Inflammatory Bowel Diseases (IBD) are a group of chronic progressive, inflammatory, autoimmune diseases affecting the gastrointestinal system, characterized by chronic relapsed alternating with remission phase, resulting in progressive disease deterioration. Ulcerative colitis (UC) and Crohn’s disease (CD) are the two main type of IBD. The incidence of IBD has been generally higher in the US and Europe compared to Asia. However, the incidence of IBD in Asia has been reported to have increased over the last two decades, the reason of which remain unknown.
Ulcerative disease and Crohn’s disease are chronic debilitating diseases that severely affect patient’s quality of life. It is estimated there are at least 2 million people suffering from ulcerative colitis, and one million people suffered from Crohn’s disease globally. Despite recent advancement in treatment, there is still significant unmet medical need in this area. In 2016, the global Ulcerative Colitis and Crohn’s Disease markets were estimated at about $5 billion and $10 billion US dollars respectively. Reistone has gained IND approvals from the US FDA and China NMPA for Ulcerative Colitis (UC) and Crohn’s Disease (CD) phase II clinical trials.
Atopic dermatitis (AD) is a chronic, inflammatory, pruritic, relapsing skin disease occurring often in patients with family history of other atopic diseases (bronchial asthma and/or allergic rhinitis). AD is one of the most common non-communicable skin diseases which affects up to 20% of children and 2–8% of adults in the world. In many instances, AD begins in childhood, which in severe cases may persist into adulthood. About one-third of adult cases develop in adulthood. The incidence of AD is increasing annually worldwide including China. In China, the prevalence of AD in students aged 6–20 years was only 0.7% in 2000; however, it had reached up to 8.3% in children aged 3 to 6 years in Shanghai in 2012. According to recent study, overall, the prevalence of AD in outpatients in China was 7.8%.
AD is characterized by inflammatory cell skin infiltration often triggered by dry skin and exposure to external allergen. The interplay between genetic, external environment and allergen contribute to the chronic pruritic skin inflammation. The JAK-STAT pathway has been shown to play an important role in the dysregulation of immune responses in AD, including the exaggeration of Th2 cell response, the activation of eosinophil, the maturation of B cells, and the suppression of regulatory T cells (Tregs). In addition, the JAK-STAT pathway, activated by IL-4, also plays a critical role in the pathogenesis of AD by upregulating epidermal chemokine, pro-inflammatory cytokines, and pro-angiogenic factors as well as by downregulating antimicrobial peptides (AMPs) and factors responsible for skin barrier function. It has been demonstrated that the disease condition can be controlled by topical JAK inhibitor in mild/moderate cases, as well as oral JAK inhibitor in severe cases.