Parenteral azacitidine improves overall survival in higher-risk myelodysplastic syndromes. An oral azacitidine formulation would allow extended dosing schedules, potentially improving safety and/or efficacy. Two Phase 1 studies evaluated the pharmacokinetics (PK) of oral azacitidine in subjects with hematologic malignancies. Study 1 evaluated different oral formulations (immediate release tablet [IRT], enteric-coated tablet, and capsule; N = 16). Study 2 assessed the effect of food (Part 1; N = 17) and gastric pH modulation with omeprazole (Part 2; N = 14) on oral azacitidine PK. Azacitidine plasma concentration-time profiles for IRT and capsule formulations were similar, with more rapid time to maximum plasma concentration (Tmax ) than the enteric-coated tablet. Study 2 evaluated only IRT formulations of oral azacitidine. Under fed condition, Tmax was delayed ∼1.5 hours but area under the concentration-time curve (AUC∞ ) and maximum plasma concentrations (Cmax ) were comparable under fed and fasted conditions. Mean azacitidine AUC∞ and Cmax increased upon omeprazole co-administration (18.3% and 13.2%, respectively, vs. oral azacitidine alone), but not to a clinically meaningful extent. High inter-subject variability in AUC∞ and Cmax (%CV range 46.4-68.9%) was observed. Oral azacitidine is rapidly absorbed with little or no effect of food on PK parameters, and does not require dose adjustments when taking a proton-pump inhibitor.
Trial registration: ClinicalTrials.gov NCT00761722 NCT01519011.
Keywords: CC-486; effect of food; formulation; oral azacitidine; pharmacokinetics; proton-pump inhibitor.
© 2014, The American College of Clinical Pharmacology.