Belenos Pipeline Updates: First Clinical Data from Lead Asset BEL512, a Long-lasting Bispecific Targeting TSLP and IL-13, Second Asset BEL336, a First-in-class Long-acting Bispecific Targeting OX40L and IL-13, Phase 1 to Start 1Q2026

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SARASOTA, Fla.--(BUSINESS WIRE)--Nov 10, 2025--

Belenos Biosciences Inc.:

• BEL512:
  • Support for Extended Dosing Intervals: Subcutaneous BEL512 (CM512) demonstrated long half-life of up to 70 days
  • Clinical Improvements:Patients dosed on Day 1, Day 15, and Day 29 achieved EASI-75 quickly at Week 6 and were maintained for over 12 weeks
  • Key Biomarker Suppression:Key biomarkers of inflammation decreased, including TARC, IgE, IL-13, TSLP, and eotaxin-3
  • Favorable Safety:Well-tolerated with no safety concerns identified, similar TEAE incidence across placebo and treatment groups
  • US Study Ongoing in Asthma, Broad Potential Across Multiple Indications:Belenos’ Proof-of-Concept study of ‘512 in patients with mild-moderate Asthma in the U.S. expected to readout in 2026. Five Phase 2 studies ongoing in China in Chronic Obstructive Pulmonary Disorder, asthma, Chronic Rhinosinusitis with Nasap Polyps, Chronic Spontaneous Urticaria and AD.
• BEL536:
  • First-in-Class Long-acting Bispecific Targeting OX40L/IL-13:CTN filed in Australia with target of initiating Phase 1 study in 1Q2026

Belenos Biosciences Inc., a private, clinical-stage biotechnology company today announced that its China partner Keymed Biosciences has reported topline results from a Phase 1b study (n=46) of BEL512 (CM512), exploring preliminary efficacy in patients with moderate-to-severe AD. Three treatments given over one month led to rapid, deep, and sustained improvements across all clinical endpoints, decreases in key inflammatory biomarkers, a favorable safety profile and pharmacokinetics supportive of long-interval dosing.

‘512 is a novel TSLP/IL-13 bispecific engineered with half-life extension. The Phase 1b testing two doses (300 mg and 600 mg) of BEL512 vs placebo highlighted significant and durable responses:

• EASI 75 300 mg group at week 6 of 50% vs 7% in placebo groups
• EASI 75 300 mg group at week 12 of 58% vs 21.4% in placebo groups
• EASI 90 300 mg group at week 12 of 41.7% vs 0% in placebo groups

These improvements were sustained through to week 24, 20 weeks after the last dose of ‘512. Both serum TSLP and IL-13 rapidly decreased after initial dose, reaching levels below the lower limit of quantification. TARC, eotaxin-3, CCL13, and IgE decreased after the first dose, and reductions were sustained through the 24 week study.

The Phase 1b study was conducted in China, and sponsored by Keymed Biosciences Ltd., (NCT06553209). It is the first study of a bispecific agent to report results in this patient population.

Belenos’ second asset, BEL536, is a first-in-class long-acting bispecific antibody developed by Keymed Biosciences and is being advanced into clinical studies by Belenos. By targeting OX40L and IL-13 it is designed to both treat symptoms and signs of disease rapidly through blockade of IL-13 and OX40L, but also with the intent of getting patients into durable disease remission.

“These first patient data underscore the potential ‘512 has to deliver rapid, deep, durable disease control,” said Donnie McGrath, MD, CEO of Belenos Biosciences Inc. “The arrival of the first patient data for ‘512, and the imminent start of our Phase 1 study for BEL536 represent significant milestones for the company. Looking ahead to the completion of our ‘512 asthma study in the U.S. and the multiple ‘512 phase 2 studies our partners at Keymed are conducting in China means that in 2026 the ‘512 program will have several clinical read-outs to support moving toward pivotal programs in 2027,” Dr. McGrath continued.

About Belenos

Founded in 2024, Belenos Biosciences is a clinical-stage biotechnology company developing transformative therapies with the goal to restore immune balance, improving clinical outcomes and achieving disease remission for patients with chronic inflammatory diseases. Belenos licensed all ex-China rights for BEL512 and BEL536 from Keymed Biosciences Ltd. www.belenosbio.com

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[email protected]

KEYWORD: CHINA UNITED STATES NORTH AMERICA ASIA PACIFIC FLORIDA

INDUSTRY KEYWORD: HEALTH OTHER SCIENCE CLINICAL TRIALS PHARMACEUTICAL SCIENCE BIOTECHNOLOGY

SOURCE: Belenos Biosciences Inc.

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PUB: 11/10/2025 03:44 PM/DISC: 11/10/2025 03:44 PM

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