Abcuro Initiates Registrational Phase 2/3 Study of ABC008 for the Treatment of Inclusion Body Myositis

ABC008 potently and selectively depletes highly cytotoxic T cells which attack and destroy muscle tissue in IBM without affecting protective T cell populations

Abcuro, Inc., a clinical-stage biotechnology company developing therapies for the treatment of autoimmune diseases and cancer through precise modulation of cytotoxic T and NK cells, today announced initiation of a registrational Phase 2/3 study of ABC008 in inclusion body myositis (IBM). ABC008 is a first-in-class anti-KLRG1 antibody capable of selectively depleting highly cytotoxic T cells, while sparing regulatory and central memory T cells.

IBM is an autoimmune disease in which highly cytotoxic T cells chronically attack muscle tissue causing patients to progressively lose muscle function, including loss of grip, dexterity, and mobility. Muscle tissue from patients with IBM shows the presence of highly differentiated, KLRG1+ cytotoxic T cells destroying muscle fibers. There are currently no available disease-modifying treatment options for IBM.

“This registrational Phase 2/3 trial in IBM represents an important milestone for patients with IBM,” said Jeffrey Wilkins, M.D., Chief Medical Officer of Abcuro. “It builds upon the compelling proof-of-mechanism observed with ABC008 to potently and selectively deplete highly cytotoxic T cells which attack and destroy muscle tissue in IBM, without affecting protective T cell populations. This approach differentiates ABC008 from broad T cell depleters whose use have been limited by adverse effects associated with broad immune-cell depletion.”

In the Phase 1 trial, potent, durable, and dose-dependent depletion of CD8+KLRG1+ T cells, the most highly cytotoxic T cells, was observed. At the dose levels being used in the Phase 2/3 trial, near complete (97%) depletion of blood target cells was observed at 28 days post injection. The registrational Phase 2/3 trial will enroll more than 200 patients across 30 global sites. Additional details about the trial are available on ClinicalTrials.gov (NCT05721573).

“There are currently no available therapeutic options for IBM, which can lead to severe disability,” said Steven A. Greenberg, M.D., co-founder of Abcuro and Chief Scientific Advisor. “We look forward to advancing ABC008 in this Phase 2/3 trial and providing a potential first-in-class therapeutic for patients in need of treatment."

About ABC008

ABC008 is a first-in-class anti-KLRG1 antibody capable of selectively depleting highly cytotoxic T cells, while sparing regulatory and central memory T cells. ABC008 has been designed to treat diseases mediated by highly cytotoxic T cells, including the autoimmune muscle disease inclusion body myositis (IBM), T cell large granular lymphocytic leukemia (T-LGLL), and mature T cell malignancies. The US Food and Drug Administration (FDA) has granted Orphan Drug Designation to ABC008 for the treatment of IBM.

About Abcuro

Abcuro is a clinical stage biotechnology company developing first-in-class immunotherapies for the treatment of autoimmune diseases and cancer through precise modulation of highly cytotoxic T and NK cells. The company’s lead program is ABC008 and is currently in clinical trials for inclusion body myositis (IBM) and T cell large granular lymphocytic leukemia. For more information, visit us on LinkedIn and at abcuro.com.

View source version on businesswire.com: https://www.businesswire.com/news/home/20230403005055/en/