FDA Grants RMAT Designation to March Bio’s CAR-T Therapy MB-105 for T-cell Lymphoma

HOUSTON, TX – November 13, 2025 — March Biosciences (March Bio), a clinical-stage biotechnology company focused on cell therapies, announced that the U.S. Food and Drug Administration (FDA) has granted Regenerative Medicine Advanced Therapy (RMAT) designation to MB-105.

MB-105 is the Company’s first-in-class, autologous CD5-targeted CAR-T cell therapy being developed for the treatment of relapsed/refractory CD5-positive T-cell lymphoma (TCL). The manufacture of this CAR-T likely relies on a lentiviral vector (LVV) to genetically modify the patient’s T-cells to express the CAR.

RMAT Status Based on Phase 2 Data

The RMAT designation was granted based on data from March Bio’s ongoing multi-center Phase 2 clinical trial (NCT06534060). Preliminary findings from the safety run-in cohort indicated evidence of clinical activity with a manageable safety profile in this patient population, which has a significant unmet medical need.

Initial results from this cohort are scheduled to be presented at the American Society of Hematology (ASH) 2025 Annual Meeting, with further updates anticipated in 2026.

“The FDA’s RMAT designation further validates MB-105’s potential to address a critical unmet medical need for patients with relapsed/refractory T-cell lymphoma, who face a median survival of only six months with current therapies,” said Sarah Hein, Co-Founder and Chief Executive Officer of March Biosciences.

Expedited Development Pathway

The RMAT designation is reserved for regenerative medicine therapies that treat serious or life-threatening diseases, where early clinical evidence suggests the potential to address an unmet medical need.

The designation provides significant benefits, including:

• Enhanced and Frequent Interaction with the FDA throughout the development process.
• Eligibility for Expedited Review mechanisms such as rolling and priority review.
• All benefits associated with the FDA’s Breakthrough Therapy and Fast Track programs.

March Bio plans to engage with the FDA immediately to define the next steps for an expedited development and review pathway for MB-105. The company is also exploring clinical and commercial development opportunities outside the United States.

About MB-105 CAR-T Therapy

MB-105 is a potential first-in-class autologous CAR-T cell therapy targeting the CD5 protein. The therapy is in development for several CD5-positive hematologic malignancies, including TCL, T-cell acute lymphoblastic leukemia (T-ALL), chronic lymphocytic leukemia (CLL), and mantle cell lymphoma (MCL). The therapy utilizes a proprietary CAR design that allows for selective targeting of malignant cells and streamlines manufacturing without additional genetic manipulation. The multicenter Phase 2 trial is currently enrolling at twelve sites across the United States.