Connect Biopharma fills Phase 2 asthma study of rademikibart
Connect Biopharma has completed enrolment in its Phase 2 Seabreeze STAT Asthma study, a randomised, double-blind, placebo-controlled trial evaluating rademikibart as an adjunct to standard of care for acute exacerbations in adults and adolescents with asthma and type 2 inflammation. The NASDAQ-listed company said it expects to report topline data in early September 2026.
The study enrolled 160 participants globally, each presenting with an acute asthma exacerbation and an eosinophil count of at least 300 cells per microlitre. Participants received a single subcutaneous dose of either rademikibart or placebo. The primary endpoint is treatment failure rate over 28 days following an acute exacerbation; the key secondary endpoint is post-bronchodilator forced expiratory volume in one second (FEV1) at week one.
Parallel COPD programme
Connect also said it expects to complete enrolment in a companion study, Seabreeze STAT COPD, this month. That trial follows the same design and enrolment target of 160 participants, with the same primary and key secondary endpoints. Topline data from the COPD cohort are expected shortly after the asthma readout. The company said it plans to seek a meeting with the FDA before the end of 2026 to align on a Phase 3 programme, contingent on the Phase 2 results.
Rademikibart is a fully human monoclonal antibody targeting interleukin-4 receptor alpha (IL-4Ra), the shared signalling subunit for both IL-4 and IL-13. By blocking IL-4Ra, the antibody is designed to suppress the Th2 inflammatory pathway implicated in atopic dermatitis, asthma and COPD. The company positions rademikibart as potentially best-in-class in the IL-4Ra class, though no head-to-head comparative data have been published.
"We anticipate that data from both studies will build on the body of evidence supporting the potential of rademikibart to deliver a differentiated therapeutic profile, including rapid onset of action for patients in both the acute and chronic treatment settings," said Barry Quart, chief executive of Connect Biopharma.
Market context
The IL-4Ra antibody space is dominated by dupilumab (Dupixent), developed by Sanofi and Regeneron, which holds approvals across atopic dermatitis, asthma, COPD and several other type 2 inflammatory indications. Dupixent generated global sales of approximately $14 billion in 2024, underscoring the commercial scale of the target class. Rademikibart's differentiation claim centres on rapid onset of action in the acute setting, a niche that dupilumab's existing label does not specifically address and for which no biologic is currently approved.
Connect holds a Greater China licence with Simcere Pharmaceutical, under which it is eligible for up to approximately $110 million in remaining development, regulatory and commercial milestones, plus tiered royalties at up to low double-digit percentages on net sales in that territory. The company reported cash runway into the second half of 2027, providing sufficient cover for both the Phase 2 readouts and initial Phase 3 planning discussions with regulators.
The September data readout will be closely watched by investors assessing whether rademikibart can carve out a credible position in the acute exacerbation setting and whether the benefit-risk profile supports a broad Phase 3 programme across both asthma and COPD.