One-Year Safety and Tolerability of Ruxolitinib Cream in Adolescents

Key Takeaways

• Treatment-emergent adverse events were reported in 40.8% of participants over 52 weeks.
• Low steady-state plasma concentrations were reported during continuous treatment, and the abstract noted no observed treatment-emergent adverse events associated with systemic Janus kinase inhibition.
• Clinical response was maintained or improved through week 52 during as-needed treatment.

Treatment-emergent adverse events occurred in 40.8% of adolescents during 52 weeks of topical ruxolitinib cream use in a phase III open-label study. Participants were 12 to 17 years old and had mild-to-moderate atopic dermatitis at study entry. Low plasma exposure during continuous treatment and sustained clinical response through week 52 were also reported over the year-long follow-up.

This open-label phase III study enrolled 103 adolescents aged 12 to 17 years with atopic dermatitis, Investigator’s Global Assessment scores of 2 or 3, and 3% to 20% affected body surface area. Patients applied 1.5% ruxolitinib cream twice daily for 8 weeks, followed by twice-daily as-needed use for 44 additional weeks. Safety was the primary endpoint, and plasma trough concentrations of ruxolitinib were a secondary endpoint. At baseline, 59.2% had an Investigator’s Global Assessment score of 3, mean affected body surface area was 8.9%, mean EASI score was 6.4, and the trial was registered as NCT05456529 on 13 July 2022.

Over 52 weeks, 42 of 103 patients had treatment-emergent adverse events, corresponding to 40.8% of the cohort. The most common events were upper respiratory tract infection in 10.7% and nasopharyngitis in 8.7%. Three patients, or 2.9%, had grade 3 or higher treatment-emergent adverse events, and investigators considered all of those events unrelated to treatment. The adverse-event profile was dominated by common infections rather than treatment-attributed severe events.

During the continuous treatment period, steady-state plasma ruxolitinib concentrations were low, with a geometric mean of 14.2 nM and a geometric coefficient of variation of 169. The abstract also reported no observed treatment-emergent adverse events associated with systemic Janus kinase inhibition. These findings appeared alongside the observed week 52 clinical outcomes. Low plasma exposure was reported alongside the observed safety findings during open-label follow-up.

Clinical improvements were maintained or improved with as-needed treatment through week 52. Reported week 52 outcomes included mean affected body surface area of 1.3%, EASI-75 in 87.0%, Investigator’s Global Assessment 0 or 1 in 82.6%, and a ≥4-point improvement from baseline in the itch Numerical Rating Scale in 41.7%. Investigators described long-term as-needed use of 1.5% ruxolitinib cream as well tolerated and efficacious in adolescents with mild-to-moderate atopic dermatitis. The year-long follow-up paired maintained disease control with longer-term safety and exposure findings.