Faculty, Staff and Student Publications

Publication Date

2-10-2025

Journal

The Journal for ImmunoTherapy of Cancer

DOI

10.1136/jitc-2024-010584

PMID

39929671

PMCID

PMC11815413

PubMedCentral® Posted Date

2-10-2025

PubMedCentral® Full Text Version

Post-print

Abstract

Background: M6223 is an intravenous (IV), Fc-competent, fully human, antagonistic, anti-T cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domains (TIGIT) antibody. Bintrafusp alfa (BA) is a bifunctional fusion protein that simultaneously blocks nonredundant immunosuppressive TGF-β and PD-(L)1 pathways.

Methods: This first-in-human, dose-escalation study in patients with advanced solid tumors (N=58; aged ≥18 years, ECOG PS≤1) evaluated M6223 alone (Part 1A, n=40; M6223 10-2400 mg every 2 weeks, n=32; M6223 2400 mg every 3 weeks, n=8) or with BA (Part 1B, n=18; M6223 300-1600 mg with BA 1200 mg; both every 2 weeks, intravenous). Primary objectives were safety, tolerability, maximum tolerated dose (MTD) and recommended dose for expansion (RDE). Additional objectives included pharmacokinetics, pharmacodynamics and clinical activity (NCT04457778).

Results: Two dose-limiting toxicities were observed: grade 3 adrenal insufficiency (Part 1A: M6223 900 mg every 2 weeks) and grade 3 anemia (Part 1B: M6223 300 mg, only BA related). MTD was not reached. Overall, median overall survival and progression-free survival were 7.6 (95% CI 4.9, 12.0) and 1.4 (95% CI 1.3, 1.8) months, respectively. Stable disease as best response was observed in 13 (32.5%) and 5 (27.8%) patients in parts 1A and 1B, respectively. M6223±BA displayed a linear pharmacokinetic profile. Anti-TIGIT mode-of-action-related pharmacodynamic effects were observed in peripheral blood and in tumor tissue. RDEs were 1600 mg every 2 weeks or 2400 mg every 3 weeks for M6223 monotherapy and 1600+1200 mg every 2 weeks for M6223+BA.

Conclusions: M6223±BA had a manageable safety profile, with RDEs defined for both monotherapy and combination therapy. Further evaluation of M6223 is ongoing in combination with the PD-L1 inhibitor avelumab in patients with advanced urothelial carcinoma (JAVELIN Bladder Medley; NCT05327530).

Keywords

Humans, Female, Male, Middle Aged, Neoplasms, Aged, Adult, Receptors, Immunologic, Antineoplastic Combined Chemotherapy Protocols, Maximum Tolerated Dose, Aged, 80 and over, Immunoglobulin Fc Fragments, Recombinant Fusion Proteins, Antibody, Immune Checkpoint Inhibitor, Immunotherapy, Solid tumor

Comments

Trial registration number: NCT04457778.

Published Open-Access

yes

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