Jiangsu Vcare’s Second-Generation Selective JAK1 Inhibitor VC005 Completes Phase II Enrollment for Ankylosing Spondylitis

　　Recently, Jiangsu Vcare PharmaTech Co., Ltd. (Jiangsu Vcare) announced the completion of Phase II clinical enrollment for its self-developed second-generation selective JAK1 inhibitor VC005 tablets in the treatment of ankylosing spondylitis (AS). Preliminary blinded analysis from the clinical trial demonstrated favorable efficacy and safety profiles for VC005.

　　About VC005

　　VC005 is a novel, highly potent, and selective JAK1 inhibitor independently developed by Jiangsu Vcare. By selectively inhibiting JAK1, the drug suppresses immune cell-mediated cytotoxicity and immune responses, while exhibiting minimal inhibitory activity against JAK2, JAK3, and TYK2(based on preclinical data). This selectivity is expected to mitigate safety concerns associated with excessive inhibition of non-target JAK isoforms, such as JAK2.

　　The drug is under development in two formulations:

　　① Oral tablets: Phase II trials for AS and moderate-to-severe AD are ongoing. Additional clinical indications, including IBD and RA, have been approved. Early Phase I studies demonstrated favorable pharmacokinetics, safety, and tolerability. ② Topical gel: Phase I trials for mild-to-moderate AD are currently underway.

　　About JAK1

　　The JAK (Janus kinase)/STAT signaling pathway plays a critical role in the pathogenesis of inflammatory diseases such as AS. Current oral JAK inhibitors lack sufficient selectivity, simultaneously inhibiting JAK1, JAK2, and JAK3, which has been linked to severe adverse events (e.g., anemia, infections, dyslipidemia, malignancies) and prompted the U.S. FDA to issue black box warnings. Since the first half of 2021, the FDA has repeatedly delayed reviews of pan-JAK inhibitors, raising concerns in the biopharmaceutical industry. Consequently, the development of highly selective JAK1 inhibitors has become imperative. To date, no selective JAK1 inhibitors for AS have been approved in China, underscoring the urgent unmet clinical need.

　　VC005 was designed with a differentiated approach, addressing these challenges during its discovery and development phases. Preclinical studies showed that VC005 achieves lower effective doses, higher tolerated doses, and reduced side effects compared to other JAK1-targeted drugs. Early human trials further confirmed its favorable metabolic profile and safety, positioning VC005 as a potential global leader in the treatment of autoimmune and inflammatory diseases.

　　About AS

　　AS is a chronic inflammatory disease primarily affecting the sacroiliac joints, spine, paravertebral soft tissues, and peripheral joints, often accompanied by extra-articular manifestations. Severe cases may lead to spinal deformity and fusion. A hallmark of AS is sacroiliitis, while enthesitis is a key pathological feature. Advanced spinal involvement typically manifests as “bamboo spine” due to vertebral fusion.

　　Epidemiologically, AS affects approximately 0.36% of the Chinese population(over 5 million individuals), with a higher prevalence in males. The disease typically onsets between 15–40 years of age, most commonly in individuals under 35 years. While the etiology remains unclear, genetic, infectious, environmental, and immune factors are implicated. AS progresses over time, causing irreversible structural damage, disability, and deformity. Current treatments focus on symptom management, as no cure exists.

　　JAK-targeted small-molecule inhibitors, unlike biologics, are non-immunogenic and avoid secondary treatment failure caused by neutralizing immune responses. VC005 represents a promising therapeutic advancement for AS patients.