Anti-ST2 Antibody Cuts Severe COPD Flares by Up to 100% in Phase 2 Trial
Mabwell's 9MW1911 monoclonal antibody slashed severe COPD exacerbations at higher doses, with Phase III expected by late 2026.
Summary
Mabwell's experimental drug 9MW1911, which blocks the ST2 receptor involved in lung inflammation, showed striking results in a mid-stage clinical trial for moderate-to-severe COPD. In 80 former smokers, the highest dose eliminated all severe flare-ups over the study period, while the second-highest dose cut severe exacerbations by 47%. Overall moderate-to-severe flares dropped by 24% and 81% at those same doses. The drug was well tolerated, with blood levels stabilizing by week 12 and scaling predictably with dose. COPD is a progressive, age-related lung disease closely tied to reduced functional capacity and shortened lifespan. These results support advancing to larger trials, with Phase III enrollment expected around late 2026.
Detailed Summary
Chronic obstructive pulmonary disease is one of the leading causes of death and disability worldwide, disproportionately affecting older adults and drastically eroding cardiorespiratory fitness and quality of life. Current treatments manage symptoms but rarely halt disease progression, making new biological approaches a significant focus of longevity-relevant medicine.
Mabwell presented Phase Ib/IIa results for 9MW1911, an intravenous monoclonal antibody targeting ST2, a receptor central to the IL-33 inflammatory signaling pathway that drives airway inflammation and tissue remodeling in COPD. The randomized, double-blind, placebo-controlled trial enrolled 80 former smokers with moderate-to-severe disease, who received infusions every four weeks at doses ranging from 100 mg to 900 mg.
The headline efficacy findings were striking. At 600 mg, annualized moderate-to-severe exacerbation rates fell by 24% and severe exacerbations by 47% versus placebo. At 900 mg, those figures improved dramatically to 81% and 100% reductions respectively. Pharmacokinetic data confirmed dose-proportional drug exposure and steady-state trough concentrations by week 12, suggesting predictable and controllable dosing behavior.
Safety and tolerability were reported as favorable across all dose groups, an important threshold for a drug intended for an older, often comorbid population. The company has completed Phase IIb enrollment, secured FDA clearance for a U.S. Phase IIa study, and anticipates launching Phase III around late 2026.
Caveats remain. The trial was small at 80 participants, and the 100% reduction in severe exacerbations at the highest dose, while remarkable, must be interpreted cautiously given the sample size and the fact that results come from the company itself rather than independent peer review. Longer trials in larger, more diverse populations will be needed to confirm durability, safety, and real-world impact on lung function decline and survival.
Key Findings
- 900 mg dose reduced severe COPD exacerbations by 100% versus placebo in Phase 2 trial.
- 600 mg dose cut severe exacerbation rates by 47% and moderate-to-severe rates by 24%.
- Drug showed dose-proportional blood levels stabilizing by week 12, supporting predictable dosing.
- Safety and tolerability reported as favorable across all four dose levels in 80 former smokers.
- Phase III trial targeting late 2026; FDA has cleared a U.S. Phase IIa IND.
Methodology
This is a news report summarizing company-presented Phase Ib/IIa clinical trial data from a medical conference (ERS 2026). The trial was randomized, double-blind, and placebo-controlled, lending design credibility, but results come from the manufacturer without independent peer-reviewed publication yet confirmed.
Study Limitations
Trial enrolled only 80 participants, limiting statistical power for the dramatic 100% exacerbation reduction claim. Data are company-reported from a conference presentation, not yet independently peer-reviewed. Long-term effects on lung function decline and mortality remain unknown.
Enjoyed this summary?
Get the latest longevity research delivered to your inbox every week.
Enter your email to subscribe: