Annualized Severe COPD Exacerbation Rate Reduced by Over 40%: Mabwell Announces Phase IIa Results for Innovative Anti-ST2 Antibody 9MW1911

• All dose groups demonstrated good safety and tolerability versus placebo, with similar adverse event (AE) incidence (70% vs. 85%).
• At the recommended Phase IIb dose (RP2D), the annualized rate of moderate-to-severe exacerbations decreased by over 30%, and severe exacerbations decreased by over 40%.

SHANGHAI, Dec. 1, 2025 /PRNewswire/ -- Mabwell (688062.SH), an innovation-driven biopharmaceutical company with a fully integrated industry chain, announced the completion of its Phase IIa clinical study for 9MW1911, a self-developed anti-ST2 monoclonal antibody, in patients with moderate-to-severe chronic obstructive pulmonary disease (COPD).

The completed Phase IIa clinical study (9MW1911-C03) was a randomized, double-blind, placebo-controlled, multiple-dose, dose-escalation trial. The study primarily evaluated the safety, tolerability, and pharmacokinetic characteristics of 9MW1911 in previously smoking patients with moderate-to-severe COPD, and included preliminary assessments of efficacy and immunogenicity. A total of 80 patients were enrolled and randomized to receive intravenous infusions of 9MW1911 (100mg, 300mg, 600mg, 900mg) or placebo once every four weeks.

The results indicated that the baseline characteristics were generally balanced across all groups, and the majority of subjects had a baseline blood eosinophil count of <300/μL. Compared to placebo (N=20), 9MW1911 was safe and well-tolerated across all dose groups, with the overall incidence of adverse events (AEs) being similar to the placebo group (70% vs. 85%). Immunogenicity was negative in all subjects, and no new safety risk signals were identified. Pharmacokinetic results suggested that drug exposure increased with escalating doses. An exposure-response model can be preliminary established to define the dose-effect relationship, providing a basis for subsequent dose selection. Efficacy data showed that the annualized rate of COPD exacerbation demonstrated a dose-dependent decrease in the treatment arms. At the recommended dose for the Phase IIb study (N=30), the annualized rate of moderate-to-severe COPD exacerbations was reduced by over 30% compared to the placebo group. Furthermore, the annualized rate of severe exacerbations was reduced by over 40% compared to the placebo group, and the proportion of patients experiencing severe exacerbations was significantly lower in the treatment group than in the placebo group (13.3% vs. 35%).

9MW1911 is an innovative anti-ST2 antibody developed using Mabwell's high-efficiency B-cell screening platform. The Phase IIb study in a larger COPD population is progressing, with first patient dosing completed in July 2025 and an interim analysis planned after data from at least 120 patients are collected. A Phase III trial is expected to begin by the end of 2026 based on the Phase II outcomes. The Phase IIa trial application has recently been accepted by the U.S. FDA.

About Mabwell

Mabwell (688062.SH) is an innovation-driven biopharmaceutical company with capabilities spanning the entire pharmaceutical value chain. The company is committed to providing more effective and accessible therapies to meet global medical needs, with a focus on oncology and aging-related diseases. Mabwell's mission is "Explore Life, Benefit Health" and its vision is "Innovation, from Ideas to Reality." For more information, please visit www.mabwell.com/en. 

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SOURCE Mabwell