Elixirgen Therapeutics Presents New Clinical Data Demonstrating Ex Vivo Telomere Elongation with EXG-34217 in Dyskeratosis Congenita at the 64th ASH Annual Meeting

  • Treatment with EXG-34217 increased the telomere length of CD34+ cells by 1.24-fold ex vivo
  • Telomere flow-FISH study suggests the potential emergence of a cell population with longer telomeres in vivo
  • No acute or long-term adverse effects were observed for 9 months

BALTIMORE, December 12, 2022 – Elixirgen Therapeutics, Inc., a clinical-stage biotechnology company focused on the discovery, development and commercialization of therapies using its controllable self-replicating RNA (c-srRNA) platform, today announced new data from a Phase 1/2 trial (NCT04211714) showing successful ex vivo telomere elongation with lead asset, EXG-34217 (autologous CD34+ hematopoietic stem cells that have been treated ex vivo with EXG-001), in a patient with dyskeratosis congenita, a telomere biology disorder (TBD) that can lead to bone marrow failure. In addition, the telomere flow-FISH study suggests the potential emergence of a cell population with longer telomeres in vivo. The data were presented in an oral presentation at the 64th American Society of Hematology (ASH) Annual Meeting, taking place December 10-13, 2022 in New Orleans, Louisiana.

“The encouraging data in this study represent the first time that ex vivo telomere elongation of CD34+ cells has been demonstrated in a patient with TBD. Dyskeratosis congenita has historically been characterized by a triad of abnormalities in the skin, nails and oral mucosa but can also include pulmonary and liver disease,” said Kasiani C. Myers, M.D., associate professor, Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, and principal investigator in the study. “In addition, due to the shortened telomeres, most patients develop bone marrow failure, which requires the need for hematopoietic stem cell transplantation (HSCT), a procedure that is accompanied with potentially life-threatening complications. The data presented here provide promising early signs of the potential of EXG-34217 to provide an alternative treatment option for bone marrow failure in these patients and their families.”

Presentation Title: Successful ex vivo telomere elongation with EXG-001 in a patient with a dyskeratosis congenita

Session Name: Gene Therapies: Advances in Clinical Gene Therapy for Hematological Disorders

Publication Number: 781

Presenter: Kasiani C. Myers, M.D., Associate Professor, Department of Pediatrics, Cincinnati Children’s Hospital Medical Center

Key Findings:

  • Zinc finger and SCAN domain containing protein 4 (ZSCAN4) is a protein that regulates telomere elongation and enhances genome stability.
  • EXG-001 is a temperature-sensitive Sendai virus vector encoding for human ZSCAN4, which is non-integrating and non-transmissible. EXG-34217 is a dose of autologous CD34+ hematopoietic stem cells (HSCs) that have been treated ex vivo with EXG-001.
  • In this Phase 1/2 trial, 2.8×106 CD34/kg were collected and treated with EXG-001 ex vivo in a functionally closed tubing system using the CliniMACS Prodigy (Miltenyi Biotec).
  • Treatment increased the telomere length of the CD34+ cells by 1.24-fold, bringing them into the healthy control range.
  • 0.85×106 CD34/kg autologous treated HSC (EXG-34217) were reinfused into the subject in February 2022 without a conditioning regimen.
  • The telomere flow-FISH study suggests the potential emergence of a cell population with longer telomeres in vivo.
  • No acute or long-term adverse effects were observed up to 9 months, and the differentiation potential of the CD34+ cells did not change after treatment.

Akihiro Ko, chief executive officer of Elixirgen Therapeutics, added, “We’re pleased to share these early positive data from our lead indication at a prestigious conference like ASH. This is a critical milestone in a process that started with the identification of ZSCAN4 by our Chief Scientific Officer, Dr. Minoru Ko, at the NIH. Our nuanced understanding of this protein has allowed us to create a novel potential treatment approach for TBD that is genotype and mutation independent. In addition, the absence of a conditioning regimen or immunosuppression is of significant importance in this radiation and chemotherapy sensitive population. We look forward to sharing additional data as we continue to enroll patients with our partners at Cincinnati Children’s Hospital Medical Center.”

About Elixirgen Therapeutics, Inc.

Elixirgen Therapeutics, Inc. is a clinical-stage biotechnology company focused on the discovery, development and commercialization of therapies using its controllable self-replicating RNA (c-srRNA) platform. The company has two products in Phase 1/2 clinical trials (NCT04211714 and NCT04863131). For more information, visit ElixirgenTherapeutics.com.

Forward-Looking Statements

This press release may contain “forward-looking” statements. Actual results may differ materially from those set forth in this press release due to the risks and uncertainties inherent in pharmaceutical research and development. Any forward-looking statements in this press release speak only as of the date of this press release, and Elixirgen Therapeutics undertakes no obligation to update or revise the statements in the future, even if new information becomes available.

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