At the European Respiratory Society (ERS) Congress 2026, Mabwell and collaborating investigators presented results from the company’s Phase Ib/IIa study in patients with chronic obstructive pulmonary disease (COPD). The randomized, double-blind, placebo-controlled trial evaluated the therapeutic efficacy and safety of 9MW1911, an anti-ST2 monoclonal antibody, in moderate-to-severe COPD. Although the efficacy findings were exploratory and not statistically significant, the results support further evaluation of IL-33/ST2 pathway inhibition in COPD, says GlobalData, a leading intelligence and productivity platform.

The study’s eligibility criteria included adult who were former smokers with a history of at least two moderate or one severe exacerbation during the prior 12 months. The study had a multiple-ascending-dose (MAD) phase, in which participants received 9MW1911 at 100, 300, 600, or 900 mg every four weeks. The MAD phase was followed by an expansion of the 300 mg and 600 mg cohorts. Treatment lasted 24 weeks, with a further 12 weeks of safety follow-up.

9MW1911 was generally well tolerated and produced a numerical trend toward a reduction in the annualized rate of COPD exacerbations in the mid-to-high dose cohorts. Disease exacerbations were numerically lower in the 600 mg and 900 mg groups than with placebo, however, the differences versus placebo did not reach significance.

The safety analysis included 80 participants: 60 received 9MW1911 and 20 received placebo. Treatment-emergent adverse events occurred in 70.0% of the 9MW1911 group and 85.0% of the placebo group. Upper respiratory tract infection was the most common event, reported in 18.3% and 25.0% of participants, respectively. No anti-drug antibodies were detected, and no new safety signal was identified.

Graysen Vigneux, Immunology Analyst at GlobalData, comments: “The safety and pharmacokinetic findings provide a reasonable foundation for continued development of 9MW1911. Repeated dosing was generally well tolerated, and the absence of detected anti-drug antibodies is encouraging, although larger studies are needed to define the long-term profile.”

Trough concentrations approached steady state at approximately week 12, with mild accumulation after repeated dosing. Exposure was approximately dose-proportional across the 300-900 mg range, supporting further assessment of the every-four-week regimen.

Vigneux adds: “9MW1911 has cleared an important early development step, but the clinical value of ST2 blockade in COPD remains to be proven. A larger trial that reproduces the 600 mg signal and links exposure to durable exacerbation reduction would materially strengthen the case for this mechanism.”

9MW1911 targets ST2, the receptor for IL-33, aiming to interrupt inflammatory responses linked to the IL-33/ST2 pathway. If the early exacerbation signal is confirmed, the antibody could offer a targeted biologic option for patients who remain at risk despite stable maintenance therapy. Future studies may also determine whether biomarkers can identify those most likely to respond.

Vigneux concludes: “The current trial was designed primarily to assess pharmacokinetics, safety, and tolerability, while the efficacy analysis was exploratory and was not designed to confirm efficacy. Larger and longer randomized studies will be required to establish an optimal dose, demonstrate a statistically and clinically meaningful exacerbation benefit, assess severe events and hospitalization, and characterize safety with longer exposure.”