Utilization and Effectiveness of Ritlecitinib in a Real-World Population With Severe AA in the US

Alopecia areata (AA) is a chronic, relapsing T-cell mediated autoimmune disease characterized by nonscarring, typically patchy hair loss that affects people of all ages, races, and genders. In the United States (US), AA has an estimated point prevalence of 1.14% (Beningo et al., 2020). The three most common subtypes of AA are defined by the affected area: * Patchy alopecia (PA), as seen in 90% of clinical diagnoses: hair loss occurring in one or more patches (ranging from coin-sized to large patches and even full scalp involvement) on the scalp or other parts of the body; * Alopecia totalis (AT): loss of all or nearly all scalp hair; * Alopecia universalis (AU): loss of all or nearly all scalp, face, and body hair Traditionally, a range of medications, including corticosteroids, immunotherapy, and minoxidil, are used to treat AA. However, few of these mainstay therapies are supported by robust clinical evidence, limiting the development of widely accepted clinical practice guidelines (Asfour et al., 2023). As a result of suboptimal effectiveness of traditional therapies, patients with AA, particularly those with extensive hair loss, have a persistent unmet medical need. Furthermore, the potential effects of AA on other subgroups, including patients with skin of color, remain undefined. As these subgroups have been historically underrepresented in clinical trials, an additional unmet medical need and evidence gap exists for these patients. Recent clinical studies have demonstrated efficacy of novel treatments for AA, including ritlecitinib, a JAK3/TEC family kinase inhibitor developed and marketed by Pfizer (King et al., 2023). Ritlecitinib was approved by the US Food and Drug Administration (FDA) in June 2023 for the treatment of severe AA in adults and adolescents aged 12 years or older. Extensive information from clinical trials exists on the safety and efficacy of ritlecitinib, which, along with JAK inhibitors such as baricitinib and deuruxolitinib that are FDA approved for severe alopecia areas in adults 18 and over, have presented needed new therapeutic options for these patients. However, little is known about the clinical effectiveness of ritlecitinib in real-world clinical practice. The objective of the current study is to evaluate patient characteristics, treatment patterns and related clinical outcomes of patients who initiated ritlecitinib to treat severe AA.