Safety and Tolerability: To date, IMC-003 has demonstrated a favorable safety and tolerability profile across all dose cohorts in both the SAD and MAD studies, with no DLTs observed. In the SAD study, the vast majority of treatment-related AEs were Grade 1, with no Grade ≥3 events. In the MAD study, consistent with SAD findings, all AEs were Grade 1 or 2, with no Grade ≥2 increases in hemoglobin. No DLTs occurred in the first three cohorts, and the safety observation period for the fourth cohort has not yet reached its assessment timepoint.

Pharmacokinetics and Pharmacodynamics: IMC-003 exhibited favorable PK characteristics and a robust safety profile in both studies. In the SAD study, pharmacodynamic effects (changes in FSH from baseline) demonstrated a dose-dependent response within the 0.03 mg/kg to 4.0 mg/kg cohorts, approaching a plateau at the 4.0 mg/kg dose level. Notably, this exposure level is significantly lower than that reported for the approved product in the same class, Winrevair® (sotatercept), at comparable pharmacodynamic efficacy. The comprehensive PK/PD and safety data generated from the Phase I healthy volunteer studies provide a strong foundation to support the ongoing Phase Ib/IIa study in PAH patients, in which the first patient was enrolled on June 30, 2026.

IMC-003 is an activin receptor type IIA (ActRIIA)-Fc fusion protein independently developed by ImmuneCare. It shares a similar mechanism of action with the approved Winrevair™ (sotatercept), fundamentally improving vascular smooth muscle cell homeostasis, reversing pulmonary vascular remodeling, and arresting disease progression from a pathogenic perspective. Compared to existing agents in its class, IMC-003 features a uniquely differentiated molecular design: the extracellular domain of the ActRIIA receptor has been genetically engineered to significantly enhance binding and blocking activity against the ligand Activin A, while simultaneously improving drug quality uniformity. Preclinical data demonstrate that the binding and signal-blocking activities of IMC-003 are more than five times greater than those of sotatercept. In Sugen5416-hypoxia and monocrotaline (MCT)-induced PAH animal models, IMC-003 significantly improved key indicators, including right ventricular systolic pressure (RVSP) and pulmonary arteriole wall area, demonstrating superior efficacy to sotatercept. Benefiting from its high selectivity for Activin A, IMC-003 is expected to achieve favorable efficacy at lower exposure levels in clinical applications, potentially reducing the risk of bleeding and demonstrating an enhanced safety profile.

About ImmuneCare

Established in Shanghai in January 2024, ImmuneCare focuses on the R&D of macromolecular drugs for cardiovascular diseases, including pulmonary arterial hypertension, and metabolic diseases. Leveraging profound industry experience and robust R&D capabilities, ImmuneCare has built a globally competitive, differentiated pipeline in the non-oncology field. Currently, its core programs are advancing rapidly:

In the cardiovascular field, ImmuneCare's independently developed IMC-003 (IMM72, ActRIIA-Fc fusion protein) has achieved a critical milestone in its development for the PAH indication. The company has completed enrollment for all planned dose cohorts in both the Phase I SAD and MAD studies. Furthermore, the first subject in the Phase Ib/IIa clinical trial in PAH patients has been enrolled and dosed, marking the official transition of IMC-003 clinical development into the patient validation stage. Preclinical data indicate that the binding and signal-blocking activities of IMC-003 are more than five times greater than those of sotatercept, demonstrating stronger efficacy potential and offering a breakthrough treatment option for this disease often referred to as "cardiovascular cancer."

In addition, ImmuneCare has developed IMC-004, a bispecific antibody targeting ActRIIA and RANKL, aiming to explore new therapeutic pathways for osteoporosis.

In the metabolic and body recomposition field, ImmuneCare has proactively established an innovative portfolio targeting unmet needs such as obesity. IMC-011 (IMM91), a monoclonal antibody targeting latent GDF8, is in the preclinical stage and has demonstrated excellent muscle-enhancing effects; IND-enabling activities are currently underway. Additionally, IMC-015 (IMM9101, a GDF8×ActRII bispecific antibody) is designed to leverage the ActRII pathway blockade strategy to address muscle loss in obese patients, achieving the dual benefits of fat loss and muscle gain. IND-enabling activities for IMC-015 are also currently in preparation.