MT-601: New Hope for Lymphoma Patients After CAR-T Relapse

Marker Therapeutics, Inc. (Nasdaq: MRKR), a clinical-stage immuno-oncology company, announced encouraging results from its Phase 1 APOLLO study investigating MT-601, a multi-antigen recognizing (MAR) T cell therapy, in relapsed lymphoma patients post anti-CD19 CAR-T therapy.

Key Findings

• Safety: MT-601 was well tolerated, with no cases of immune-effector cell-associated neurotoxicity syndrome (ICANS) and one instance of Grade 1 cytokine release syndrome (CRS). No dose-limiting toxicities (DLTs) were reported.
• Efficacy: Among 9 evaluable patients, 78% (7) achieved objective responses, with 44% (4) achieving complete responses (CR). Lymphodepletion enhanced MAR-T cell expansion and persistence.
• Durability: Follow-up data (6–12 months) is available for three patients, with ongoing monitoring to assess long-term response durability.

Addressing Unmet Needs

Despite the success of CD19 CAR-T therapies, 40–60% of patients relapse within a year and lack approved treatment options. MT-601 offers a non-engineered approach to expanding tumor-specific T cells, minimizing mutagenesis risks while targeting diverse tumor antigens.

Leadership Comments

Dr. Monic Stuart, CMO, highlighted the significance of responses in heavily pre-treated patients:

“This is a tremendous achievement offering hope to patients and their families.”

Dr. Juan Vera, CEO, emphasized MT-601’s potential to address a critical unmet need:

“Our therapy offers a safer, effective option for relapsed lymphoma patients with no approved alternatives.”

Next Steps

Marker will continue enrolling participants in the APOLLO study to gather additional safety and efficacy data, advancing MT-601 development as a promising therapy for relapsed lymphoma patients.