quad-pill and Drug-Related-Side-Effects-and-Adverse-Reactions

The development of HIV-1 integrase strand transfer inhibitors (INSTIs) has been a major therapeutic breakthrough in the management of HIV-1 infection. The first HIV-1 integrase inhibitor, raltegravir, was licensed in 2007 and was subsequently approved for use in treatment-naive patients. Since then, newer members of the INSTI class have been developed, including elvitegravir (EVG), which is in advanced clinical development and is being developed for use in both treatment-naive and treatment-experienced patients. EVG utilizes pharmacokinetic boosting to achieve adequate serum levels with once-daily dosing. Boosting agents with which it is being studied include ritonavir and cobicistat. In addition, EVG is being studied as a once-daily INSTI in a coformulated fixed-dose combination pill with the agents tenofovir disoproxil fumarate, emtricitabine and cobicistat (QUAD pill), which has the additional potential benefit of convenient once-daily dosing. The in vitro activity, pharmacokinetic and pharmacodynamic properties, results of Phase I-III clinical trials, resistance profile and drug-drug interactions of EVG will be reviewed in this article.

Topics: Adenine; Carbamates; Clinical Trials, Phase I as Topic; Clinical Trials, Phase II as Topic; Clinical Trials, Phase III as Topic; Deoxycytidine; Drug Combinations; Drug Interactions; Drug Resistance, Viral; Drug-Related Side Effects and Adverse Reactions; Elvitegravir, Cobicistat, Emtricitabine, Tenofovir Disoproxil Fumarate Drug Combination; HIV Infections; HIV Integrase Inhibitors; HIV-1; Humans; Organophosphonates; Quinolones; Randomized Controlled Trials as Topic; Thiazoles

Elvitegravir (EVG), a HIV integrase inhibitor, is metabolized primarily by CYP3A, and secondarily by UGT1A1/3; Efavirenz (EFV), a HIV non-nucleoside reverse transcriptase inhibitor, is metabolized by Cytochrome P450 (CYP) 2B6 and induces CYP3A and uridine diphosphate glucuronosyltransferase (UGT) with residual effects post discontinuation because of long T1/2 (40-55 hours). This study evaluated the pharmacokinetics after switching from efavirenz/emtricitabine/tenofovir disoproxil fumarate (EFV/FTC/TDF) to elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate (EVG/COBI/FTC/TDF).. Healthy subjects (n = 32 including n = 8 CYP2B6 poor metabolizers) received EVG/COBI/FTC/TDF (150/150/200/300 mg) on days 1-7, and after a washout, received EFV/FTC/TDF (600/200/300 mg) on days 15-28 and switched to EVG/COBI/FTC/TDF (150/150/200/300 mg) for 5 weeks (days 29-62). Pharmacokinetic assessments occurred on days 7, 28, 35, and 42; trough samples (Ctrough) were collected periodically until day 63. Safety was assessed throughout the study.. Twenty-nine subjects completed with 3 adverse events leading to discontinuation; no grade ≥3 adverse events were reported. Post-EFV/FTC/TDF, mean EVG area under concentration (AUCtau) was 37% and 29% lower and mean Ctrough ∼3- and ∼5-fold above IC95, respectively, on days 35 and 42, and 7-8-fold above IC95 by 5 weeks. COBI AUCtau returned to normal by day 42. EVG glucuronide, GS-9200, AUCtau was higher (46% and 32% on days 35 and 42, respectively) postswitch. CYP2B6 poor metabolizers displayed higher EFV AUCtau and Cmax (125% and 91%, respectively) versus non-poor metabolizers, and lower EVG and COBI exposures. EFV Ctrough was >IC90 (10 ng/mL) in all subjects postswitch. FTC and tenofovir (TFV) exposures were unaffected.. After EFV/FTC/TDF to EVG/COBI/FTC/TDF switch, EVG and/or EFV exposures were in an active range. These findings support further evaluation of switching regimens in HIV-1 patients.

Topics: Adolescent; Adult; Anti-HIV Agents; Drug Combinations; Drug-Related Side Effects and Adverse Reactions; Efavirenz, Emtricitabine, Tenofovir Disoproxil Fumarate Drug Combination; Elvitegravir, Cobicistat, Emtricitabine, Tenofovir Disoproxil Fumarate Drug Combination; Female; Healthy Volunteers; Humans; Male; Middle Aged; Treatment Outcome; Young Adult

The purpose of this study is to assess postmarketing safety and tolerability of Stribild (elvitegravir [EVG]/cobicistat [COBI]/tenofovir disoproxil fumarate [TDF]/emtricitabine [FTC]).. A retrospective, pharmacoepidemiologic study in 2 outpatient HIV clinics in the Southeast United States was conducted among adults receiving EVG/COBI/TDF/FTC. We evaluated incidence and treatment-related adverse events, including change in serum creatinine (SCr).. Patients were primarily treatment experienced (n = 173, 60%), African American (n = 210, 73%), and males (n = 187, 65%). One hundred ninety-five (68%) patients had any increase in SCr, and 65 (23%) had an increase of ≥0.3 mg/dL. Mean SCr change from baseline to peak was 0.2 mg/dL. Being treatment experienced (odds ratio [OR] = 2.21, 95% confidence interval [CI]: 1.12-4.38) was associated with SCr ≥0.3 mg/dL, while body mass index ≥30 kg/m(2) (OR = 0.41, 95% CI: 0.18-0.93) was protective. Twenty (7%) patients discontinued therapy, 3 due to acute kidney injury.. Our results demonstrate limited adverse events and low discontinuation rates associated with EVG/COBI/TDF/FTC.

Topics: Adult; Anti-HIV Agents; Creatinine; Drug-Related Side Effects and Adverse Reactions; Elvitegravir, Cobicistat, Emtricitabine, Tenofovir Disoproxil Fumarate Drug Combination; Female; HIV Infections; Humans; Kidney Function Tests; Male; Middle Aged; Retrospective Studies; Southeastern United States