Connect Biopharma’s IV Rademikibart Shows Rapid Lung Function Gains in Phase 1, Signals Potential in Acute Exacerbations
Written by: Mennatullah Mansour, PharmD
Reviewed By: Pharmacally Editorial Team
Connect Biopharma has announced positive preliminary topline results from a Phase 1 clinical pharmacology study assessing intravenous (IV) rademikibart, a next-generation monoclonal antibody targeting interleukin-4 receptor alpha (IL-4Rα). The data suggest the therapy could play a meaningful role in managing acute exacerbations of asthma and chronic obstructive pulmonary disease (COPD), an area where treatment options have remained largely unchanged for years.
Barry Quart, Pharm.D., CEO and Director of Connect Biopharma, noted that a single IV dose of rademikibart led to rapid improvements in lung function that were sustained for up to four weeks. He also pointed to a distinct bronchodilator-like effect that appears to extend beyond IL-4Rα inhibition, supporting the drug’s potential use in both acute episodes and long-term disease management.
In the study, a 300 mg IV dose produced early and clinically relevant gains in lung function. Improvements in forced expiratory volume in one second (FEV1) were seen within 15 minutes, ranging from 100 mL to more than 400 mL. Compared with previously reported 600 mg subcutaneous dosing (NCT04773678), IV administration demonstrated a faster onset of lung function improvement. Across both asthma and COPD groups, average FEV1 increases of approximately 200–400 mL was maintained through Day 29, while patients receiving placebo showed a gradual decline.
The Phase 1 trial (CBP-201-105) followed a single-dose, placebo-controlled design. In Part A, different infusion durations (30, 15, and 2 minutes) were evaluated in healthy participants, with no meaningful differences observed in safety or pharmacokinetics. Based on these findings, a 2-minute IV push was selected for Part B. This portion enrolled patients with stable asthma (n=12) and COPD (n=10), who were randomized in a 4:1 ratio to receive rademikibart or placebo. Baseline lung function reflected moderate impairment, with mean FEV1 values of 1.9 L in asthma and 1.55 L in COPD.
The safety profile observed in the study was favorable. There were no reports of serious or severe adverse events, and no participants discontinued treatment due to safety concerns.
Beyond its role in suppressing inflammation, rademikibart may also exert a direct bronchodilatory effect that is not solely dependent on IL-4Rα blockade. This dual activity could distinguish it from currently available biologics. In clinical practice, acute exacerbations are typically managed with β-agonists and systemic corticosteroids, which primarily address symptoms rather than the underlying type 2 inflammatory process.
Rademikibart works by targeting IL-4Rα, a shared component of the interleukin-4 and interleukin-13 receptor complexes, both of which are central to type 2 (Th2) inflammation. Inhibiting this pathway is expected to reduce inflammatory signaling across multiple disease settings.
This biological pathway is already well established in Atopic Dermatitis, where IL-4 and IL-13 contribute to skin inflammation, barrier dysfunction, and itching. Targeting IL-4Rα has been shown to improve disease severity and symptom control in dermatology, and rademikibart is being developed with the aim of extending these benefits across respiratory and allergic conditions.
Looking ahead, the company is progressing rademikibart into the Phase 2 Seabreeze STAT program for acute exacerbations in asthma and COPD, with results expected in mid-2026. Connect Biopharma also plans to engage with the U.S. Food and Drug Administration to discuss the design of a potential Phase 3 program.
Reference
Connect Biopharma Holdings Ltd. Connect Biopharma reports positive Phase 1 results of IV rademikibart in asthma and COPD, 30 March 2026, https://investors.connectbiopharma.com/news-releases/news-release-details/connect-biopharma-announces-positive-topline-data-its-phase-1
Efficacy and Safety of CBP-201 in Patients with Moderate to Severe Persistent Asthma with Type 2 Inflammation, ClinicalTrials.gov ID NCT04773678, https://clinicaltrials.gov/study/NCT04773678
About the Writer
Mennatullah Mansour is pursuing a PharmD and is based in Alexandria, Egypt. She is driven by a strong passion for continuous learning and professional development, with a focus on pharmaceutical care, patient health, and medication safety. Her interests include prescription processing, patient counseling, and interpreting clinical information. She brings a detail-oriented approach and a strong ability to translate medical knowledge into clear, accurate, and reliable content for healthcare audiences.