Open-label, BID application to all affected areas identified at BSLN for 4 weeks (maximum use trial (MUsT) period). The next 4 weeks (treatment extension period) will be applied BID to active lesions only for the next 4 weeks for a total treatment period of 8 weeks. Eligible participants will be offered option to continue into 44-wk LTS period of BID to treat as-needed to active lesions. All participants will have 30 day safety follow-up visit.
This is an open-label maximum use trial to evaluate ruxolitinib safety, tolerability and blood levels after its topical application twice daily to affected areas (≥ 35% BSA) in pediatric participants with atopic dermatitis (AD) and to determine if its systemic bioavailability results in any adverse events.