Pfizer has presented results from two Phase III studies, TRANQUILLO and TRANQUILLO 2, evaluating ritlecitinib (Litfulo) in non-segmental vitiligo, with TRANQUILLO enrolling 607 adolescent and adult patients with active or stable disease and TRANQUILLO 2 enrolling 1,567 adults. Both trials measured the proportion of patients achieving at least a 50% reduction in total body vitiligo area scoring index (T-VASI 50) and at least a 75% reduction in facial vitiligo area scoring index (F-VASI 75) at week 52.

In TRANQUILLO, 8.98% of ritlecitinib 50 mg patients reached T-VASI 50 versus 1.98% for placebo and 12.47% reached F-VASI 75 versus 2.48%, while in TRANQUILLO 2, 13.02% of ritlecitinib 100 mg patients reached T-VASI 50 versus 2.40% and 21.86% reached F-VASI 75 versus 2.40%.

Ritlecitinib is an oral JAK3/TEC kinase family dual inhibitor that achieves JAK isoform-selective inhibition through covalent interaction with the JAK3-specific residue CYS-909, offering a toxicity advantage over first-generation pan-JAK inhibitors. It was approved in China, Europe and the US in 2023 for severe alopecia areata in patients aged 12 years and older.