Immune-Onc Therapeutics Announces Publication of Positive Phase 1 Results for IO-202 in CMML and AML in Blood Neoplasia
– Study shows rapid and durable responses in HMA-naïve CMML and monocytic AML, with positive correlation to LILRB4 expression –
– 100% of efficacy-evaluable HMA-naïve CMML patients experienced clinical benefits–
– IO-202 was well tolerated both as monotherapy and in combination with standard of care in a total of 69 CMML and AML patients treated –
PALO ALTO, CA, Sept. 2, 2025 -- Immune-Onc Therapeutics, Inc. (“Immune-Onc”), a private, clinical-stage biopharmaceutical company advancing novel therapies in immunology and oncology by targeting myeloid cell inhibitory receptors, today announced the publication of comprehensive data from its Phase 1 clinical study of IO-202, a first-in-class anti-LILRB4 antibody, in Blood Neoplasia. The paper reports on the Phase 1a dose escalation data of IO-202 as monotherapy and in combination with azacitidine (AZA) in patients with relapsed/refractory (R/R) acute myeloid leukemia (AML) and R/R chronic myelomonocytic leukemia (CMML), as well as the Phase 1b dose expansion data of IO-202 combined with AZA for the treatment of hypomethylating agent (HMA)-naïve CMML.
Across both Phase 1a and Phase 1b, the study demonstrated that IO-202, as monotherapy or in combination with azacitidine (AZA), was well tolerated and showed encouraging efficacy signals in patients with HMA-naïve CMML and monocytic AML, two diseases with limited treatment options and poor outcomes.
“CMML is an undertreated cancer where current therapies often fall short, especially for patients with aggressive disease or mutations linked to poor outcomes,” said Courtney DiNardo, M.D., MSCE, lead study investigator and a professor in the Department of Leukemia at the University of Texas MD Anderson Cancer Center in Houston. “In this study, we saw rapid and durable responses across clinical and molecular subgroups, including patients with high-risk mutations like ASXL1 and KRAS, which are associated with drug resistance and disease progression.”
Among 18 efficacy-evaluable HMA-naïve CMML patients in the dose expansion cohort, all (100%) achieved some form of investigator-assessed clinical benefit, including symptomatic improvement, a decrease in transfusions, reduced blasts and/or monocytes, and resolution of thrombocytopenia. The complete response (CR) rate was 27.8%, and the overall response rate (ORR) was 66.7% as defined by IWG 2015 criteria.1 Seven of these 18 patients (38.9%) were bridged to allogeneic hematopoietic cell transplantation, the only treatment currently recognized as potentially curative in CMML. Among patients with high LILRB4 expression (n=6), the CR rate was 33.3% and the ORR was 100%, supporting IO-202’s mechanism of action via antibody-dependent cellular cytotoxicity and antibody-dependent cellular phagocytosis.
“These results reinforce the potential of IO-202 to make a difference for people living with myeloid malignancies with very limited treatment options available,” said Charlene Liao, Ph.D., chief executive officer of Immune-Onc. “We are particularly encouraged by the activity seen in HMA-naïve CMML and the opportunity to quickly bring a novel therapy to patients who need better outcomes. As we move toward a pivotal study, our focus remains on delivering meaningful therapeutic advances for patients.”
The full manuscript is now available online in Blood Neoplasia. To access the paper, visit https://www.sciencedirect.com/science/article/pii/S2950328025000615.
ABOUT ACUTE MYELOID LEUKEMIA (AML)
AML, the most common acute leukemia (blood and bone marrow cancer) in adults, is characterized by the proliferation of abnormal myeloblasts (a type of white blood cell) in the bone marrow. Nearly 20,000 new cases are expected in the U.S. in 2020.2 Despite advances in treatment, fewer than 30 percent of AML patients are alive five years after initial diagnosis.3
ABOUT CHRONIC MYELOMONOCYTIC LEUKEMIA (CMML)
CMML is a rare form of blood cancer, with an incidence predicted to increase due to more permissive diagnostic criteria by both the World Health Organization (WHO) and the International
Consensus Classification (ICC).4,5 To date, three hypomethylating agents (HMAs) have been approved to treat CMML based on studies that predominantly enrolled patients with myelodysplasia syndrome (MDS), with only a small subset of patients with CMML included.7
ABOUT LILRB4 (also known as ILT3)
LILRB4, also known as ILT3, is an immune-modulatory transmembrane protein found on monocytes and monocyte-derived cells. LILRB4 is expressed on certain hematologic cancer cells, such as myelomonocytic leukemia blasts, and on certain pathogenic cells involved in autoimmunity and inflammatory processes.
ABOUT IO-202
IO-202 is a first-in-class IgG1 antibody with specific, high-affinity binding to LILRB4 and depletes LILRB4-positive cells via antibody-dependent cellular cytotoxicity and antibody-dependent cellular phagocytosis. As a targeted therapy, IO-202 has broad potential in blood cancers.
IO-202 has successfully completed a first-in-human, multicenter, open-label Phase 1 study in the U.S., which included dose escalation in patients with relapsed/refractory (R/R) acute myeloid leukemia (AML) and R/R chronic myelomonocytic leukemia (CMML), and dose expansion in hypomethylating agent (HMA)-naïve CMML patients.
The U.S. Food and Drug Administration granted IO-202 Fast Track Designations for the treatment of patients with relapsed or refractory acute myeloid leukemia (AML) and relapsed or refractory CMML, respectively. The FDA has also granted IO-202 Orphan Drug Designations for the treatment of AML and CMML, respectively.
ABOUT IMMUNE-ONC THERAPEUTICS, INC.
Immune-Onc Therapeutics Inc. (“Immune-Onc”) is a private, clinical-stage biopharmaceutical company developing novel therapies in immunology and oncology by targeting myeloid cell inhibitory receptors.
Immune-Onc has a differentiated pipeline with a current focus on targeting the Leukocyte Immunoglobulin-Like Receptor subfamily B (LILRB). Immune-Onc’s focused platform approach has led to the development of several promising therapeutics across various stages of development. These include IO-108, an antagonist antibody targeting LILRB2 (also known as ILT4), in Phase 1b/2 clinical development for solid tumors, and IO-202, a first-in-class antibody targeting LILRB4 (also known as ILT3), in Phase 1b clinical development for the treatment of acute myeloid leukemia (AML) and chronic myelomonocytic leukemia (CMML). Additional assets in Immune-Onc’s pipeline include IO-312 (a novel bispecific antibody targeting LILRB4 and CD3), IO-106 (first-in-class antagonist antibody targeting LAIR1), and undisclosed immunology and oncology programs.
Immune-Onc has established agreements with leading biopharmaceutical companies, including BeOne, Regeneron and Roche, to support its global product development plans for IO-108 and IO-202. It has received research grants from the National Cancer Institute (NCI) of the National Institutes of Health (NIH) and the California Institute for Regenerative Medicine (CIRM) and investment from The Leukemia & Lymphoma Society Therapy Acceleration Program® (LLS TAP®). Headquartered in Palo Alto, California, Immune-Onc has assembled a diverse team with deep expertise in drug development and proven track records of success at leading biopharmaceutical companies. For more information, please visit www.immune-onc.com and follow us on X and LinkedIn.
MEDIA CONTACT
Tara Cooper
The Grace Group
tara@gracegroup.us
media@immuneonc.com
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