March Biosciences Announces First Patient Dosed in Phase 2 Clinical Trial of First-in-Class CD5 CAR-T Cell Therapy for T-Cell Lymphoma

March Biosciences recently announced the first patient has been dosed in its Phase 2 clinical trial evaluating MB-105, a first-in-class CD5-targeted CAR-T cell therapy for patients with relapsed or refractory CD5-positive T-cell lymphoma.

“This represents a significant milestone in advancing MB-105 as a potential treatment option for patients with T-cell lymphoma who currently face extremely limited therapeutic choices,” said Sarah Hein, Co-Founder and Chief Executive Officer of March Biosciences. “CAR-T therapies have revolutionized the treatment of B-cell lymphomas and leukemias but have not successfully addressed the rarer T-cell lymphomas and leukemias. We are optimistic that this larger trial will further validate MB-105’s potential to address the critical unmet needs of these patients and look forward to reporting our first clinical readouts.”

The Phase 2 trial is a multi-center, single-arm, two-stage, open-label study designed to evaluate the safety and efficacy of MB-105 in patients with relapsed or refractory CD5-positive T-cell lymphoma. It will enroll approximately 46 patients across both stages. The trial will be conducted at leading cancer centers across the United States, with the first patient dosed at The University of Texas MD Anderson Cancer Center. The trial is led by Swaminathan P. Iyer, M.D., Professor in the Department of Lymphoma/Myeloma at MD Anderson.

The Phase 2 trial builds on promising Phase 1 results in T-cell lymphoma, where MB-105 demonstrated both a favorable safety profile and durable remissions in heavily pretreated patients with relapsed/refractory T-cell lymphoma. CD5 CAR-T cells were successfully manufactured for 93% of attempted production runs. Importantly, the therapy showed a manageable safety profile with no grade 3 or higher cytokine release syndrome or neurologic events observed. The unique CAR design enabled selective targeting of malignant cells while preserving normal T-cell function.

Additional information on the Phase 2 trial, which is currently enrolling patients, can be found on www.clinicaltrials.gov, NCT identifier NCT06534060.

This milestone follows the company’s successful Series A financing in October 2024, which was led by Mission BioCapital and 4BIO Capital, with participation from KdT Ventures, Alexandria Venture Investments, Volnay Therapeutics, Modi Ventures, and Mansueto Investments. Existing investors TMC Venture Fund, Cancer Focus Fund, Small Ventures, and Portal Innovations also participated in the round. Following the financing, the company has rapidly achieved significant clinical and regulatory milestones, including receiving FDA orphan drug designation for MB-105 in January 2025, which provides various development incentives and seven years of market exclusivity following potential FDA approval.

MB-105 is an orphan-drug designated, first-in-class autologous CD5-targeted CAR-T cell therapy in development for CD5-positive hematologic malignancies, including T-cell lymphoma (TCL), T-cell acute lymphoblastic leukemia (T-ALL), chronic lymphocytic leukemia (CLL), and mantle cell lymphoma (MCL). The therapy employs a proprietary CAR design that enables selective targeting of malignant cells while preserving normal T-cell function. The Phase 2 clinical trial of MB-105 (NCT06534060) is currently enrolling for patients with relapsed / refractory T cell lymphoma.

Houston-based March Biosciences, launched from the Center for Cell and Gene Therapy (Baylor College of Medicine, Houston Methodist Hospital, Texas Children’s Hospital), is dedicated to addressing challenging cancers unresponsive to current immunotherapies. Its lead asset, MB-105, is a CD5-targeted CAR-T cell therapy currently in Phase 2 clinical development for patients with relapsed / refractory T-cell lymphoma. The company has raised over $52 million to date, inclusive of venture financing, support from the Cancer Prevention & Research Institute of Texas (CPRIT), and the NIH SBIR program. Learn more at www.march.bio.