Characterization And Clinical Outcomes of AA Patients Treated With Ritlecitinib

Alopecia areata (AA) is a chronic relapsing autoimmune disease characterized by nonscarring hair loss affecting children, adolescents, and adults across all ages, races, and genders. AA primarily affects the scalp; however, it also can affect nails, eyelashes, eyebrows, and other hair follicles on the patient's body. The 3 main types of AA are:

• Patchy alopecia (PA), as seen in 90% of clinical diagnoses

• Alopecia totalis (AT), that affects all scalp hair

• Alopecia universalis (AU), involving all scalp, face, and body hair Dermatologist preferences for utility and order of skin-directed therapies to treat AA vary widely, with treatment choices based on various factors such as patients' age, disease duration and severity (Meah et al., 2020).

Ritlecitinib is a bioavailable small molecule that irreversibly binds to Janus kinase-3 (JAK3) and Tyrosine kinase Expressed in the hepatocellular Carcinoma kinase family (TEC). Ritlecitinib 50 mg once daily was approved by the FDA 23 June 2023 and EMA 20 July 2023 for the treatment of severe alopecia areata in adults and adolescents 12 years of age and older. In Japan, ritlecitinib was approved on 26 June 2023 for the treatment of alopecia areata (limited to intractable cases involving widespread hair loss). Additional countries have since approved ritlecitinib. Those approvals are based on the results of the ritlecitinib pivotal phase 2b/3 study (ALLEGRO 2b/3) which examined efficacy and safety of ritlecitinib in AA patients globally.

Despite positive results from the ALLEGRO program, there is still lack of evidence on ritlecitinib patients' characteristics and clinical outcomes in routine clinical practice. The investigators will evaluate patient and disease characteristics, treatment patterns, and clinical and patient-reported outcomes among patients with AA who are receiving ritlecitinib.

The aim of this study is to measure effectiveness of ritlecitinib in a real-world setting. Ritlecitinib will be prescribed to patients according to the approved product label. Treatment will be guided by clinical judgement of the treating physician ie, study investigators, according to standard of care, independently of this study.