The enzyme arginase-1 (ARG1) plays a role in immune regulation through the degradation of the amino acid L-arginine. A depletion of L-arginine suppresses T cell function. ARG1-producing cells in the tumor microenvironment thereby inhibit L-arginine-dependent T cell-mediated anti-tumor effects. ARG1-specific anti-regulatory T cells (anti-Tregs) have been identified in cancer patients and healthy donors. We hypothesize that the ARG1 peptide vaccine will activate and stimulate ARG1-specific anti-Tregs to proliferate and infiltrate the otherwise immunosuppressive tumor microenvironment.
The aim of the study is to assess the safety and immunomodulatory characteristics of an ARG1 peptide vaccine in patients with metastatic solid tumors.
In this clinical phase I trial we aim to treat ten patients with metastatic solid tumors following the treatment with standard of care agents. The ARG1 peptide vaccines will be administered subcutaneously every third week for 45 weeks. The primary endpoint is to evaluate safety and toxicity. Immune responses will be assessed using blood- and tumor tissue samples. Clinical responses are evaluated using RECIST 1.1.
Eudra CT no: 2018-000719-26