MT-5111

Promising Therapy for HER2 Cancer Patients

MT-5111 is a second generation engineered toxin body (ETB) consisting of a single-chain variable fragment (scFv) with an affinity for HER2, fused to the enzymatically active de-immunized Shiga-like toxin-A subunit (SLTA). MT-5111 specifically binds and kills HER2 expressing cells in a manner consistent with SLTA mediated cellular cytotoxicity.

MT-5111 is designed to avoid competition with and to overcome the primary mechanisms of tumor resistance to current HER2 targeted therapies. MT-5111 may provide benefits to patients with HER2-positive cancers by potentially overcoming mechanisms of tumor resistance to existing HER2 targeted therapies.

Program	Partner	Indication (Target)	Preclinical	Phase 1	Phase 2	Phase 3	Next Stage
MT-5111		Multiple - solid tumors (HER2)	Preclinical Phase complete	Phase 1 Phase in progress	Phase 2 Phase not started	Phase 3 Phase not started

Completed

In-progress

Planning

Key Benefits

Designed to Overcome Resistance Mechanisms

MT-5111 has a wholly unique mechanism of action that does not appear subject to the resistance mechanisms associated with Mabs, TKIs, or ADCs.
MT-5111 binds in the presence of trastuzumab, pertuzumab or T-DM1.
It has reduced ADA and innate immune response (de-immunized STLA scaffold).
MT-5111 has picomolar efficacy against HER2+ cells.
Its activity is retained in the presence of T-DM1 refractory cells in pre-clinical and clinical models.

Clinical Overview

The Phase 1 study in patients with HER2 positive solid tumors began dosing in the fourth quarter of 2019 with the HER2- positive breast cancer expansion cohort expected to be initiated in the first half of 2021. Dose escalation will continue to determine the Recommended Phase II Dose while the breast cancer expansion cohort collects efficacy and safety data.

Posters & Presentations

To learn more about the MT-5111 candidate, explore our research publications.

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