Absorption
The rate of absorption (tmax) of miglustat was approximately 2 to 3 hours. At the clinical dose, 260 mg, plasma miglustat attained a Cmax of approximately 3000 ng/mL and an AUC0-∞ of approximately 25,000 ng h/mL.
Effect of food
A significant food effect was observed and resulted in a decreased Cmax by 36% and delayed absorption by approximately 2 hours (see section 4.2).
Metabolism
Miglustat is largely unmetabolised with < 5% of a radiolabeled dose recovered as glucuronides.
Miglustat is not a substrate of OAT1, OAT3, OATP1B1, OATP1B3, MATE1, MATE2-K, BCRP, or BSEP. Miglustat is a weak substrate of P-glycoprotein (P-gp) and a substrate of uptake transporters OCT1 (expressed in the liver) and OCT2 (expressed in the kidney). As miglustat is largely renally excreted unmetabolised, OCT1-inhibitors are not expected to result in a clinically meaningful interaction. OCT2 inhibitors are not expected to have a clinically meaningful impact on the renal excretion and exposure of miglustat based on data in patients with severe renal impairment. P-glycoprotein (P-gp)-inhibitors are not expected to result in a clinically meaningful interaction with miglustat in the intestine based on fasting recommendations and the rapid absorption of miglustat (tmax of 2 hours).
Miglustat is not a known substrate or inhibitor of cytochrome P450 enzymes; consequently, significant interactions are unlikely with drugs that are substrates of cytochrome P450 enzymes.
Based upon in vitro transporter study, miglustat is not an inhibitor of OAT1, OAT3, OCT1, OCT2, OATP1B1, OATP1B3 or BSEP transporters. Clinically meaningful interactions in the intestine with P-gp and BCRP substrates and in the liver at the portal vein with OCT1, OATP1B1 and OATP1B3 are not expected based on fasting recommendations and the rapid absorption of miglustat.
Elimination
The terminal elimination half-life was approximately 6 hours for miglustat. Oral clearance was approximately 10.5 L/h and terminal phase volume of distribution was approximately 90 L.
Linearity
Miglustat demonstrated dose proportional kinetics.
Special populations
Gender, elderly, and race/ethnicity
Based on pooled population pharmacokinetic analysis, gender, age (18 to 74 years), and race/ethnicity did not have clinically meaningful effect on the exposure to miglustat in combination with cipaglucosidase alfa.
Hepatic impairment
The pharmacokinetics of miglustat in combination with cipaglucosidase alfa therapy have not been evaluated in patients with hepatic impairment.
Renal impairment
The AUC0-24hr of miglustat increased by 21%, 32%, and 41% in patients with mild (creatinine clearance [CLcr] 60 to 89 mL/minute, estimated by Cockcroft-Gault), moderate (CLcr 30 to 59 mL/minute), and severe (CLcr 15 to 29 mL/minute) renal impairment, respectively, compared to patients with normal renal function. The effect of end stage renal disease on the pharmacokinetics of miglustat is unknown.