Tyrosine Protein Kinase JAK 2 Phospho-Tyr8, 9

Background: Upadacitinib is an oral Janus kinase (JAK) inhibitor with greater inhibitory potency for JAK1 than JAK2, JAK3, and tyrosine kinase 2. We aimed to assess the efficacy and safety of upadacitinib compared with placebo for the treatment of moderate-to-severe atopic dermatitis.

Psoriasis and psoriatic arthritis (PsA) are inflammatory immune-mediated conditions which can cause considerable disability and reduced quality of life. Management can be complex as clinical heterogeneity may lead to different treatment pathways. Tofacitinib is a novel, oral Janus Kinase (JAK) inhibitor with proven efficacy in rheumatoid arthritis. Areas covered: This review analyzes recent studies of tofacitinib in psoriatic disease treatment. The relevant literature was identified using clinicaltrials.gov, PubMed, and Google Scholar. Tofacitinib efficacy was demonstrated in PsA by the OPAL Broaden and OPAL Beyond phase-III studies, and received FDA and EMA approval. Tofacitinib was superior to placebo for the treatment of moderate-to-severe plaque psoriasis in the OPT Pivotal 1 and 2, OPT Retreatment studies, but FDA approval was declined for this indication based on issues of clinical efficacy and long-term safety. Expert commentary: Tofacitinib is an important oral drug for the treatment of PsA. However, the long-term safety data require further evaluation. Tofacitinib and other JAK inhibitors show potential to broaden the treatment options in PsA and other inflammatory conditions.

Background: Ruxolitinib, a selective inhibitor of Janus kinase (JAK) 1 and 2, has clinically significant activity in myelofibrosis. Methods: In this double-blind trial, we randomly assigned patients with intermediate-2 or high-risk myelofibrosis to twice-daily oral ruxolitinib (155 patients) or placebo (154 patients). The primary end point was the proportion of patients with a reduction in spleen volume of 35% or more at 24 weeks, assessed by means of magnetic resonance imaging. Secondary end points included the durability of response, changes in symptom burden (assessed by the total symptom score), and overall survival. Results: The primary end point was reached in 41.9% of patients in the ruxolitinib group as compared with 0.7% in the placebo group (P<0.001). A reduction in spleen volume was maintained in patients who received ruxolitinib; 67.0% of the patients with a response had the response for 48 weeks or more. There was an improvement of 50% or more in the total symptom score at 24 weeks in 45.9% of patients who received ruxolitinib as compared with 5.3% of patients who received placebo (P<0.001). Thirteen deaths occurred in the ruxolitinib group as compared with 24 deaths in the placebo group (hazard ratio, 0.50; 95% confidence interval, 0.25 to 0.98; P=0.04). The rate of discontinuation of the study drug because of adverse events was 11.0% in the ruxolitinib group and 10.6% in the placebo group. Among patients who received ruxolitinib, anemia and thrombocytopenia were the most common adverse events, but they rarely led to discontinuation of the drug (in one patient for each event). Two patients had transformation to acute myeloid leukemia; both were in the ruxolitinib group. Conclusions: Ruxolitinib, as compared with placebo, provided significant clinical benefits in patients with myelofibrosis by reducing spleen size, ameliorating debilitating myelofibrosis-related symptoms, and improving overall survival. These benefits came at the cost of more frequent anemia and thrombocytopenia in the early part of the treatment period. (Funded by Incyte; COMFORT-I ClinicalTrials.gov number, NCT00952289.).