Cimeio Therapeutics Presents Additional Proof-of-Concept Data for SCIP Platform

–Poster session at ASGCT meeting describes key progress with shielded CD45 cells–

Cambridge, MA and Basel, Switzerland, May 16, 2023

Cimeio Therapeutics, a biotechnology company developing a novel approach to cell therapies, presented data for its CD45 Shielded Cell & Immunotherapy Pair (SCIP) program at the American Society of Gene and Cell Therapy’s Annual Meeting in Los Angeles. The findings build upon prior successful studies using CD117 and CD123 variants and collectively provide further proof of concept for Cimeio’s platform, which offers a novel and promising therapeutic approach to improve the outcomes for patients with benign and malignant hematological diseases in need of a hematopoietic stem cell (HSC) transplant.

The new study demonstrates that a genetically engineered variant of the cell surface receptor CD45 is fully functional and, importantly, evades a paired immunotherapy directed against the wild-type molecule.

CD45 is a pan-hematopoietic marker critical for the function of immune cells. While eradication of CD45+ cells could represent a universal approach to reset the hematopoietic system for hematologic malignancies or severe autoimmune diseases, the current application of CD45-targeted cell-depleting therapies is limited by potentially severe toxicities due to the near ubiquitous expression of the target on hematopoietic cells. In contrast, the molecular shielding of CD45 will allow a patient to develop a healthy, protected and fully functional hematopoietic system, ensuring the paired immunotherapy targets just the diseased host cells.

A poster titled, “Molecular Shielding of the Pan-Hematopoietic Marker CD45 May Enable a Targeted Universal Approach for Replacement of the Hematopoietic System,” was authored by Lukas T. Jeker, M.D., Ph.D., co-founder of Cimeio and Professor of Experimental Transplantation Immunology & Nephrology at the Department of Biomedicine, University of Basel and at the Basel University Hospital, Switzerland.

Key takeaways from the poster are as follows:

  • Engineered HSCs were generated expressing a stable variant of CD45 and demonstrated no binding to the paired immunotherapy
  • A novel, humanized, potent CD45-targeting antibody-drug conjugate (ADC) was developed that killed CD45 cancer cells in vitro while sparing edited cells from depletion
  • In vivo experiments showed efficient engraftment and differentiation of the engineered CD45 variant HSCs, as well as shielding and strong enrichment in combination with the CD45 immunotherapy

“Cimeio’s platform continues to show potential as a safe and efficient method to enable HSC transplants for patients suffering from a variety of severe diseases,” said Dr. Jeker. “I look forward to the continued progress of the CD45 program, as well as the additional programs in the company’s deep pipeline of medicines.”

About Cimeio

Cimeio is an applied gene editing and immunotherapy company developing a portfolio of Shielded-Cell & Immunotherapy Pairs™ (SCIP), which has the potential to transform hematopoietic stem cell transplant. Cimeio’s technology platform is based on the design and expression of modified variants of naturally occurring cell surface proteins in HSCs. These novel variants maintain their function but are resistant to depletion when targeted by a paired immunotherapy which has high affinity for the wild-type version of these proteins. This technology has significant therapeutic potential, which Cimeio is using to develop curative treatments for patients with genetic diseases, hematologic malignancies, and severe autoimmune disorders. For more information, please visit

Steve Edelson

ASGCT Abstract

899 Molecular Shielding of the Pan-Hematopoietic Marker CD45 May Enable a Universal Approach for Replacement of the Hematopoietic System

We recently demonstrated that single amino acid substitutions engineered into CD123 or CD117 expressed by hematopoietic stem and progenitor cells (HSPCs) protected the cells from cytotoxicity by matching immunotherapies but preserved CD123 and CD117 function, respectively. Here, we describe the identification of a CD45 shielding variant paired with the development of a new and potent CD45-targeting ADC (CIM053-ADC).