Crisaborole

1 INDICATIONS AND USAGE EUCRISA is indicated for topical treatment of mild to moderate atopic dermatitis in adult and pediatric patients 3 months of age and older. EUCRISA is a phosphodiesterase 4 inhibitor indicated for topical treatment of mild to moderate atopic dermatitis in adult and pediatric patients 3 months of age and older. ( 1 )

2 DOSAGE AND ADMINISTRATION Apply a thin layer of EUCRISA twice daily to affected areas. Once clinical effect is achieved, consider reducing application to once daily [see Clinical Studies (14) ] . EUCRISA is for topical use only and not for ophthalmic, oral, or intravaginal use. • Apply a thin layer twice daily to affected areas. ( 2 ) • Once clinical effect is achieved, consider reducing application to once daily. ( 2 ) • For topical use only. ( 2 ) • Not for ophthalmic, oral, or intravaginal use. ( 2 )

6 ADVERSE REACTIONS The most common adverse reaction occurring in ≥1% in subjects is application site pain. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Pfizer Inc. at 1-800-438-1985 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. In two double-blind, vehicle-controlled clinical trials (Trial 1 and Trial 2), 1012 subjects 2 to 79 years of age with mild to moderate atopic dermatitis were treated with EUCRISA twice daily for 4 weeks. The adverse reaction reported by ≥1% of EUCRISA-treated subjects is listed in Table 1. Table 1: Adverse Reaction Occurring in ≥1% of Subjects in Atopic Dermatitis Trials through Week 4 Adverse Reaction EUCRISA Twice Daily N=1012 n (%) Vehicle Twice Daily N=499 n (%) Application site pain Refers to skin sensations such as burning or stinging. 45 (4) 6 (1) Less common (<1%) adverse reactions in subjects treated with EUCRISA included contact urticaria [see Warnings and Precautions (5.1) ]. In one double-blind, vehicle-controlled trial including an initial open-label period (Trial 3), 497 subjects 3 months of age and older with mild to moderate atopic dermatitis received EUCRISA twice daily for up to 8 weeks. This was followed by a double-blind period, during which 135 subjects out of 270 randomized subjects received EUCRISA and 135 subjects received vehicle once daily for 52 weeks or until they developed a flare. The adverse reactions observed in the open-label period were similar to the known safety profile of twice daily treatment with EUCRISA. The adverse reactions observed with once daily treatment were similar to vehicle [see Clinical Studies (14) ] . 6.2 Postmarketing Experience The following adverse reactions have been identified during postapproval use of EUCRISA. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure: Skin and Subcutaneous: allergic contact dermatitis

12.3 Pharmacokinetics Absorption The PK of EUCRISA were investigated in 33 pediatric subjects 2 to 17 years of age with mild to moderate atopic dermatitis and a mean ± SD body surface area (BSA) involvement of 49 ± 20% (range 27% to 92%). In this study, subjects applied approximately 3 mg/cm 2 of EUCRISA ointment (dose range was approximately 6 g to 30 g per application) twice daily for 8 days. Plasma concentrations were quantifiable in all the subjects. The mean ± SD maximum plasma concentration (C max ) and area under the concentration time curve from 0 to 12 hours post dose (AUC 0–12 ) for crisaborole on Day 8 were 127 ± 196 ng/mL and 949 ± 1240 ng h/mL, respectively. Systemic concentrations of crisaborole were at steady state by Day 8. Based on the ratios of AUC 0–12 between Day 8 and Day 1, the mean accumulation factor for crisaborole was 1.9. The PK of EUCRISA were investigated in 13 subjects 4 months to less than 24 months of age. The mean ± SD C max and AUC 0–12 for crisaborole were 188 ± 100 ng/mL and 1164 ± 550 ng∙h/mL, respectively. Distribution Based on an in vitro study, crisaborole is 97% bound to human plasma proteins. Elimination Metabolism Crisaborole is substantially metabolized into inactive metabolites. The major metabolite 5-(4-cyanophenoxy)-2-hydroxyl benzylalcohol (metabolite 1), is formed via hydrolysis; this metabolite is further metabolized into downstream metabolites, among which 5-(4-cyanophenoxy)-2-hydroxyl benzoic acid (metabolite 2), formed via oxidation, is also a major metabolite. PK of metabolites 1 and 2 were assessed in the PK study described above and the systemic concentrations were at or near steady state by Day 8. Based on the ratios of AUC 0–12 between Day 8 and Day 1, the mean accumulation factors for metabolites 1 and 2 were 1.7 and 6.3, respectively. Excretion Renal excretion of metabolites is the major route of elimination. Drug Interaction Studies In vitro studies using human liver microsomes indicated that under the conditions of clinical use, crisaborole and metabolite 1 are not expected to inhibit cytochrome P450 (CYP) 1A2, 2B6, 2C8, 2C9, 2C19, 2D6, and 3A4. In vitro human liver microsomes studies for metabolite 2 showed that it did not inhibit activities of CYP2C19, 2D6, and 3A4; was a weak inhibitor of CYP1A2 and 2B6; and a moderate inhibitor of CYP2C8 and 2C9. The most sensitive enzyme, CYP2C9, was further investigated in a clinical trial using warfarin as a CYP2C9 substrate. The results of this study showed no drug interaction potential. In vitro studies in human hepatocytes showed that under the conditions of clinical use, crisaborole and metabolites 1 and 2 are not expected to induce CYP enzymes. In vitro studies showed that crisaborole and metabolite 1 did not inhibit the activities of uridine diphosphate (UDP)-glucuronosyltransferase (UGT) 1A1, 1A4, 1A6, 1A9, 2B7, and 2B15. Metabolite 2 did not inhibit UGT1A4, 1A6, 2B7, and 2B15. Metabolite 2 showed weak inhibition of UGT1A1, however, no clinically significant drug interactions are expected between crisaborole (and its metabolites) and UGT1A1 substrates at therapeutic concentrations. Metabolite 2 showed moderate inhibition of UGT1A9 and may result in a moderate increase of the concentrations of sensitive UGT1A9 substrates. In vitro studies indicate that under the condition of clinical use, crisaborole and metabolites 1 and 2 are not expected to cause clinically significant interactions with substrates of P-glycoprotein and organic anionic or cationic transporters. Crisaborole and metabolite 1 are not expected to inhibit breast cancer resistance protein (BCRP); metabolite 2 is expected to inhibit BCRP at therapeutic concentrations.