HANGZHOU, China, SHANGHAI & BOSTON — July 14, 2026
Lynk Pharmaceuticals Co., Ltd. has announced the successful completion of patient enrollment in its Phase III clinical trial evaluating zemprocitinib, a next-generation selective JAK1 inhibitor, for the treatment of active ankylosing spondylitis (AS). The milestone, achieved on July 9, 2026, represents a significant advancement in the company’s late-stage clinical development program and moves zemprocitinib closer to becoming a potential new oral treatment option for patients living with this chronic inflammatory disease. The randomized, double-blind, placebo-controlled, multicenter study has enrolled 352 patients and is progressing according to plan, with ongoing treatment, patient follow-up, and data collection. As ankylosing spondylitis continues to impose a substantial burden on patients through chronic pain, spinal inflammation, reduced mobility, and progressive disability, the successful completion of enrollment marks an important step toward addressing a significant unmet medical need with a potentially safer and more selective targeted therapy.
Phase III Study Advances Late-Stage Clinical Development
The Phase III clinical trial has been designed to comprehensively evaluate the efficacy and safety of zemprocitinib capsules in adults with active ankylosing spondylitis. The study utilizes a randomized, double-blind, placebo-controlled, multicenter design, the gold standard for late-stage clinical research, with the primary endpoint measuring the proportion of patients achieving an Assessment of SpondyloArthritis International Society 40% (ASAS40) response at Week 16. Completion of patient enrollment enables the program to advance into the next stage of clinical evaluation while maintaining planned timelines for treatment administration, monitoring, and statistical analysis. Ankylosing spondylitis is a progressive autoimmune disease that primarily affects the spine and sacroiliac joints, causing persistent inflammation, chronic pain, stiffness, reduced physical function, and impaired quality of life. Although biologics and nonsteroidal anti-inflammatory drugs remain standard therapies, many patients continue to experience inadequate disease control or concerns regarding long-term treatment safety, creating ongoing demand for innovative oral therapies.
Selective JAK1 Inhibitor Demonstrates Promising Clinical Profile
Zemprocitinib has been developed as a second-generation selective JAK1 inhibitor, designed to deliver strong anti-inflammatory efficacy while minimizing safety risks associated with less selective first-generation Janus kinase (JAK) inhibitors. Preclinical research and clinical studies have demonstrated that the investigational therapy effectively inhibits multiple JAK1-mediated inflammatory signaling pathways, supporting its development across several autoimmune and inflammatory diseases. Previous Phase III clinical trials evaluating rheumatoid arthritis and atopic dermatitis demonstrated that zemprocitinib successfully achieved both primary and key secondary efficacy endpoints, while maintaining a favorable safety and tolerability profile. Importantly, rates of serious adverse events and adverse events of special interest (AESIs) remained comparable with placebo, accompanied by reassuring laboratory safety findings. These encouraging results provide strong scientific support for continued development in ankylosing spondylitis and strengthen confidence in the therapy’s broader clinical potential.
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Lynk Pharmaceuticals Expands Autoimmune Disease Pipeline
The successful completion of enrollment further reinforces Lynk Pharmaceuticals’ strategy of developing innovative small-molecule therapies for autoimmune and inflammatory diseases through advanced precision drug discovery technologies. Founded by experienced pharmaceutical research leaders from Pfizer, MSD, and Johnson & Johnson, the company combines AI-assisted drug design, protein degradation technologies, translational medicine, and clinical development expertise to accelerate the creation of differentiated oral medicines. Beyond zemprocitinib, Lynk continues advancing a diversified pipeline targeting JAK-STAT, TYK2, and other important inflammatory signaling pathways through both internal research and strategic global collaborations. As the Phase III ankylosing spondylitis program progresses toward completion, the company expects the study to generate robust clinical evidence supporting future regulatory submissions, bringing zemprocitinib closer to becoming a potential best-in-class oral JAK1 inhibitor capable of improving long-term outcomes for patients with chronic inflammatory diseases.
Source: Lynk Pharmaceuticals press release
