Novel T-Cell Therapy MT-401 Under Evaluation in Post-Transplant AML

Mythili Koneru, MD, PhD

The multitumor-associated antigen (MultiTAA)-specific T-cell product MT-401 is under investigation as a potential treatment option for patients with acute myeloid leukemia (AML) following allogeneic stem cell transplant in both the adjuvant and active disease settings.¹

In the multicenter phase 2 trial (NCT04511130), investigators are evaluating the safety and efficacy of MT-401 in this population. In the adjuvant setting, about 120 patients will be randomized 1:1 to receive either MT-401 at 90 days following transplant or standard-of-care observation. Additionally, MT-401 will be administered to 40 patients with active disease as part of a single arm.

The primary objective of the trial is relapse-free survival (RFS) for the cohort with adjuvant disease, while it is complete response and duration of complete response for the cohort with active disease. Additional end points for the adjuvant cohort include overall survival (OS) and graft-versus-host disease RFS; additional end points in the active disease cohort were overall response rate, duration of response, progression-free survival, and OS.

In January 2021, the FDA lifted a partial hold on the phase 2 trial.² Two months later, in March 2021, the first patient on the trial was dosed with MT-401.

“We are pleased to have dosed the first patient with MT-401 in our Company-sponsored clinical trial, particularly in a patient population in which there remains a critical unmet need,” Mythili Koneru, MD, PhD, chief medical officer of Marker Therapeutics, stated in a press release. “Today, adult patients with post-transplant AML have a 25% chance of 5-year survival. In various investigator-sponsored phase 1 trials at the Baylor College of Medicine, our MultiTAA-specific T-cell therapies have been generally well tolerated and demonstrated durable anticancer responses across a broad range of cancers—including post-transplant AML. Based on these results, we believe that MT-401 has the potential to become a meaningful treatment option for patients suffering from this disease.”

A topline readout of the active disease group in the trial is anticipated in Q1 2022.

In April 2020, the product was granted an orphan drug designation by the FDA.³ The decision was supported by data from investigator-sponsored trials. The candidate was noted to be well tolerated and a clinical benefit across several liquid and solid tumors, which suggests that the agent is able to prompt a patient’s own T cells to expand for a more durable antitumor effect.

References

1. Marker Therapeutics announces dosing of first patient in phase 2 trial of MT-401 in acute myeloid leukemia following stem cell transplant. News release. Marker Therapeutics, Inc. March 3, 2021. Accessed April 1, 2021. https://prn.to/3sFnqge
2. Marker Therapeutics announces FDA lifted partial clinical hold on phase 2 AML clinical trial. News release. Marker Therapeutics, Inc. January 5, 2021. Accessed April 1, 2021. https://prn.to/3sKegzb
3. Marker Therapeutics receives FDA orphan drug designation for its multi-antigen targeted T cell therapy for acute myeloid leukemia. News release. Marker Therapeutics, Inc. April 29, 2020. Accessed April 1, 2021. https://prn.to/3mc5hnT