Ritlecitinib: A Review in Severe Alopecia Areata.

Ritlecitinib (Litfulo®) is an oral dual inhibitor of Janus kinase (JAK) 3 and the tyrosine kinase expressed in hepatocellular carcinoma (TEC) family of kinases. It is approved in several countries worldwide for the treatment of severe alopecia areata in adults and adolescents 12 years of age and older. In the pivotal, randomized, double-blind, placebo-controlled, phase 2b/3 ALLEGRO trial in adults and adolescents with alopecia areata with ≥ 50% scalp hair loss, ritlecitinib 50 mg once daily significantly increased the proportion of patients achieving ≤ 20% scalp hair loss at week 24 compared with placebo. Ritlecitinib also improved patient-reported outcomes, including Patient's Global Impression of Change responses. Response rates for key efficacy outcomes in the pivotal trial continued to increase through 48 weeks and were sustained for up to 3 years in the open-label phase 3 ALLEGRO-LT trial. Longer-term treatment was also associated with improvements in health-related quality of life. Ritlecitinib was generally well tolerated, with most adverse events being of mild or moderate severity. While further data are needed to fully characterize long-term safety, currently available data suggest that ritlecitinib is a valuable new option for the treatment of severe alopecia areata, including in adolescents for whom approved treatment options are limited.