ClinicalTrials.gov posted results on 2026-08-04 for NCT03917381, a phase 1/2 study in patients with solid tumors that included pembrolizumab in combination cohorts. The record listed 429 enrolled participants and reported dose-escalation safety findings for acasunlimab, also known as GEN1046.
Background
The trial, titled GEN1046 Safety Trial in Patients With Malignant Solid Tumors, evaluated acasunlimab alone and with standard treatments, including docetaxel and pembrolizumab, with or without chemotherapy. According to the record, all subjects received active drug and no one received placebo.
Trial design
This was an ACTIVE_NOT_RECRUITING phase 1/2 study in solid tumors. The posted results cover dose-escalation cohorts of acasunlimab at 25 mg, 50 mg, 80 mg, 100 mg, 140 mg, 200 mg, 400 mg, 800 mg, and 1200 mg. The record also listed expansion cohorts combining acasunlimab with pembrolizumab and with pembrolizumab and standard chemotherapy.
Key results
Dose-limiting toxicities were reported in 1 participant at 25 mg, 0 at 50 mg, 1 at 80 mg, 0 at 100 mg, 2 at 140 mg, 1 at 200 mg, and 0 at 400 mg, 800 mg, and 1200 mg.
Treatment-emergent adverse events were reported in 4 participants at 25 mg, 5 participants at 50 mg, and 9 participants at 80 mg in the posted dose-escalation data.
What this means
The posted record provides an early safety snapshot for acasunlimab programs that include pembrolizumab combination testing in solid tumors. The presence of dose-limiting toxicities in some cohorts, alongside the reported adverse-event counts, gives clinicians and researchers a concrete look at tolerability across the tested dose range, although the posted data do not include efficacy outcomes.
Source
This information is based on ClinicalTrials.gov trial results for NCT03917381, posted on 2026-08-04. The record is available at clinicaltrials.gov.