Keymed Biosciences Inc. (stock code: 02162) announced that its Phase II clinical study of CM512, a first-in-class long-acting TSLP × IL-13 bispecific antibody, met every predefined endpoint in patients with chronic rhinosinusitis with nasal polyps (CRSwNP). Data unblinding and preliminary statistical analysis confirmed efficacy, safety and tolerability across all tested doses.

CM512 produced rapid and durable clinical benefits. Nasal polyp size and nasal congestion improved as early as Week 4, and a single administration sustained efficacy for 24 weeks. At Week 24, the change from baseline in nasal polyp score was statistically superior to placebo, accompanied by significant improvements in total symptom and Lund-Mackay scores as well as olfactory function. Inflammation in the sinus cavities was also markedly reduced.

Safety outcomes were favorable. The incidence of treatment-emergent adverse events in CM512 groups matched that of placebo, no serious adverse events occurred, and anti-drug antibody formation remained extremely low.

The randomized, double-blind, placebo-controlled Phase II study enrolled patients in China across three active dosing regimens—300 mg every 12 weeks, 300 mg every 24 weeks and 600 mg every 24 weeks—over a 24-week treatment period with an additional 12-week safety follow-up. Endpoints evaluated efficacy (primary: nasal polyp score at Week 24), safety, pharmacokinetics, pharmacodynamics and immunogenicity.

Based on these findings, Keymed Biosciences is moving rapidly into Phase III development and has selected 300 mg every 24 weeks as the dosing regimen. CM512 was granted Breakthrough Therapy Designation by China’s Center for Drug Evaluation on 23 July 2026 for CRSwNP.

The company cautioned that successful development, launch or commercialisation of CM512 is not guaranteed and advised shareholders and investors to exercise care when dealing in the company’s shares.