Atopic Dermatitis (AD) is complex with heterogeneous symptoms (e.g. skin-pain, sleep disturbance), signs (e.g. lichenification, prurigo nodules, follicular accentuation), and longitudinal course (intermittent, persistent). These disparate signs and symptoms should be addressed in optimize disease control.
Multiple extracellular cytokines are upregulated in skin of AD patients, including interleukins 4, 5, 13, 22, 31 and thymic stromal lymphopoietin, all of which signal intracellularly through Janus Kinase (JAK)-Signal Transducer and Activator of Transcription (STAT) pathways. Differential cytokine expression is proposed to underlie clinical variability. It may be necessary to inhibit signaling of multiple cytokines to achieve adequate control of AD.
Dupilumab is currently the only biologic treatment approved in the United States for moderate-severe AD. Dupilumab revolutionized AD management. However, there remain unmet needs, including the need for faster and more potent efficacy, and oral treatment options. Recently, oral JAK-inhibitors were investigated as treatments for moderate-severe AD. Multiple JAK-inhibitors demonstrated strong and rapid efficacy across multiple clinician-reported and patient-reported outcomes.
- Miao et al. recently conducted a meta-analysis of 10 randomized controlled trials and found that patients receiving JAK inhibitors showed significantly higher efficacy for eczema area and severity index (EASI) and Numeric Rating Scale (NRS)-itch scores and similar rates of adverse-events.
- Kim et al. pooled data from 3 randomized controlled trials of abrocitinib and found significantly higher proportions of clinically meaningful responses for itch in patients receiving abrocitinib 200 mg and 100 mg vs placebo as early as week 2 which continued through week 12.
- Lio et al. performed a post-hoc analysis of a phase 3 study of conducted in North America and found significant improvements for itch severity and sleep disturbance in patients treated with baricitinib 1 mg and 2 mg vs placebo. In particular, patients who achieved improvement of itch or sleep disturbance compared to those who did not were more likely to report having no impact on quality of life impact and improved work productivity.
This new therapeutic class will be an important addition to our therapeutic armamentarium and has potential to transform the AD treatment landscape.
- Many patients prefer taking pills over injections.
- Rapid-onset of efficacy for JAK-inhibitors will certainly be appreciated by patients, especially when trying to control tough flares. It may even guide clinical decision-making. Patients who have a good clinical response to JAK-inhibitors tend to do so within 4-8 weeks. By 8 weeks, if patients have no clinical response, they are likely not going to respond and may benefit from switching to alternative therapies.
- JAK-inhibitors can have robust efficacy, with higher doses of upadacitinib and abrocritinib showing greater efficacy than dupilumab at 12-16 weeks. This makes them attractive options to consider in patients who previously failed dupilumab.
- On the other hand, JAK-inhibitors have laboratory monitoring requirements, including complete blood count, comprehensive metabolic panel, lipid panel, etc.
- JAK-inhibitors warrant adverse-event monitoring for headache, nausea, acne, herpesvirus infections, risk of venous thromboembolism, etc.
Future research is needed to identify patient subsets who will benefit most from JAK-inhibitor therapy and where to position these agents in treatment guidelines.