Belenos Biosciences Announces Positive Topline Results from a Phase 2 Clinical Trial of BEL512 in Chronic Rhinosinusitis with Nasal Polyps (CRSwNP)

The research met its primary and all secondary endpoints at Week 24. Rapid onset of clinical action was observed with significant advancement as early as Week 4. Durable clinical activity was demonstrated following single-dose administration, helping 6- month dosing for the management of CRSwNP

Belenos Biosciences, Inc., a clinical-stage biotechnology organization advancing long-acting bispecific antibodies for chronic inflammatory diseases, announced that '512 met its primary and all secondary endpoints in a double-blind, placebo-controlled Phase 2 clinical research in adults with inadequately controlled CRSwNP (NCT06930612). ‘512 is known as BEL512 ex-China and CM512 in Greater China.

The study was conducted in China by Belenos’ partner, Keymed Biosciences, and enrolled 120 patients with CRSwNP with a Nasal Polyp Score of ≥5, with at least 2 polyps per nostril and a Nasal Congestion Score of 2-3 at baseline. Patients were randomized to receive either 300 mg '512 every 12 weeks, 300 mg '512 every 24 weeks, 600 mg '512 every 24 weeks, or placebo via subcutaneous injection on top of daily intranasal corticosteroid treatment (mometasone furoate nasal spray. Treatment lasted 24 weeks, followed by a 12-week safety follow-up.

The main endpoint was change from baseline at week 24 in Nasal Polyp Score (NPS). Additional endpoints evaluated in the study were:

• Nasal Congestion Score (NCS)
• Loss of Smell (LoS) Score
• Total Symptom Score (TSS)
• Sinus CT Lund-Mackay (LMK) score
• Sinonasal Outcome Test-22 (SNOT-22)

The research met its primary and secondary endpoints with statistically noteworthy improvements in the ‘512 treatment groups vs placebo at W24. Improvements were achieved by W4, and durable effects were observed during the management and follow-up periods.

‘512 was well tolerated across all dosing groups, with overall treatment-emergent adverse event (TEAE) rates similar to placebo, no severe TEAEs, no discontinuations in treatment groups, no severe side effects, and minimal anti-drug antibodies (ADA).

Based on the output of this research, ‘512 is presently being evaluated by the Center for Drug Evaluation (CDE) of China’s National Medical Products Administration (NMPA) in its Breakthrough Therapy program for the management of CRSwNP.

“These results provide important clinical validation for simultaneously targeting TSLP and IL-13 in treating CRSwNP,” said Donnie McGrath, M.D., CEO of Belenos Biosciences. “The magnitude, speed of onset, and durability of improvement across objective measures of nasal polyp disease and the symptoms that matter most to patients, in conjunction with infrequent dosing, indicate that BEL512 may offer patients an attractive treatment option. These findings further strengthen our conviction in BEL512 as a potentially best-in-class therapy across multiple respiratory and inflammatory diseases. We congratulate our partners at Keymed Biosciences on a well-executed study.” Keymed is rapidly shifting to initiate a Phase 3 study in CRSwNP in China in the near future, and Belenos will be initiating a Phase 3 study ex-China in the first half of 2027.

According to Towards Healthcare, the sinusitis drugs market is projected to grow significantly, with estimates indicating the market size will increase from USD 2.47 billion in 2026 to approximately USD 4.16 billion by 2035. The market is expanding at a CAGR of 5.96% between 2026 and 2035. Sinusitis medicines relieve painful facial pressure, shrink swollen nasal passageways, clear trapped mucus, and treat specific bacterial infections, creating it easier to breathe and significantly enhancing daily comfort during a sinus flare-up. These medicines support to lowers sinusitis symptoms like nasal congestion and hence enhance clearing the sinuses. These are comparatively safer and more efficient to use than other types of sinus therapeutics.

About Chronic Rhinosinusitis with Nasal Polyps:

Chronic Rhinosinusitis (CRS) affects between 10.9%-13.4% of the Western population, and the more serious subtype of CRSwNP accounts for around 18-20% of all CRS cases. CRSwNP is a long-term inflammatory disease of the nasal passages and sinuses characterized by the growth of nasal polyps. The condition is characterized by nasal obstruction, congestion, facial pressure, impaired or lost sense of smell, sleep disturbance, and often comorbid asthma. Many patients remain symptomatic despite intranasal corticosteroids, systemic corticosteroids, biologic therapy, or endoscopic sinus operation.

About BEL512

BEL512, known as CM512 in Greater China, is an investigational, long-acting bispecific antibody intended to inhibit thymic stromal lymphopoietin, or TSLP, and interleukin-13, or IL-13. By targeting an upstream epithelial alarmin and a central downstream effector cytokine, BEL512 is designed to offer broad and tough control of type 2 inflammation.

BEL512 is being developed for chronic inflammatory diseases characterized by epithelial-immune dysregulation, involving CRSwNP, asthma, long-term obstructive pulmonary disease, and atopic dermatitis. Belenos holds advancement and commercialization rights to BEL512 outside Greater China.

About Belenos Biosciences

Founded in 2024, Belenos Biosciences is a clinical-stage biotechnology company developing transformative therapies with the goal of restoring immune balance, enhancing clinical results, and achieving disease remission for patients with chronic inflammatory diseases. Belenos licensed all ex-China rights for BEL512 and BEL536 from Keymed Biosciences Ltd.

A recent report by Towards Healthcare highlights that the sinusitis drugs market is growing, as these medications are applicable to clear the mucus that gets collected in the sinuses. Decongestants are available both as nasal sprays and pills. These supports to lowers sinusitis symptoms like nasal congestion and therefore enhance clearing the sinuses. These are comparatively harmless and more efficient to use than other types of sinus therapeutics. These therapeutics support the cure of bacterial infections that occur in the skin and respiratory system. Skipping a dose of this medicine is not advisable, as this increases the risk of further infection. Allergic reactions trigger sinusitis infections. Antihistamines are available in the form of spray, tablet, or syrup. These help to get relief from allergic symptoms such as sneezing, itchy eyes, nasal stuffiness, and mucus production. Some of the antihistamines recommended by doctors are Cetirizine, Clemastine, Loratadine, and Desloratadine.