This is a Phase 1 randomized study in healthy participants to estimate the relative bioavailability of abrocitinib oral suspension (Test formulation) compared to commercial abrocitinib tablet (Reference formulation) under fasted condition. The effect of an acid-reducing agent on the pharmacokinetics of the commercial tablet formulation will be evaluated by administering abrocitinib 200 mg commercial tablet with famotidine 40 mg, as an acid-reducing agent. Assessment of taste and palatability of six different abrocitinib suspension formulations will also be performed. This study consists of 2 parts, as listed below:~Part A~Part A of the study will be an open label, randomized, single dose, crossover, 3-treatment, 6 sequence, 3-period design in healthy male and/or female adult participants (18-55 years). Healthy participants will be screened within 28 days prior to the first administration of the study intervention to confirm that they meet the participant selection criteria for the study. Eligible participants will be admitted to the CRU on Day -1 and will be confined in the CRU until discharge, on Day 2 of Period 9 in Part B, after completing both Parts A and B of the study. In Part A, participants will be randomized to receive one of the following: a single 200 mg dose of abrocitinib commercial tablet (Treatment A), a single 200 mg dose of abrocitinib oral suspension formulation 1 (Treatment B), or famotidine (40 mg) administered 120 minutes before a single 200 mg dose of abrocitinib commercial tablet (Treatment C). All participants will be fasting for at least 10 hours before taking abrocitinib.~Part B~Part B will be a single-blind, randomized, 6-period, crossover study in healthy male and/or female adult participants (18-55 years). For any new healthy participants joining Part B only, screening will be performed within 28 days prior to the first administration of the study intervention to confirm that they meet the participant selection criteria for the study. New participants enrolled in Part B only will be admitted to the CRU on Day -1 and will be confined in the CRU until discharge, which is Day 2 of Period 9. On Day 1 of each treatment period under fasted conditions, participants will receive a famotidine tablet (40 mg with 240 mL of room temperature water) administered 120 minutes before a single 200 mg dose of abrocitinib oral suspensions (Formulations 1 to 6) or administered a single 200 mg dose of abrocitinib oral suspension alone (Formulations 1 to 6), after a fast of at least 10 hours before abrocitinib administration.
This study consists of 2 parts: Part A is to estimate the relative bioavailability of a single 200 mg dose of abrocitinib oral suspension (Test formulation) compared to the commercial abrocitinib tablet (200 mg) (Reference formulation). The effect of an acid-reducing agent on the pharmacokinetics of abrocitinib and its metabolites will also be evaluated by administering abrocitinib 200 mg commercial tablet with or without famotidine 40 mg, as an acid-reducing agent. Part B is to assess the taste and palatability of six different abrocitinib oral suspension formulations. Additionally, the safety and tolerability of abrocitinib tablet (in Part A) and abrocitinib oral suspension formulations (in Part B) will be assessed when given with or without famotidine 40 mg once daily.