The currently proposed doses for the pediatric study are derived from a population
pharmacokinetic (PK) model built using the systemic TQ exposure data from adults in
part 1 of Study TAF112582. The population PK model incorporated allometric scaling
for bodyweight. Based on this population PK model, a 60 kg adult on 300mg dose will
have a median AUC(0-∞) of 96 μg.h/mL (95% prediction interval 55-162 μg.h/mL). The
proposed starting doses for this pediatric study are predicted to achieve a similar target
exposure after accounting for the subjects’ bodyweight. The lower prediction limit
AUC(0-∞) of 55 μg.h/mL from the model is also consistent with the cut-off obtained
from the CART analysis (AUC(0-∞) of 56.4 μg.h/mL) and therefore provides a high
degree of confidence in the efficacy in the pediatric population using this PK bridging
approach.