Goedele De Smedt

Efficacy and safety of TMC125 (etravirine) in treatment-experienced HIV-1-infected patients in DUET-2: 24-week results from a randomised, double-blind, placebo-controlled trial

BACKGROUND TMC125 (etravirine) is a non-nucleoside reverse-transcriptase inhibitor (NNRTI) with activity against NNRTI-resistant HIV-1 in phase IIb trials. The aim of DUET-2 is to examine the efficacy, tolerability, and safety of TMC125 in treatment-experienced patients. METHODS In this continuing randomised, double-blind, placebo-controlled, phase III trial, HIV-1-infected patients on failing antiretroviral therapy with evidence of resistance to currently available NNRTIs and at least three primary protease inhibitor mutations were eligible for enrolment if on stable (8 weeks unchanged) antiretroviral therapy with plasma HIV-1 RNA greater than 5000 copies per mL. Patients were randomly assigned to receive either TMC125 (200 mg) or placebo, each given twice daily with darunavir-ritonavir, investigator-selected nucleoside/nucleotide reverse transcriptase inhibitors, and optional enfuvirtide. The primary endpoint was the proportion of patients with confirmed viral load below 50 copies per mL at week 24 (FDA time-to-loss of virological response algorithm). Analyses were by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00255099. FINDINGS 591 patients were randomised and treated (295 patients in the TMC125 group and 296 in the placebo group). By week 24, 51 (17%) patients in the TMC125 group and 73 (25%) in the placebo group had discontinued, mainly because of virological failure. 183 (62%) patients in the TMC125 group and 129 (44%) in the placebo group achieved confirmed viral load below 50 copies per mL at week 24 (difference 18%, 95% CI 11-26; p=0.0003). The type and frequency of adverse events were much the same in the two groups. INTERPRETATION In treatment-experienced patients, treatment with TMC125 led to better virological suppression at week 24 than did placebo. The safety and tolerability profile of TMC125 was generally comparable with placebo.

Once-daily simeprevir (TMC435) with pegylated interferon and ribavirin in treatment-naïve genotype 1 hepatitis C: The randomized PILLAR study

The phase IIb, double‐blind, placebo‐controlled PILLAR trial investigated the efficacy and safety of two different simeprevir (SMV) doses administered once‐daily (QD) with pegylated interferon (Peg‐IFN)‐α‐2a and ribavirin (RBV) in treatment‐naïve patients with HCV genotype 1 infection. Patients were randomized to one of five treatments: SMV (75 or 150 mg QD) for 12 or 24 weeks or placebo, plus Peg‐IFN and RBV. Patients in the SMV arms stopped all treatment at week 24 if response‐guided therapy (RGT) criteria were met; patients not meeting RGT continued with Peg‐IFN and RBV until week 48, as did patients in the placebo control group. Sustained virologic response (SVR) rates measured 24 weeks after the planned end of treatment (SVR24) were 74.7%‐86.1% in the SMV groups versus 64.9% in the control group (P < 0.05 for all comparisons [SMV versus placebo], except SMV 75 mg for 24 weeks). Rapid virologic response (HCV RNA <25 IU/mL undetectable at week 4) was achieved by 68.0%‐75.6% of SMV‐treated and 5.2% of placebo control patients. According to RGT criteria, 79.2%‐86.1% of SMV‐treated patients completed treatment by week 24; 85.2%‐95.6% of these subsequently achieved SVR24. The adverse event profile was generally similar across the SMV and placebo control groups, with the exception of mild reversible hyperbilirubinemia, without serum aminotransferase abnormalities, associated with higher doses of SMV. Conclusion: SMV QD in combination with Peg‐IFN and RBV significantly improves SVR rates, compared with Peg‐IFN and RBV alone, and allows the majority of patients to shorten their therapy duration to 24 weeks. (Hepatology 2013; 58:1918–1929)

Simeprevir Increases Rate of Sustained Virologic Response Among Treatment-Experienced Patients With HCV Genotype-1 Infection: A Phase IIb Trial

BACKGROUND & AIMS Simeprevir (TMC435) is an oral NS3/4 protease inhibitor in phase III trials for chronic hepatitis C virus (HCV) infection. We performed a phase IIb, randomized, double-blind, placebo-controlled trial to evaluate the efficacy and safety of the combination of simeprevir, peginterferon-α2a (PegIFN), and ribavirin (RBV) in patients with HCV genotype-1 infection previously treated with PegIFN and RBV. METHODS We analyzed data from patients who did not respond (null response), had a partial response, or relapsed after treatment with PegIFN and RBV, randomly assigned to receive simeprevir (100 or 150 mg, once daily) for 12, 24, or 48 weeks plus PegIFN and RBV for 48 weeks (n = 396), or placebo plus PegIFN and RBV for 48 weeks (n = 66). All patients were followed for 24 weeks after planned end of treatment; the primary end point was the proportion of patients with sustained virologic response (SVR; undetectable HCV RNA) at that time point. RESULTS Overall, rates of SVR at 24 weeks were significantly higher in the groups given simeprevir than those given placebo (61%-80% vs 23%; P < .001), regardless of prior response to PegIFN and RBV (simeprevir vs placebo: prior null response, 38%-59% vs 19%; prior partial response, 48%-86% vs 9%; prior relapse, 77%-89% vs 37%). All groups had comparable numbers of adverse events; these led to discontinuation of simeprevir or placebo and/or PegIFN and RBV in 8.8% of patients given simeprevir and 4.5% of those given placebo. CONCLUSIONS In treatment-experienced patients, 12, 24, or 48 weeks simeprevir (100 mg or 150 mg once daily) in combination with 48 weeks PegIFN and RBV significantly increased rates of SVR at 24 weeks compared with patients given placebo, PegIFN, and RBV and was generally well tolerated. ClinicalTrials.gov number: NCT00980330.

Efficacy and safety of etravirine in treatment-experienced, HIV-1 patients: pooled 48 week analysis of two randomized, controlled trials.

Objective:To evaluate the efficacy, safety and virologic resistance profile of etravirine (TMC125), a next-generation nonnucleoside reverse transcriptase inhibitor, over 48 weeks in treatment-experienced adults infected with HIV-1 strains resistant to a nonnucleoside reverse transcriptase inhibitor and other antiretrovirals. Design:DUET-1 (NCT00254046) and DUET-2 (NCT00255099) are two identically designed, randomized, double-blind phase III trials. Methods:Patients received twice-daily etravirine 200 mg or placebo, each plus a background regimen of darunavir/ritonavir, investigator-selected nucleoside/nucleotide reverse transcriptase inhibitors and optional enfuvirtide. Eligible patients had documented nonnucleoside reverse transcriptase inhibitor resistance, at least three primary protease inhibitor mutations at screening and were on a stable but virologically failing regimen for at least 8 weeks, with plasma viral load more than 5000 copies/ml. Pooled 48-week data from the two trials are presented. Results:Patients (1203) were randomized and treated (n = 599, etravirine; n = 604, placebo). Significantly more patients in the etravirine than in the placebo group achieved viral load less than 50 copies/ml at week 48 (61 vs. 40%, respectively; P < 0.0001). Significantly fewer patients in the etravirine group experienced at least one confirmed or probable AIDS-defining illness/death (6 vs. 10%; P = 0.0408). Safety and tolerability in the etravirine group was comparable to the placebo group. Rash was the only adverse event to occur at a significantly higher incidence in the etravirine group (19 vs. 11%, respectively, P < 0.0001), occurring primarily in the second week of treatment. Conclusion:At 48 weeks, treatment-experienced patients receiving etravirine plus background regimen had statistically superior and durable virologic responses (viral load less than 50 copies/ml) than those receiving placebo plus background regimen, with comparable tolerability and no new safety signals reported since week 24.

Resistance profile of etravirine: combined analysis of baseline genotypic and phenotypic data from the randomized, controlled Phase III clinical studies.

Objective:To refine the genotypic and phenotypic correlates of response to the nonnucleoside reverse transcriptase inhibitor etravirine. Design:Initial analyses identified 13 etravirine resistance-associated mutations (RAMs) and clinical cutoffs (CCOs) for etravirine. A multivariate analysis was performed to refine the initial etravirine RAM list and improve the predictive value of genotypic resistance testing with regard to virologic response and relationship to phenotypic data. Methods:Week 24 data were pooled from the phase III studies with TMC125 to Demonstrate Undetectable viral load in patients Experienced with ARV Therapy (DUET). The effect of baseline resistance to etravirine on virologic response (<50 HIV-1 RNA copies/ml) was studied in patients not using de-novo enfuvirtide and excluding discontinuations for reasons other than virologic failure (n = 406). Clinical cutoffs for etravirine were established by analysis of covariance models and sliding fold change in 50% effective concentration (EC50) windows (Antivirogram; Virco BVBA, Mechelen, Belgium). Etravirine RAMs were identified as those associated with decreased virologic response/increased etravirine fold change in EC50. Relative weight factors were assigned to the etravirine RAMs using random forest and linear modeling techniques. Results:Baseline etravirine fold change in EC50 predicted virologic response at week 24, with lower and preliminary upper clinical cutoffs of 3.0 and 13.0, respectively. A fold change in EC50 value above which etravirine provided little or no additional efficacy benefit could not be established. Seventeen etravirine RAMs were identified and attributed a relative weight factor accounting for the differential impact on etravirine fold change in EC50. Virologic response was a function of etravirine-weighted genotypic score. Conclusion:The weighted genotypic scoring algorithm optimizes resistance interpretations for etravirine and guides treatment decisions regarding its use in treatment-experienced patients.

Antiviral activity of TMC435 monotherapy in patients infected with HCV genotypes 2-6: TMC435-C202, a phase IIa, open-label study

BACKGROUND & AIMS TMC435 is an investigational, once-daily, oral NS3/4A protease inhibitor currently in phase III development for the treatment of hepatitis C virus (HCV) infection. Phase I and II studies in patients infected with HCV genotype 1 have demonstrated that TMC435 is generally well tolerated, has a pharmacokinetic profile that supports once daily dosing, and demonstrates potent antiviral activity. This phase IIa study (TMC435-C202; NCT00812331) was conducted to investigate the antiviral activity, safety, tolerability, and pharmacokinetics of TMC435 in treatment-naїve patients infected with HCV genotypes 2-6. METHODS The study consisted of 7 days of monotherapy with TMC435 (200mg once daily). Patients could begin treatment with pegylated interferon/ribavirin from day 8 with a follow-up period up to days 37-42. RESULTS Thirty-seven patients were enrolled in Germany, Belgium and Thailand. For the primary end point at day 8, the mean (± standard error) change in plasma HCV ribonucleic acid (log(10)IU/ml) from baseline was the greatest for genotypes 6 (-4.35 ± 0.29) and 4 (-3.52 ± 0.43), followed by genotypes 2 (-2.73 ± 0.71) and 5 (-2.19 ± 0.39). No antiviral activity was evident for genotype 3. Viral breakthrough occurred in six patients during the monotherapy phase and in six additional patients during PegIFN/RBV-only period. All adverse events were mild or moderate and there were no discontinuations during the TMC435 monotherapy period. CONCLUSIONS The results of this phase IIa proof-of-concept trial provide evidence that TMC435 has a spectrum of activity against multiple HCV genotypes, except for genotype 3. In this study, TMC435 was generally safe and well tolerated.

Clinical Pharmacokinetics and Pharmacodynamics of Etravirine

Etravirine is a next-generation non-nucleoside reverse transcriptase inhibitor (NNRTI) developed for the treatment of HIV-1 infection. It has a high genetic barrier to the emergence of viral resistance, and maintains its antiviral activity in the presence of common NNRTI mutations. The pharmacokinetics of etravirine in HIV-infected patients at the recommended dosage of 200 mg twice daily demonstrates moderate intersubject variability and no time dependency. Due to substantially lower exposures when taken on an empty stomach, etravirine should be administered following a meal. The drug is highly protein bound (99.9%) to albumin and α1-acid glycoprotein and shows a relatively long elimination half-life of 30–40 hours. Etravirine is metabolized by cytochrome P450 (CYP) 3A, 2C9 and 2C19; the metabolites are subsequently glucuronidated by uridine diphosphate glucuronosyltransferase. Renal elimination of etravirine is negligible. Etravirine has the potential for interactions by inducing CYP3A and inhibiting CYP2C9 and 2C19; it is a mild inhibitor of P-glycoprotein but not a substrate. The drug interaction profile of etravirine has been well characterized and is manageable. No dosage adjustments are needed in patients with renal impairment or mild to moderate hepatic impairment. Race, sex, bodyweight and age do not affect the pharmacokinetics of etravirine. In the two phase III trials DUET-1 and DUET-2, no relationship was demonstrated between the pharmacokinetics of etravirine and the primary efficacy endpoint of viral load below 50 copies/mL or the safety profile of etravirine.

Virologic response and characterisation of HCV genotype 2-6 in patients receiving TMC435 monotherapy (study TMC435-C202).

BACKGROUND & AIMS TMC435 is a potent, once-daily, investigational hepatitis C virus (HCV) NS3/4A protease inhibitor in phase III clinical development. In the phase II trial TMC435-C202 (NCT00812331), TMC435 displayed potent activity in genotype 4, 5 and 6 patients and in 3/6 genotype 2 patients, whereas no activity was observed with genotype 3. METHODS Thirty-seven patients received TMC435 monotherapy (200 mg once daily) for 7 days. HCV RNA, NS3 protease sequences and the corresponding phenotypes were evaluated. RESULTS Genotype and isolate-specific baseline polymorphisms at NS3 positions known to affect HCV protease inhibitor activity were present in all genotypes. Consistent with the antiviral activity observed in genotypes 4 and 6, TMC435 was active in vitro against all genotype 4 isolates, and against most genotype 6 polymorphisms when tested as single or double mutants. In contrast, in genotype 3 where no HCV RNA decline was observed, isolates displayed >700-fold increases in EC(50) attributed to the D168Q polymorphism. In genotypes 2 and 5, HCV RNA changes from baseline to Day 3 ranged between -0.3 to -3.6 and -1.5 to -4.0 log(10)IU/ml, respectively, and isolates or site-directed mutants displayed intermediate in vitro susceptibility to TMC435 with fold changes in EC(50) between 15 and 78. Viral breakthrough in genotypes 4-6 was associated with emerging mutations including Q80R, R155K and/or D168E/V. CONCLUSIONS Sequence and phenotypic analyses of baseline isolates identified polymorphisms which could explain the differences in antiviral activity between genotypes. Pathways of TMC435 resistance in genotypes 2-6 were similar to those identified in genotype 1.

A pharmacokinetic study of etravirine (TMC125) co-administered with ranitidine and omeprazole in HIV–negative volunteers

AIMS Etravirine is a next-generation non-nucleoside reverse transcriptase inhibitor (NNRTI) with activity against wild-type and NNRTI-resistant HIV. Proton pump inhibitors and H(2)-antagonists are frequently used in the HIV-negative-infected population, and drug-drug interactions have been described with other antiretrovirals. This study evaluated the effect of steady-state omeprazole and ranitidine on the pharmacokinetics of a single dose of etravirine. METHODS In an open-label, randomized, one-way, three-period crossover trial, HIV-negative volunteers randomly received a single dose of 100 mg etravirine alone (treatment A); 11 days of 150 mg ranitidine b.i.d. (treatment B); and 11 days of 40 mg omeprazole q.d. (treatment C). A single dose of 100 mg etravirine was co-administered on day 8 of sessions 2 and 3. Each session was separated by a 14-day wash-out. RESULTS Nineteen volunteers (seven female) participated. When a single dose of etravirine was administered in the presence of steady-state ranitidine, etravirine least squares means ratios (90% confidence interval) for AUC(last) and C(max) were 0.86 (0.76, 0.97) and 0.94 (0.75, 1.17), respectively, compared with administration of etravirine alone. When administered with steady-state omeprazole, these values were 1.41 (1.22, 1.62) and 1.17 (0.96, 1.43), respectively. Co-administration of a single dose of etravirine and ranitidine or omeprazole was generally safe and well tolerated. CONCLUSIONS Ranitidine slightly decreased etravirine exposure, whereas omeprazole increased it by approximately 41%. The increased exposure of etravirine when co-administered with omeprazole is attributed to CYP2C19 inhibition. Considering the favourable safety profile of etravirine, these changes are not clinically relevant. Etravirine can be co-administered with proton pump inhibitors and H(2) antagonists without dose adjustments.

Pharmacokinetic and pharmacodynamic study of the concomitant administration of methadone and TMC125 in HIV-negative volunteers.

TMC125 is a nonnucleoside reverse transcriptase inhibitor (NNRTI) with potent in vitro activity against wild–type and NNRTI‐resistant HIV‐1. TMC125 is an inducer of CYP3A and an inhibitor of CYP2C. This trial evaluated the effect of TMC125 on the pharmacokinetics and pharmacodynamics of methadone. In an open‐label, add‐on, 1‐way interaction trial, 16 male HIV‐negative volunteers on stable methadone maintenance therapy received 100 mg TMC125 bid for 14 days. Plasma concentrations and pharmacokinetic parameters of R‐ and S‐methadone isomers were determined on days −1, 7, and 14 and of TMC125 on days 7 and 14. Safety and tolerability were assessed. The LSmeans ratios (90% confidence interval) for AUC24h, Cmax, and Cmin of the pharmacologically active R‐methadone were 1.08 (1.02–1.13), 1.03 (0.97–1.09), and 1.12 (1.05–1.19), respectively, on day 7 and 1.06 (0.99–1.13), 1.02 (0.96–1.09), and 1.10 (1.02–1.19), respectively, on day 14 compared with methadone alone. No withdrawal symptoms were observed; dose adjustment of methadone was not required. The concomitant administration of TMC125 and methadone was generally safe and well tolerated. TMC125 has no clinically relevant effect on the pharmacokinetics or pharmacodynamics of methadone. No dose adjustment for methadone is anticipated when coadministered with TMC125.