Fourteen healthy participants for each cohort of Arm A are stabilized on a fixed regimen of pravastatin (Arm A1), simvastatin (Arm A2), or atorvastatin (Arm A3) for 4 days. A baseline pharmacokinetic (PK) evaluation is completed on Day 4. Pravastatin (or simvastatin or atorvastatin) dosing stops following the Day 4 dose and PK evaluation. On Day 5, a ritonavir and saquinavir combination regimen is initiated and continued through Day 18 of the study. Pravastatin (or simvastatin or atorvastatin) dosing resumes on Day 15 and continues through Day 18. A repeat PK evaluation of pravastatin (or simvastatin or atorvastatin) in the context of combination therapy is carried out on Day 18.