Connect Biopharma Presents Data Supporting Rademikibart at the European Respiratory Society Congress 2025

Rhea-AI Summary

Connect Biopharma (NASDAQ:CNTB) presented promising data for rademikibart, their investigational anti-IL-4Rα antibody, at the European Respiratory Society Congress 2025. The Phase 2b trial results showed significant improvements in lung function and asthma control, particularly in patients with elevated type 2 inflammatory markers.

Key findings include a 507 mL improvement in prebronchodilator FEV1 at Week 24 in patients with high EOS and FeNO levels, and substantial reductions in asthma exacerbations (63% reduction in high EOS patients and 69% reduction in high FeNO patients). The company expects to report topline data from ongoing Phase 2 Seabreeze STAT studies for acute exacerbations in asthma and COPD in 1H 2026.

Positive

• None.

Negative

• Lower treatment response and higher placebo effect observed in Polish patient subgroup
• Treatment efficacy varies significantly based on patient biomarker levels
• Some baseline imbalances in trial populations may have impacted treatment effects

Insights

Clinical Pulmonology Specialist

Promising Phase 2b data shows rademikibart significantly improves lung function in type 2 inflammation asthma patients, supporting its best-in-class potential.

Connect Biopharma's presentation at ERS 2025 showcases compelling post-hoc analyses of their Phase 2b trial for rademikibart, their anti-IL-4Rα antibody targeting moderate-to-severe asthma. The data reveals stratified efficacy based on inflammatory biomarkers, a critical distinction in today's precision medicine landscape. Patients with elevated eosinophils (≥300 cells/μL) and FeNO (≥25 ppb) showed remarkable FEV1 improvements of 507 mL at 24 weeks—approximately 5× greater than those with low biomarkers (108 mL). This demonstrates clear biomarker-guided response prediction, essential for targeting appropriate patient populations.

The 63-69% reduction in exacerbations in biomarker-positive patients represents particularly meaningful clinical benefit, as exacerbations drive morbidity, healthcare utilization, and lung function decline. Regional differences observed between Poland and other sites highlight the importance of trial execution factors and baseline patient characteristics in respiratory studies. The data strategically positions rademikibart against established IL-4Rα inhibitors like dupilumab, with the rapid onset suggesting potential advantages in the competitive type 2 inflammation space. These insights have appropriately shaped site selection for the ongoing Seabreeze STAT trials in asthma and COPD, potentially increasing probability of success in upcoming readouts expected in 1H26.

Biotech Investment Analyst

Connect Biopharma's ERS Congress presentation strengthens rademikibart's competitive positioning in the lucrative type 2 inflammation market. The stratified biomarker analysis reveals exceptional response in patients with elevated eosinophils and FeNO—precisely the population where biologics deliver maximum value. The 507 mL FEV1 improvement in this subgroup exceeds typical responses seen with approved biologics, positioning rademikibart favorably against established competitors like dupilumab and tezepelumab.

The exacerbation reduction of 63-69% in biomarker-positive patients represents meaningful clinical and economic value, as exacerbations drive substantial healthcare costs. From a development perspective, the identification of regional differences in placebo response demonstrates thoughtful clinical operations, with the company wisely applying these insights to site selection strategies for the ongoing Seabreeze STAT trials in both asthma and COPD.

The simultaneous development in COPD represents a significant opportunity, as this indication has proven challenging for biologic therapies. With topline data expected in 1H26 for both indications, Connect has positioned itself for potential value inflection within a reasonable timeframe. The IL-4Rα mechanism is clinically validated by dupilumab's success, but the opportunity for rademikibart to demonstrate differentiated efficacy and potentially best-in-class status represents meaningful upside potential for this clinical-stage company.

– Rademikibart demonstrated rapid and significant improvement in lung function and asthma control in patients, with greatest improvements observed in those with elevated baseline levels of key type 2 inflammatory markers –

– Significant reduction in annualized exacerbations observed in patients with one or more elevated type 2 inflammatory markers at baseline –

– Data supports ongoing Phase 2 Seabreeze STAT studies for acute exacerbations in asthma and COPD; expect to report topline data from both studies in 1H26 –

SAN DIEGO, Sept. 29, 2025 (GLOBE NEWSWIRE) -- Connect Biopharma Holdings Limited (Nasdaq: CNTB) (Connect Biopharma, Connect or the Company), a clinical-stage biopharmaceutical company focused on transforming care for the treatment of inflammatory diseases, today presented data supporting rademikibart, the Company’s investigational, next-generation, potentially best-in-class anti-interleukin-4-receptor alpha (IL-4Rα) antibody, at the European Respiratory Society (ERS) Congress 2025, taking place September 27 – October 1, 2025, in Amsterdam, Netherlands and virtually.

“We are excited to share additional analyses from our Phase 2b asthma study at ERS. These data continue to expand our data package for rademikibart and reinforce its potential to deliver best-in-class efficacy for patients with moderate to severe asthma and COPD,” said Barry Quart, Pharm.D., CEO and Director of Connect Biopharma. “These data build on previously reported Phase 2b study outcomes demonstrating rapid and sustained lung function improvements, with the greatest outcomes being observed in patients with elevated levels of key type 2 inflammatory biomarkers. In addition, these analyses have helped to refine our clinical development plans and clinical site strategies for our ongoing Seabreeze STAT asthma and COPD studies. We look forward to reporting topline data from both in the first half of 2026.”

Abstract Title: Rapid and Sustained FEV₁ Improvements with Rademikibart in Type 2 Asthma: Impact of Eosinophils and FeNO

• Results from the Company’s Phase 2b trial of rademikibart in moderate-to-severe asthma were evaluated in a post-hoc analysis to investigate the efficacy of rademikibart in subgroups of patients with asthma based on baseline levels of type 2 inflammatory biomarkers, indicated by blood eosinophil counts (EOS) of <300 or ≥300 cells/μL and fractional exhaled nitric oxide (FeNO) levels of <25 or ≥25 ppb.
• Rademikibart treatment led to rapid and sustained improvement in lung function and asthma control in subgroups with elevated baseline markers of Type 2 inflammation, with greatest improvements observed in patients with both high EOS and high FeNO.
• At Week 24, treatment with rademikibart improved prebronchodilator FEV₁ by 507 mL in patients with high EOS and high FeNO, 284 mL in patients with low EOS and high FeNO, 209 mL in patients with high EOS and low FeNO, and 108 mL in patients with low EOS and low FeNO.
• In addition to lung function and asthma control, a reduction in asthma exacerbations was observed in subgroups with at least one high type 2 inflammatory biomarker at baseline, with a 63% reduction in patients with high EOS and a 69% reduction in patients with high FeNO.
• These results highlight rademikibart’s potential to improve lung function and reduce asthma exacerbations, particularly in patients with elevated markers of Type 2 inflammation.
  

Abstract Title: Rademikibart in Moderate-to-Severe Asthma: Impact of Eosinophils and Regional Differences on Response

• A post-hoc analysis of the Company’s Phase 2b trial of rademikibart in moderate-to-severe asthma investigated the prespecified primary endpoint, absolute change in prebronchodilator FEV₁ at Week 12, in subgroups of patients enrolled in Poland and in the Rest of the World (ROW).
• Rademikibart rapidly and significantly improved lung function in adults with asthma, with greater benefit observed in patients with higher baseline EOS, in both the overall trial population and ROW subgroup.
• In Poland, placebo response was greater and rademikibart response was less than in the ROW subgroup and overall trial population. Four patients in the placebo group demonstrated unusually large improvements in lung function, potentially related to baseline factors, such as EOS <150 cells/μL, high FEV₁, and/or daily use of inhalers.
• In Poland, rademikibart-treated patients also had milder disease compared to the ROW subgroup, increased percent predicted FEV₁, and despite similar FeNO levels, this baseline imbalance may have impacted treatment effects.
• These results underscore the importance of rigorous trial conduct and comprehensive patient guidance and have informed the Company’s ongoing Phase 2 Seabreeze STAT clinical site strategy.
  

The presentations will be available on Connect’s website under the publications and presentations section.

About Rademikibart
Rademikibart is a fully human monoclonal antibody targeting interleukin-4 receptor alpha (IL-4Rα), a common subunit of interleukin-4 receptor (IL-4) and interleukin-13 receptor (IL-13). We believe that by binding with IL-4Rα, rademikibart can block the functions of IL-4 and IL-13 effectively, thereby blocking the T helper 2 (Th2) inflammatory pathway to achieving the goal of treating Th2 related inflammatory diseases such as atopic dermatitis and asthma.

About Connect Biopharma
Connect Biopharma is a clinical-stage biopharmaceutical company dedicated to transforming care for asthma and COPD. Headquartered in San Diego, California, the Company is advancing rademikibart, a next-generation, potentially best-in-class antibody designed to target IL-4Rα. The Company is currently conducting global clinical studies of rademikibart for the treatment of acute exacerbations of asthma and COPD, areas with significant unmet need. Connect also has an exclusive license and collaboration agreement for rademikibart with Simcere in China.

For more information visit www.connectbiopharma.com.

Forward-Looking Statements
This press release contains “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, as amended (the “Act”). Forward-looking statements are statements that are not of historical fact and include, without limitation, statements regarding future events, our future financial condition, results of operations, business strategy and plans, prospective products (as well as their potential to achieve a differentiated, competitive, or favorable benefit or profile or trend, including on safety, tolerability, improvement, maintenance, clinical response, dosing, efficacy and/or convenience), planned or expected product approval applications or approvals, anticipated milestones, expected data readouts and enrollments, research and development plans and costs, potential future partnerships, expectations about existing partnerships, timing and likelihood of success, objectives of management for future operations, future results of anticipated product development efforts, and adequacy of existing cash and potential partnership funding to fund operations and capital expenditure requirements, as well as statements regarding industry trends. These statements are based on management’s current expectations of future events only as of the date of this press release and are inherently subject to a number of risks, uncertainties and assumptions, some of which cannot be predicted or quantified and some of which are beyond our control, including, among other things: the ability of our clinical trials to demonstrate safety and efficacy of our product candidates and other positive results; whether we will need expanded or additional trials in order to obtain regulatory approval for our product candidates; our ability to obtain and maintain regulatory approval of our product candidates; existing regulations and regulatory developments in the U.S., the PRC, Europe and other jurisdictions; the ability of our current cash and investments position to support planned operations; our plans and ability to obtain, maintain, protect and enforce our intellectual property rights and our proprietary technologies, including extensions of existing patent terms where available; our continued reliance on third parties to conduct additional clinical trials of our product candidates, and for the manufacture of our product candidates for preclinical studies and clinical trials; and the degree of market acceptance of our product candidates, if approved, by physicians, patients, healthcare payors and others in the medical community.

Words such as “aim,” “anticipate,” “believe,” “could,” “expect,” “feel,” “goal,” “intend,” “look forward to,” “may,” “optimistic,” “plan,” “potential,” “promising,” “will,” and similar expressions are intended to identify forward-looking statements, though not all forward-looking statements necessarily contain these identifying words. The inclusion of forward-looking statements should not be regarded as a representation by Connect Biopharma that any of its expectations, projections or plans will be achieved. Actual results may differ materially due to the risks and uncertainties inherent in our business and other risks described in our filings with the U.S. Securities and Exchange Commission (the “SEC”). Further information regarding these and other risks is included under the heading “Risk Factors” in our annual and periodic reports filed with the SEC. These forward-looking statements should not be taken as forecasts or promises nor should they be taken as implying any indication, assurance or guarantee that the assumptions on which such forward-looking statements have been made are correct or exhaustive or, in the case of the assumptions, fully stated in this presentation. Drug development and commercialization involve a high degree of risk, and only a small number of research and development programs result in commercialization of a product. Results in early-stage clinical trials may not be indicative of full results or results from later stage or larger scale clinical trials and do not ensure regulatory approval. You are cautioned not to place undue reliance on the scientific data presented or any forward-looking statements, which speak only as of the date of such presentation(s) or such statements. Except as required by law, Connect Biopharma undertakes no obligation to publicly update any forward-looking statements, whether because of new information, future events or otherwise. Connect Biopharma claims the protection of the safe harbor for forward-looking statements contained in the Act for all forward-looking statements.

This press release discusses our product candidate, rademikibart, which is under clinical investigation and has not yet been approved for marketing by the U.S. Food and Drug Administration, the National Medical Products Administration, or by any other regulatory agency. No representation is made as to the safety or effectiveness of rademikibart for the uses for which it is being studied. The trademarks included herein are the property of the owners thereof and are used for reference purposes only.

Investor Relations Contact:
Alex Lobo
Precision AQ
Alex.Lobo@precisionaq.com
(212) 698-8802

Media Contact:
Ignacio Guerrero-Ros, Ph.D., or David Schull
Russo Partners, LLC
Ignacio.guerrero-ros@russopartnersllc.com
David.schull@russopartnersllc.com
(858) 717-2310 or (646) 942-5604

FAQ

What were the key findings of Connect Biopharma's (CNTB) rademikibart Phase 2b trial?

The trial showed significant improvements in lung function, with a 507 mL improvement in FEV1 at Week 24 in patients with high EOS and FeNO levels, and 63-69% reduction in asthma exacerbations in patients with elevated inflammatory markers.

When will Connect Biopharma report results from the Seabreeze STAT studies?

Connect Biopharma expects to report topline data from both Seabreeze STAT studies in the first half of 2026.

How does rademikibart's efficacy vary among different patient groups?

Rademikibart showed the greatest efficacy in patients with elevated type 2 inflammatory markers, particularly those with high blood eosinophil counts (EOS) and high fractional exhaled nitric oxide (FeNO) levels.

What is rademikibart's mechanism of action?

Rademikibart is an investigational next-generation anti-interleukin-4-receptor alpha (IL-4Rα) antibody designed to treat inflammatory diseases.

What were the regional differences in rademikibart's trial results?

The study showed lower treatment response and higher placebo effects in Polish patients compared to Rest of World (ROW), potentially due to baseline factors and milder disease characteristics in the Polish subgroup.