EF-M2 (Immutalon) Multiple Ascending Dose Study in Moderate-to-Severe Rheumatoid Arthritis

Overview

This is a first-in-human, open-label, phase I/IIa, multiple ascending dose study of EF-M2 (Immutalon), a macrophage-modulating investigational product intended to shift macrophages toward an anti-inflammatory (M2-like) phenotype via a CLEC10A-mediated mechanism. The study will enroll adults with moderate-to-severe rheumatoid arthritis. Participants will receive EF-M2 as subcutaneous injections for 4 weeks in sequential dose cohorts (1, 3, 5, or 7 mcg administered twice weekly; optional expanded pharmacodynamic cohorts may receive 3 or 5 mcg three times weekly). The total number of injections will be 8-12 depending on the regimen. Dose escalation is sequential and overseen by an independent data safety monitoring board (DSMB), with sentinel dosing at the start of each new cohort. Participants may be followed off drug for up to 8-12 weeks after treatment, for a total participation time of up to 16 weeks (including screening). The primary objective is to evaluate safety, tolerability, and immunogenicity. Secondary objectives include assessing pharmacodynamic markers of M2 polarization (e.g., changes in ARG1/iNOS and IL-10/TNF-α ratios and M2-associated cell phenotypes) and exploring associations with clinical activity measures.

This phase I/IIa, open-label, multicenter, multiple ascending dose (MAD) study evaluates EF-M2 (Immutalon) administered subcutaneously to adults with moderate-to-severe rheumatoid arthritis. The trial is designed primarily to characterize safety/tolerability and immunogenicity and to describe pharmacodynamic (PD) evidence of macrophage M2 polarization rather than to demonstrate definitive clinical efficacy. Participants are enrolled into sequential dose cohorts. Each participant receives EF-M2 for 4 weeks: Cohorts 1-4 receive 1, 3, 5, or 7 mcg twice weekly (8 injections total). If needed, expanded PD cohorts may evaluate 3 mcg or 5 mcg administered three times weekly (12 injections total) to better understand whether increased dosing frequency strengthens the M2 PD signature and where a plateau may begin. Dose escalation is sequential and occurs only after DSMB review of safety and PD data; sentinel dosing is used in each new cohort (the first 2 participants receive initial dosing with an observation period before full cohort enrollment continues). Key assessments include adverse event monitoring, physical examinations and vital signs at visits, laboratory safety testing at scheduled time points, and immunogenicity testing (anti-drug antibodies, with neutralizing antibodies assessed if antibodies are detected). Pharmacodynamic assessments are based on blood markers measured over time (e.g., soluble cytokines and macrophage/monocyte markers), with PD endpoints including change in ARG1/iNOS and IL-10/TNF-α ratios and changes in M2-associated cell phenotypes. Study timing includes screening up to 28 days, 4 weeks of treatment, and an off-drug follow-up period of 8-12 weeks (total participation up to 16 weeks). Example follow-up assessments extend through Day 112. The planned sample size is approximately 32 participants (8 per cohort across four dose levels), with up to 48 participants if both expanded PD cohorts are activated.