Immune-Onc Therapeutics to Present Positive Interim Data from IO-202 Phase 1b in CMML at 2024 EHA Congress

Immune-Onc Therapeutics, Inc. ("Immune-Onc"), a clinical-stage biopharmaceutical company specializing in novel therapies for immunology and oncology by targeting myeloid cell inhibitory receptors, recently announced that it will present additional positive interim Phase 1b expansion cohort data for IO-202 in patients with chronic myelomonocytic leukemia (CMML) at the 2024 European Hematology Association (EHA) Annual Meeting. The meeting will be held both virtually and in Madrid, Spain, from June 13 to 16.

Chronic myelomonocytic leukemia (CMML) is a rare hematologic malignancy characterized by poor survival outcomes and a lack of effective standard therapies. Current treatment options are limited to hypomethylating agents (HMA) such as azacitidine (AZA), which only achieve a complete remission (CR) rate of 7-17%. CMML remains incurable with conventional therapy and poses a risk of progressing into acute myeloid leukemia (AML).

In the interim data from the Phase 1b study, patients with CMML treated with a combination of IO-202 and AZA showed promising early-cycle responses. A 53.8% CR rate (7 out of 13 patients) was observed, with remissions lasting ten months and ongoing. These results were based on the International Working Group 2023 response criteria. Additionally, IO-202 demonstrated favorable tolerability.

Dr. Courtney DiNardo, a Phase 1b investigator and professor at the University of Texas MD Anderson Cancer Center, emphasized the critical need for innovative treatments for CMML due to its poor prognosis and potential progression to AML. Dr. DiNardo expressed optimism regarding the Phase 1b trial data, which showed sustained complete remissions among CMML patients, supporting the potential of IO-202 in combination with AZA as a frontline therapy for CMML.

Charlene Liao, Ph.D., CEO of Immune-Onc, highlighted the favorable tolerability and consistent efficacy response of IO-202. She stated that the drug's mechanism of action is well understood, supporting its further study as a treatment option for both AML and CMML patients. Liao also mentioned the company's plans to collaborate with investigators and the FDA for a registrational study in frontline CMML patients.

The details of the poster presentation are as follows:
- Abstract Number: P792
- Title: Targeting LILRB4 (ILT3) Using IO-202 in Patients with Chronic Myelomonocytic Leukemia (CMML): Interim Efficacy, Safety, and Mechanism of Action Data from the Phase 1b Expansion Cohort
- Presenter: Dr. Ahmed Aribi, assistant professor, Division of Leukemia, City of Hope in Duarte, CA
- Session Title: Myelodysplastic Syndromes – Clinical
- Session Date and Time: Friday, June 14, 6-7 p.m. CEST

Chronic myelomonocytic leukemia (CMML) is a rare blood cancer affecting approximately 1,100 individuals annually in the United States. It is characterized by a high monocyte count and dysplastic features in the bone marrow. The only FDA-approved therapies for CMML are hypomethylating agents, including azacitidine, which have a limited complete response rate.

LILRB4 (also known as ILT3) is an immune-modulatory transmembrane protein found on monocytes and monocyte-derived cells. It is expressed on certain hematologic cancer cells, such as myelomonocytic leukemia blasts, and on pathogenic cells involved in autoimmunity and inflammatory processes.

IO-202 is a first-in-class IgG1 antibody with specific, high-affinity binding to LILRB4. It depletes LILRB4 positive cells via antibody-dependent cellular cytotoxicity and antibody-dependent cellular phagocytosis, making it a targeted therapy with broad potential in blood cancers and autoimmune and inflammatory diseases. IO-202 has completed the dose escalation part of its first-in-human, multicenter, open-label Phase 1 study in the U.S. and has advanced to the dose expansion stage to evaluate its combination with azacitidine in newly diagnosed CMML patients.

The U.S. Food and Drug Administration (FDA) has granted IO-202 Fast Track Designations and Orphan Drug Designations for the treatment of patients with relapsed or refractory acute myeloid leukemia (AML) and relapsed or refractory CMML.