André Mattar

First-line lenvatinib plus pembrolizumab versus chemotherapy for advanced endometrial cancer: 1-Year follow-up after final analysis of the ENGOT-en9/LEAP-001 phase 3 trial

The phase 3 ENGOT-en9/LEAP-001 trial (NCT03884101) comparing first-line lenvatinib+pembrolizumab with carboplatin+paclitaxel did not meet pre-specified statistical criteria for overall survival or progression-free survival in participants with advanced/recurrent endometrial cancer. We report results after an additional year of follow-up (overall median 54.5 [range; 46.5-69.0] months). Eligible participants were adult females with stage III to IV or recurrent, histologically confirmed endometrial cancer. Measurable or non-measurable disease per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 and radiographically apparent disease per blinded independent central review was required. Participants were randomly allocated 1:1 to lenvatinib+pembrolizumab or chemotherapy (paclitaxel+carboplatin). The primary end points were overall survival and progression-free survival per RECIST version 1.1 by blinded independent central review. Secondary end points included objective response rate per RECIST version 1.1 by blinded independent central review and safety. The median overall survival (95% confidence interval [CI]) was 30.9 (range; 25.4-37.6) months with lenvatinib+pembrolizumab versus 29.4 (range; 26.2-34.8) months with chemotherapy in mismatch repair-proficient endometrial cancer (hazard ratio [HR] 0.99, 95% CI 0.82 to 1.21), 37.9 (range; 32.2-43.0) versus 32.3 (range; 27.2-35.7) months in all-comers (HR 0.91, 95% CI 0.77 to 1.09), and not reached in either treatment group in mismatch repair-deficient endometrial cancer (HR 0.60, 95% CI 0.39 to 0.93]). Corresponding results for progression-free survival were 9.6 (range; 8.2-11.9) versus 10.2 (range; 8.4-10.5) months (HR 1.01, 95% CI 0.83 to 1.22), 12.5 (range; 10.3-15.1) versus 10.2 (range; 8.4-10.4) months (HR 0.92, 95% CI 0.77 to 1.10]), and 31.8 (22.5 to not reached) versus 9.0 (range; 8.2-17.1) months (HR 0.62, 95% CI 0.41-0.93). Objective response rates were 50.6% versus 54.7%, 55.7% versus 55.5%, and 72.0% versus 58.0%, respectively. No new safety signals were identified. The results were consistent with those at the final analysis. The mismatch repair-proficient, all-comer, and mismatch repair-deficient populations continued to demonstrate antitumor activity for lenvatinib+pembrolizumab after an additional year of follow-up. These results should be interpreted with caution due to the exploratory nature of the analysis. ClinicalTrials.gov No. NCT03884101.

First-Line Lenvatinib Plus Pembrolizumab Versus Chemotherapy for Advanced Endometrial Cancer: A Randomized, Open-Label, Phase III Trial

PURPOSE Lenvatinib plus pembrolizumab (len + pembro) significantly improved progression-free survival (PFS) and overall survival (OS) versus chemotherapy in previously treated advanced or recurrent endometrial cancer (aEC) in the phase III Study 309/KEYNOTE-775. We report results from the phase III, randomized, open-label European Network of Gynaecological Oncological Trial-en9/LEAP-001 study (ClinicalTrials.gov identifier: NCT03884101 ) that evaluated len + pembro versus chemotherapy in first-line aEC. METHODS Patients with stage III to IV or recurrent, radiographically apparent EC and no previous chemotherapy or disease progression ≥6 months after neo/adjuvant platinum-based chemotherapy were randomly assigned 1:1 to lenvatinib 20 mg once daily plus pembrolizumab 200 mg once every 3 weeks or paclitaxel 175 mg/m 2 plus carboplatin AUC 6 mg/mL/min once every 3 weeks. Primary end points were PFS and OS, evaluated in the mismatch repair-proficient (pMMR) and all-comers populations. Noninferiority was assessed for OS at final analysis (FA) for len + pembro versus chemotherapy (multiplicity-adjusted, one-sided nominal alpha, .0159; null hypothesis–tested hazard ratio [HR], 1.1). RESULTS Eight hundred forty-two patients were randomly assigned (len + pembro, n = 420 [pMMR population, n = 320]; chemotherapy, n = 422 [pMMR population, n = 322]). At FA (data cutoff, October 2, 2023), median PFS (95% CI) in the pMMR population was 9.6 (8.2 to 11.9) versus 10.2 (8.4 to 10.5) months with len + pembro versus chemotherapy (hazard ratio [HR], 0.99 [95% CI, 0.82 to 1.21]) and among all-comers was 12.5 (10.3 to 15.1) versus 10.2 (8.4 to 10.4) months (HR, 0.91 [95% CI, 0.76 to 1.09]; descriptive analyses). Median OS (95% CI) in the pMMR population was 30.9 (25.4 to 37.7) versus 29.4 (26.2 to 35.4) months with len + pembro versus chemotherapy (HR, 1.02 [95% CI, 0.83 to 1.26]; noninferiority P = .246, not statistically significant per multiplicity control strategy) and among all-comers was 37.7 (32.2 to 43.6) versus 32.1 (27.2 to 35.7) months (HR, 0.93 [95% CI, 0.77 to 1.12]). Grade ≥3 treatment-related adverse events occurred in 331/420 (79%) versus 274/411 (67%) treated patients. CONCLUSION First-line len + pembro did not meet prespecified statistical criteria for PFS or OS versus chemotherapy in pMMR aEC.