Immune-Onc Therapeutics has announced the dosing of the first subject in its Phase I clinical trial designed to evaluate IO-202 for treating advanced solid tumour patients.

The first-in-class myeloid checkpoint inhibitor IO-202 acts on Leukocyte Immunoglobulin-Like Receptor B4 (LILRB4, which is also known as ILT3).

The clinical trial comprises dose escalation and dose expansion portions.

During the dose escalation, the tolerability, safety, pharmacokinetics, and pharmacodynamics of IO-202 will be evaluated alone and in combination with anti-PD-1 pembrolizumab.

The dose expansion part will use the recommended dose of IO-202 for the Phase II trial in combination with pembrolizumab in multiple types of solid tumours.

Furthermore, the trial will explore various biomarkers for a mechanistic understanding of clinical data and inform future trials.

The trial is expected to provide an opportunity for identifying IO-202’s preliminary efficacy signals as a single agent and as a combination with a PD-1 inhibitor in advanced solid tumour patients.

Immune-Onc Therapeutics chief medical officer Paul Woodard said: “We are very pleased to announce the initiation of our Phase I study of IO-202 in solid tumours, a significant achievement in our development strategy targeting the LILRB family of myeloid checkpoints to overcome immune suppression in the tumour microenvironment.

“We believe by targeting the LILRB4 checkpoint, IO-202 may reverse the immunosuppressive effects of tumour-associated monocytic myeloid cells, enhance dendritic cell function, and promote T cell activation – thereby, unleashing the antitumour activities of the immune system and increasing the therapeutic benefit of T cell checkpoint inhibitors.”

IO-202 has broad potential as an immunotherapy in blood cancers as well as solid tumours and is currently being evaluated in two clinical studies.

This January, Immune-Onc obtained the US Food and Drug Administration approval for its Investigational New Drug application to start the trial of IO-202.