Efficacy and safety of TMC278 in treatment-naïve, HIV-1-infected patients with HBV/HCV co-infection enrolled in the phase III ECHO and THRIVE trials

Emtricitabine/rilpivirine/tenofovir disoproxil fumarate for the treatment of HIV-1 infection in adults

This paper reviews the current literature and information on the combination drug Complera(™) (rilpivirine/emtricitabine/tenofovir disoproxil fumarate) that was approved by the Food and Drug Administration (FDA) in August 2011. PubMed, Cochrane and Embase (2001-2014) were searched for primary and review articles on rilpivirine, emtricitabine, and tenofovir disoproxil fumarate, individually or in combination. Data from drug manufacturer and product label was also used. Clinical trial reports were selected, extracted and analyzed to include relevant and recent ones. Selected English-language trials were limited to those with human subjects and included both safety and efficacy outcomes. Results from two phase 3 randomized double blind trials (ECHO and THRIVE) showed that rilpivirine is non-inferior to efavirenz in suppressing viral load below 50 copies/mL in anti-retroviral therapy (ART) naïve human immunodeficiency virus (HIV) infected patients. In addition, psychiatric disturbances, rash and increase in lipid levels occurred less frequently with rilpivirine when compared to efavirenz. However, virological failure and drug resistance were higher with rilpivirine in patients with baseline viral load >100,000 copies/mL. Rilpivirine showed cross resistance to efavirenz and etravirine. Efavirenz, on the other hand, did not demonstrate cross resistance to rilpivirine and etravirine, leaving the latter drugs as options for use in case of virological failure with efavirenz. Complera(™) remains an acceptable alternative treatment to Atripla(™) in ART naïve patients who have a pre-ART plasma HIV RNA <100,000 copies/mL and CD4 count >200 cells/mm(3) with non-inferior efficacy and better safety and tolerability.

Rilpivirine, a novel non-nucleoside reverse transcriptase inhibitor for the management of HIV-1 infection: a systematic review

Rilpivirine (RPV) is a second-generation non-nucleoside reverse transcriptase inhibitor (NNRTI). It remains active against HIV strains harbouring mutations that affect first-generation agents. RPV is dosed once daily with food and has been coformulated into a single tablet containing tenofovir and emtricitabine. Two Phase III studies of treatment-naive patients found RPV and efavirenz to have similar safety and efficacy. However, suboptimal virological suppression with RPV occurred more commonly in patients with higher baseline viral loads (>100,000 copies/ml). The most common mutation that emerged during RPV therapy was E138K, which often occurred in combination with M184I. E138K is likely to cause cross-resistance to other NNRTIs thereby limiting the further utilization of this class.

Rilpivirine versus efavirenz with tenofovir and emtricitabine in treatment-naive adults infected with HIV-1 (ECHO): a phase 3 randomised double-blind active-controlled trial

BACKGROUND

Efavirenz with tenofovir-disoproxil-fumarate and emtricitabine is a preferred antiretroviral regimen for treatment-naive patients infected with HIV-1. Rilpivirine, a new non-nucleoside reverse transcriptase inhibitor, has shown similar antiviral efficacy to efavirenz in a phase 2b trial with two nucleoside/nucleotide reverse transcriptase inhibitors. We aimed to assess the efficacy, safety, and tolerability of rilpivirine versus efavirenz, each combined with tenofovir-disoproxil-fumarate and emtricitabine.

METHODS

We did a phase 3, randomised, double-blind, double-dummy, active-controlled trial, in patients infected with HIV-1 who were treatment-naive. The patients were aged 18 years or older with a plasma viral load at screening of 5000 copies per mL or greater, and viral sensitivity to all study drugs. Our trial was done at 112 sites across 21 countries. Patients were randomly assigned by a computer-generated interactive web response system to receive either once-daily 25 mg rilpivirine or once-daily 600 mg efavirenz, each with tenofovir-disoproxil-fumarate and emtricitabine. Our primary objective was to show non-inferiority (12% margin) of rilpivirine to efavirenz in terms of the percentage of patients with confirmed response (viral load <50 copies per mL intention-to-treat time-to-loss-of-virological-response [ITT-TLOVR] algorithm) at week 48. Our primary analysis was by intention-to-treat. We also used logistic regression to adjust for baseline viral load. This trial is registered with ClinicalTrials.gov, number NCT00540449.

FINDINGS

346 patients were randomly assigned to receive rilpivirine and 344 to receive efavirenz and received at least one dose of study drug, with 287 (83%) and 285 (83%) in the respective groups having a confirmed response at week 48. The point estimate from a logistic regression model for the percentage difference in response was -0.4 (95% CI -5.9 to 5.2), confirming non-inferiority with a 12% margin (primary endpoint). The incidence of virological failures was 13% (rilpivirine) versus 6% (efavirenz; 11%vs 4% by ITT-TLOVR). Grade 2-4 adverse events (55 [16%] on rilpivirine vs 108 [31%] on efavirenz, p<0.0001), discontinuations due to adverse events (eight [2%] on rilpivirine vs 27 [8%] on efavirenz), rash, dizziness, and abnormal dreams or nightmares were more common with efavirenz. Increases in plasma lipids were significantly lower with rilpivirine.

INTERPRETATION

Rilpivirine showed non-inferior efficacy compared with efavirenz, with a higher virological-failure rate, but a more favourable safety and tolerability profile.

FUNDING

Tibotec.

Rilpivirine versus efavirenz with two background nucleoside or nucleotide reverse transcriptase inhibitors in treatment-naive adults infected with HIV-1 (THRIVE): a phase 3, randomised, non-inferiority trial

BACKGROUND

The non-nucleoside reverse transcriptase inhibitor (NNRTI), rilpivirine (TMC278; Tibotec Pharmaceuticals, County Cork, Ireland), had equivalent sustained efficacy to efavirenz in a phase 2b trial in treatment-naive patients infected with HIV-1, but fewer adverse events. We aimed to assess non-inferiority of rilpivirine to efavirenz in a phase 3 trial with common background nucleoside or nucleotide reverse transcriptase inhibitors (N[t]RTIs).

METHODS

We undertook a 96-week, phase 3, randomised, double-blind, double-dummy, non-inferiority trial in 98 hospitals or medical centres in 21 countries. We enrolled adults (≥18 years) not previously given antiretroviral therapy and with a screening plasma viral load of 5000 copies per mL or more and viral sensitivity to background N(t)RTIs. We randomly allocated patients (1:1) using a computer-generated interactive web-response system to receive oral rilpivirine 25 mg once daily or efavirenz 600 mg once daily; all patients received an investigator-selected regimen of background N(t)RTIs (tenofovir-disoproxil-fumarate plus emtricitabine, zidovudine plus lamivudine, or abacavir plus lamivudine). The primary outcome was non-inferiority (12% margin on logistic regression analysis) at 48 weeks in terms of confirmed response (viral load <50 copies per mL, defined by the intent-to-treat time to loss of virologic response [TLOVR] algorithm) in all patients who received at least one dose of study drug. This study is registered with ClinicalTrials.gov, number NCT00543725.

FINDINGS

From May 22, 2008, we screened 947 patients and enrolled 340 to each group. 86% of patients (291 of 340) who received at least one dose of rilpivirine responded, compared with 82% of patients (276 of 338) who received at least one dose of efavirenz (difference 3.5% [95% CI -1.7 to 8.8]; p(non-inferiority)<0.0001). Increases in CD4 cell counts were much the same between groups. 7% of patients (24 of 340) receiving rilpivirine had a virological failure compared with 5% of patients (18 of 338) receiving efavirenz. 4% of patients (15) in the rilpivirine group and 7% (25) in the efavirenz group discontinued treatment due to adverse events. Grade 2-4 treatment-related adverse events were less common with rilpivirine (16% [54 patients]) than they were with efavirenz (31% [104]; p<0.0001), as were rash and dizziness (p<0.0001 for both) and increases in lipid levels were significantly lower with rilpivirine than they were with efavirenz (p<0.0001).

INTERPRETATION

Despite a slightly increased incidence of virological failures, a favourable safety profile and non-inferior efficacy compared with efavirenz means that rilpivirine could be a new treatment option for treatment-naive patients infected with HIV-1.

FUNDING

Tibotec.