Immune-Onc Therapeutics has announced data from the dose escalation part of the Phase I trial of IO-202, a IgG1 monoclonal antibody, for the treatment of acute myeloid leukaemia (AML) and chronic myelomonocytic leukaemia (CMML).

Evaluating the tolerability and safety of IO-202 in successive cohorts of relapsed or refractory (R/R) AML and CMML patients is the primary objective of the open-label, multicentre study.

The clinical response rate of IO-202 as a single agent and in combination with azacitidine (AZA), as well as the assessment of the pharmacokinetics, immunogenicity, and pharmacodynamic biomarker effects are included as secondary and exploratory objectives.

IO-202 was found to be well-tolerated with no dose-limiting toxicities and a maximum tolerated dose was not reached.

One AML patient treated in the monotherapy cohorts achieved a partial response while one CMML patient demonstrated clinical benefit for more than a year.

Complete Remission has been achieved in an AML patient with high LILRB4 expression treated in the combination therapy cohorts and will be ongoing for over ten months.

Three of five CMML patients in these cohorts achieved clinical benefits, including optimal marrow response.

Immune-Onc chief medical officer Paul Woodard said: “Based on the data, we have developed a patient enrichment strategy for the ongoing dose expansion Phase of the study to select AML patients who would most likely respond to IO-202.

“We are also pleased to receive the FDA Fast Track designation for IO-202 for the treatment of R/R CMML, which follows the R/R AML Fast Track designation received in 2022.

“We look forward to working closely with the FDA and trial investigators to accelerate the clinical development of IO-202 in hematologic malignancies.”