Abstract
INTRODUCTION: Early prediction of abrocitinib efficacy in atopic dermatitis (AD) could help identify candidates for an early dose increase. A predictive model determined week 12 efficacy based on week 4 responses in patients receiving abrocitinib 100 mg/day and assessed the effect of an abrocitinib dose increase on platelet counts. METHODS: Analysis included the phase 3 trials JADE MONO-1 (NCT03349060), MONO-2 (NCT03575871), COMPARE (NCT03720470), and TEEN (NCT03796676). For platelet counts and simulations, a phase 2 psoriasis trial (NCT02201524) and phase 2b (NCT02780167) and phase 3 (MONO-1, MONO-2, and REGIMEN (NCT03627767)) abrocitinib trials were pooled. A training-and-validation framework assessed potential predictors of response at week 4: score and score change from baseline in the Eczema Area and Severity Index (EASI), Investigator's Global Assessment (IGA), and Peak Pruritus Numerical Rating Scale (PP-NRS), and percentage change from baseline in EASI. The dependent variables at week 12 were ≥ 75% improvement in EASI (EASI-75) and IGA score of 0 (clear) or 1 (almost clear) and ≥ 2-point improvement from baseline. The probability of each variable to predict week 12 EASI-75 and IGA responses was calculated. RESULTS: In the training cohort (n = 453), 72% of the ≥ 50% improvement in EASI (EASI-50) at week 4 responders and 16% of the nonresponders with abrocitinib 100 mg achieved EASI-75 at week 12; 48% and 6% of the week 4 EASI-50 responders and nonresponders, respectively, achieved week 12 IGA response. Similar results occurred with week 4 IGA = 2, ≥ 4-point improvement from baseline in PP-NRS, or EASI = 8 responders/nonresponders. Platelet counts after an abrocitinib dose increase from 100 to 200 mg were similar to those seen with continuous dosing with abrocitinib 100 mg or 200 mg. CONCLUSION: Achieving week 4 clinical responses with abrocitinib 100 mg may be useful in predicting week 12 responses. Week 4 nonresponders may benefit from a dose increase to abrocitinib 200 mg, and those that receive this dose increase are likely to achieve treatment success at week 12, with no significant impact on platelet count recovery. Video abstract available for this article. CLINICAL TRIAL REGISTRATION: NCT03349060, NCT03575871, NCT03720470, NCT03796676, NCT02201524, NCT02780167 and NCT03627767.