Lynk Pharmaceuticals Co Ltd, a clinical-stage drug development company focused on immune and inflammatory diseases, announced on Tuesday the completion of patient enrolment in the Phase III clinical trial evaluating its core product zemprocitinib capsules for the treatment of active ankylosing spondylitis (AS).

The randomised, double-blind, placebo-controlled, multicentred clinical trial is designed to evaluate the efficacy and safety of zemprocitinib in patients with active AS. The primary endpoint is the proportion of patients achieving an Assessment of SpondyloArthritis international Society 40% response (ASAS40) at Week 16. A total of 352 patients have now been enrolled, and the study is proceeding as planned with ongoing treatment, follow-up, and data collection.

According to Lynk, preclinical and clinical studies have shown that zemprocitinib potently and dose-dependently inhibits multiple JAK1-related inflammatory signalling pathways, supporting its therapeutic potential across multiple indications. Previously reported 24-week Phase III data in rheumatoid arthritis and 52-week Phase III data in atopic dermatitis demonstrated that zemprocitinib achieved the primary and key secondary endpoints, while showing rapid and sustained efficacy together with a favourable safety and tolerability profile. Rates of serious adverse events and adverse events of special interest (AESIs) were comparable to placebo, and laboratory safety parameters were also favourable.