Ruxolitinib, the first topical JAK inhibitor, has received FDA approval for the short-term treatment of mild to moderate atopic dermatitis.
Biopharmaceutical company Incyte has been granted approval by the FDA for Opzelura™ (ruxolitinib) cream, the first, topical janus kinase (JAK) inhibitor used in the treatment of mild to moderate atopic dermatitis (AD). More specifically, Opzelura™ can be used for the short-term and non-continuous, chronic treatment of AD in non-immunocompromised patients, 12 years of age and older whose disease is not adequately controlled with topical prescription therapies. The importance of inhibition of JAK is based on the fact that the janus kinase (JAK)-signal transducer and activator of transcription (STAT), or JAK-STAT pathway, has been shown to play an essential role in the dysregulation of immune responses in AD. Although there are four separate JAK-STAT pathways, ruxolitinib, is a selective inhibitor of only JAK1 and JAK2, effectively suppressing the cytokine signalling involved in AD pathogenesis.
The efficacy of ruxolitinib was examined in a 2020 study among adult patients with mild to moderate AD. Participants were randomised for 8 weeks to three different strengths of ruxolitinib; 1.5% cream, applied twice daily or once daily, a 0.5% and 0.15% cream, vehicle or triamcinolone cream 0.1% applied twice daily for 4 weeks, then vehicle for 4 weeks.
The results showed that all concentrations of ruxolitinib were more effective after 4 weeks than placebo, the greatest improvement occurred with the 1.5% strength, based on an improvement in the Eczema Area and Severity Index (71.6% vs 15.5%; ruxolitinib vs placebo, p < .0001). Interestingly, the authors of the study reported that use of ruxolitinib 1.5% both once a twice daily produced a numerically greater improvements compared with triamcinolone after 4 weeks but that the difference was not statistically significant.
Based on these early finding, the company conducted two phase 3, randomised, placebo-controlled trials comparing topical ruxolitinib 0.75% and 1.5% in patients 12 years and over with mild to moderate AD. The primary outcome was Investigator’s Global Assessment treatment success at week 8 (i.e., an investigator’s Global Assessment score of 0/1 and ≥2-grade improvement from baseline). The results were published in May 2021 and showed that significantly more patients achieved the primary outcome at week 8 with 0.75% ruxolitinib (50.0% vs 15.1%, ruxolitinib vs placebo) and 1.5% ruxolitinib (53.8% and 7.6%), both with p < 0.001.
The company have now released data on the trial’s secondary outcomes which included the proportion of participants with at least a 4-point improvement in the itch Numerical Rating Scale (NRS), and the proportion of participants with at least a 6-point improvement in the Patient-Reported Outcomes Measurement Information System (PROMIS) Short Form. The latest data release show that 20.9% and 23.8% of patients using 0.75% and 1.5% topical ruxolitinib achieved a greater than 6-point improvement in sleep scores. Similarly, 41.5% and 51.5% using the 0.75% and 1.5% creams had at least a 4-point improvement in NRS.
Now that ruxolitinib has been approved by the FDA, the company intends to seek EMA approval.