iLeukon Therapeutics Inc, a San Diego-based clinical-stage biotechnology company, announced on Tuesday new clinical results from the ongoing first-in-human Phase I trial (NCT05978102) of ILKN421H.

These results were revealed at the 2025 Society for Immunotherapy of Cancer (SITC) Annual Meeting in National Harbor, Maryland.

This study assessed ILKN421H, a lipid-nanoparticle (LNP)-formulated mRNA encoding a non-alpha HSA–IL-2 variant (IL-2v), as monotherapy along with pembrolizumab in patients with advanced solid tumours, including first-line non-small cell lung cancer (NSCLC). The presentation highlighted the product's unique scientific design and distinct pharmacologic advantages that enable potent immune activation with a favourable safety profile.

The benefits of ILKN421H in preclinical research include Stem-like CD8+ T Cell Amplification, Lymphoid specific expression and reduced systemic exposure and overcoming the Cytokine-Sink effect and a remarkable amplification of CD8+ T and NK cells.

According to the company, ILKN421H was well tolerated with no dose-limiting toxicities (DLTs) and the maximum tolerated dose (MTD) was not reached. It was also seen in the study that there were no Grade 4 adverse events (AEs), no treatment-related deaths, and no serious adverse events (SAEs) occurring in over one patient.