FDA Designates MB-105 to Speed Review for Relapsed T-Cell Lymphoma

The U.S. Food and Drug Administration (FDA) has granted a regenerative medicine advanced therapy designation to MB-105, a CD5-targeted CAR-T cell therapy, in development for relapsed/refractory CD5-positive T-cell lymphoma, according to a news release from March Biosciences.

“The FDA’s regenerative medicine advanced therapy 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,” Sarah Hein, co-founder and chief executive officer of March Biosciences, said in the news release. “We are encouraged by the responses observed to date and look forward to working closely with the FDA to advance MB-105 as efficiently as possible.”

The FDA granted RMAT status to MB-105 based on early results from an ongoing, multi-center phase 2 clinical trial. In this first group of patients, the treatment showed early signs of benefit with side effects that doctors could manage. These patients have few effective treatment options today, so researchers say there is a strong need for new therapies like this one.

Initial data from the trial will be shared at the American Society of Hematology 2025 Annual Meeting, with more updates expected in 2026. The company developing MB-105 also plans to work closely with the FDA to support a faster development and review process.

This designation is a special FDA program created to speed up the development and review of regenerative medicine treatments for serious diseases, especially when early research shows the therapy could help patients who don’t have many options. This status gives companies the same support offered through the breakthrough therapy and fast track programs. That means more frequent communication with the FDA and access to faster review pathways, such as rolling review and priority review, to help treatments reach patients sooner.

What is MB-105?

MB-105 is an emerging cell therapy called CAR-T, which uses a patient’s own immune cells to better recognize and attack cancer. It is designed to target CD5-positive blood cancers, including T-cell lymphoma, T-cell acute lymphoblastic leukemia (a fast-growing T-cell blood cancer), chronic lymphocytic leukemia and mantle cell lymphoma.

This treatment uses a specially designed CAR that aims to focus on cancer cells while keeping the manufacturing process more streamlined, without extra genetic changes. MB-105 has received both Orphan Drug Designation and Regenerative Medicine Advanced Therapy designation from the FDA for patients with relapsed or refractory CD5-positive T-cell lymphoma, meaning the disease has returned or not responded to treatment.

A multicenter phase 2 clinical trial is currently enrolling patients at 12 sites across the United States.

What is Relapsed or Refractory CD5-Targeted T-cell Lymphoma?

Relapsed or refractory T-cell lymphoma refers to cancers that begin in T cells, a type of white blood cell, and either return after treatment (relapsed) or do not respond to therapy at all (refractory). These lymphomas are considered aggressive and can be harder to treat because they have already shown resistance to standard approaches. Symptoms vary but may include swollen lymph nodes, fatigue, fever, and weight loss.

CD5-targeted refers to a treatment approach designed to recognize and bind to CD5, a protein found on the surface of certain T cells and some cancer cells, including specific types of T-cell lymphomas and leukemias. Because CD5 can be present on malignant cells, therapies that target this protein may help destroy cancer cells while limiting effects on other parts of the body.

Reference

1. “March Biosciences Receives FDA Regenerative Medicine Advanced Therapy (RMAT) Designation for MB-105 in Relapsed/Refractory CD5-Positive T-Cell Lymphoma,” by March Biosciences. News Release. Nov. 11, 2025.

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