PURPOSE: Trastuzumab deruxtecan (T-DXd) is a human epidermal growth factor 2 (HER2)–directed antibody-drug conjugate approved in HER2-expressing breast and gastric cancers and HER2-mutant non–small-cell lung cancer. Treatments are limited for other HER2-expressing solid tumors. METHODS: This open-label phase II study evaluated T-DXd (5.4 mg/kg once every 3 weeks) for HER2-expressing (immunohistochemistry [IHC] 3+/2+ by local or central testing) locally advanced or metastatic disease after ≥1 systemic treatment or without alternative treatments. The primary end point was investigator-assessed confirmed objective response rate (ORR). Secondary end points included safety, duration of response, progression-free survival (PFS), and overall survival (OS). RESULTS: At primary analysis, 267 patients received treatment across seven tumor cohorts: endometrial, cervical, ovarian, bladder, biliary tract, pancreatic, and other. The median follow-up was 12.75 months. In all patients, the ORR was 37.1% (n = 99; [95% CI, 31.3 to 43.2]), with responses in all cohorts; the median DOR was 11.3 months (95% CI, 9.6 to 17.8); the median PFS was 6.9 months (95% CI, 5.6 to 8.0); and the median OS was 13.4 months (95% CI, 11.9 to 15.5). In patients with central HER2 IHC 3+ expression (n = 75), the ORR was 61.3% (95% CI, 49.4 to 72.4), the median DOR was 22.1 months (95% CI, 9.6 to not reached), the median PFS was 11.9 months (95% CI, 8.2 to 13.0), and the median OS was 21.1 months (95% CI, 15.3 to 29.6). Grade ≥3 drug-related adverse events were observed in 40.8% of patients; 10.5% experienced adjudicated drug-related interstitial lung disease (ILD), with three deaths. CONCLUSION: Our study demonstrates durable clinical benefit, meaningful survival outcomes, and safety consistent with the known profile (including ILD) in pretreated patients with HER2-expressing tumors receiving T-DXd. Greatest benefit was observed for the IHC 3+ population. These data support the potential role of T-DXd as a tumor-agnostic therapy for patients with HER2-expressing solid tumors.

Standard therapy for advanced endometrial cancer after failure of platinum-based chemotherapy remains unclear. 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. 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. 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.)

PURPOSE: Patients with advanced endometrial carcinoma have limited treatment options. We report final primary efficacy analysis results for a patient cohort with advanced endometrial carcinoma receiving lenvatinib plus pembrolizumab in an ongoing phase Ib/II study of selected solid tumors. METHODS: Patients took lenvatinib 20 mg once daily orally plus pembrolizumab 200 mg intravenously once every 3 weeks, in 3-week cycles. The primary end point was objective response rate (ORR) at 24 weeks (ORR_Wk24); secondary efficacy end points included duration of response (DOR), progression-free survival (PFS), and overall survival (OS). Tumor assessments were evaluated by investigators per immune-related RECIST. RESULTS: At data cutoff, 108 patients with previously treated endometrial carcinoma were enrolled, with a median follow-up of 18.7 months. The ORR_Wk24 was 38.0% (95% CI, 28.8% to 47.8%). Among subgroups, the ORR_Wk24 (95% CI) was 63.6% (30.8% to 89.1%) in patients with microsatellite instability (MSI)–high tumors (n = 11) and 36.2% (26.5% to 46.7%) in patients with microsatellite-stable tumors (n = 94). For previously treated patients, regardless of tumor MSI status, the median DOR was 21.2 months (95% CI, 7.6 months to not estimable), median PFS was 7.4 months (95% CI, 5.3 to 8.7 months), and median OS was 16.7 months (15.0 months to not estimable). Grade 3 or 4 treatment-related adverse events occurred in 83/124 (66.9%) patients. CONCLUSION: Lenvatinib plus pembrolizumab showed promising antitumor activity in patients with advanced endometrial carcinoma who have experienced disease progression after prior systemic therapy, regardless of tumor MSI status. The combination therapy had a manageable toxicity profile.

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported. We report the final prespecified analysis for overall survival (OS), along with updated progression-free survival (PFS) and objective response rate (ORR), and safety from the open-label, randomized, phase III Study 309/KEYNOTE-775. In total, 827 patients with advanced, recurrent, or metastatic endometrial cancer (EC) were randomly assigned to receive lenvatinib 20 mg orally once daily plus pembrolizumab 200 mg intravenously once every 3 weeks (n = 411) or chemotherapy of the treating physician's choice (doxorubicin 60 mg/m² intravenously once every 3 weeks or paclitaxel 80 mg/m² intravenously once weekly [3 weeks on; 1 week off] [n = 416]). Efficacy was reported for patients with mismatch repair proficient (pMMR) tumors and all-comers, and by subgroups (histology, prior therapy, MMR status). Updated safety was also reported. Lenvatinib plus pembrolizumab showed benefits in OS (pMMR HR, 0.70; 95% CI, 0.58 to 0.83; all-comer HR, 0.65; 95% CI, 0.55 to 0.77), PFS (pMMR HR, 0.60; 95% CI, 0.50 to 0.72; all-comer HR, 0.56; 95% CI, 0.48 to 0.66), and ORR (pMMR patients, 32.4% v 15.1%; all-comers, 33.8% v 14.7%) versus chemotherapy. OS, PFS, and ORR favored lenvatinib plus pembrolizumab in all subgroups of interest. No new safety signals were observed. Lenvatinib plus pembrolizumab continued to show improved efficacy versus chemotherapy and manageable safety in patients with previously treated advanced EC.