Sarasota, Fla., August 11, 2026
Belenos Biosciences announced positive topline results from a Phase 2 clinical trial of BEL512 in adults with inadequately controlled chronic rhinosinusitis with nasal polyps (CRSwNP). The randomized, double-blind, placebo-controlled study met its primary and all secondary endpoints at Week 24, demonstrating statistically significant improvements in nasal polyp burden and disease-related symptoms. The results support the continued development of BEL512 as a potentially long-acting treatment for chronic inflammatory diseases.
BEL512 Demonstrates Significant Clinical Benefits in CRSwNP
The Phase 2 study, conducted in China by Belenos’ partner Keymed Biosciences, enrolled 120 patients with CRSwNP. Participants received either 300 mg BEL512 every 12 weeks, 300 mg every 24 weeks, 600 mg every 24 weeks, or placebo through subcutaneous injection, alongside daily intranasal corticosteroid treatment. The primary endpoint was the change from baseline in Nasal Polyp Score (NPS) at Week 24, while secondary assessments included nasal congestion, loss of smell, total symptom scores, sinus CT findings, and the SNOT-22 quality-of-life assessment. The study achieved its primary and secondary objectives, with significant improvements compared with placebo. Importantly, clinical activity was observed as early as Week 4, indicating a rapid onset of treatment effect. The benefits remained durable throughout the treatment and follow-up periods, supporting the potential of BEL512 for infrequent dosing intervals.
Long-Acting Bispecific Antibody Advances Targeted Inflammation
BEL512 is an investigational long-acting bispecific antibody designed to simultaneously inhibit thymic stromal lymphopoietin (TSLP) and interleukin-13 (IL-13), two important pathways involved in type 2 inflammation. TSLP functions as an upstream epithelial cytokine that helps initiate and amplify inflammatory responses, while IL-13 contributes to mucus production, tissue inflammation, impaired barrier function, and airway remodeling. By targeting both pathways within a single molecule, BEL512 is designed to provide broad and durable control of type 2 inflammation. The candidate is being developed for several chronic inflammatory conditions, including CRSwNP, asthma, chronic obstructive pulmonary disease, and atopic dermatitis. In the Phase 2 CRSwNP trial, BEL512 was reported to be well tolerated across all dosing groups, with treatment-emergent adverse-event rates similar to placebo, no severe treatment-emergent adverse events, no serious adverse events, and no treatment discontinuations in the active treatment groups. Minimal anti-drug antibody findings were also reported.
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China Breakthrough Therapy Designation and Phase 3 Plans
The positive Phase 2 results have strengthened the development pathway for BEL512, also known as CM512 in Greater China. The candidate was recently included in the Breakthrough Therapy program of China’s National Medical Products Administration (NMPA) Center for Drug Evaluation (CDE) for CRSwNP. The designation provides an important regulatory milestone as the program advances toward registrational development. Keymed Biosciences plans to initiate a Phase 3 study in China, while Belenos expects to begin an ex-China Phase 3 study during the first half of 2027. Detailed Phase 2 findings are expected to be presented at a future scientific meeting and submitted for publication in a peer-reviewed medical journal. The latest results provide clinical validation for the strategy of simultaneously targeting TSLP and IL-13 and position BEL512 as a promising candidate for patients with chronic inflammatory disease who require durable disease control and potentially less frequent treatment.
Source: Belenos Biosciences press release
