308 Particulate matter promotes melanin production via endoplasmic reticulum stress

Abstract

Treatment with ruxolitinib cream (Janus kinase [JAK] 1/JAK2 inhibitor) in adult patients with vitiligo resulted in substantial repigmentation over 52 weeks in a phase 2 dose-ranging study (NCT03099304). We assessed maintenance of repigmentation among responders from the phase 2 study following ruxolitinib discontinuation after 104 weeks of treatment. Patients initially randomized to ruxolitinib cream (1.5% twice daily [BID], 1.5% once daily [QD], 0.5% QD, or 0.15% QD) with evidence of facial repigmentation at Week 24 who completed 1 follow-up visit 1, 3, or 6 months after an additional 52 weeks of 1.5% ruxolitinib cream BID (Weeks 52e104) were analyzed. Loss of repigmentation was defined as an increase in Vitiligo Area Severity Index score during the last follow-up visit vs Week 104 on ruxolitinib cream. The analysis included 16 patients (1.5% BID, n¼3; 1.5% QD, n¼5; 0.5% QD, n¼3; 0.15% QD, n¼5 [including 2 patients rerandomized to 1.5% BID/0.5% QD after Week 24]). Twelve patients (75.0%) maintained total body repigmentation and 13 (81.3%) maintained facial repigmentation during follow-up of 1e6 months; no patients from the 1.5% ruxolitinib BID treatment group (with 2 years' exposure) experienced repigmentation loss. There were no significant differences in baseline serum levels of chemokine (C-X-C motif) ligand (CXCL) 9, CXCL10, or interleukin-15 in patients who experienced loss vs maintenance of repigmentation after ruxolitinib cream discontinuation. This exploratory analysis suggests that some repigmentation with ruxolitinib cream may be maintained post-discontinuation; larger follow-up studies are required to confirm these findings.