Efficacy and safety of lucitanib + nivolumab in patients with advanced gynecologic malignancies: Phase 2 results from the LIO-1 study (NCT04042116; ENGOT-GYN3/AGO/LIO)

5517

Background: LIO-1 is assessing the oral antiangiogenic, multikinase inhibitor lucitanib in combination with the programmed cell death receptor 1 (PD-1) inhibitor nivolumab. Individualized lucitanib dose titration is being explored to maximize lucitanib exposure and potential clinical benefit of the combination. Here, we present data from stage 1 of a Simon 2-stage design across 4 different types of advanced gynecologic cancers from the phase 2 part of LIO-1. Methods: Patients (pts) with advanced, recurrent, or metastatic endometrial cancer (EC, who received ≥1 prior platinum-based chemotherapy); cervical cancer (CC, who received ≥1 prior platinum-based chemotherapy ± bevacizumab); high-grade ovarian cancer (OC, who received ≥2 prior chemotherapies); or EC/OC with clear-cell histology (EOCC, who received ≥1 prior platinum-based chemotherapy + taxane) were enrolled. Prior PD-1 or programmed cell death ligand 1 (PD-L1) inhibitor treatment was excluded, except for up to 10 pts in the EC cohort. Pts received lucitanib at a starting dose of 6 mg once daily (QD), escalating to 8 mg QD and then 10 mg QD if safety-based titration criteria were met, plus intravenous nivolumab 480 mg every 28 days. The data cutoff was Jan 10, 2022. Results: Across cohorts, 100 pts were enrolled to stage 1; 27 (27%) remain on treatment. To date, 28 (28%) have escalated to lucitanib 8 mg, and 17 (17%) have escalated to the maximum dose of 10 mg. Confirmed responses per RECIST v1.1 have been reported in 5/22 (22.7%; 5 partial responses [PRs]) EC pts, 7/22 (31.8%; 2 complete responses [CRs], 5 PRs) CC pts, 4/33 (12.1%; 4 PRs) OC pts, and 5/23 (21.7%; 1 CR, 4 PRs) EOCC pts. Response duration ranges from 1.9+ to 13.1+ months. Of 5 pts with EC who received prior PD-1 inhibitor, there were 2 PRs, and 1 pt with ongoing stable disease of 7+ months. Grade ≥3 treatment-emergent adverse events (TEAEs) considered related to study treatment were reported in 43 (43%) pts, with hypertension the most frequent (n = 25 [25%]). Forty-six (46%) pts had a lucitanib-related TEAE that led to lucitanib interruption and 12 (12%) had one that led to lucitanib dose reduction. Eleven (11%) and 8 (8%) pts discontinued lucitanib and nivolumab, respectively, due to a treatment-related TEAE. Safety results were generally consistent across tumor cohorts. Conclusions: The combination of lucitanib + nivolumab is active in the treatment of advanced gynecological malignancies and has a manageable safety profile through effective dose titration. Stage 2 enrollment has continued in the CC cohort. Biomarker analysis is ongoing, and more mature efficacy and safety data will be presented at the meeting. Clinical trial information: NCT04042116.

KEYNOTE-C93/GOG-3064/ENGOT-en15: A phase 3, randomized, open-label study of first-line pembrolizumab versus platinum-doublet chemotherapy in mismatch repair deficient advanced or recurrent endometrial carcinoma

TPS5623

Background: Carboplatin-paclitaxel chemotherapy (with trastuzumab for HER2+ uterine serous carcinoma) is the standard of care first-line systemic treatment for recurrent or metastatic endometrial carcinoma (EC), which has a 5-year relative survival rate of only 17%. Worse survival outcomes have been shown for the mismatch repair deficient (dMMR) subtype of EC. Pembrolizumab (pembro), an anti-PD-1 antibody, showed compelling antitumor activity in previously treated, advanced MSI-H/dMMR EC in the phase 2 KEYNOTE-158 study (ORR, 48%; median duration of response [DOR], not reached; O’Malley JCO 2022). KEYNOTE-C93/GOG-3064/ENGOT-en15 (NCT05173987) is a phase 3, randomized, open-label study evaluating first-line pembro versus carboplatin-paclitaxel chemotherapy in patients with dMMR advanced or recurrent EC. Methods: Patients aged ≥18 years with histologically confirmed stage III/IV recurrent EC including carcinosarcoma (mixed Mullerian tumor), radiographically evaluable disease (measurable or nonmeasurable per RECIST v1.1), no prior systemic therapy (prior radiation with or without radiosensitizing chemotherapy > 2 weeks before first dose or prior hormonal therapy ≥1 week before randomization is permitted), and an ECOG PS ≤1 are eligible. Patients must have central confirmation of dMMR status. Approximately 350 patients will be randomized 1:1 to receive pembro 400 mg IV Q6W for 18 cycles (̃2 years) or carboplatin AUC 5 or 6 mg/mL/min IV Q3W and paclitaxel 175 mg/m2 IV Q3W for 6 cycles (with option for > 6 cycles). Trastuzumab is permitted for patients in the chemotherapy arm with HER2+ serous EC. Randomization is stratified by disease status (newly diagnosed advanced EC vs recurrent EC) and histology (endometrioid vs nonendometrioid). Treatment will continue for the specified number of cycles or until PD or unacceptable toxicity. Patients in the chemotherapy arm have the option to receive pembro following confirmed PD by blinded independent central review (BICR). Tumor imaging will be performed Q9W from randomization to week 54 and Q12W thereafter. AEs will be assessed from randomization to 30 days (90 days for serious AEs) after treatment discontinuation and graded per NCI CTCAE version 5.0. Dual primary endpoints are PFS per RECIST v1.1 by BICR and OS. Secondary endpoints are ORR, disease control rate, and DOR per RECIST v1.1 by BICR; PFS per RECIST v1.1 by investigator review; PFS2 (ie, time from randomization to PD per investigator assessment or death from any cause after start of subsequent anticancer therapy); safety; and patient-reported outcomes. PFS and OS will be estimated by the Kaplan-Meier method, with treatment differences assessed by the stratified log-rank test and HRs with 95% CIs determined using a Cox proportional hazard model. Enrollment is ongoing. Clinical trial information: NCT05173987.

Use of Khorana score to predict VTE in patients undergoing chemotherapy for uterine cancer

5589

Background: Gynecologic cancers are associated with a high risk of venous thromboembolism (VTE). The Khorana score is a clinically-validated tool to assess risk of VTE in cancer patients (using disease site, BMI and blood counts). Recent ASCO clinical practice guidelines have recommended patients with a Khorana score of 2 or greater be offered pharmacologic thromboprophylaxis during systemic chemotherapy. For women with uterine cancer, the utility of the Khorana score is still unknown. Methods: A retrospective cohort study was performed from January 2016 to January 2020. All patients with uterine cancer were screened. Patients receiving chemotherapy, both neoadjuvant (NACT) and adjuvant (ACT), were included. VTE was evaluated for 12 months following the first cycle of chemotherapy. The Khorana score was calculated for each patient using both a high risk score of ≥2 and ≥3 and the patients were stratified based on NACT vs ACT. Logistic regression and chi-square were used to evaluate the prognostic utility of the Khorana score as well as other clinico-pathologic criteria on development of VTE. Results: A total of 265 patients were included. The majority of patients were obese (160, 60.4%) and 60 years or older (188, 70.9%). The most common histology was endometrioid (107, 40.4%) followed by serous (71, 26.8%) and the majority were advanced-stage (169, 63.8%). Most women underwent hysterectomy during treatment (243, 91.7%) followed by ACT (228, 86.0%). 14% (37) had NACT. 24 patients developed VTE (9.1%), which was higher, but not statistically different, with NACT vs ACT (13.5% vs 8.3%, p = 0.35). Demographics including age, race and BMI nor pathologic data including histology, grade or stage significantly correlated with development of VTE. Similarly, treatment factors including undergoing hysterectomy and radiation treatment were not statistically significant in regards to VTE. The proportion of patients with high Khorana score (both ≥2 and ≥3) was similar between groups. In the whole cohort, high Khorana score (defined either as ≥2 or ≥3) did not significantly predict VTE; however, the model using ≥3 was more predictive (OR 1.154, 95%CI 0.402-2.907, p = 0.7326). In the NACT cohort, neither model was predictive of VTE (both with OR < 1). In the ACT group, Khorana ≥3 was a better prediction model, but was still not statistically significant (OR 1.557, 95%CI 0.480-4.343, p = 0.4213). Conclusions: Although validated in other cancer types, the Khorana score was found to be a poor predictor of VTE in this population. A defined high risk Khorana score of ≥3 (per the original validation study) better predicted VTE than a score of ≥2 (per guidelines). Independent of the Khorana score, demographic and pathologic data were poor predictors of VTE. At this time, use of the Khorana score to guide routine thromboprophylaxis in patients undergoing chemotherapy for uterine cancer should be used with caution.

LIO-1: Lucitanib + nivolumab in patients with advanced solid tumors—Updated phase 1b results and initial experience in phase 2 ovarian cancer cohort

5538

Background: The phase (Ph) 1b part of LIO-1 (NCT04042116; ENGOT-GYN3/AGO/LIO) assessed the oral antiangiogenic, multikinase inhibitor lucitanib + immune checkpoint inhibitor nivolumab, confirming the recommended Ph2 dose (RP2D) of lucitanib as 6 mg QD + nivolumab (480 mg IV every 28 days). To maximize lucitanib exposure and potential clinical benefit of the combination, individualized lucitanib dose titration is being explored in a Ph2 part, across 4 recurrent gynecologic malignancies (endometrial, cervical, ovarian, and ovarian/endometrial clear-cell cancers) using a Simon 2-stage design. We present updated Ph1b data and describe initial experience for the first 24 patients (pts) enrolled in the Ph2 ovarian cancer (OC) cohort. Methods: In Ph1b, pts with advanced, metastatic solid tumors received lucitanib at 6, 8, and 10 mg QD + nivolumab (in a 4+3 dose escalation). In the Ph2 OC cohort, pts with recurrent high-grade epithelial ovarian, fallopian tube, or primary peritoneal cancer (excluding clear-cell histology) with ≥2 prior chemotherapy regimens (including ≥1 platinum doublet) received the combination at RP2D; lucitanib dose was escalated from 6 mg to 8 mg and then to 10 mg QD for pts who met safety-based titration criteria. Visit cutoff was Feb 1, 2021. Results: In the Ph1b part (N = 17), median treatment duration was 109 days (range 14–505+). There has been 1 confirmed complete response (CR; anal cancer) and 1 confirmed partial response (PR; cervical cancer) per RECIST v1.1 with durations of 7.1 and 12.8 months, respectively. Ten pts had stable disease (SD), 3 had progressive disease, and 2 were nonevaluable; 3 pts remain on treatment. Overall disease control rate (CR + PR + SD ≥16 wk) was 47.1%. One dose-limiting toxicity (DLT; grade [G] 3 proteinuria) was observed in a pt receiving lucitanib 6 mg, leading to lucitanib discontinuation; no DLTs were seen at 8 or 10 mg. G ≥3 treatment-emergent adverse events (TEAEs) reported in ≥2 pts included hypertension (HTN; n = 4), fatigue (n = 2), and proteinuria (n = 2). Of the first 24 pts enrolled in the Ph2 OC cohort, 13 (54%) remain on treatment (median duration 59 [2–167+] days). Most frequent any-grade TEAEs were HTN (n = 10), fatigue (n = 8), nausea (n = 7), and proteinuria (n = 6). The only G ≥3 TEAE experienced in ≥2 pts was HTN (n = 4); 1 pt discontinued due to G4 HTN/G2 angina pectoris and 1 pt to G2 colonic perforation. To date, 21 pts have completed ≥1 cycle; 11 met safety-based dose-titration criteria, 10 of whom escalated to the 8 mg lucitanib dose. Of these, 5 pts subsequently escalated to 10 mg. One pt required dose reduction from 6 mg to 4 mg lucitanib. Conclusions: Ph1b data suggest that lucitanib + nivolumab has promising signs of antitumor activity. A safety-based dose-titration strategy appears feasible with manageable toxicity, based on experience from the Ph2 OC cohort to date; efficacy data from this cohort will also be presented. Clinical trial information: NCT04042116.

Differences in self-reported health-related quality of life in heterosexual and sexual minority women surviving cancer: 2013 to 2018 national health interview survey

e19038

Background: Health related quality of life (HRQoL) is associated with excess morbidity and mortality after cancer diagnosis. While a growing body of research indicates that sexual minority women (lesbian and bisexual women; SMW) experience greater risk for cancer diagnoses and cancer-related mortality, there is a paucity of evidence describing HRQoL in this population. This is a critical omission as assessment of sexual orientation differences in HRQoL may inform clinical interventions to improve health and survival of SMW after cancer diagnosis. This study examined associations between sexual orientation and HRQoL domains among female cancer survivors. Methods: Data from the 2013-2018 National Health Interview Survey (NHIS) was pooled. HRQoL was defined using individual indices across physical health, mental health, social, and financial domains. The association between sexual orientation and individual indices of HRQoL was assessed using weighted multivariable logistic regression analyses. Results: The sample included 97909 heterosexual, 1424 lesbian, and 1235 bisexual women who reported a cancer diagnosis. Sexual minority women were more likely to be college graduates (p < 0.001) and employed (p < 0.001); however, they had higher rates of being uninsured (p = 0.01) than their heterosexual counterparts. Reproductive cancers—including breast, ovarian, cervical, and uterine—accounted for 51% of cancer diagnoses in heterosexual women and 57.2% in SMW (p = 0.06). Sexual minority and heterosexual women had more similarities than differences in individual indices of HRQoL; however, several pertinent differences were noted. Specifically, SMW had higher odds of moderate (OR 1.46 [1.01-2.13]) and severe psychological distress (OR 2.10 [1.17-3.77]); chronic health conditions, including COPD (OR 1.72 [1.06-2.80]) and heart disease (OR 1.93 [1.32-2.83]); financial concerns about retirement (OR 1.36 [1.01-1.83]); food insecurity (OR 2.13 [1.23-3.68]), and severe food insecurity (OR 2.44 [1.28-4.67]). Conclusions: Sexual minority women with cancer diagnoses report worse indices of HRQoL. Poorer HRQoL may influence excess morbidity and mortality evidenced in these populations; however, future longitudinal studies are needed to assess prospective risk. Given our results, implementing interventions in the cancer setting to identify sexual minority patients in need of physical and mental health and financial services may reduce disparities.

A randomized phase II study of cabozantinib and nivolumab versus nivolumab in recurrent endometrial cancer

6010

Background: The efficacy of treatment for recurrent endometrial cancer (EC) remains limited. Vascular endothelial growth factor and inflammatory chemokines are proangiogenic factors and immune modulators involved in immune suppression. Reprogramming the tumor microenvironment by combining antiangiogenic and immunotherapy (IO) could enhance antitumor responses. Methods: A 2:1 randomized phase 2 trial compared the combination of cabozantinib and nivolumab (Arm A) versus nivolumab (Arm B) in recurrent EC. Primary endpoint was progression free survival (PFS) assessed by RECIST 1.1 (NCT03367741). Women with recurrent measurable EC were eligible. There were no limits on prior therapy, but at least one prior platinum-based chemotherapy was required. Patients (pts) were stratified according to MSI status and assessed by CT every 8 weeks. Cabozantinib was given at 40 mg daily (Arm A) and nivolumab at 240 mg, on D1 and D15 of a 28-day cycle for 4 cycles, followed by 480 mg every 4 weeks (Arms A & B). Pts with carcinosarcoma or prior IO were enrolled in an exploratory cohort and received combination treatment (Arm C). A baseline biopsy was required for all pts. CyTOF analysis was performed on fresh biopsies. Results: 76 evaluable pts were enrolled (Arm A: 36, Arm B: 18, Arm C: 9 carcinosarcoma, and 20 post IO including 7 pts crossed over from Arm B). 55% of pts had received ≥3 prior lines of therapy. Two pts were MSI high in Arm A and none in Arm B. The Kaplan-Meier estimated median PFS was 5.3 (95% CI: 3.5-9.5) months in Arm A and 1.9 (95% CI: 1.6-3.8) months in Arm B, with a log-rank p = 0.07, which met the significance level of 0.1 used for sample size calculation. Objective response rate (ORR) was 25% for Arm A and 16.7% for Arm B; stable disease (SD) was seen in 44.4% vs 11.1%, respectively. Clinical benefit (ORR+SD) was significantly higher in arm A vs B (p < 0.001). In Arm C-carcinosarcoma, one patient had a partial response (11.9 months duration) and four SD. In Arm C-prior IO, six pts responded and eight had SD. The most common related AEs in Arm A were diarrhea (47.2%), elevated liver enzymes (44.4%), fatigue (38.9%), anorexia, hypertension, and nausea (30.6%), mainly grade 1/2. Preliminary CyTOF analysis across treatment arms identified multiple immune subsets for further interrogation including activated CD8+ and CD4+ T cells. Conclusions: Cabozantinib plus nivolumab demonstrates improved PFS compared to nivolumab in heavily pre-treated women with recurrent EC. In-depth CyTOF analysis of the tumor microenvironment to identify predictive immune biomarkers of response is ongoing. Clinical trial information: NCT03367741.

Clinicopathologic characteristics associated with long-term survival in advanced epithelial ovarian cancer: an NRG Oncology/Gynecologic Oncology Group ancillary data study

OBJECTIVE

To identify clinicopathologic factors associated with 10-year overall survival in epithelial ovarian cancer (EOC) and primary peritoneal cancer (PPC), and to develop a predictive model identifying long-term survivors.

METHODS

Demographic, surgical, and clinicopathologic data were abstracted from GOG 182 records. The association between clinical variables and long-term survival (LTS) (>10years) was assessed using multivariable regression analysis. Bootstrap methods were used to develop predictive models from known prognostic clinical factors and predictive accuracy was quantified using optimism-adjusted area under the receiver operating characteristic curve (AUC).

RESULTS

The analysis dataset included 3010 evaluable patients, of whom 195 survived greater than ten years. These patients were more likely to have better performance status, endometrioid histology, stage III (rather than stage IV) disease, absence of ascites, less extensive preoperative disease distribution, microscopic disease residual following cyoreduction (R0), and decreased complexity of surgery (p<0.01). Multivariable regression analysis revealed that lower CA-125 levels, absence of ascites, stage, and R0 were significant independent predictors of LTS. A predictive model created using these variables had an AUC=0.729, which outperformed any of the individual predictors.

CONCLUSIONS

The absence of ascites, a low CA-125, stage, and R0 at the time of cytoreduction are factors associated with LTS when controlling for other confounders. An extensively annotated clinicopathologic prediction model for LTS fell short of clinical utility suggesting that prognostic molecular profiles are needed to better predict which patients are likely to be long-term survivors.

Influence of tumor size on outcomes following pelvic exenteration

OBJECTIVE

Pelvic exenteration (PE) is often the only curative option for locally advanced or recurrent pelvic malignancies. Despite radical surgery, recurrence risk and morbidity remain high. In this study, we sought to determine tumor size effect on perioperative outcomes and subsequent survival in patients undergoing PE.

METHODS

Retrospective chart review was performed for female patients who underwent PE at two comprehensive cancer centers from 2000 to 2015. Demographics, complications and outcomes were recorded. Statistical analyses were performed using chi-square, student's t-test, logistic regression, non-parametric tests, log-rank test, and Cox proportional hazards.

RESULTS

Of 151 women who underwent PE, 144 had available pathologic tumor size. Gynecologic oncology, surgical oncology, and urology performed 84, 29, and 31 exenterations, respectively. Tumor dimensions ranged from 0 to 25.5cm. Perioperative complications, 30-day mortality, reoperation, and readmission rates were not associated with tumor size. Obesity and prior radiation increased risk for major perioperative complication while anterior exenterations decreased risk. Larger tumors were more likely to undergo total pelvic exenteration (OR 1.14; 95%CI 1.03-1.27), have positive margins (OR 1.11; 95%CI 1.02-1.22), and recur (65%, 42% and 20% for tumors >4cm, ≤4cm and no residual tumor respectively, p=0.016). Tumor size >4cm and positive margins were associated with worse overall survival amongst gynecologic oncology patients.

CONCLUSION

Tumor size was not associated with perioperative morbidity. Larger tumors were associated with positive margins, more extensive resection, and worse survival in gynecologic oncology patients. Larger studies are needed to further understand tumor size impact on PE outcomes within specific tumor types.

The mutational spectrum of FOXA2 in endometrioid endometrial cancer points to a tumor suppressor role

BACKGROUND

Forkhead box protein A2 (FOXA2) plays an important in development, cellular metabolism and tumorigenesis. The Cancer Genome Atlas (TCGA) identified a modest frequency of FOXA2 mutations in endometrioid endometrial cancers (EEC). The current study sought to determine the relationship between FOXA2 mutation and clinicopathologic features in EEC and FOXA2 expression.

METHODS

Polymerase chain reaction (PCR) amplification and sequencing were used to identify mutations in 542 EEC. Western blot, quantitative reverse transcriptase PCR (qRT-PCR) and immunohistochemistry (IHC) were used to assess expression. Methylation analysis was performed using combined bisulfite restriction analysis (COBRA) and sequencing. Chi-squared, Fisher's exact, Student's t- and log-rank tests were performed.

RESULTS

Fifty-one mutations were identified in 49 tumors (9.4% mutation rate). The majority of mutations were novel, loss of function (LOF) (78.4%) mutations, and most disrupted the DNA-binding domain (58.8%). Six recurrent mutations were identified. Only two tumors had two mutations and there was no evidence for FOXA2 allelic loss. Mutation status was associated with tumor grade and not associated with survival outcomes. Methylation of the FOXA2 promoter region was highly variable. Most tumors expressed FOXA2 at both the mRNA and protein level. In those tumors with mutations, the majority of cases expressed both alleles.

CONCLUSION

FOXA2 is frequently mutated in EEC. The pattern of FOXA2 mutations and expression in tumors suggests complex regulation and a haploinsufficient or dominant-negative tumor suppressor function. In vitro studies may shed light on how mutations in FOXA2 affect FOXA2 pioneer and/or transcription factor functions in EEC.

Effect of chemotherapy delays and dose reductions on progression free and overall survival in the treatment of epithelial ovarian cancer

INTRODUCTION

Hematologic, gastrointestinal, and neurologic complications are common side effects of the platinum and taxane-based chemotherapy used in the primary treatment of epithelial ovarian cancer (EOC). These side effects and the impact of the resultant chemotherapy dose modification on disease free interval have not been extensively studied. The goal of this study was to determine the effect of chemotherapy delays and dose reductions on progression free survival (PFS) and overall survival (OS).

METHODS

A review of patients with primary epithelial ovarian, peritoneal, and fallopian tube carcinoma treated between 1/2000 and 12/2007 was performed. Inclusion criteria were advanced stage disease and first line chemotherapy with a platinum and taxane regimen. Cox proportional hazard models were used to determine the effect of chemotherapy reductions and delays on PFS and OS.

RESULTS

One hundred and fifty seven patients met the inclusion criteria. Patients were divided into four groups: no delays or reductions (48%), delay only (27%), reduction only (8%), and both delay and reduction (18%). The mean number of delays/reductions per patient was 1.1 (range=0-5) and therapy was delayed a mean of 8 days. The most common reasons for delays/reductions were neutropenia (n=51), thrombocytopenia (n=45), and neuropathy (n=18). There were no differences detected in PFS or OS between groups.

CONCLUSIONS

There were no differences detected in survival between patients who required dose adjustments and treatment delays and those who did not. The lack of association between survival and chemotherapy alterations suggests that in specific circumstances patients with advanced ovarian cancer should have individualized treatment plans.