Magenta Pauses Dose Escalation Trial of Conditioning Agent Following Patient Death

Magenta Therapeutics said it voluntarily paused a dose escalation trial of its conditioning agent MGTA-117 in relapsed/refractory acute myeloid leukemia and myelodysplastic syndrome after the latest participant dosed died from respiratory failure and cardiac arrest that could possibly be related to the drug.

Conditioning is a critical component necessary in stem cell transplantation to prepare a patient’s body to receive edited cells, which carry the corrected gene and must engraft in the patient’s bone marrow to be effective. Today’s conditioning regimens rely on nonspecific chemotherapy or radiation, which are associated with significant toxicities.

Magenta says its antibody drug conjugate MGTA-117 precisely targets only hematopoietic stem and progenitor cells, sparing immune cells, and has shown high selectivity, potent efficacy, wide safety margins and broad tolerability in non-human primate models.

The company reported the known information to the U.S. Food and Drug Administration as a Suspected Unexpected Serious Adverse Reaction (SUSAR). After consultation with the trial’s safety Cohort Review Committee Magenta voluntarily paused dosing in the clinical trial and is working to evaluate the totality of available data and determine next steps for the development of MGTA-117.

Author: Rare Daily Staff