Connect Biopharma: rademikibart cuts COPD failure rate 81% in Ph2
Connect Biopharma has reported positive topline data from its Phase 2 Seabreeze STAT COPD trial, saying rademikibart reduced the rate of treatment failure by 81% at four weeks compared with placebo (p=0.0122) in adults with chronic obstructive pulmonary disease and type 2 inflammation. The Nasdaq-listed company said it will now seek FDA alignment on a Phase 3 registrational programme.
The randomised, double-blind, placebo-controlled study enrolled 159 participants globally, all with an eosinophil count of at least 300 cells per microlitre who had experienced an acute COPD exacerbation. Participants received a single subcutaneous dose of rademikibart or placebo on top of standard of care. The primary endpoint was treatment failure within 28 days, defined broadly to include death, hospital readmission, emergency department revisit, or the need to intensify pharmacological treatment.
Trial results
Beyond the primary endpoint, the data showed rademikibart reduced new moderate to severe COPD exacerbations by 85% at four weeks versus placebo (p=0.030), and new emergency department visits and hospital admissions fell by 100% in the rademikibart arm (p=0.0137). Rescue inhaler use was significantly lower from week two through week seven, and COPD symptom scores improved significantly at week two (p=0.0197). A 70 mL improvement in post-bronchodilator FEV1 at week four was reported, though this did not reach statistical significance (p=0.1607). The safety profile was described as comparable to placebo, with a lower incidence of adverse events in the rademikibart arm.
Chief executive Barry Quart noted that 2025 claims data suggest COPD patients attending an emergency department for an acute exacerbation generate approximately $6 billion in healthcare costs in the following 30 days. "This study demonstrated that rademikibart completely eliminated those return visits while decreasing new moderate to severe COPD exacerbations by 85% compared to placebo," he said.
Market and competitive context
Rademikibart is a fully human monoclonal antibody targeting interleukin-4 receptor alpha, the same receptor subunit blocked by dupilumab, Sanofi and Regeneron's established IL-4Rα inhibitor already approved in asthma and atopic dermatitis. Connect positions rademikibart as a next-generation, potentially best-in-class agent in this mechanistic class, though head-to-head data versus dupilumab are not yet available and the "best-in-class" characterisation remains to be tested in later-stage studies.
The COPD biologics landscape is developing rapidly. GlaxoSmithKline's mepolizumab and AstraZeneca's benralizumab, both targeting the IL-5 pathway, are approved for eosinophilic COPD in certain markets, while dupilumab received a US approval for COPD with type 2 inflammation in mid-2024. Connect's data, targeting the post-exacerbation recovery window with a single dose, carve out a distinct positioning if Phase 3 can replicate the signal. The 100% reduction in return hospital visits is a striking headline figure, though the absolute event numbers in a 159-patient study warrant scrutiny; the company has not yet released the full dataset.
Connect also holds a Greater China licence agreement with Simcere Pharmaceutical, under which it is eligible to receive up to approximately $99 million in remaining development, regulatory and commercial milestones, plus tiered royalties. The near-term milestone for investors is the FDA pre-Phase 3 meeting, for which no date has been disclosed.