Keymed Biosciences Reports Phase III Stapokibart Data for Atopic Dermatitis Treatment

Keymed Biosciences Inc. (HKEX: 02162) released long-term efficacy and safety data from a Phase III clinical trial of stapokibart injection for moderate-to-severe atopic dermatitis (AD) at the European Academy of Allergy and Clinical Immunology (EAACI) Congress 2024. The results highlighted sustained effectiveness and a favorable safety profile for the drug, with no new safety concerns identified.

The study was a multicenter, randomized, double-blind, placebo-controlled Phase III trial designed to evaluate the efficacy, safety, pharmacokinetics, pharmacodynamics, and immunogenicity of stapokibart in patients suffering from moderate-to-severe AD. A total of 476 patients entered the maintenance treatment phase, equally divided into two groups. At the 52-week mark, 92.5% of patients continuing stapokibart treatment and 88.7% of those transitioning from placebo to stapokibart achieved a 75% improvement in Eczema Area and Severity Index (EASI-75). Furthermore, an Investigator's Global Assessment (IGA) score of 0/1 with a reduction of two or more points was noted in 67.3% and 64.2% of patients, respectively. A four-point reduction in the weekly average of daily Peak Pruritus Numerical Rating Scale (PP-NRS) was achieved by 67.3% and 60.5% of patients, respectively. Only one patient (0.9%) relapsed during the maintenance period.

Safety data showed that stapokibart was well-tolerated over 52 weeks, consistent with the initial 16-week double-blind period, without new safety signals. Initially, 500 adult patients with moderate-to-severe AD were randomized in a 1:1 ratio to receive either 300 mg of stapokibart (with a 600 mg loading dose) or a placebo every two weeks for 16 weeks. During the subsequent 36-week maintenance period, stapokibart patients continued their regimen, while those initially on placebo were switched to receive the same dosage of stapokibart. Topical medications for AD were allowed during the maintenance period.

The trial had co-primary endpoints: the proportion of patients achieving a 75% improvement in EASI score (EASI-75) and an IGA score of 0/1 with a reduction of at least two points from baseline at week 16. Secondary efficacy measures included EASI score, IGA score, and PP-NRS.

Stapokibart, also known as CM310, is a humanized antibody targeting the interleukin-4 receptor alpha subunit (IL-4Rα). It is the first domestically produced IL-4Rα antibody drug approved for clinical trials by the National Medical Products Administration (NMPA) of China. By targeting IL-4Rα, Stapokibart can inhibit the signaling of interleukin-4 (IL-4) and interleukin-13 (IL-13), key cytokines that prompt type 2 inflammation. The drug has demonstrated a promising safety profile and efficacy in previous trials. Its new drug application for treating moderate-to-severe atopic dermatitis in adults was accepted by the NMPA and granted priority review on December 7, 2023.

Keymed Biosciences Inc. focuses on addressing unmet clinical needs with high-quality, affordable, and innovative therapies both in China and globally. The company has developed a comprehensive platform for biological drug development, encompassing target validation, lead molecule discovery, preclinical evaluation, process development, translational research, clinical development, and manufacturing. This integrated approach has enabled Keymed to efficiently and cost-effectively develop a diverse pipeline of antibody-based therapies, including monoclonal antibodies, antibody drug conjugates (ADCs), and bispecific antibodies.