The study is divided in two parts. Part I will evaluate PK, safety and tolerability of a single oral dose of two different formulations of GS-248 in fasting conditions. Part II will evaluate PK, safety and tolerability of one of the two different formulations of GS-248 in fed conditions.~In Part I, a single oral dose of GS-248 in two different solid formulations will be administered to 14 healthy subjects. All subjects will first receive Formulation A and then Formulation B. A wash-out period of at least 4 days will be applied between the IMP administrations. Both doses contain 120 mg GS 248. For Part I, subjects will come to the clinic for single dose administration of Formulation A or Formulation B, respectively, and PK and safety assessments. Safety assessments include AE reporting, physical examination, ECG, vital signs, body temperature, and blood sampling for analysis of safety laboratory parameters.~After evaluation of the PK profiles of Formulation A and B in Part I of the study, one formulation will be selected to be given following intake of a standardised breakfast in Part II of the study. Subjects will return to the clinic for a second dose of the selected formulation, yet now in fed conditions. The assessments during fed conditions will be the same as during fasting conditions except that the subjects will consume a high-fat high-calorie breakfast 30 minutes prior to IMP administration.
The study will collect information about pharmacokinetics (PK), safety and tolerability following a single dose of GS-248 in two different oral solid formulations in capsules to healthy subjects. It will also collect information about pharmacokinetics (PK), safety and tolerability following a single dose of one of the two formulations of GS-248 in fed condition.