Rademikibart Treatment for Moderate-to-Severe, Uncontrolled Asthma: A Phase 2B Randomized Trial.

Abstract

Rationale: Rademikibart (formerly CBP-201) is an IL-4Rα-targeting antibody.

Objectives: To evaluate rademikibart in adults with moderate-to-severe, persistent, uncontrolled asthma.

Methods: In this global phase 2b trial (NCT04773678), 322 patients were randomized 1:1:1 to two rademikibart groups (150 mg or 300 mg every other week, following a 600 mg loading dose) or placebo, administered subcutaneously, for 24 weeks.

Measurements and main results: Prebronchodilator (trough) forced expiratory volume in the first second of expiration (FEV₁) at Week 12 (primary endpoint) improved with rademikibart 150 mg and 300 mg: least squares mean changes (95% CI), above placebo, were +140 mL (+44-236 mL; p=0.005) and +189 mL (+92-286 mL; p<0.001), respectively. Prebronchodilator trough FEV₁ improvements occurred rapidly during Week 1, were sustained through Week 24, and greatest in patients with high baseline blood eosinophils (patients with ≥300 eosinophils/mL experienced placebo-adjusted FEV₁ improvement at Week 24 of +420 mL [95% CI, +239-600 mL] in the 300 mg group). Rapid and sustained statistically significant improvements were also observed in percent predicted FEV₁ and Asthma Control Questionnaire score across 24 weeks. Through Week 24, proportions of patients with ≥1 exacerbation were 7.5% (150 mg) and 9.3% (300 mg) vs 16.7% (placebo). 88% of patients completed treatment. Treatment-emergent adverse events (TEAEs) were generally similar to placebo, and no eosinophilia was observed. Injection site reactions were mostly mild. The most common TEAEs (10-12% of patients) were cough, COVID-19, and dyspnea.

Conclusions: Rapid and sustained improvements in lung function and asthma control were gained across 24 weeks of rademikibart therapy. Clinical trial registration available at www.

Clinicaltrials: gov, ID: NCT04773678.