Summary: This is a multicenter, randomized, double-blind, placebo-controlled, parallel-group clinical trial designed to evaluate the efficacy and safety of efavirenz in patients with Creutzfeldt-Jakob disease (CJD). A total of 246 eligible participants will be enrolled across 21 study centers nationwide. Participants will be randomly assigned in a 1:1 ratio to receive either efavirenz or placebo. Participa...

Summary: The main goal of this clinical study is to test how CYP2B6 genetic variations and efavirenz (cornerstone in HIV-1 therapy) dictate the disposition (PK) of CYP2B6 substrate (methadone) and PK and effect (PD) of CYP1A2 substrate (tizanidine). Specifically, the investigators will test whether efavirenz produces CYP2B6 genotype dependent unanticipated DDIs with CYP2B6 (methadone) and CYP1A2 (tizanidin...

Summary: The goal of this clinical study is to provide continued access to the study drug(s) to children and adolescents with human immunodeficiency virus type 1 (HIV-1) who completed their participation in an applicable parent study and to monitor for adverse events. The primary objectives of this study are as follows: * To provide continued access to the study drug received in the parent protocol or swit...