No Clinically Relevant Drug-Drug Interactions Between Methadone or Buprenorphine-Naloxone and Antiviral Combination Glecaprevir and Pibrentasvir

The combination of glecaprevir (formerly ABT-493), a nonstructural protein 3/4A (NS3/4A) protease inhibitor, and pibrentasvir (formerly ABT-530), an NS5A protein inhibitor, is being developed as treatment for HCV genotype 1 to 6 infection. The pharmacokinetics, pharmacodynamics, safety, and tolerability of methadone or buprenorphine-naloxone when coadministered with the glecaprevir-pibrentasvir combination in HCV-negative subjects on stable opioid maintenance therapy were investigated in a phase 1, single-center, two-arm, multiple-dose, open-label sequential study. Subjects received methadone (arm 1) or buprenorphine-naloxone (arm 2) once daily (QD) per their existing individual prescriptions alone (days 1 to 9) and then in combination with glecaprevir at 300 mg QD and pibrentasvir at 120 mg QD (days 10 to 16) each morning. Dose-normalized exposures were similar with and without glecaprevir and pibrentasvir for ()- and ()-methadone (≤5% difference) and for buprenorphine and naloxone (≤24% difference); the norbuprenorphine area under the curve was 30% higher with glecaprevir and pibrentasvir, consistent with maximum and trough plasma concentrations that increased by 21% to 25%. No changes in pupil response, short opiate withdrawal scale score, or desire for drugs questionnaire were observed when glecaprevir and pibrentasvir were added to methadone or buprenorphine-naloxone therapy. No dose adjustment is required when glecaprevir and pibrentasvir are coadministered with methadone or buprenorphine-naloxone.