square meter, administered intravenously weekly [with a cycle of 3 weeks on and 1 week off]). The two primary end points were progression-free survival as assessed on blinded independent central review according to the Response Evaluation Criteria in Solid Tumors, version 1.1, and overall survival. The end points were evaluated in patients with mismatch repair-proficient (pMMR) disease and in all patients. Safety was also assessed. RESULTS: A total of 827 patients (697 with pMMR disease and 130 with mismatch repair-deficient disease) were randomly assigned to receive lenvatinib plus pembrolizumab (411 patients) or chemotherapy (416 patients). The median progression-free survival was longer with lenvatinib plus pembrolizumab than with chemotherapy (pMMR population: 6.6 vs. 3.8 months; hazard ratio for progression or death, 0.60; 95% confidence interval [CI], 0.50 to 0.72; P<0.001; overall: 7.2 vs. 3.8 months; hazard ratio, 0.56; 95% CI, 0.47 to 0.66; P<0.001). The median overall survival was longer with lenvatinib plus pembrolizumab than with chemotherapy (pMMR population: 17.4 vs. 12.0 months; hazard ratio for death, 0.68; 95% CI, 0.56 to 0.84; P<0.001; overall: 18.3 vs. 11.4 months; hazard ratio, 0.62; 95% CI, 0.51 to 0.75; P<0.001). Adverse events of grade 3 or higher occurred in 88.9% of the patients who received lenvatinib plus pembrolizumab and in 72.7% of those who received chemotherapy. CONCLUSIONS: Lenvatinib plus pembrolizumab led to significantly longer progression-free survival and overall survival than chemotherapy among patients with advanced endometrial cancer. (Funded by Eisai and Merck Sharp and Dohme [a subsidiary of Merck]; Study 309-KEYNOTE-775 ClinicalTrials.gov number, NCT03517449.).

Decreased HER2 expression in endometrial cancer following anti-HER2 therapy.

Trastuzumab has demonstrated clinical efficacy in the treatment of HER2-positive serous endometrial cancer (EC), which led to its incorporation into standard-of-care management of this aggressive disease. Acquired resistance remains an important challenge, however, and its underlying mechanisms in EC are unknown. To define the molecular changes that occur in response to anti-HER2 therapy in EC, targeted next-generation sequencing (NGS), HER2 immunohistochemistry (IHC), and fluorescence in situ hybridization (FISH) were performed on pre- and post-treatment tumour samples from 14 patients with EC treated with trastuzumab or trastuzumab emtansine. Recurrent tumours after anti-HER2 therapy acquired additional genetic alterations compared with matched pre-treatment ECs and frequently showed decreased HER2 protein expression by IHC (7/14, 50%). Complete/near-complete absence of HER2 protein expression (score 0/1+) observed post-treatment (4/14, 29%) was associated with retained HER2 gene amplification (n = 3) or copy number neutral status (n = 1). Whole-exome sequencing performed on primary and recurrent tumours from the latter case, which exhibited genetic heterogeneity of HER2 amplification in the primary tumour, revealed selection of an early HER2-non-amplified clone following therapy. Our findings demonstrate that loss of target expression, by selection of HER2-non-amplified clones or, more commonly, by downregulation of expression, may constitute a mechanism of resistance to anti-HER2 therapy in HER2-positive EC. © 2023 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Pathogenic germline variants in patients with endometrial cancer of diverse ancestry.

BACKGROUND: Racial disparities in outcomes exist in endometrial cancer (EC). The contribution of ancestry-based variations in germline pathogenic variants (gPVs) is unknown. METHODS: Germline assessment of ≥76 cancer predisposition genes was performed in patients with EC undergoing tumor-normal Memorial Sloan Kettering Cancer Center Integrated Mutation Profiling of Actionable Cancer Targets sequencing from January 1, 2015 through June 30, 2021. Self-reported race/ethnicity and Ashkenazi Jewish ancestry data classified patients into groups. Genetic ancestry was inferred from Memorial Sloan Kettering Cancer Center Integrated Mutation Profiling of Actionable Cancer Targets. Rates of gPV and genetic counseling were compared by ancestry. RESULTS: Among 1625 patients with EC, 216 (13%) had gPVs; 15 had >1 gPV. Rates of gPV varied by self-reported ancestry (Ashkenazi Jewish, 40/202 [20%]; Asian, 15/124 [12%]; Black/African American (AA), 12/171 [7.0%]; Hispanic, 15/124 [12%]; non-Hispanic (NH) White, 129/927 [14%]; missing, 5/77 [6.5%]; p = .009], with similar findings by genetic ancestry (p < .001). We observed a lower likelihood of gPVs in patients of Black/AA (odds ratio [OR], 0.44; 95% CI, 0.22-0.81) and African (AFR) ancestry (OR, 0.42; 95% CI, 0.18-0.85) and a higher likelihood in patients of Ashkenazi Jewish genetic ancestry (OR, 1.62; 95% CI; 1.11-2.34) compared with patients of non-Hispanic White/European ancestry, even after adjustment for age and molecular subtype. Somatic landscape influenced gPVs with lower rates of microsatellite instability-high tumors in patients of Black/AA and AFR ancestry. Among those with newly identified gPVs (n = 114), 102 (89%) were seen for genetic counseling, with lowest rates among Black/AA (75%) and AFR patients (67%). CONCLUSIONS: In those with EC, gPV and genetic counseling varied by ancestry, with lowest rates among Black/AA and AFR patients, potentially contributing to disparities in outcomes given implications for treatment and cancer prevention. PLAIN LANGUAGE SUMMARY: Black women with endometrial cancer do worse than White women, and there are many reasons for this disparity. Certain genetic changes from birth (mutations) can increase the risk of cancer, and it is unknown if rates of these changes are different between different ancestry groups. Genetic mutations in 1625 diverse women with endometrial cancer were studied and the lowest rates of mutations and genetic counseling were found in Black and African ancestry women. This could affect their treatment options as well as their families and may make disparities worse.

Characterization and Management of Adverse Reactions in Patients With Advanced Endometrial Cancer Receiving Lenvatinib Plus Pembrolizumab.

BACKGROUND: Lenvatinib plus pembrolizumab significantly improved efficacy compared with chemotherapy in patients with advanced endometrial cancer (aEC) regardless of microsatellite instability status or histologic subtype, who had disease progression following prior platinum-based therapy, in Study-309/KEYNOTE-775. The safety profile of the combination was generally consistent with that of each monotherapy drug and of the combination in patients with endometrial cancer and other solid tumors. Given the medical complexity of patients with aEC, this paper aims to characterize key adverse reactions (ARs) of the combination treatment and review management strategies, providing a guide for AR management to maximize anticancer benefits and minimize treatment discontinuation. MATERIALS AND METHODS: In Study-309/KEYNOTE-775, patients received lenvatinib (20 mg orally once daily) plus pembrolizumab (200 mg intravenously every 3 weeks) or chemotherapy (doxorubicin or paclitaxel). The incidence and median time to the first onset of ARs, dose modifications, and concomitant medications are described. Key ARs characterized include hypothyroidism, hypertension, fatigue, diarrhea, musculoskeletal disorders, nausea, decreased appetite, vomiting, stomatitis, weight decreased, proteinuria, and palmar-plantar erythrodysesthesia syndrome. RESULTS: As expected, the most common any-grade key ARs included: hypothyroidism, hypertension, fatigue, diarrhea, and musculoskeletal disorders. Grades 3-4 key ARs with incidence ≥10% included: hypertension, fatigue, and weight decreased. Key ARs first occurred within approximately 3 months of treatment initiation. AR management strategies consistent with the prescribing information and the study protocol are discussed. CONCLUSION: Successful AR management strategies for lenvatinib plus pembrolizumab include education of the patient and entire treatment team, preventative measures and close monitoring, and judicious use of dose modifications and concomitant medications. CLINICALTRIALS.GOV ID: NCT03517449.

Impact of adjuvant therapy on oncologic outcomes in uterine-confined clear cell carcinoma of the endometrium.

OBJECTIVES: To determine the impact of adjuvant therapy on oncologic outcomes in patients with 2009 International Federation of Gynecology and Obstetrics (FIGO) stage IA, IB, or II endometrial clear cell carcinoma (ECCC). METHODS: We conducted a retrospective review at 4 international institutions. Patients with newly diagnosed clinical stage I or II disease of either clear cell or mixed histology with a clear cell component treated between 01/01/2000-12/31/2015 were included. Oncologic outcomes were assessed for patients based on adjuvant treatment received, including chemotherapy, radiation, or chemotherapy with radiation. RESULTS: Of 125 patients identified and analyzed, 77 (61.6%) had clear cell histology and 118 (94.4%) had stage I disease. Median age at diagnosis was 65 years (range, 33-91). All patients underwent hysterectomy, bilateral salpingo-oophorectomy, and lymph node assessment. Twenty-five patients (20.0%) underwent surgical management alone and 100 (80.0%) received adjuvant therapy: 20 (16.0%) received postoperative chemotherapy, 47 (37.6%) received postoperative radiation, and 33 (26.4%) received postoperative chemotherapy with radiation. Median follow-up was 88.4 months (range, <1-234). Progression-free survival (PFS) or overall survival (OS) did not significantly differ between surgery alone and type of adjuvant therapy (P = 0.18 and P = 0.56, respectively). Patients with mixed ECCC did not have a survival advantage over those with pure ECCC (5-year PFS rate, 85.0% vs 82.7%, P = 0.77; 5-year OS rate, 88.3% vs 91.2%, P = 0.94). CONCLUSIONS: Receipt of adjuvant therapy in surgically staged I/II ECCC did not appear to offer a survival advantage over observation alone. Adjuvant therapy in early-stage ECCC with consideration of molecular classification should be evaluated.

A phase 2 trial of zanidatamab in HER2-overexpressed advanced endometrial carcinoma and carcinosarcoma (ZW25-IST-2).

OBJECTIVE: HER2 overexpression is associated with decreased overall survival in metastatic endometrial cancer. Trastuzumab with chemotherapy has demonstrated efficacy for first-line management of advanced HER2+ endometrial carcinoma, but HER2-directed therapy in the recurrent setting is limited. Zanidatamab (ZW25), a humanized, bispecific antibody that simultaneously binds the 2 distinct HER2 epitopes bound by trastuzumab and pertuzumab, has demonstrated safety and activity in HER2+ tumors. Here, we report the results of a phase 2, open-label study evaluating the efficacy and safety of zanidatamab in patients with HER2+ metastatic endometrial carcinoma/carcinosarcoma who received prior treatment. METHODS: We enrolled 16 patients with HER2+ endometrial carcinoma/carcinosarcoma after progression on ≤2 lines of therapy on a single-arm phase 2 study of zanidatamab. The primary endpoint was overall response rate (ORR; complete or partial response) by Response Evaluation Criteria in Solid Tumors version 1.1. HER2 immunohistochemistry and fluorescence in situ hybridization (FISH) were performed on pretreatment samples. Intratumor HER2 genetic heterogeneity was assessed. RESULTS: This study did not meet its primary efficacy endpoint. Although a clinical benefit rate of 37.5% was observed by 24 weeks, only 1 patient achieved a partial response (ORR, 6.2%). Eight patients had HER2 intratumor heterogeneity or lacked HER2 amplification by FISH. Decreased HER2 expression on repeat pretreatment samples was observed in 3 (75%) of 4 patients evaluated. CONCLUSIONS: We observed a low response rate to zanidatamab in recurrent HER2+ endometrial carcinoma/carcinosarcoma, which may be driven by downregulation of HER2 expression. Repeat HER2 testing should be considered prior to second-line HER2-directed therapy. CLINICALTRIALS: govidentifier: NCT04513665.

Basket study of oral progesterone antagonist onapristone extended release in progesterone receptor-positive recurrent granulosa cell, low-grade serous ovarian cancer, or endometrioid endometrial cancer.

OBJECTIVE: To determine the safety and efficacy of the oral progesterone antagonist onapristone extended release (onapristone-XR) in patients with recurrent progesterone receptor (PR)-positive adult-type granulosa cell tumor (aGCT), low-grade serous ovarian cancer (LGSOC), or endometrioid endometrial cancer (EEC). METHODS: This single-institution phase II study included patients with PR-positive aGCT, LGSOC, or EEC who received ≥1 prior line of chemotherapy. Patients were enrolled from 5/2019-5/2020. PR status was evaluated via immunohistochemistry. Eligible patients had PR expression ≥1% on tissue collected within 3 years of enrollment. Patients received 50 mg of onapristone-XR twice daily until disease progression or treatment discontinuation. Adverse events were graded by Common Terminology Criteria for Adverse Events version 5.0. The primary endpoint was overall response rate (ORR) by Response Evaluation Criteria in Solid Tumors 1.1. Secondary endpoints were response duration, clinical benefit rate (CBR), and safety. RESULTS: Five patients with LGSOC and 1 with EEC enrolled, but both cohorts closed early due to slow accrual. Fourteen patients with aGCT enrolled and completed stage 1 accrual. No responses were observed. Four patients with LGSOC were evaluable, with median PFS of 4.4 months (range, 1.8-NE) and CBR of 50% (range, 6.8%-93.2%). All 14 patients with aGCT were evaluable, with median PFS of 2.8 months (range, 1.6-4.9), 6-month PFS rate of 21.4% (range, 5.2%-44.8%), 12-month PFS rate of 14.3% (range, 2.3%-36.6%), and a CBR of 35.7% (range, 12.8%-64.9%). CONCLUSIONS: The study did not meet its primary endpoint. While onapristone-XR was well tolerated in all 3 arms, no objective responses were observed.

Long-term follow-up of efficacy and safety of selinexor maintenance treatment in patients with TP53wt advanced or recurrent endometrial cancer: A subgroup analysis of the ENGOT-EN5/GOG-3055/SIENDO study.

OBJECTIVE: To report long-term efficacy and safety of selinexor maintenance therapy in adults with TP53 wild-type (TP53wt) stage IV or recurrent endometrial cancer (EC) who achieved partial remission (PR) or complete remission (CR) following chemotherapy. METHODS: Analysis of the prespecified, exploratory subgroup of patients with TP53wt EC from the phase 3 SIENDO study was performed. Progression-free survival (PFS) benefit in patients with TP53wt EC and across other patient subgroups were exploratory endpoints. Safety and tolerability were also assessed. RESULTS: Of the 263 patients enrolled in the SIENDO trial, 113 patients had TP53wt EC; 70/113 (61.9%) had TP53wt/proficient mismatch repair (pMMR) EC, and 29/113 (25.7%) had TP53wt/deficient mismatch repair (dMMR) EC. As of April 1, 2024, the median PFS (mPFS) for TP53wt patients who received selinexor compared with placebo was 28.4 versus 5.2 months (36.8-month follow-up, HR 0.44; 95% CI 0.27-0.73). A benefit in mPFS was seen with selinexor versus placebo regardless of MMR status (patients with TP53wt/pMMR EC: 39.5 vs 4.9 months, HR 0.36; 95% CI 0.19-0.71; patients with TP53wt/dMMR EC: 13.1 vs 3.7 months, HR 0.49; 95% CI 0.18-1.34). Selinexor treatment was generally manageable, with no new safety signals identified. CONCLUSION: In the phase 3 SIENDO study, selinexor maintenance therapy showed a promising efficacy signal and a manageable safety profile in the prespecified subgroup of patients with TP53wt EC who achieved a PR or CR following chemotherapy. These results are being further evaluated in an ongoing randomized phase 3 trial (NCT05611931).

Oncologic outcomes based on lymphovascular space invasion in node-negative FIGO 2009 stage I endometrioid endometrial adenocarcinoma: a multicenter retrospective cohort study.

BACKGROUND: The 2023 International Federation of Gynecology and Obstetrics (FIGO) staging system includes lymphovascular invasion quantification as a staging criterion for endometrioid endometrial carcinomas; no lymphovascular invasion and focal invasion (≤4 vessels involved) are grouped as one category, and substantial invasion as another. OBJECTIVE: To assess the association between lymphovascular invasion and oncologic outcomes. METHODS: We retrospectively identified patients with FIGO 2009 stage I endometrioid endometrial cancer treated surgically with total hysterectomy and lymph node assessment at two tertiary care centers between January 1, 2012, and December 31, 2019. Lymphovascular space invasion was categorized as focal (<5 vessels involved), substantial (≥5 vessels involved), and no lymphovascular invasion using WHO criteria. RESULTS: Of 1555 patients included, 65 (4.2%) had substantial, 119 (7.7%) had focal, and 1371 (88.2%) had no lymphovascular invasion. Median age was 64 years (range 24-92). Thirty-five patients (53.8%) with substantial, 44 (37%) with focal, and 115 (8.4%) with no lymphovascular invasion had stage IB disease (p<0.001); 21 (32.3%) with substantial, 24 (20.2%) with focal, and 91 (6.6%) with no lymphovascular invasion had grade 3 disease (p<0.001). Thirty-six patients (55.4%) with substantial, 80 (67.2%) with focal, and 207 (15.1%) with no lymphovascular invasion received adjuvant treatment (p<0.001). Median follow-up was 61.5 months (range 0.8-133.9). Five-year progression-free survival rates were 68.7% (substantial), 70.5% (focal), and 90.7% (no invasion) (p<0.001). On multivariate analysis, any lymphovascular invasion was associated with increased risk of progression/death (adjusted HR (aHR)=1.84 (95% CI 1.73 to 1.96) for focal; 2.17 (95% CI 1.96 to 2.39) for substantial). Compared with focal, substantial lymphovascular invasion was associated with an aHR for disease progression of 1.18 (95% CI 1.00 to 1.39). CONCLUSIONS: Focal and substantial lymphovascular invasion were associated with increased risk of disease progression and do not appear to be prognostically distinct. Focal versus no lymphovascular invasion have different prognostic outcomes and should not be combined into one category.

Prognosis of isolated tumor cells and use of molecular classification in early stage endometrioid endometrial cancer.

OBJECTIVE: We assessed the prognosis and molecular subtypes of early stage endometrioid endometrial cancer with isolated tumor cells within sentinel lymph nodes (SLNs) compared with node negative disease. METHODS: Patients diagnosed with stage IA, IB, or II endometrioid endometrial cancer and primary surgical management were identified from January 1, 2007 to December 31, 2019. All SLNs underwent ultrastaging according to the institutional protocol. Patients with cytokeratin positive cells, micrometastases, and macrometastases were excluded. Clinical, pathology, and molecular subtype data were reviewed. RESULTS: Overall, 1214 patients with early stage endometrioid endometrial cancer met the inclusion criteria, of whom 1089 (90%) had node negative disease and 125 (10%) had isolated tumor cells. Compared with node negative disease, the presence of isolated tumor cells had a greater association with deep myometrial invasion, lymphovascular space invasion, receipt of adjuvant therapy, and adjuvant chemotherapy with or without radiation (p<0.01). There was no significant difference in survival rates between patients with isolated tumor cells and node negative disease (3 year progression free survival rate 94% vs 91%, respectively, p=0.21; 3 year overall survival rate 98% vs 96%, respectively, p=0.45). Progression free survival did not significantly differ among patients with isolated tumor cells who received no adjuvant therapy or chemotherapy with or without radiation (p=0.31). There was no difference in the distribution of molecular subtypes between patients with isolated tumor cells (n=28) and node negative disease (n=194; p=0.26). Three year overall survival rates differed significantly when stratifying the entire cohort by molecular subtype (p=0.04). CONCLUSIONS: Patients with isolated tumor cells demonstrated less favorable uterine pathologic features and received more adjuvant treatment with similar survival compared with patients with nodenegative disease. Among the available data, molecular classification did not have a significant association with the presence of isolated tumor cells, although copy number-high status was a poor prognostic indicator in early stage endometrioid endometrial cancer.

Procedural interventions for oligoprogression during treatment with immune checkpoint blockade in gynecologic malignancies: a case series.

OBJECTIVE: To evaluate the feasibility and outcomes of performing procedural interventions, defined as surgical resection, tumor ablation, or targeted radiation therapy, for oligoprogressive disease among patients with gynecologic malignancies who are treated with immune checkpoint blockade. METHODS: Patients with gynecologic cancers treated with immune checkpoint blockade between January 2013 and October 2021 who underwent procedural interventions including surgical resection, interventional radiology ablation, or radiation therapy for oligoprogressive disease were identified. Procedures performed before immune checkpoint therapy initiation or ≥6 months after therapy completion were excluded. Long immunotherapy duration prior to intervention was defined as ≥6 months. Progression-free survival and overall survival were calculated from procedure date until disease progression or death, respectively. RESULTS: During the study period, 886 patients met inclusion criteria and received immune checkpoint blockade therapy. Of these, 34 patients underwent procedural interventions for oligoprogressive disease; 7 underwent surgical resection, 3 underwent interventional radiology ablation, and 24 underwent radiation therapy interventions. Primary disease sites included uterus (71%), ovary (24%), and cervix (6%). Sites of oligoprogression included abdomen/pelvis (26%), bone (21%), lung (18%), distant lymph node (18%), brain (9%), liver (6%), and vagina (3%). Most tumors (76%) did not exhibit microsatellite instability or mismatch repair deficiency. Approximately half (53%) of the patients had long immune checkpoint therapy duration prior to intervention. Median progression-free survival following the procedure was 5.3 months (95% CI, 3.1-9.9), and median overall survival was 21.7 months (95% CI, 14.9-not estimable). Long versus short immune checkpoint therapy duration prior to procedure and length of immune checkpoint therapy had no effect on progression-free or overall survival. CONCLUSIONS: Procedural interventions for patients with oligoprogression on immune checkpoint blockade therapy are feasible and demonstrate favorable outcomes. With expanding use of immune checkpoint therapy, it is important to investigate combined modalities to maximize therapeutic benefit for patients with gynecologic cancers.

Long-term outcomes of patients with recurrent ovarian cancer treated with a polyvalent vaccine with bevacizumab combination.

BACKGROUND: To characterize the safety, immunogenicity, and outcomes of patients with high-grade serous ovarian cancer (HGSOC) in second or greater remission treated with a polyvalent antigen-KLH plus OPT-821 vaccine construct and bevacizumab. METHODS: Patients with recurrent HGSOC were treated with the vaccine plus bevacizumab at our institution from 01/05/2011 to 03/20/2012. Follow-up continued until 03/2021. Blood/urine samples were collected. "Responders" had an immunogenic response to ≥ 3 antigens; "non-responders" to ≤ 2 antigens. RESULTS: Twenty-one patients were treated on study. One developed a dose-limiting toxicity (grade 4 fever). Two (10%) experienced bevacizumab-related grade 3 hypertension. Thirteen (68%) and 16 (84%) of 19 responded to ≥ 3 and ≥ 2 antigens, respectively (Globo-H, GM2, TF cluster Tn, MUC-1). Four of 21 patients were alive > 5 years post-treatment. Responders and non-responders had a median PFS of 4.9 months (95% CI: 2.8-8.1) and 5.0 months (95% CI: 0.7-cannot estimate), respectively; median OS was 30.7 months (95% CI: 16.9-52.0) and 34.2 months (95% CI: 12.8-cannot estimate), respectively. On two-timepoint analysis (baseline, week 17), increased IL-8 exhibited improved PFS (HR as 10-unit increase, 0.43; p = 0.04); increased PDGF exhibited worse OS (HR as 10-unit increase, 1.01; p = 0.02). CONCLUSIONS: This is the longest follow-up of vaccine administration with bevacizumab in patients with ovarian cancer. The vaccine was well tolerated with bevacizumab. Response was not associated with improved survival. On two-timepoint analysis, increased IL-8 was associated with significant improvement in PFS; increased PDGF with significantly worse OS. For all timepoint measurements, cytokine levels were not significantly associated with survival. TRIAL REGISTRATION: NCT01223235.

HER2 Genetic Intratumor Heterogeneity Is Associated With Resistance to Trastuzumab and Trastuzumab Emtansine Therapy in Recurrent High-Grade Endometrial Cancer.

Anti-HER2 targeted therapies have recently demonstrated clinical activity in the treatment of high-grade endometrial carcinomas (ECs), particularly serous carcinomas with HER2 amplification and/or overexpression. Intratumor heterogeneity of HER2 amplification or HER2 genetic intratumor heterogeneity (G-ITH) has been associated with resistance to anti-HER2 therapies in breast and gastroesophageal cancers; however, its clinical relevance in EC is unknown. To characterize HER2 G-ITH in EC, archival specimens from a clinically annotated cohort of 57 ECs treated with trastuzumab or trasutuzmab emtansine in the recurrent (n = 38) or adjuvant (n = 19) setting were subjected to central pathology review, HER2 assessment by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH), and next-generation sequencing. HER2 G-ITH, defined as HER2 amplification in 5% to 50% of tumor cells examined by FISH, was identified in 36% (19/53) of ECs and was associated with lower HER2 copy number and levels of protein expression. HER2 IHC revealed spatially distinct areas of strong expression juxtaposed with areas of low/absent expression in tumors with the "cluster" pattern of G-ITH, whereas the "mosaic" pattern was typically associated with a diffuse admixture of cells with variable levels of HER2 expression. HER2 G-ITH was frequently observed in cases with IHC/FISH or FISH/next-generation sequencing discrepancies and/or with an equivocal/negative FISH result (9/13, 69%). Although the objective response rate to anti-HER2 therapy in recurrent ECs was 52% (13/25) for tumors lacking HER2 G-ITH, none (0%, 0/10) of the patients with HER2 G-ITH achieved a complete or partial response (P = .005). HER2 G-ITH was significantly associated with worse progression-free survival (hazard ratio, 2.88; 95% CI, 1.33-6.27; P = .005) but not overall survival. HER2 IHC score, HER2/CEP17 ratio, HER2 copy number, histologic subtype, and other genetic alterations, including PIK3CA hotspot mutations, were not significantly associated with therapeutic response or survival outcomes. Treatment responses were not restricted to serous carcinomas, supporting consideration of anti-HER2 therapy in patients with HER2-positive high-grade ECs of non-serous histology. Our results demonstrate that HER2 G-ITH is an important determinant of response to trastuzumab and trastuzumab emtansine in EC, providing a rationale for the development of novel therapeutic strategies to target HER2-nonamplified resistant tumor subpopulations, such as HER2 antibody-drug conjugates with bystander effects.

Tyrosine kinase inhibitor toxicities: A society of gynecologic oncology review and recommendations.

OBJECTIVE: Oral tyrosine kinase inhibitors (TKIs) have new indications for treatment in gynecologic malignancies. These targeted drugs have both unique and overlapping toxicities, which require careful attention and management. New combination therapies with immune-oncology agents have demonstrated promise in endometrial cancer. This review examines common adverse events associated with TKIs and provides readers with an evidence-based review on current uses and strategies for the management of these medications. METHODS: A comprehensive review of the medical literature on TKI use in gynecologic cancer was undertaken by a committee approach. Details of each drug, its molecular target, and relevant data on both clinical efficacy and side effects were compiled and organized for clinical use. Information on drug-related secondary effects and management strategies for specific toxicities, including dose reduction and concomitant medications, were gathered. RESULTS: TKIs can potentially offer improved response rates and durable responses for a group of patients who were previously without an effective standard second-line therapy. The combination of lenvatinib and pembrolizumab represents a more targeted approach to the drivers of endometrial cancer; however, there remains significant drug-related toxicity, and thus dose reduction and dose delay are frequently required. Toxicity management requires frequent check-ins and management strategies to help patients find the highest tolerable dose. TKIs are expensive and patient financial toxicity is as critical a measure of a drug's utility as any drug side effect. Many of these drugs have patient assistance programs, which should be fully utilized to minimize cost. CONCLUSIONS: Future studies are needed to expand the role of TKIs into new molecularly driven groups. Attention to cost, durability of response, and long-term toxicity management is needed to ensure all eligible patients have access to treatment.

Adverse events and oncologic outcomes with combination lenvatinib and pembrolizumab for the treatment of recurrent endometrial cancer.

OBJECTIVE: To evaluate adverse events (AEs) of combination lenvatinib plus pembrolizumab for the treatment of recurrent endometrial cancer (EC) and to assess outcomes by lenvatinib starting dose. METHODS: We retrospectively reviewed patients with recurrent EC treated with lenvatinib plus pembrolizumab at our institution between 10/1/2019-11/30/2021. Starting dose of lenvatinib was defined as standard (20 mg) or reduced (10 mg/14 mg). AEs were manually extracted through chart review and graded using Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. PFS, overall survival (OS), and duration of response (DOR) were analyzed. RESULTS: Forty-three patients were identified; median age was 67 years (range, 54-85). The most common histologies were serous (35%), endometrioid (23%), and carcinosarcoma (21%). Starting lenvatinib doses were 10 mg (n = 10), 14 mg (n = 10), and 20 mg (n = 23). Median number of cycles received was 8 (range, 1-42). Twenty-four patients (56%) required ≥1 lenvatinib dose reduction; 3 (7%) discontinued lenvatinib, and 1 (2%) discontinued pembrolizumab for intolerance or AE. Thirty-six patients (84%) experienced grade ≥ 3 AEs; hypertension, weight loss, anemia, fatigue, and thrombocytopenia were most common. The standard dose group experienced significantly shorter observed PFS vs the reduced dose group (P = .02). There was no difference in DOR (P = .09) or OS (P = .27) between the groups. CONCLUSION: In clinical practice, AEs associated with combination lenvatinib plus pembrolizumab were common and comparable to Study 309/KEYNOTE-775 findings. AEs were similar regardless of starting lenvatinib dose. Further dose optimization studies of lenvatinib plus pembrolizumab may be indicated in recurrent EC. Clinical trial data remain the gold standard to guide starting lenvatinib dosing.

Isolated vaginal recurrence in women with stage I endometrial cancer.

OBJECTIVE: To compare clinical and pathologic characteristics of women with surgical stage I endometrial carcinoma by location of first recurrence and describe characteristics of isolated vaginal recurrence. METHODS: Patients with 2009 International Federation of Obstetrics and Gynecology (FIGO) stage I endometrial carcinoma treated at two large cancer centers from 1/1/2009-12/31/2017 were identified. Sarcoma histology was excluded. Recurrences were grouped into isolated vaginal or extravaginal. Isolated vaginal recurrences were localized by anatomic location within the vaginal vault. Clinical and pathologic variables were compared with chi-square analysis, and Kaplan-Meier curves with log-rank tests. RESULTS: Of 2815 women identified, 278 (10%) experienced a recurrence. Sixty-one patients (2%) had an isolated vaginal recurrence, including 42 (69%) at the vaginal apex; 217 (8%) had an extravaginal recurrence, including 18 with a vaginal component. Median time to recurrence was 11 months (range, 1-68) for isolated vaginal recurrence and 20 months (range, 1-98) for extravaginal recurrence (P < .004). Of 960 patients (34%) treated with adjuvant vaginal brachytherapy (VBT), 156 (16%) recurred; 19 (2%) had an isolated vaginal recurrence, including 16 (84%) at the vaginal apex. Three-year PFS rates for isolated vaginal recurrence were 97.6% (SE ± 0.4%) with minimally invasive surgery (MIS) versus 96.9% (SE ± 1.1%) with open (P = .8), and for extravaginal recurrence were 91.8% (SE ± 0.7%) with MIS versus 90.8% (SE ± 1.8%) with open (P = .8). CONCLUSIONS: Isolated vaginal recurrences in stage I endometrial cancer are detected earlier than non-vaginal recurrences. Surgical approach does not appear to impact recurrence. Adjuvant VBT after primary surgery carries a 1%-2% risk of isolated vaginal apex recurrence.

Laparoscopy with or without robotic assistance does not negatively impact long-term oncologic outcomes in patients with uterine serous carcinoma.

OBJECTIVES: We sought to compare outcomes between minimally invasive surgery (MIS) and laparotomy in patients with clinical stage I uterine serous carcinoma (USC). METHODS: Patients who underwent surgery for newly diagnosed USC between 11/1/1993 and 12/31/2017 were retrospectively identified and assigned to either the MIS cohort or the laparotomy cohort. Patients with conversion to laparotomy were analyzed with the MIS cohort. Chi-square and Mann-Whitney tests were used to compare categorical and continuous variables, respectively. Kaplan-Meier curves were used to estimate survival and compared using the log-rank test. RESULTS: In total, 391 patients met inclusion criteria; 242 underwent MIS (35% non-robotic and 65% robotic-assisted laparoscopies) and 149 underwent laparotomy. Age, BMI, stage, and washings status did not differ between cohorts. Patients who underwent MIS were less likely to have lymphovascular space invasion (LVSI; 35.1% vs 48.3%), had fewer nodes removed (median, 9 vs 15), and lower rates of paraaortic nodal dissection (44.6% vs 65.1%). Rates of adjuvant therapy did not differ between cohorts. Median follow-up times were 63.0 months (MIS cohort) vs 71.0 months (laparotomy cohort; P = .04). Five-year PFS rates were 58.7% (MIS) vs 59.8% (laparotomy; P = .1). Five-year OS rates were 65.2% (MIS) compared to 63.5% (laparotomy; P = .2). On multivariable analysis, higher stage, deep myometrial invasion, and positive washings were associated with decreased PFS. Age ≥ 65 years, higher stage, LVSI, and positive washings were associated with shorter OS. CONCLUSIONS: MIS does not compromise outcomes in patients with newly diagnosed USC and should be offered to these patients to minimize surgical morbidity.

A randomized phase 2 study of sapanisertib in combination with paclitaxel versus paclitaxel alone in women with advanced, recurrent, or persistent endometrial cancer.

OBJECTIVE: This phase 2 study investigated sapanisertib (selective dual inhibitor of mTORC1/2) alone, or in combination with paclitaxel or TAK-117 (a selective small molecule inhibitor of PI3K), versus paclitaxel alone in advanced, recurrent, or persistent endometrial cancer. METHODS: Patients with histologic diagnosis of endometrial cancer (1-2 prior regimens) were randomized to 28-day cycles on four treatment arms: 1) weekly paclitaxel 80 mg/m2 (days 1, 8, and 15); 2) weekly paclitaxel 80 mg/m2 + oral sapanisertib 4 mg on days 2-4, 9-11, 16-18, and 23-25; 3) weekly sapanisertib 30 mg, or 4) sapanisertib 4 mg + TAK-117 200 mg on days 1-3, 8-10, 15-17, and 22-24. RESULTS: Of 241 patients randomized, 234 received treatment (paclitaxel, n = 87 [3 ongoing]; paclitaxel+sapanisertib, n = 86 [3 ongoing]; sapanisertib, n = 41; sapanisertib+TAK-117, n = 20). The sapanisertib and sapanisertib+TAK-117 arms were closed to enrollment after futility analyses. After a median follow-up of 14.4 (paclitaxel) versus 17.2 (paclitaxel+sapanisertib) months, median progression-free survival (PFS; primary endpoint) was 3.7 versus 5.6 months (hazard ratio [HR] 0.82; 95% confidence interval [CI] 0.58-1.15; p = 0.139); in patients with endometrioid histology (n = 116), median PFS was 3.3 versus 5.7 months (HR 0.66; 95% CI 0.43-1.03). Grade ≥ 3 treatment-emergent adverse event rates were 54.0% with paclitaxel versus 89.5% paclitaxel+sapanisertib. CONCLUSIONS: Our findings support inclusion of chemotherapy combinations with investigational agents for advanced or metastatic disease. The primary endpoint was not met and toxicity was manageable. TRIAL REGISTRATION: ClinicalTrials.gov number, NCT02725268.

Durvalumab with or without tremelimumab in patients with persistent or recurrent endometrial cancer or endometrial carcinosarcoma: A randomized open-label phase 2 study.

INTRODUCTION: Our understanding of the biologic heterogeneity of endometrial cancer has improved, but which patients benefit from single-agent versus combination immune checkpoint blockade remains unclear. METHODS: We conducted a single-center, randomized, open-label, phase 2 study of durvalumab 1500 mg (Arm 1) versus durvalumab 1500 mg plus tremelimumab 75 mg every 4 weeks (Arm 2) in patients with endometrial carcinoma. The primary endpoints were overall response rate (ORR) and progression-free survival (PFS) at 24 weeks. Patients were stratified by mismatch repair (MMR) status and carcinosarcoma histology. Using a Simon two-stage minimax design, we determined 40 patients per arm would provide 90% power and Type 1 error of 10%. RESULTS: Eighty-two patients were enrolled; 77 were evaluable for toxicity (Arm 1: 38, Arm 2: 39) and 75 evaluable for efficacy (Arm 1: 37, Arm 2: 38). Patient were stratified by MMR status (Arm 1: 5, Arm 2: 4 were MMR-deficient). The ORR in Arm 1 was 10.8% (one-sided 90% CI: 4.8-100%); the ORR in Arm 2 was 5.3% (one-sided 90% CI: 1.4-100%). Since the primary endpoint of ORR was not met, 24-week PFS was not compared to historical controls per protocol specification. No new safety signals were identified. CONCLUSIONS: In these patients with predominantly MMR-proficient endometrial cancer, there was limited response with single-agent and combined immune checkpoint blockade. The pre-specified efficacy thresholds were not met for further evaluation. A deeper understanding of potential mechanisms of resistance to immunotherapy in MMR-proficient endometrial cancer is needed for the development of novel therapeutic approaches.

Integration of clinical sequencing and immunohistochemistry for the molecular classification of endometrial carcinoma.

PURPOSE: Using next generation sequencing (NGS), The Cancer Genome Atlas (TCGA) found that endometrial carcinomas (ECs) fall under one of four molecular subtypes, and a POLE mutation status, mismatch repair (MMR) and p53 immunohistochemistry (IHC)-based surrogate has been developed. We sought to retrospectively classify and characterize a large series of unselected ECs that were prospectively subjected to clinical sequencing by utilizing clinical molecular and IHC data. EXPERIMENTAL DESIGN: All patients with EC with clinical tumor-normal MSK-IMPACT NGS from 2014 to 2020 (n = 2115) were classified by integrating molecular data (i.e., POLE mutation, TP53 mutation, MSIsensor score) and MMR and p53 IHC results. Survival analysis was performed for primary EC patients with upfront surgery at our institution. RESULTS: Utilizing our integrated approach, significantly more ECs were molecularly classified (1834/2115, 87%) as compared to the surrogate (1387/2115, 66%, p < 0.001), with an almost perfect agreement for classifiable cases (Kappa 0.962, 95% CI 0.949-0.975). Discrepancies were primarily due to TP53 mutations in p53-IHC-normal ECs. Of the 1834 ECs, most were of copy number (CN)-high molecular subtype (40%), followed by CN-low (32%), MSI-high (23%) and POLE (5%). Histologic and genomic variability was present amongst all molecular subtypes. Molecular classification was prognostic in early- and advanced-stage disease, including early-stage endometrioid EC. CONCLUSIONS: The integration of clinical NGS and IHC data allows for an algorithmic approach to molecularly classifying newly diagnosed EC, while overcoming issues of IHC-based genetic alteration detection. Such integrated approach will be important moving forward given the prognostic and potentially predictive information afforded by this classification.