Agenus Highlights Cell Therapy–Driven Immune Priming Strategy in PD-1 Refractory Gastroesophageal Cancer

Apr 18, 2026-

Agenus Inc. announced new data from an investigator-initiated Phase II study conducted at Memorial Sloan Kettering Cancer Center evaluating a multi-agent immunotherapy and cell therapy regimen in patients with advanced PD-1 refractory gastroesophageal adenocarcinoma. The findings were presented at the AACR Annual Meeting 2026, highlighting a novel immune priming and treatment sequencing strategy in a patient population with significant unmet need.

The study evaluated a combination of botensilimab and balstilimab with agenT-797, MiNK Therapeutics’ allogeneic invariant natural killer T (iNKT) cell therapy, alongside ramucirumab and paclitaxel. Investigators explored whether induction treatment with agenT-797, administered alone or with checkpoint inhibitors, could enhance downstream responses when followed by the full combination regimen.

In the study population (n=17), the regimen achieved a disease control rate of 77%, with a subset of patients experiencing survival beyond 20 months. Patients receiving the induction strategy demonstrated improved progression-free survival, with a median of 6.9 months compared to 3.5 months in those treated without induction. Overall survival also trended higher in the induction group, reaching 9.5 months versus 5.2 months, with 43% of induction-treated patients remaining alive at both 12 and 18 months.

Although the study did not meet its primary endpoint of overall response rate, the durability of disease control and survival outcomes suggests meaningful clinical activity in this refractory setting. Correlative analyses revealed increased intratumoral T cell and dendritic cell infiltration, activation of peripheral CD4 and CD8 T cells, and formation of tertiary lymphoid structures, supporting the role of immune priming and tumor microenvironment reprogramming.

The safety profile was consistent with the known effects of the individual therapies, with common adverse events including fatigue, fever, gastrointestinal symptoms, and immune-related toxicities. Ongoing biomarker analyses are expected to further refine patient selection and optimize sequencing strategies for future studies.