LITFULOTM (Ritlecitinib) Capsules: A Janus Kinase 3 Inhibitor for the Treatment of Severe Alopecia Areata.

LITFULOTM (ritlecitinib) capsules were recently approved for the treatment of severe alopecia areata in adolescents and adults, aged ≥12 years. Ritlecitinib is the active ingredient and a dual inhibitor of Janus kinase 3 and the tyrosine kinase expressed in hepatocellular carcinoma kinase family. It prevents immune attack on the hair follicles that leads to hair loss. In a phase 2b-3 dose-dependant study, five doses of oral ritlecitinib and placebo administered once daily (QD) were investigated. Ritlecitinib demonstrated efficacy in achieving the primary outcome, Severity of Alopecia Tool (SALT) score of ≤20, at week 24 (31% [38/124] 200-mg ritlecitinib QD for 4 weeks, then 50 mg QD for 20 weeks; 22% [27/121] 200-mg ritlecitinib QD for 4 weeks, then 30 mg QD for 20 weeks; 23% [29/124] 50-mg ritlecitinib QD; 14% [17/119] 30-mg ritlecitinib QD; 2% [1/59] 10-mg ritlecitinib QD; and 2% [2/130] placebo). Mild to moderate common adverse effects were observed, which included headache, nasopharyngitis, and upper respiratory tract infection. The recommended regimen of ritlecitinib capsules is 50 mg QD with without food and swallowed whole.