A total of 850 patients were randomly assigned to the investigational (423 patients) and control (427 patients) arms: 421 and 426 of whom were treated in the respective arms. In the investigational arm, 2 patients completed treatment and 93 patients remained on therapy. Reasons for discontinuation included progressive disease (206 patients), side effects (72 patients), clinical progression (25 patients), patient decision (18 patients), physician decision (3 patients), and protocol violation (2 patients). In the control arm, 23 patients completed treatment and 70 patients remained on therapy. Reasons for discontinuation included progressive disease (202 patients), side effects (73 patients), clinical progression (22 patients), patient decision (25 patients), physician decision (10 patients), and follow-up loss (1 patient).
Baseline characteristics were well balanced between treatment groups, Sun said. Within the investigational arm, the median age was 64; 49% were above 65. Most patients were male (78%), Asian (66%), and from East Asia (66%). ECOG performance status was 1 in 64% of cases, and most patients had a PD-L1 CPS of 10 or greater (66%). Ninety-nine percent of patients did not have brain metastases and had stage 4B disease. The preferred choice of chemotherapy was modified FOLFOX6 (65%), followed by FP (24%) and TP (10%).
Per the study design, efficacy was evaluated in all randomized patients, whereas safety was limited to all randomized patients who received at least one dose of study therapy. PFS and ORR were not tested for statistical significance since OS was not positive. The data cutoff for this analysis was May 8, 2025, at which point approximately 482 OS events had occurred, or 42 months had passed since the first participant had been randomized.
What Additional Efficacy Data Were Presented?
Sun stated that the OS results were consistent across prespecified subgroups, including PD-L1 status (CPS greater or equal to 10 versus CPS less than 10), region (East Asia versus North America and Western Europe versus rest of the world), and chemotherapy (FP versus TP versus modified FOLFOX).
Additional results indicated that the median PFS in all randomized patients was 7.2 months in the Lenvima arm versus 6.9 months in the control arm. The 12- and 24-month PFS rates were 31% and 12% in the investigational arm versus 23% and 15% in the control arm.
The median PFS in patients with a PD-L1 CPS of at least 10 was 8.1 months in the Lenvima arm versus 6.9 months in the control arm. The 12- and 24-month PFS rates were 36% and 16% in the investigational arm versus 25% and 14% in the control arm.
The ORR was 62.2% in the Lenvima arm versus 54.8% in the chemoimmunotherapy arm. In the Lenvima arm, best responses included complete response (16.3%), stable disease (22%), and progressive disease (8%); 7.3% of patients were not evaluable. In the control arm, best responses included complete response (19.2%), partial response (35.6%), stable disease (29.7%), and progressive disease (8.9%); 5.4% of patients were not evaluable.
The median DOR was 8.1 months in the Lenvima arm and 17% of patients experienced a response lasting 24 months or longer. In the control arm, the median DOR was 6.8 months and 21% of patients experienced a response lasting at least 24 months.
What Were the Key Safety Data That Were Presented?
The median duration of treatment exposure was 7.1 months in the Lenvima arm versus 5.6 months in the control arm. In the investigational arm, any-grade side effects occurred in 99.5% of patients (grade 3 [severe] or higher, 81.2%; grade 5 [death], 9.7%). Side effects leading to drug discontinuation occurred in 33.3% of patients. Treatment-related side effects occurred in 97.1% of patients.
In the control arm, any-grade side effects occurred in 99.3% of patients (grade 3 or higher, 79.1%; grade 5, 11.5%). Side effects leading to drug discontinuation occurred in 39% of patients. Treatment-related side effects occurred in 96.5% of patients.
Side effects that occurred in at least 15% of patients in either arm in order of frequency were decreased neutrophil count, nausea, hypertension, diarrhea, decreased platelet count, anemia, hypothyroidism, stomatitis, decreased white blood cell count, fatigue, decreased appetite, palmar plantar erythrodysesthesia syndrome, proteinuria, aspartate aminotransferase increase, vomiting, rash, weight decrease, constipation, alanine aminotransferase increase, pyrexia, increased lipase, increased amylase, peripheral neuropathy, hypoalbuminemia, and pneumonia.
Immune-mediated side effects and infusion reactions in the experimental arm included adrenal insufficiency, colitis, encephalitis, gastritis, hepatitis, hyperthyroidism, hypophysitis, hypothyroidism, infusion reactions, myocarditis, myositis, nephritis, pancreatitis, pneumonitis, severe skin reactions, thyroiditis, type 1 diabetes mellitus, and vasculitis.
“Safety profiles were generally consistent with the known safety profiles of Lenvima in combination with Keytruda and chemotherapy or the Keytruda plus chemotherapy regimen,” Sun concluded.
References
- “Lenvatinib Plus Pembrolizumab and Chemotherapy Versus Pembrolizumab and Chemotherapy in Untreated Metastatic Esophageal Squamous Cell Carcinoma” by Dr. Jong-Mu Sun, et al., ESMO Congress 2025.
- “Efficacy and Safety of Pembrolizumab Plus Lenvatinib Plus Chemotherapy in Participants With Metastatic Esophageal Carcinoma” by Dr. Jong-Mu Sun, et al., ClinicalTrials.gov.
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