Topical delgocitinib (JTE-052) is a novel Janus kinase inhibitor that has been shown to be effective in adults with eczema. Eczema is an itchy, inflammatory skin rash that lasts chronically and it can fluctuate. It is seen more in childhood and the majority of patients experience resolution with age.
The goal of treatment is to minimize symptoms with minimal pharmacologic intervention. Currently topical steroids and calcineurin inhibitors (Elidel, Protopic) form the mainstay of controlling skin inflammation. Long term usage of steroids though can lead to safety concerns such as skin atrophy. Other topical treatments can cause irritation at the application site.
New therapies are needed in patients, especially in pediatrics. Numerous immunologic pathways are involved in atopic dermatitis. One pathway, the Janus kinase (JAK) can lead to inflammatory factors. Delgocitinib is a JAK inhibitor under development in Japan by Torii Pharmaceutical. A recent Phase 2 study examined delgocitinib ointment in pediatric patients with atopic dermatitis.
Patients were between 2-15 years of age and received 0.25% or 0.5% delgocitinib twice daily for 4 weeks. The results showed:
- Skin inflammation and itching scores in both delgocitinib groups were significantly improved compared with those in the placebo group at the end of treatment.
- Delgocitinib ointment was well tolerated during the 4 week treatment period.
Janus kinase inhibitors are a potential therapeutic option for patients with eczema. Dupilumab, an inhibitor of both IL-4 and IL-13 has been approved for eczema. Nemolizumab, an inhibitor of IL-31 signaling, has received attention for its anti-itching effects.
In addition to the anti-inflammatory effect, delgocitinib ointment has a promoting effect on the production of filaggrin, which plays an important role in skin barrier function.
Side effects from delgocitinib were minimal in the study, some adverse effects that were seen were, nasopharyngitis, impetigo and urticaria. No irritation or burning sensations were seen. Because this was a small short study, comparing delgocitinib with other topical steroids, tacrolimus or Eucrisa should not be done. Because eczema requires long term treatment, a phase 3 long term study will need to be done. Other Janus kinase topical inhibitors being studied are tofacitinib and ruxolitinib.
Overall, delgocitinib ointment markedly and rapidly improved clinical signs and symptoms in patients with atopic dermatitis. It was well tolerated and it may be a promising therapeutic option.