Immatics NV (IMTX)

[FACT-MASTER]

IMTX: Presentation on Phase 1a/1b IMA401 tomorrow at ESMO/24

Remember IMA401 is in collaboration with BMS ( https://immatics.com/our-pipeline/)

ESMO Abstract

https://cslide.ctimeetingtech.com/esmo2024/attendee/confcal/show/session/232#presentation-abstract-895832222418

Abstract
Background
T cell-engaging bispecifics are designed to redirect T cells to cancer antigens. IMA401 is a next-gen T cell engaging receptor (TCER®) combining a high-affinity TCR domain against an HLA-A*02:01-presented MAGEA4/8 peptide, a low-affinity T cell-recruiting antibody and an Fc part for half-life extension. The target peptide exhibits a >5-fold higher density compared to the MAGEA4-derived peptide targeted by other bispecifics or cell therapies.

Methods
This ongoing Phase 1a/1b first-in-human clinical trial evaluates IMA401 in patients (pts) with recurrent/refractory solid tumors. HLA-A*02:01+ and MAGEA4/8+ pts received initially QW then Q2W iv. IMA401 infusions. Primary objectives: MTD and/or RP2D. Secondary objectives: safety, tolerability, PK, initial anti-tumor activity.

Results
As of April 1, 2024, 25 heavily pretreated cancer pts received IMA401 across the first dose levels (DL1-7, 6.6µg-2.5mg). IMA401 showed manageable tolerability with most common (≥30%) treatment-related adverse events being transient lymphopenia (G1-4) and CRS (G1/2). High-grade (G3/4) neutropenia observed at DL7 did not reoccur after the introduction of dexamethasone pre-treatment. MTD/RP2D was not reached and dose escalation is ongoing. Median terminal half-life was 15.0 days. 55% (11/20) of efficacy-evaluable pts treated in the escalation phase, including initial low MABEL-based starting DLs, achieved disease control (SD/PR). Among these were pts with ovarian cancer, sqNSCLC, gastric cancer, HNSCC, melanoma, and neuroendocrine carcinoma. 45% (9/20) of the pts showed shrinkage of target lesions (median -21.7%), including 3 pts with durable confirmed PRs at 4+, 10+ and 11+ months after first infusion.

Conclusions
IMA401 was well tolerated and its single-agent anti-tumor activity was demonstrated by durable objective responses and disease control. The prolonged half-life prompted a switch to treatment every 2 weeks already during dose escalation. The data of this ongoing Phase 1 dose escalation trial provide first clinical PoC for the next-gen half-life extended TCER® format and its potential in multiple solid tumors.

Clinical trial identification
NCT05359445.

Legal entity responsible for the study
Immatics Biotechnologies GmbH.