Rademikibart Improves Lung Function in Patients with Asthma within 24 Hours

Rademikibart treatment of asthma leads to rapid lung function improvements within 24 hours of the first dose, according to recent findings, and these improvements are sustained over time.1

These findings, highlighting rademikibart’s potential as a fast-acting therapeutic option for individuals with type 2 inflammation, were presented at the 2025 American Thoracic Society (ATS) International Conference in San Francisco. The study from which the results were drawn, titled ‘Rapid Improvement In Lung Function Observed With Rademikibart In Patients With Moderate-to-severe Uncontrolled Asthma,’ was authored by a team of investigators led by Raúl Collazo, PhD, vice president and Global Head of Medical Affairs for Connect Biopharma.

Asthma is known to impact over 26 million individuals within the US, and Collazo and colleagues noted its connection to type 2 inflammation driven by interleukin (IL)-4 and IL-13. Rademikibart was designed as a monoclonal antibody to target the IL-4 receptor alpha (IL-4Ra), thereby inhibiting signaling from both drivers of inflammation in patients with asthma.

Prior phase 2b findings on rademikibart demonstrated that the medication’s use led to clinically meaningful and statistically significant enhancements in lung function that investigators noted as early as the first week.2 The data had shown these benefits continue throughout a 24-week treatment period, according to the study’s spirometry assessments.

The design of the phase 2b clinical study was global, randomized, and placebo-controlled, with the investigative team enrolling a total of 322 subjects. These participants were randomized by the team to be treated either with a 600 mg loading dose of rademikibart (n = 214) or with a placebo (n =1 08).

The post hoc analysis presented at ATS involved an assessment of at-home spirometry data, as such information is recognized for greater variability as a result of a lack of professional guidance. This data was evaluated to determine whether lung function improvements could be detected in the first week of rademikibart utilization, prior to the Day 7 visit to the clinic, following a single loading dose in those with moderate-to-severe uncontrolled asthma.

Specifically, Collazo and coauthors looked at absolute change from baseline (CFB) in pre-bronchodilator forced expiratory volume in a single second (FEV₁), a result which they evaluated using self-administered home spirometry from Days 1 - 7. They used baseline blood eosinophil counts—≤300 cells/μL versus ≥300 cells/μL—for subgroup analyses.

Overall, improvements in in-clinic FEV₁, seen after a single 600 mg dose on Day 0 of the first week, were observed by the investigators as 232 mL and 175 mL in the 150 mg and 300 mg cohorts of the study, respectively.1 Results of home spirometry data indicated to the team that roughly 75% of the improvements in Day 7 FEV₁ were already seen within approximately 24 hours of dosing.

The full observed benefits, additionally, were seen by patients by Day 2. Collazo et al highlighted that study participants with baseline eosinophil counts of ≥300 cells/μL had more pronounced gains in FEV₁. They also noted that the medication was generally well tolerated, aligning with earlier findings.

These findings highlight rademikibart potential as a fast-acting intervention for individuals living with type 2 inflammation-driven asthma. They also suggest the drug may be helpful in early treatment scenarios, including shortly after acute exacerbations of asthma or chronic obstructive pulmonary disease.

For additional information on data presented at ATS 2025, view our latest conference coverage.

References

1. Collazo R, Wechsler ME, et al. Rapid Improvement In Lung Function Observed With Rademikibart In Patients With Moderate-to-severe Uncontrolled Asthma. Abstract presented at the American Thoracic Society (ATS) International Conference 2025 in San Francisco, CA, from May 18 - May 21, 2025.

2. Kerwin E, Yang T, Su N, et al. Rademikibart Treatment for Moderate-to-Severe, Uncontrolled Asthma: A Phase 2B Randomized Trial. Am. J. Respir. Crit. Care Med. 2025; 0(ja). doi: 10.1164/rccm.202409-1708OC.