FAQ: FDA RMAT Designation for March Biosciences' MB-105 CAR-T Therapy

What is MB-105 and what does it treat?

MB-105 is a first-in-class autologous CD5-targeted CAR-T cell therapy being developed for CD5-positive hematologic malignancies, including T-cell lymphoma, T-cell acute lymphoblastic leukemia, chronic lymphocytic leukemia, and mantle cell lymphoma.

What is RMAT designation and why is it important?

RMAT (Regenerative Medicine Advanced Therapy) designation is an FDA program that expedites development and review of regenerative medicine therapies for serious diseases where early evidence shows potential to address unmet medical needs. It provides enhanced FDA interactions and eligibility for expedited review mechanisms.

Why is this therapy significant for T-cell lymphoma patients?

This therapy addresses a critical unmet medical need for patients with relapsed/refractory T-cell lymphoma, who currently face a median survival of only six months with existing treatments.

What clinical evidence supports the RMAT designation?

The designation was based on data from March Bio’s ongoing Phase 2 clinical trial (NCT06534060), where preliminary findings from the safety run-in cohort showed evidence of clinical activity with a manageable safety profile.

When will more data about MB-105 be available?

Initial results from the safety run-in cohort will be presented at the American Society of Hematology 2025 Annual Meeting, with additional updates anticipated in 2026.

What benefits does RMAT designation provide?

RMAT designation provides all the benefits of the FDA’s Breakthrough Therapy and Fast Track programs, including enhanced and frequent interactions with the FDA throughout development, and eligibility for expedited review mechanisms such as rolling and priority review.

What other regulatory designations has MB-105 received?

MB-105 has received both Orphan Drug Designation and Regenerative Medicine Advanced Therapy designation from the FDA for the treatment of relapsed/refractory CD5-positive T-cell lymphoma.

What are the next steps for MB-105 development?

March Biosciences plans to engage with the FDA on next steps to support an expedited development and review pathway, and will explore clinical and commercial development outside the United States as data mature.

How does MB-105’s CAR design differ from other CAR-T therapies?

MB-105 employs a proprietary CAR design that enables selective targeting of malignant cells and streamlined manufacturing without additional genetic manipulation.