Drug Interaction Study Between Dolutegravir and Prednisone

Study Summary

Dolutegravir (DTG, GSK1349572 is an integrase inhibitor that is currently in Phase 3 clinical development for the treatment of human immunodeficiency virus (HIV) infection. DTG is primarily metabolized by UDP-glucuronosyltransferase (UGT1A1) with cytochrome P450 (CYP)3A4 pathway as a minor route. Corticosteroids have demonstrated induction effects on UGTs and CYP3A4. Corticosteroids are often used in HIV-infected subjects and have the potential to reduce DTG exposure due to enzyme induction when co-administered. The primary objective of this study is to determine whether concomitant prednisone administration can affect the pharmacokinetics (PK) of DTG. The study is a two part, two period, open label study. Part 1 will evaluate the effect of a high prednisone dose on DTG PK with the potential for an additional Part 2 depending on the results from Part 1. In Part 1, approximately 12 healthy subjects will receive DTG 50mg q24h for 5 days in Period 1. Subjects will then be administered DTG 50mg q24h in combination with prednisone 60mg for 5 days followed by a 5 day taper (total duration of 10 days) in Period 2. PK data of DTG will be obtained from Part 1 and used to inform decision making on the need for Part 2. If DTG exposure is reduced by more than 50% in Part 1, Part 2 will be carried out where a second cohort of subjects will receive DTG 50mg q24h DTG for 5 days in Period 1 followed by DTG 50mg q24h in combination with prednisone 20mg for 5 days followed by a 5 day taper (total duration of 10 days) in Period 2. Safety evaluations and serial PK samples for DTG will be collected during each treatment period. A follow-up visit will occur 7-14 days after the last dose of study drug. All doses of study drugs will be taken following a moderate fat meal. This study will be conducted at one center in the United States, with healthy adult male and female subjects.

Interventions

• DRUG Prednisone
• DRUG Dolutegravir