Worldwide Clinical and Real-World Exposure to Baricitinib

Abstract

Introduction: Baricitinib (BARI), an oral selective JAK inhibitor, is approved in many geographies for adults with rheumatoid arthritis or alopecia areata and for patients as young as age 2 years with atopic dermatitis or juvenile idiopathic arthritis. It is also approved in the US for hospitalized patients with COVID-19 infection. We report the worldwide clinical trial and real-world exposure to BARI across a range of diseases, ages and racial backgrounds. Methods: Real-world patient exposure estimates were calculated based on total mg sold, average daily dose, and average length of therapy as reported to regulatory agencies through the cumulative timeframe ending Jan. 31, 2024. Clinical trial exposures were based on actual exposures from completed trials through Feb. 13, 2024, and estimates were made for ongoing blinded trials based on the enrolment/randomization schemes Results: In the real-world setting, an estimated 1,836,600 patients have been exposed to the following BARI doses: 1 mg, ~2,000 (0.1%); 2 mg, ~524,900 (28.6%); 4 mg, ~1,309,600 (71.3%). Of these estimated exposures, ~ 57% were for COVID-19 with the remaining for all other indications combined. Across 59 clinical trials (completed and ongoing), an estimated 14,660 subjects (548 healthy volunteers and 14,112 patients) have received BARI since June 2008. Exposures from completed studies include 10,276 patients (62% female), 399 of whom were <18 yrs of age (≤1 month, N=4; 1 month - ≤2 yrs, N=24; >2 - ≤12 yrs, N=111; >12 - ≤18 yrs, N=260), 8820 were >18 to ≤65 yrs, 1027 were >65 yrs, and 30 had age unknown. An additional 467 adolescent and pediatric patients down to the age of 2 have been treated with BARI for atopic dermatitis in an ongoing clinical trial, bringing the total number of patients <18 years of age to 866 across dermatologic, rheumatologic, other autoimmunologic, and acute infectious diseases (excluding alopecia areata for which there is an ongoing pediatric trial). Clinical trial exposures by racial and ethnic background are as follows: Asian, N=2,491; Black, N=450; Caucasian, N=6,237; other, N=496; multiple, N=135; unknown, N=467. Conclusion: There has been extensive real-world exposure to BARI across indications and populations, and BARI is a well-studied molecule in clinical trials, across varied disease states, racial populations and ages. Since average daily dose and length of therapy may vary over time, real-world exposures are only an estimate of total patients receiving BARI. Exposures in clinical trials include patients as young as less than 1 month of age up to patients over the age of 65 years. While these exposures do not indicate efficacy or safety, they provide data to establish the overall profile of the drug and can inform on its performance over time across a variety of populations.