Page 4 of 50 2 SYNOPSIS Title: A Bioavailability Study to Assess the Bioequivalence of Alfacalcidol Capsule and Oral Drop Formulations: A Comparative, Randomized, Single-Dose, 4-Way Crossover Bioavailability Study of LEO Pharma A/S Alfacalcidol (One-Alpha ) Capsules and Oral Drops Following a Dose of 10 µg in Healthy Adult Volunteers under Fasting Conditions Objective: The objective of this study was to evaluate the bioequivalence of a 10 µg dose of alfacalcidol administered as a capsule formulation and as an oral drop formulation in healthy subjects under fasting conditions. Study Design: This was a comparative, randomized, single-dose, 4-way crossover, 4-sequence, bioavailability study of LEO Pharma A/S alfacalcidol (One-Alpha ) capsules and oral drops following a dose of 10 µg in healthy adult volunteers under fasting conditions. Seventy-two (72) healthy, non-smoking volunteers (43 males and 29 females) were enrolled in this study. Subjects were divided in two groups for dosing: Group 1 (Subject Nos. 1 36) and Group 2 (Subject Nos. 37 72). Sixty four (64) subjects (39 males and 25 females) completed the study. In each period, subjects were housed in the study unit from at least 48 hours before dosing until completion of the 36-hour blood draw, and returned for the 48-hour blood draw. Each single oral dose was separated by a washout period of 14 days. Methods: Due to analytical limitations, the bioavailability assessment of the 1α-hydroxyvitamin D 3 (alfacalcidol) formulations was based on its active metabolite, 1,25-dihydroxyvitamin D 3 (calcitriol), in serum. AUC 0-t, Cmax and tmax pharmacokinetic parameters were calculated for unadjusted and baseline adjusted calcitriol concentrations. AUCinf, AUC/AUCinf, half-life and kel pharmacokinetic parameters were calculated for baseline adjusted calcitriol concentrations only. Analyses of variance (ANOVA) were performed on the ln-transformed baseline adjusted AUC 0-t, AUCinf, and
Page 5 of 50 Cmax. As secondary analysis, ANOVA were performed on the ln-transformed unadjusted AUC 0-t and Cmax. Initially, the ANOVA model included group, sequence, period nested within group, formulation, and formulation*group interaction as fixed effects, and subject nested within group*sequence as a random effect. Sequence was tested using subject nested within group*sequence as the error term. The Formulation*group effect was tested at a 5% level of significance. This term was not statistically significant and was dropped from the final ANOVA model. The 90% confidence intervals for the ratios of least-squares means (LSM) were derived by exponentiation of the confidence intervals obtained for the difference between formulation LSM resulting from the analyses on the ln-transformed baseline adjusted AUC 0-t, AUCinf and Cmax and ln-transformed unadjusted AUC 0-t and Cmax pharmacokinetic parameters. Results: The mean PK parameters for baseline unadjusted calcitriol in serum following the administration of alfacalcidol (One-Alpha ) as capsules and oral drops are listed below. Summary of Geometric Mean Pharmacokinetic Parameters (CV%) for Baseline Unadjusted Calcitriol Treatment AUC 0-t (pg.h/ml) Cmax (pg/ml) A B C D 5403 (19.1%) 5517 (20.8%) 5490 (18.4%) n=67 5783 (19.1%) 181 (19.6%) 187 (22.6%) 188 (19.2%) n=67 202 (17.8%) Comparisons of Interest: Ratios of LSM (90% Confidence intervals) B vs A 101.5 (99.2% 103.8%) 102.5 (99.8% 105.3%)
Page 6 of 50 C vs A 102.2 (99.8% 104.5%) 104.8 (102.0% 107.7%) 107.4% 112.3% D vs A (105.0% 109.9%) (109.4% 115.4%) (A) A single 10 µg dose (as 40 capsules of 0.25 µg strength) of alfacalcidol capsules (B) A single 10 µg dose (as 20 capsules of 0.50 µg strength) of alfacalcidol capsules (C) A single 10 µg dose (as 10 capsules of 1 µg strength) of alfacalcidol capsules (D) A single 10 µg dose (as 5 ml) of alfacalcidol oral drops The mean PK parameters for baseline adjusted calcitriol in serum following the administration of alfacalcidol (One-Alpha ) as capsules and oral drops are listed below. Summary of Geometric Mean Pharmacokinetic Parameters (CV%) for Baseline Adjusted Calcitriol Treatment AUC 0-t (pg.h/ml) AUCinf (pg.h/ml) Cmax (pg/ml) A 1931 (46.8%) 2184 (42.1%) n=68 108 (29.2%) B 1996 (49.3%) 2259 (45.1%) n=64 113 (34.2%) C 2067 (46.2%) n=66 2220 (47.3%) n=60 118 (27.5%) n=66 D 2320 (31.8%) 2529 (28.7%) n=65 130 (21.9%) Comparisons of Interest: Ratios of LSM (90% Confidence intervals) B vs A 103.0% (94.8% 112.0%) 101.3% (93.7% 109.4%) 104.2 (99.7% 108.9%) C vs A 108.4% (99.5% 118.1%) 101.5% (93.7% 109.9%) 110.0 (105.2% 115.1%) 120.8% 115.4 121.2% D vs A (111.0% 131.3%) (106.8% 124.6%) (115.9% 126.7%) (A) A single 10 µg dose (as 40 capsules of 0.25 µg strength) of alfacalcidol capsules (B) A single 10 µg dose (as 20 capsules of 0.50 µg strength) of alfacalcidol capsules
Page 7 of 50 (C) A single 10 µg dose (as 10 capsules of 1 µg strength) of alfacalcidol capsules (D) A single 10 µg dose (as 5 ml) of alfacalcidol oral drops Conclusions: Baseline Unadjusted Results Following a single 10 µg dose of alfacalcidol, the rate and extent of exposure (Cmax and AUC 0-t) of calcitriol were slightly higher for the oral drop formulation compared to the capsules. The 90% confidence intervals of the ratios of LSM of the test formulations to the reference formulation (40 x 0.25 µg capsules) were within 80-125% for calcitriol unadjusted AUC 0-t and Cmax in serum. The results for unadjusted PK parameters are presented for information purpose only. Baseline Adjusted Results The rate and extent of exposure (Cmax and AUC 0-t) of calcitriol were similar after a single 10 µg dose of alfacalcidol administered as 20 capsules of 0.5 µg or 10 capsules of 1 µg compared to 40 capsules of 0.25 µg. The 90% confidence intervals of the ratio of LSM of the test formulations to the reference formulation were within 80-125% for calcitriol baseline adjusted AUC 0-t and Cmax. Following a single 10 µg dose of alfacalcidol administered as oral drops the rate and extent of exposure of calcitriol was slightly higher to that observed after the administration of 40 capsules of 0.25 µg. The ratios of LSM were within 80-125% for calcitriol baseline adjusted AUC 0-t and Cmax. However, the 90% confidence interval of the ratio of LSM of the test to reference formulation was not within the 80-125% criteria. Based on these results, the 10 µg dose of alfacalcidol (One-Alpha ) administered as 20 capsules of 0.5 µg (B) or 10 capsules of 1 µg (C) are bioequivalent to the 40 capsules of 0.25 µg (A) in healthy subjects under fasting conditions.
Page 8 of 50 Software: The oral drops (D) of alfacalcidol (One-Alpha ) appeared to have a slightly higher bioavailability than the 40 capsules of 0.25 µg (A) in healthy subjects under fasting conditions. The following software programs were used to generate the report, tables and figures for this study: Microsoft Excel 2003, Microsoft Word 2003, PhAST 2.3-001 and SAS System for Windows release 6.12. Archiving: The contents of this report are archived at, as per SOP No..