Cimeio Therapeutics Presents Data for its CD45 Universal Heme ADC at ASH

— Preclinical data for Cimeio’s CD45 universal heme ADC and shielded HSCs demonstrate effective depletion of an aggressive AML cell line in vivo —

— First data for Cimeio’s CD33 shielded HSCs show that cells are protected from antibody binding while maintaining CD33 receptor expression —

Basel, Switzerland and Cambridge, MA, December 11, 2023

Cimeio Therapeutics, the leading biotechnology company in the field of epitope shielding, presented data for its CD45 and CD33 programs during this weekend’s American Society of Hematology (ASH) meeting in San Diego. The two studies provide further evidence that epitope editing allows for the development of powerful immunotherapies that would not be safe to administer without first protecting healthy cells.

The first abstract, titled “Hematopoietic Stem Cells Expressing Engineered CD45 Enable a Near Universal Targeted Therapy for Hematologic Diseases,” demonstrated the efficacy of Cimeio’s proprietary CD45 targeting ADC (CIM053-ADC) at depleting an aggressive AML cancer cell line in vivo, while the CD45 engineered HSCs were fully protected, engrafted and reconstituted the hematopoietic system in humanized mice. After just two doses of CIM053-ADC, all mice were cancer-free while the healthy hematopoietic cells were unaffected. This study demonstrates the potential of CD45-targeted ADC therapy for patients with hematologic malignancies.

The second abstract, titled “Base Edited HSPCs Are Shielded From CD33 Therapy but Preserve CD33 Expression,” showed how Cimeio’s CD33 shielding variant effectively protected cells from a CD33 antibody, while maintaining CD33 expression. CD33 is a useful target for AML and other diseases of HSCs.

Collectively, these studies further underscore the potential for Cimeio’s therapies, when coupled with its shielding technology, to transform the treatment of hematologic malignancies, genetic, and autoimmune diseases.

“AML patients who have residual disease at the time of a bone marrow transplant have a high risk for relapse,” said Corey Cutler, M.D., M.P.H., Medical Director of the Stem Cell Transplantation Program at the Dana Farber Cancer Institute and Professor of Medicine at Harvard Medical School. “An effective therapy that could be given post-transplant to treat residual disease and prevent relapse, but would not affect the newly transplanted cells, would be a real advancement in the way we treat AML. Bone marrow transplant has the potential to cure patients of their leukemia, and improving upon this approach through epitope shielding and novel post-transplant therapies is an exciting possibility.”

About Cimeio

Cimeio is the leader of the field of epitope editing and is developing a portfolio of Shielded-Cell & Immunotherapy Pairs™ (SCIP), novel immunotherapies which have the potential to transform treatment of hematologic diseases. Cimeio develops state-of-the-art immunotherapies, along with paired, modified variants of naturally occurring cell surface proteins in HSCs. These novel epitope edited variants maintain their function but are resistant to depletion when targeted by the paired immunotherapy which has high affinity for the wild-type version of these proteins. These immunotherapies have significant therapeutic potential, which Cimeio is using to develop curative treatments for patients with hematologic malignancies, autoimmune disorders, and genetic diseases. Shielded Cell and Immunotherapy Pairs and SCIP are trademarks of Cimeio Therapeutics, Inc. For more information, please visit

Steve Edelson