rifampin and doravirine

Doravirine, a novel nonnucleoside reverse transcriptase inhibitor for the treatment of human immunodeficiency virus 1 (HIV-1), is predominantly cleared by cytochrome P450 (CYP) 3A4 and metabolized to an oxidative metabolite (M9). Coadministration with rifabutin, a moderate CYP3A4 inducer, decreased doravirine exposure. Based on nonparametric superposition modeling, a doravirine dose adjustment from 100 mg once daily to 100 mg twice daily during rifabutin coadministration was proposed. However, M9 exposure may also be impacted by induction, in addition to the dose adjustment. As M9 concentrations have not been quantified in previous clinical studies, a physiologically based pharmacokinetic model was developed to investigate the change in M9 exposure when doravirine is coadministered with CYP3A inducers. Simulations demonstrated that although CYP3A induction increases doravirine clearance by up to 4.4-fold, M9 exposure is increased by only 1.2-fold relative to exposures for doravirine 100 mg once daily in the absence of CYP3A induction. Thus, a 2.4-fold increase in M9 exposure relative to the clinical dose of doravirine is anticipated when doravirine 100 mg twice daily is coadministered with rifabutin. In a subsequent clinical trial, doravirine and M9 exposures, when doravirine 100 mg twice daily was coadministered with rifabutin, were found to be consistent with model predictions using rifampin and efavirenz as representative inducers. These findings support the dose adjustment to doravirine 100 mg twice daily when coadministered with rifabutin.

Topics: Adult; Alkynes; Benzoxazines; Computer Simulation; Cyclopropanes; Cytochrome P-450 CYP3A; Cytochrome P-450 CYP3A Inducers; Dose-Response Relationship, Drug; Drug Interactions; Female; Humans; Male; Middle Aged; Models, Biological; Pyridones; Reverse Transcriptase Inhibitors; Rifabutin; Rifampin; Triazoles; Young Adult

Doravirine (DOR) is a non-nucleoside reverse transcriptase inhibitor indicated for the treatment of HIV-1. Its use in combination with rifapentine (RPT), an antituberculosis (TB) antibiotic, may reduce the exposure of DOR compromising viral suppression in those living with HIV-1 co-infected with TB. We conducted a prospective, phase I, open label, two-period, fixed sequence, drug interaction study to evaluate the effect of once-weekly RPT and isoniazid (INH) on the pharmacokinetics (PKs) of DOR in healthy volunteers. DOR 100 mg was administered alone twice-daily for 4 days in period 1. In period 2, once-weekly RPT + INH were co-administered with multiple doses of DOR 100 mg twice-daily for study days 7, 14, and 21. Plasma was obtained for DOR PKs when given alone and co-administered with RPT + INH. Eleven healthy volunteers enrolled and completed the study. The geometric mean ratios and 90% confidence intervals for DOR area under the concentration-time curve from zero to 12 hours (AUC

Topics: Adolescent; Adult; Antitubercular Agents; Area Under Curve; Drug Administration Schedule; Drug Interactions; Female; Healthy Volunteers; HIV Infections; Humans; Isoniazid; Male; Middle Aged; Prospective Studies; Pyridones; Reverse Transcriptase Inhibitors; Rifampin; Triazoles; Tuberculosis; Young Adult

Doravirine is a novel, next-generation, non-nucleoside reverse transcriptase inhibitor in development for the treatment of human immunodeficiency virus-1 infection in combination with other antiretrovirals. Doravirine is a substrate for cytochrome P450 (CYP) 3A and P-glycoprotein. Rifampin (rifampicin) is used for treating tuberculosis in patients who are co-infected with human immunodeficiency virus. Rifampin demonstrates organic anion-transporting polypeptide 1B1 and P-glycoprotein inhibition after single-dose administration and CYP3A and P-glycoprotein induction after multiple-dose administration. The objective of this study was to evaluate the effects of co-administration of single and multiple doses of rifampin on doravirine pharmacokinetics.. In period 1 of this open-label, two-period, fixed-sequence study in healthy adults, subjects received single-dose doravirine 100 mg; blood samples for measuring plasma concentration were collected pre-dose and up to 72 h post-dose. In period 2, following a 7-day washout, subjects received doravirine 100 mg and rifampin 600 mg on day 1, rifampin 600 mg daily on days 4-18, with doravirine 100 mg co-administered on day 17; blood samples were collected pre-dose and up to 72 h post-dose on day 1 and up to 48 h post-dose on day 17. Safety assessments included adverse events, physical examinations, vital signs, and clinical laboratory measurements.. Ten subjects completed the study. Doravirine area under the concentration-time curve from time zero extrapolated to infinity and plasma concentration at 24 h post-dose were comparable in the presence and absence of single-dose rifampin [geometric mean ratios (90% confidence intervals)] of 0.91 (0.78-1.06) and 0.90 (0.80-1.01), respectively. Doravirine maximum plasma concentration increased when co-administered with single-dose rifampin vs. doravirine alone, geometric mean ratio (90% confidence interval): 1.40 (1.21-1.63). Reductions in doravirine geometric mean ratios (90% confidence interval), area under the concentration-time curve from time zero extrapolated to infinity: 0.12 (0.10-0.15), plasma concentration at 24 h post-dose: 0.03 (0.02-0.04), maximum plasma concentration: 0.43 (0.35-0.52), and apparent terminal half-life were observed when co-administered with multiple-dose rifampin vs. doravirine administered alone. Doravirine was well tolerated. Adverse events were mild and resolved by study completion.. Doravirine co-administration with single-dose rifampin indicated that inhibition of organic anion-transporting polypeptide uptake transporters and P-glycoprotein has little impact on doravirine pharmacokinetics. Long-term co-administration of rifampin or other strong CYP3A inducers with doravirine will likely reduce its efficacy.

Topics: Adult; Area Under Curve; ATP Binding Cassette Transporter, Subfamily B, Member 1; Cytochrome P-450 CYP3A; Cytochrome P-450 CYP3A Inducers; Half-Life; Humans; Liver-Specific Organic Anion Transporter 1; Male; Middle Aged; Pyridones; Reverse Transcriptase Inhibitors; Rifampin; Triazoles; Young Adult