Connect Biopharma Announces Positive Topline Data from Phase 1 Study of IV Rademikibart in Asthma and COPD Patients

Key Highlights

• Rapid and Sustained Lung Function Improvement: Rademikibart, administered as a single 300 mg intravenous (IV) push over just 2 minutes, produced a rapid and clinically significant improvement in FEV₁ (forced expiratory volume in 1 second) in both asthma and COPD patients, with increases of 100 mL to >400 mL observed in many patients as early as 15 minutes post-dosing. These improvements were generally maintained through Day 29.
• Clinical Confirmation of Unique Bronchodilator Effect: The results provide strong clinical evidence that rademikibart has a unique and beneficial bronchodilatory effect, confirming earlier preclinical findings. The improvement was more rapid than previously observed with subcutaneous administration, highlighting the potential utility of IV dosing for acute exacerbations.
• Well-Tolerated Safety Profile: Rademikibart was generally well-tolerated, with no serious adverse events (AEs), severe AEs, or discontinuations due to AEs reported in the study.
• Ongoing Phase 2 Studies: Recruitment is ongoing for the Phase 2 Seabreeze STAT studies in acute exacerbations of asthma and COPD, with topline data expected in mid-2026.
• Potential to Transform Acute Care: Rademikibart’s rapid bronchodilation, especially in COPD patients, addresses a major unmet need and could impact the current standard of care, which relies on β-agonist bronchodilators and systemic steroids.
• Upcoming Company Event: Connect Biopharma will host a conference call and webcast on March 30, 2026, at 8:00 a.m. ET to discuss these results and future plans.

Study Details

The Phase 1 clinical pharmacology study (CBP-201-105) was a randomized, placebo-controlled trial evaluating single-dose IV rademikibart. In Part A, healthy volunteers received 300 mg rademikibart via different infusion rates (30, 15, or 2 minutes), with no differences in safety or pharmacokinetics, leading to the selection of the 2-minute IV push for Part B. Part B enrolled adults with stable asthma (n=12) and COPD (n=10), who were mostly current smokers with a mean baseline eosinophil count of 330 cells/μL.

• The mean baseline FEV₁ was 1.9 L in asthma and 1.55 L in COPD cohorts.
• The majority of patients showed meaningful FEV₁ increases (≥200 mL) as early as 15 minutes after dosing.
• The effect was sustained, with mean improvements of 200-400 mL generally maintained through Day 29, while placebo patients trended downward.

Expert Commentary

“Current standard of care relies on β-agonist bronchodilators and systemic steroids, but many patients could benefit from the rapid bronchodilation observed with IV rademikibart, with the added benefit of directly addressing the underlying inflammatory drivers of disease. I am not aware of any other biologic with rapid bronchodilator-like effects seen in this study, especially in COPD patients where the need is greatest.” – Dr. Michael Wechsler, National Jewish Health, Denver, CO

Pipeline and Financial Implications

• Phase 2 Seabreeze STAT Studies: Ongoing for acute exacerbations in both asthma and COPD, with topline data expected mid-2026. Positive data and FDA alignment on a Phase 3 program could be major catalysts for the company’s valuation and share price.
• Global Rights and Milestones: Connect Biopharma holds global rights to rademikibart except in Greater China, where it is exclusively licensed to Simcere Pharmaceutical. Connect is eligible to receive up to \$110 million in remaining milestones and royalties up to low double-digit percentages on net sales in Greater China.
• Significant Market Opportunity: The burden of acute exacerbations in asthma and COPD remains high, with limited innovation in acute care for decades. A new, rapid-acting biologic could capture significant market share and drive shareholder value.

About Rademikibart

Rademikibart is a fully human monoclonal antibody targeting interleukin-4 receptor alpha (IL-4Rα), a component of both IL-4 and IL-13 receptors. By blocking IL-4Rα, rademikibart inhibits the T helper 2 (Th2) inflammatory pathway, making it a promising therapy for Th2-related diseases such as atopic dermatitis, asthma, and COPD.

Shareholder Considerations

• The topline Phase 1 data is a significant positive development, demonstrating rapid and sustained efficacy and a clean safety profile—key attributes for acute and chronic care therapies.
• The upcoming Phase 2 data in mid-2026 represents a potentially major catalyst. Success in these studies could drive substantial upside for Connect Biopharma’s shares, especially if the company proceeds rapidly to pivotal Phase 3 trials with FDA support.
• The program’s unique mechanism and effect—bronchodilation independent of β-agonists—could differentiate rademikibart in a crowded respiratory market and support premium pricing.
• Investors should monitor further data releases, regulatory interactions, and updates on licensing revenues from Greater China.

Conference Call Information

Date: March 30, 2026
Time: 8:00 a.m. ET
Access: Pre-register for dial-in and PIN, or join the live webcast via the Connect Biopharma investor website. An archive will be available for 90 days.

Contact Information

• Investor Relations: Alex Lobo, Precision AQ, [email protected], (212) 698-8802
• Media Contacts: Ignacio Guerrero-Ros, Ph.D., or David Schull, Russo Partners, LLC, [email protected], [email protected], (858) 717-2310 or (646) 942-5604

Disclaimer: This article is for informational purposes only and does not constitute investment advice or a recommendation to buy or sell any securities. All statements regarding Connect Biopharma and its product candidates are based on the latest available information as of March 30, 2026. Drug development and commercialization involve significant risks, and there is no guarantee that rademikibart will be approved by regulatory agencies or achieve commercial success. Investors should consult official filings with the Securities and Exchange Commission and their financial advisors before making investment decisions.

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