A Study to Evaluate Doravirine Pharmacokinetics When Coadministered With Acid‐Reducing Agents

Efficacy, Safety, and Tolerability of Doravirine/Lamivudine/Tenofovir Disoproxil Fumarate Fixed-Dose Combination Tablets in Adolescents Living With HIV: Results Through Week 96 from IMPAACT 2014

BACKGROUND

IMPAACT 2014 study is a phase I/II, multicenter, open-label, nonrandomized study of doravirine (DOR) co-formulated with lamivudine (3TC) and tenofovir disoproxil fumarate (TDF) as fixed-dose combination (DOR FDC) in adolescents with HIV-1. We report the efficacy, safety, and tolerability of DOR FDC through 96 weeks.

METHODS

Participants were adolescents aged 12 to <18 years who weighed at least 45 kg and who were either antiretroviral (ARV)-naïve or virologically suppressed without documented resistance mutations to DOR/3TC/TDF. The efficacy endpoint was the proportion of participants with HIV-1 RNA <40 copies/mL assessed at weeks 48 and 96 using the observed failure approach. Safety and tolerability outcomes were incidence of adverse events (AEs) and treatment discontinuations.

RESULTS

A total of 45 adolescents, median age 15 (range, 12-17) years, 58% females, were enrolled and 2 (4.4%) participants were ARV naïve. Of the 45 participants, 42 (93.3%) completed the study and 41 (91.1%) completed the study treatment. At week 48, 41/42 (97.6%; 95% confidence interval [CI], 87.4-99.9) and week 96, 37/40 (92.5%; 95% CI, 79.6-98.4) participants had achieved or maintained HIV-1 RNA <40 copies/mL. There were no treatment-related discontinuations due to AEs and no drug-related AEs ≥grade 3 or deaths.

CONCLUSIONS

We found once-daily dosing of DOR FDC to be safe and well tolerated for maintaining viral suppression through 96 weeks in adolescents living with HIV-1.

An update on drug-drug interactions associated with proton pump inhibitors

INTRODUCTION

Proton pump inhibitors (PPIs) block the gastric H/K-ATPase, therefore inhibiting acid gastric secretion, leading to an increased pH (>4). They account for an extremely high number of prescriptions worldwide. Numerous drug-drug interactions have been described with PPIs, but all the described interactions do not have clinical significance.

AREAS COVERED

This review will discuss the latest updates on drug-drug interactions with PPIs, focusing on the last ten-year publications in the following areas: anti-infective agents, anticancer drugs, antiplatelet agents and anticoagulants, and antidiabetics.

EXPERT OPINION

Although pharmacokinetic interactions of PPIs have been described with many drugs, their clinical relevance remains controversial. However, given the extremely high number of people being treated with PPIs, clinicians should remain vigilant for interactions that may be clinically significant and require dose adjustment or therapeutic monitoring. Interestingly, not all PPIs have the same pharmacokinetic and pharmacodynamic profile, with some having a strong potential to inhibit CYP2C19, such as omeprazole, esomeprazole and lansoprazole, while others, pantoprazole, rabeprazole and dexlansoprazole, are weak CYP2C19 inhibitors. These may be preferred depending on co-prescribed treatments.In addition, new formulations have been developed to prevent some of the gastric pH-dependent drug interactions and should be evaluated in further large-scale prospective comparative studies.

Brief Report: Switching to DOR/3TC/TDF Maintains HIV-1 Virologic Suppression Through Week 144 in the DRIVE-SHIFT Trial

BACKGROUND

In the primary analysis of the DRIVE-SHIFT trial, switching to doravirine/lamivudine/tenofovir disoproxil fumarate (DOR/3TC/TDF) maintained suppression of HIV-1 through week 48. Here, we present long-term efficacy and safety outcomes through week 144 of the DRIVE-SHIFT trial.

METHODS

This phase 3, randomized, open-label trial evaluated switching from a stable antiretroviral regimen to once-daily DOR/3TC/TDF in adults with HIV-1 suppressed for ≥6 months and no previous virologic failure. Participants switched at day 1 [immediate switch group (ISG); n = 447] or week 24 [delayed switch group (DSG); n = 209]. Nine ISG participants who completed week 48 but did not enter extension-1 were excluded from week 144 efficacy analyses.

RESULTS

At week 144, HIV-1 RNA <50 copies/mL was maintained in 80.1% of the ISG (351/438) and 83.7% of the DSG (175/209), while 2.7% (12/438) and 4.8% (10/209), respectively, had HIV-1 RNA ≥50 copies/mL (Food and Drug Administration Snapshot approach). Protocol-defined virologic failure after switch occurred in 2.1% of ISG (9/438) and 3.3% of DSG (7/209); no viral resistance to doravirine was detected in 4 participants with samples available. Reductions in fasting lipids were observed at 24 weeks after switch and maintained through week 144. The mean weight change from switch to week 144 was +1.4 kg for ISG and +1.2 kg for DSG. The most common adverse events were nasopharyngitis (16.2%), headache (12.3%), and diarrhea (9.1%). Overall, 4.1% discontinued because of adverse events, and no deaths occurred.

CONCLUSIONS

These results confirm that switching to once-daily DOR/3TC/TDF is a generally well-tolerated option for maintaining viral suppression in adults considering a change in therapy.

REGISTRATION

ClinicalTrials.gov NCT02397096.

Clinical Pharmacokinetics of the Novel HIV-1 Non-Nucleoside Reverse Transcriptase Inhibitor Doravirine: An Assessment of the Effect of Patient Characteristics and Drug-Drug Interactions

Doravirine (MK-1439) is a novel non-nucleoside reverse transcriptase inhibitor indicated for the combination treatment of human immunodeficiency virus type-1 (HIV-1) infection. The recommended dose is 100 mg once daily. This review summarizes the pharmacokinetics of doravirine, the influence of intrinsic factors, and its drug-drug interaction (DDI) profile. Following oral administration, doravirine is rapidly absorbed (median time to maximum plasma concentration, 1-4 h) and undergoes cytochrome P450 (CYP)3A-mediated oxidative metabolism. Steady-state geometric means for AUC0-24, C24, and Cmax in individuals with HIV-1 following administration of doravirine 100 mg once daily are 37.8 μM·h, 930 nM, and 2260 nM, respectively. Age, gender, severe renal impairment, and moderate hepatic impairment have no clinically meaningful effect on doravirine pharmacokinetics, and there is limited potential for DDIs. No dose adjustment is necessary when doravirine is co-administered with strong CYP3A inhibitors. However, doravirine is contraindicated with strong CYP3A inducers (e.g., rifampin), and dose adjustment of doravirine is recommended for co-administration with the moderate CYP3A inducer, rifabutin. Included in this review are clinical trial data from phase I pharmacokinetic trials, including DDI trials and trials in participants with renal and hepatic disease but without HIV-1 infection (N = 326), as well as phase I, II, and III safety and efficacy trials in participants living with HIV-1 (N = 991). Based on these data, the pharmacokinetic profile of doravirine supports its use in diverse populations living with HIV-1 and allows co-administration with various antiretroviral agents and treatments for commonly occurring co-morbidities.

Doravirine dose selection and 96-week safety and efficacy versus efavirenz in antiretroviral therapy-naive adults with HIV-1 infection in a Phase IIb trial

BACKGROUND

The safety and efficacy of doravirine were compared with that of efavirenz as initial treatment of adults living with HIV-1 infection (NCT01632345).

METHODS

A Phase IIb double-blind trial with participants stratified by screening HIV-1 RNA (≤ or >100,000 copies/ml) and randomized 1:1:1:1:1 to receive once-daily doravirine (25, 50, 100 or 200 mg) or efavirenz 600 mg (Part I) for up to 96 weeks, with open-label tenofovir disoproxil fumarate 300 mg/emtricitabine 200 mg (TDF/FTC). After dose selection at week 24, doravirine 100 mg was provided to participants receiving the other doses of doravirine and additional participants were randomized 1:1 to receive once-daily doravirine 100 mg or efavirenz 600 mg for 96 weeks with TDF/FTC (Part II). Primary outcomes were the proportion of participants with HIV-1 RNA <40 copies/ml at week 24, and central nervous system (CNS) adverse events (AEs) by weeks 8 and 24 (Parts I+II combined).

RESULTS

210 and 132 participants were randomized in Parts I and II, respectively, and 216 (108 on doravirine 100 mg, 108 on efavirenz) were evaluable for Parts I+II combined. At week 24, the proportion of participants with HIV-1 RNA <40 copies/ml was 72.9% for doravirine 100 mg and 73.1% for efavirenz (difference -0.5 [95% CI -12.3, 11.2]). In addition, CNS AEs were reported by 26.9% and 47.2% of doravirine and efavirenz recipients, respectively (difference -20.4 [95% CI -32.6, -7.5]; P=0.002).

CONCLUSIONS

Doravirine 100 mg with TDF/FTC demonstrated similar antiretroviral activity and superior CNS safety compared with efavirenz 600 mg with TDF/FTC.

Pharmacokinetics, safety and tolerability of long-acting parenteral intramuscular injection formulations of doravirine

WHAT IS KNOWN AND OBJECTIVE

Doravirine is a non-nucleoside reverse transcriptase inhibitor indicated for the treatment of human immunodeficiency virus (HIV)-1 infection. This phase 1 study in healthy adults investigated the pharmacokinetics, safety and tolerability of long-acting parenteral (LAP) microsuspension formulations of doravirine administered as an intramuscular (IM) injection.

METHODS

After confirmation of tolerability and safety of oral doravirine, 36 participants were randomized 1:1:1 to receive IM doravirine 200 mg as Treatment A (1 × 1 mL, 20% [200 mg/mL] suspension), B (1 × 0.66 mL, 30% [300 mg/mL] suspension) or C (2 × 0.5 mL, 20% suspension). Blood samples were taken as venous plasma, venous dried blood spots (DBS) and fingerstick DBS.

RESULTS AND DISCUSSION

Plasma concentration-time profiles following IM treatments demonstrated rapid initial doravirine release, with initial peak ~4 days post-injection, followed by decline over the next ~6 days; a second peak was reached at ~24-36 days, corresponding to prolonged and sustained release, with measurable concentrations up to Day 183. Treatment C was associated with highest peak concentrations and shortest time to maximum concentration. Elimination half-lives for all IM formulations were prolonged versus oral administration (~46-58 days vs ~11-15 hours). Oral doravirine and IM doravirine were generally well tolerated; injection-site pain was the most common adverse event for IM doravirine. Doravirine concentrations from DBS samples showed strong correlations to venous plasma concentrations.

WHAT IS NEW AND CONCLUSIONS

Novel doravirine LAP IM injection formulations investigated in this study demonstrated sustained plasma doravirine concentrations over a course of >20 weeks.

Switching to Doravirine/Lamivudine/Tenofovir Disoproxil Fumarate (DOR/3TC/TDF) Maintains HIV-1 Virologic Suppression Through 48 Weeks: Results of the DRIVE-SHIFT Trial

BACKGROUND

Doravirine is a novel, nonnucleoside reverse transcriptase inhibitor with demonstrated efficacy in treatment-naive adults with HIV-1.

METHODS

In this open-label, active-controlled, noninferiority trial, adults with HIV-1 virologically suppressed for ≥6 months on 2 nucleoside reverse transcriptase inhibitors plus a boosted protease inhibitor, boosted elvitegravir, or a non-nucleoside reverse transcriptase inhibitor were randomized (2:1) to switch to once-daily, single-tablet doravirine 100 mg with lamivudine 300 mg and tenofovir disoproxil fumarate 300 mg (DOR/3TC/TDF) or to continue their current therapy (Baseline Regimen) for 24 weeks. The primary endpoint was the proportion of participants with HIV-1 RNA <50 copies/mL (defined by the FDA Snapshot approach), with the primary comparison between DOR/3TC/TDF at week 48 and Baseline Regimen at week 24 and a secondary comparison between the groups at week 24 (noninferiority margin, -8%).

RESULTS

Six hundred seventy participants (447 DOR/3TC/TDF, 223 Baseline Regimen) were treated and included in the analyses. At week 24, 93.7% on DOR/3TC/TDF vs 94.6% on Baseline Regimen had HIV-1 RNA <50 copies/mL [difference -0.9 (-4.7 to 3.0)]. At week 48, 90.8% on DOR/3TC/TDF had HIV-1 RNA <50 copies/mL, demonstrating noninferiority vs Baseline Regimen at week 24 [difference -3.8 (-7.9 to 0.3)]. In participants on ritonavir-boosted protease inhibitor at entry, mean reductions in fasting LDL-C and non-HDL-C at week 24 were significantly greater for DOR/3TC/TDF vs Baseline Regimen (P < 0.0001). Adverse events occurred in 68.9% on DOR/3TC/TDF and 52.5% on Baseline Regimen by week 24, leading to treatment discontinuation in 2.5% and 0.4%, respectively.

CONCLUSIONS

Switching to once-daily DOR/3TC/TDF is a generally well-tolerated option for maintaining viral suppression in patients considering a change in therapy.

REGISTRATION

ClinicalTrials.gov NCT02397096.

Clinical Pharmacodynamics, Pharmacokinetics, and Drug Interaction Profile of Doravirine

Doravirine is a novel non-nucleoside reverse transcriptase inhibitor (NNRTI) that has demonstrated good efficacy, tolerability, and safety for the treatment of patients with human immunodeficiency virus (HIV)-1 infection in phase III clinical trials. Doravirine achieved non-inferiority when compared with efavirenz- and darunavir/ritonavir-based regimens. Fewer adverse effects, including neuropsychiatric effects were observed with doravirine compared with efavirenz. Key pharmacodynamic and pharmacokinetic characteristics as well as drug-drug interactions and the resistance profile were assessed in this clinical review. Doravirine is a pyridinone NNRTI with potent antiviral activity against wild-type HIV-1 virus and common NNRTI variants. Studies in healthy volunteers and HIV-infected individuals have shown that doravirine has a favorable pharmacokinetic profile for once-daily dosing, with an elimination half-life of around 15 h, median time to maximum plasma concentrations of 1-4 h, and time to steady-state concentration of 7 days. The pharmacokinetics of doravirine are not greatly influenced by sex, age, race, or hepatic impairment. Although no dose adjustment is required for doravirine in renal impairment when given as a single tablet, the fixed-dose combination tablet of doravirine/lamivudine/tenofovir disoproxil fumarate is not recommended in patients with a creatinine clearance of < 50 mL/min. Doravirine has a low potential for drug-drug interactions and does not impact on the pharmacokinetics of other drugs. However, it is metabolized via cytochrome P450 (CYP) 3A enzymes and is thus susceptible to interactions with CYP3A inhibitors and inducers. Strong CYP3A inhibitors can significantly increase doravirine exposure; however, this is not considered to be clinically relevant. Conversely, strong CYP3A inducers, such as rifampin, are contraindicated with doravirine owing to a significant reduction in exposure with potential for impaired virological efficacy. Moderate CYP3A inducers, such as rifabutin, may be co-administered if the doravirine dose is increased to 100 mg twice daily. Doravirine has a unique resistance profile and has demonstrated in vitro activity against some of the most common, clinically relevant NNRTI-resistant mutations. Prevalence of baseline NNRTI resistance to doravirine appears to be low in treatment-naïve cohorts. Further data on the efficacy of doravirine in patients with previous treatment experience and/or transmitted NNRTI resistance are required to further inform its place in the current armamentarium of drugs for the treatment of HIV infection.

Doravirine: A Return of the NNRTI Class?

Objective: To compare and contrast doravirine (DOR) with other agents in the nonnucleoside reverse transcriptase inhibitor (NNRTI) class, review safety and efficacy data from both completed and ongoing clinical trials, and outline the potential place in therapy of DOR. Data Sources: A literature search using the PubMed database (inception to June 2019) was conducted using the search terms HIV, doravirine, non-nucleoside reverse transcriptase inhibitor, NNRTI, and MK-1439. Study Selection and Data Extraction: Clinical data were limited to those published in the English language from phase 2 or 3 clinical trials. Ongoing trials were identified through ClinicalTrials.gov. Data Synthesis: DOR was approved by the US Food and Drug Administration on the strength of 2 phase 3 randomized, double-blind, noninferiority clinical trials with additional studies currently underway examining its utility in other clinical scenarios. Relevance to Patient Care and Clinical Practice: The role of NNRTIs as part of antiretroviral (ARV) therapy has diminished in recent years given the introduction of more tolerable individual ARV agents and regimens. Despite this, new agents are still needed in the therapeutic arena because treatment failure as well as intolerance can still occur with many first-line therapies. The optimal place in therapy of DOR remains to be defined. Conclusions: DOR is a new NNRTI that represents a potential treatment option for treatment-naïve patients, without many of the previously described untoward effects of the NNRTI class.