Invimestrocel is being investigated for multiple indications, including ischemic stroke.
Athersys has begun patient enrollment in the third and final cohort of its phase 2 MATRICS-1 study (NCT04533464) evaluating invimestrocel (MultiStem) cell therapy for the potential treatment of patients following resuscitation from hemorrhagic trauma.1
“We’re excited to move forward and initiate cohort 3 of this important trial with our partners at UTHealth Houston, Hermann-Texas Medical Center and Department of Defense/Medical Technology Enterprise Consortium based on a positive data safety monitoring board review. MultiStem’s unique mechanism of action has the potential to address the often-fatal complications that occur following a severe traumatic event. The final cohort will utilize clinical product manufactured using a 3D bioreactor process and all doses are readily available through our contract manufacturer,” Dan Camardo, chief executive officer, Athersys, said in a statement.1
Approximately 140 patients will be enrolled in cohort 3 of the double-blind, placebo-controlled MATRICS-1 studyto be randomized to treatment with invimestrocel cells or placebo within hours of hospitalization. Participants will be trauma patients with severe injuries who have survived initial treatment and are admitted to the intensive care unit. The cells are manufactured using Athersys’ novel 3D bioreactor-based process, which was first implemented in cohort 2. Invimestrocelis designed to reduce inflammatory damage, upregulate reparative aspects of the local and systemic immune system, and protect at-risk tissue at the site of injury and therefore treat complications due to trauma.
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“When administered soon after a traumatic injury, MultiStem holds potential to reduce the inflammatory cascade and mitigate secondary tissue damage. With the third cohort now being enrolled, I’m pleased we have entered the final stretch of our important research to try to improve trauma outcomes,” principal investigator Charles S. Cox Jr, MD, FACS, George and Cynthia Mitchell Distinguished Chair in Neurosciences and Glassell Family Distinguished Chair, Department of Pediatric Surgery, McGovern Medical School, UTHealth Houston and Memorial Hermann-Texas Medical Center, added.2
Athersys previously announced that enrollment had completed in the second cohort of the MATRICS-1 trial in January 2023.2 At that time, the company also provided an update that its phase 3 MASTERS-2 trial (NCT03545607) evaluating invimestrocel for the treatment of ischemic stroke had reached the halfway mark in enrollment. Later, in April, Athersys met with the FDA in a Type B Meeting about the MASTERS-2 trial, in which the FDA approved the company’s proposed modifications to the trial.3 The modifications included changing the primary endpoint timing to 365 days after treatment, no longer capping the concomitant reperfusion therapy that participants are allowed to receive, and an interim analysis conducted by an independent statistician to potentially adjust sample sizes depending on the findings.
“The MASTERS-2 clinical trial protocol changes agreed to by the FDA reflect what we have learned from the completed MultiStem Phase 2 MASTERS-1 trial and the TREASURE clinical trial run in Japan by our partner Healios, as well as the significant evolution of standard of care in treating acute ischemic stroke. We appreciate the FDA’s guidance, which we believe ultimately willbenefit stroke patients worldwide,” Camardo said in a statement at that time.3 “We view the outcome of our meeting as the best-case scenario. Although changing the primary endpoint to Day 365 extends the duration of MASTERS-2, we believe our accepted modifications enable accelerated patient enrollment and provide a higher conviction for demonstrating treatment potential.”