The real design bet Connect Biopharma is making with Seabreeze STAT is not whether rademikibart works in chronic asthma — that territory belongs to dupilumab, approved for add-on maintenance in moderate-to-severe eosinophilic asthma since 2018. The bet is whether a single subcutaneous dose of an IL-4Rα antibody, given during an acute exacerbation, can change outcomes in the 28 days that follow. That is a different clinical question, and enrollment of all 160 participants in the Phase 2 Seabreeze STAT Asthma study now sets a September 2026 topline readout in motion.
The trial design is worth examining closely. Every enrolled participant required an eosinophil count of at least 300 cells per microliter, confirming type 2 inflammation at the point of exacerbation, and each received a single subcutaneous dose of rademikibart or placebo on top of standard care. The primary endpoint is treatment failure rate over 28 days, a composite that captures hospitalization, return visits, and escalation of therapy. The key secondary endpoint, post-bronchodilator FEV1 at Week 1, directly tests whether the drug produces rapid functional recovery. That Week 1 window matters because Phase 1 data published in March 2026 showed rademikibart, given as a single IV push, produced rapid lung function improvement in both stable asthma and stable COPD patients. Whether that signal holds in the unstable, actively inflamed state is what Seabreeze STAT is built to answer.
The parallel COPD arm adds strategic weight. Connect expects to complete enrollment of a matching 160-participant COPD cohort in June 2026, with topline data following shortly after the asthma readout. Taken together, both studies share identical designs — single-dose, adjunct, eosinophil-gated, 28-day primary endpoint — which means the FDA alignment meeting Connect is planning for later this year will need to address Phase 3 strategy across two indications simultaneously. That is an ambitious regulatory schedule, and the company has acknowledged a cash runway extending into the second half of 2027, which gives it roughly one year of runway past these readouts before needing to raise or partner.
The single number to watch in September is not the headline p-value but the treatment failure rate in the placebo arm. If placebo failure runs unusually low, it compresses the detectable effect size in a 160-person study and complicates Phase 3 powering assumptions regardless of directionality. A high placebo failure rate, on the other hand, would validate the population selection and make any drug benefit clearly legible.
Jon Napitupulu is Director of Media Relations at The Clinical Trial Vanguard. Jon, a computer data scientist, focuses on the latest clinical trial industry news and trends.
