Katia Boven

TMC278, a Next-Generation Nonnucleoside Reverse Transcriptase Inhibitor (NNRTI), Active against Wild-Type and NNRTI-Resistant HIV-1

ABSTRACT Nonnucleoside reverse transcriptase inhibitors (NNRTIs) have proven efficacy against human immunodeficiency virus type 1 (HIV-1). However, in the setting of incomplete viral suppression, efavirenz and nevirapine select for resistant viruses. The diarylpyrimidine etravirine has demonstrated durable efficacy for patients infected with NNRTI-resistant HIV-1. A screening strategy used to test NNRTI candidates from the same series as etravirine identified TMC278 (rilpivirine). TMC278 is an NNRTI showing subnanomolar 50% effective concentrations (EC50 values) against wild-type HIV-1 group M isolates (0.07 to 1.01 nM) and nanomolar EC50 values against group O isolates (2.88 to 8.45 nM). Sensitivity to TMC278 was not affected by the presence of most single NNRTI resistance-associated mutations (RAMs), including those at positions 100, 103, 106, 138, 179, 188, 190, 221, 230, and 236. The HIV-1 site-directed mutant with Y181C was sensitive to TMC278, whereas that with K101P or Y181I/V was resistant. In vitro, considerable cross-resistance between TMC278 and etravirine was observed. Sensitivity to TMC278 was observed for 62% of efavirenz- and/or nevirapine-resistant HIV-1 recombinant clinical isolates. TMC278 inhibited viral replication at concentrations at which first-generation NNRTIs could not suppress replication. The rates of selection of TMC278-resistant strains were comparable among HIV-1 group M subtypes. NNRTI RAMs emerging in HIV-1 under selective pressure from TMC278 included combinations of V90I, L100I, K101E, V106A/I, V108I, E138G/K/Q/R, V179F/I, Y181C/I, V189I, G190E, H221Y, F227C, and M230I/L. E138R was identified as a new NNRTI RAM. These in vitro analyses demonstrate that TMC278 is a potent next-generation NNRTI, with a high genetic barrier to resistance development.

Efficacy and safety of rilpivirine (TMC278) versus efavirenz at 48 weeks in treatment-naive HIV-1-infected patients: pooled results from the phase 3 double-blind randomized ECHO and THRIVE Trials.

Background:Pooled analysis of phase 3, double-blind, double-dummy ECHO and THRIVE trials comparing rilpivirine (TMC278) and efavirenz. Methods:Treatment-naive HIV-1–infected adults were randomized 1:1 to rilpivirine 25 mg once daily or efavirenz 600 mg once daily, with background tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) (ECHO) or TDF/FTC, zidovudine/lamivudine, or abacavir/lamivudine (THRIVE). The primary endpoint was confirmed response [viral load <50 copies per milliliter; intent-to-treat time-to-loss-of-virologic-response (ITT-TLOVR) algorithm] at week 48. The pooled data set enabled analyses of subgroups and predictors of response/virologic failure. Results:Confirmed responses were 84% (rilpivirine) and 82% (efavirenz). The difference in response rates (95% confidence interval) was 2.0% (–2.0% to 6.0%). The incidence of virologic failure was 9% (rilpivirine) versus 5% (efavirenz). Responses in ITT-TLOVR and ITT-snapshot analyses were consistent. Responses were similar for rilpivirine and efavirenz by background regimen, gender, race and clade. Suboptimal adherence and higher baseline viral load resulted in lower responses, higher virologic failure, and development of resistance in both groups; the effects on virologic failure were more apparent with rilpivirine. CD4+ cell count increased over time in both groups. Rilpivirine compared with efavirenz gave smaller incidences of adverse events leading to discontinuation (3% vs. 8%, respectively), treatment-related grade 2–4 adverse events (16% vs. 31%), rash (3% vs. 14%), dizziness (8% vs. 26%), abnormal dreams/nightmares (8% vs. 13%), and grade 2−4 lipid abnormalities. Conclusions:At week 48, rilpivirine 25 mg once daily and efavirenz 600 mg once daily had comparable response rates. Rilpivirine had more virologic failures and improved tolerability versus efavirenz.

Efficacy and safety of TMC278 in antiretroviral-naive HIV-1 patients: week 96 results of a phase IIb randomized trial

Objective:TMC278 is a next-generation nonnucleoside reverse transcriptase inhibitor highly active against wild-type and nonnucleoside reverse transcriptase inhibitor-resistant HIV-1 in vitro. The week 96 analysis of TMC278-C204, a large dose-ranging study of TMC278 in treatment-naive HIV-1-infected patients, is presented. Design:Phase IIb randomized trial. Methods:Three hundred sixty-eight patients were randomized and treated with three blinded once-daily TMC278 doses 25, 75 or 150 mg, or an open-label, active control, efavirenz 600 mg once daily, all with two nucleoside reverse transcriptase inhibitors. The primary analysis was at week 48. Results:No TMC278 dose–response relationship for efficacy and safety was observed. TMC278 demonstrated potent antiviral efficacy comparable with efavirenz over 48 weeks that was sustained to week 96 (76.9–80.0% and 71.4–76.3% of TMC278-treated patients with confirmed viral load <50 copies/ml, respectively; time-to-loss of virological-response algorithm). Median increases from baseline in CD4 cell count with TMC278 at week 96 (138.0–149.0 cells/μl) were higher than at week 48 (108.0–123.0 cells/μl). All TMC278 doses were well tolerated. The incidences of the most commonly reported grade 2–4 adverse events at least possibly related to study medication, including nausea, dizziness, abnormal dreams/nightmare, dyspepsia, asthenia, rash, somnolence and vertigo, were low and lower with TMC278 than with efavirenz. Incidences of serious adverse events, grade 3 or 4 adverse events and discontinuations due to adverse events were similar among groups. Conclusion:All TMC278 doses demonstrated potent and sustained efficacy comparable with efavirenz in treatment-naive patients over 96 weeks. TMC278 was well tolerated with lower incidences of neurological and psychiatric adverse events, rash and lower lipid elevations than those with efavirenz. TMC278 25 mg once daily was selected for further clinical development.

Week 96 efficacy and safety of rilpivirine in treatment-naive, HIV-1 patients in two Phase III randomized trials.

Background:In the week 48 primary analysis of ECHO and THRIVE, rilpivirine demonstrated noninferior efficacy and more favourable tolerability versus efavirenz in treatment-naive, HIV-1-infected adults. Pooled 96-week results are presented. Methods:Patients (N = 1368) received rilpivirine 25 mg once-daily (q.d.) or efavirenz 600 mg q.d., with two background nucleoside/nucleotide reverse transcriptase inhibitors, in two randomized, double-blind, double-dummy Phase III trials. Results:At week 96, response rate (% confirmed viral load <50 copies/ml; intent-to-treat, time-to-loss-of-virologic response) was 78% in both groups. Responses were similar for both treatments by background regimen, sex, race, and in patients with more than 95% adherence (M-MASRI) or baseline viral load 100 000 copies/ml or less. Responses were lower and virologic failure higher for rilpivirine versus efavirenz in patients with 95% or less adherence or baseline viral load more than 100 000 copies/ml. Beyond week 48, the incidence of virologic failure was comparable (3 versus 2%) between treatment groups, rilpivirine resistance-associated mutations were consistent with those observed in year 1, there were few adverse events in both groups and no new safety concerns. Over 96 weeks, discontinuations due to adverse events (4 versus 9%), treatment-related grade 2–4 adverse events (17 versus 33%), rash (4 versus 15%), dizziness (8 versus 27%) and abnormal dreams/nightmares (8 versus 13%), and grade 2–4 lipid abnormalities were lower with rilpivirine than efavirenz. Only 2 and 4% of patients in the rilpivirine and efavirenz treatment groups, respectively, reported at least possibly treatment-related grade 2–4 adverse events during the second year of treatment. Conclusions:Rilpivirine 25 mg q.d. and efavirenz 600 mg q.d. had comparable responses at week 96. Rilpivirine had more virologic failures but improved tolerability versus efavirenz. The majority of virologic failures occurred in the first 48 weeks.

Impact of food and different meal types on the pharmacokinetics of rilpivirine.

The objective of the study was to determine the impact of food and different meal types on the pharmacokinetics of rilpivirine, a nonnucleoside reverse transcriptase inhibitor. In this open‐label, randomized, crossover study, healthy volunteers received a single, oral 75 mg dose of rilpivirine either with a normal‐fat breakfast (reference), under fasting conditions, with a high‐fat breakfast, or with a protein‐rich nutritional drink. Pharmacokinetic parameters were determined by non‐compartmental methods and analyzed using a linear mixed‐effects model. Safety was assessed throughout. The least‐squares mean ratio for area under the plasma concentration–time curve to last timepoint was 0.57 (90% confidence interval [CI]: 0.46–0.72) under fasting conditions compared to dosing with a normal‐fat breakfast. With a high‐fat breakfast or only a protein‐rich nutritional drink, the corresponding values were 0.92 (90% CI: 0.80–1.07) and 0.50 (90% CI: 0.41–0.61), respectively, compared to dosing with a normal‐fat breakfast. Under all conditions, rilpivirine was generally safe and well tolerated. Administration of rilpivirine under fasting conditions or with only a protein‐rich nutritional drink substantially lowered the oral bioavailability when compared to administration with a normal‐fat breakfast. Rilpivirine bioavailability was similar when administered with a high‐fat or normal‐fat breakfast. Rilpivirine should always be taken with a meal to ensure adequate bioavailability.

96-Week resistance analyses of rilpivirine in treatment-naive, HIV-1-infected adults from the ECHO and THRIVE Phase III trials.

BACKGROUND In the ECHO/THRIVE 96-week efficacy analysis, the response rate was 78% with rilpivirine (RPV) and efavirenz (EFV) plus two nucleoside/nucleotide reverse transcriptase inhibitors. METHODS For resistance analyses, virological failures (VFs) were genotyped and/or phenotyped at baseline and failure. RESULTS In the overall 96-week resistance analyses, the proportion of VFs was higher with RPV (96/686, 14%) versus EFV (52/682, 8%), but similar within weeks 48-96 (22/686, 3% versus 16/682, 2%). In genotyped VFs, treatment-emergent non-nucleoside reverse transcriptase inhibitor (NNRTI) resistance-associated mutations (RAMs) were as common with RPV (46/86, 53%) versus EFV (20/42, 48%), but nucleoside/nucleotide reverse transcriptase inhibitor RAMs were more common with RPV (48/86, 56%) than EFV (11/42, 26%). In RPV VFs, E138K+M184I remained the most frequent combination. Among RPV VFs with phenotypic RPV resistance, cross-resistance was observed with nevirapine (16/35, 46%), EFV (30/35, 86%) and etravirine (32/35, 91%). Among patients with baseline viral load (VL)≤100,000 copies/ml, there were fewer VFs (RPV: 28/368, 8%; EFV: 20/329, 6%), fewer VFs with treatment-emergent NNRTI RAMs (RPV: 10/27, 37%; EFV: 6/17, 35%), and less phenotypic resistance to RPV and other NNRTIs, than in patients with baseline VL>100,000 copies/ml (VFs: 68/318, 21% [RPV], 32/353, 9% [EFV]; NNRTI RAMs: 36/59, 61% [RPV], 14/32, 56% [EFV]). Among RPV VFs with baseline VL≤100,000 copies/ml observed within weeks 48-96, only 1/7 had phenotypic resistance to RPV. CONCLUSIONS During the second year of treatment in ECHO/THRIVE, few VFs with emerging NNRTI RAMs (no new RPV RAMs) occurred.

Pre-existing mutations in the rilpivirine Phase III trials ECHO and THRIVE: prevalence and impact on virological response.

BACKGROUND Rilpivirine (RPV), a non-nucleoside reverse transcriptase inhibitor (NNRTI), was approved for HIV-1 infected, antiretroviral treatment-naive adults based on data from two Phase III trials. In the screening population, the prevalence of 49 NNRTI resistance-associated mutations (RAMs) and the impact of allowed NNRTI RAMs on virological response to an RPV- or efavirenz (EFV)-containing regimen were analysed. METHODS ECHO and THRIVE were global, Phase III, doubleblind, double-dummy, randomized trials in antiretroviral treatment-naive, HIV-1-infected adults to determine whether RPV 25 mg once daily had non-inferior efficacy versus EFV 600 mg once daily, both given with tenofovir/emtricitabine (ECHO) or tenofovir/emtricitabine, zidovudine/lamivudine or abacavir/lamivudine (THRIVE). The prevalence of 49 NNRTI RAMs, including the predefined list of 39 NNRTI RAMs used to exclude patients with potential resistance to RPV or EFV, was investigated at screening by population sequencing (including mixtures) using the virco(®)TYPE HIV-1 genotyping assay. RESULTS Of the 1,796 screened patients in whom genotypic resistance results were available, 372 (21%) had NNRTI RAMs. Of 527 screening failures, 148 (28%) were due to the presence of NNRTI RAMs. The presence of allowed NNRTI RAMs was associated with comparable response rates to the overall population (RPV 84.3% versus EFV 82.3%, intent-to-treat time-to-loss-of-virological-response): V90I (82.4% and 100% for RPV and EFV, respectively), V106I (85.7% and 93.3%), V179I (87.7% and 94.0%) and V189I (100.0% and 88.9%). CONCLUSIONS Analysis of the ECHO and THRIVE screened population suggests that transmitted NNRTI resistance is prevalent in treatment-naive patients but prevalence of the 15 RPV RAMs remains low. The four allowed NNRTI RAMs present at baseline did not affect RPV response at week 48.

Change in vitamin D levels and risk of severe vitamin D deficiency over 48 weeks among HIV-1-infected, treatment-naive adults receiving rilpivirine or efavirenz in a Phase III trial (ECHO).

BACKGROUND This analysis assessed changes in serum 25-hydroxyvitamin D (25[OH]D; the precursor form of active vitamin D) in antiretroviral-naive adults receiving rilpivirine or efavirenz over 48 weeks in a randomized, double-blind, Phase III trial (ECHO). METHODS ECHO included 690 patients randomized 1:1 to receive rilpivirine 25 mg once daily (n=346) or efavirenz 600 mg once daily (n=344), plus tenofovir disoproxil fumarate/emtricitabine. 25(OH)D was measured in stored serum samples collected at baseline, and weeks 24 and 48. Proportions of patients with optimal/sufficient (≥30 ng/ml), insufficient (21-29 ng/ml), deficient (10-20 ng/ml) and severely deficient (<10 ng/ml) 25(OH)D levels were determined. Data are presented for patients with paired baseline and week 48 25(OH)D data (rilpivirine, n=292; efavirenz, n=290). RESULTS After 48 weeks, mean 25(OH)D levels remained largely unchanged from baseline with rilpivirine (-0.2 ng/ml; P=0.57 versus no change), but were significantly reduced with efavirenz (-2.5 ng/ml; P<0.0001 versus no change). When adjusting for season of randomization and the combined variable of race (Black/African American, White/Caucasian, Asian, other race) and ethnicity (Hispanic or Latino and not Hispanic or not Latino), the conclusion about the treatment difference between the rilpivirine and efavirenz treatment groups remained valid. At baseline the proportion of patients with severe 25(OH)D deficiency was similar in both groups (5%) but was significantly lower with rilpivirine than efavirenz at week 48 (5% versus 9%, respectively; P=0.032). Furthermore, of the patients with 25(OH)D insufficiency/deficiency at baseline, the proportion who developed severe 25(OH)D deficiency at week 48 was significantly lower with rilpivirine than efavirenz (2% versus 8%, respectively; P=0.0079). CONCLUSIONS Rilpivirine had little effect on 25(OH)D, whereas efavirenz resulted in a significant reduction in 25(OH)D levels and an increase in the risk of severe 25(OH)D deficiency.

Long-Term Efficacy, Safety and Tolerability of TMC278 in HIV-1-Infected Antiretroviral-Naïve Patients: Week 192 Results from a Phase IIb Randomized Trial

TMC278-C204 (NCT00110305), a 96-week trial of the nonnucleoside reverse transcription inhibitor (NNRTI) rilpivirine (RPV, TMC278) in 368 HIV-1-infected, treatment-naive patients, was extended to investigate long-term safety and efficacy. Week 192 analysis results are presented. This was a long-term follow-up of a Phase IIb, randomized trial. No significant RPV dose-response relationships with respect to the primary endpoint (composite ITT-TLOVR algorithm) were observed at week 48 or 96. All RPV-treated patients were switched to open-label 75 mg qd at week 96 and then to 25 mg qd, the Phase III dose, at approximately week 144 as it gave the best benefit-risk balance. All control patients continued receiving open-label efavirenz (EFV) 600 mg qd. At week 192, 59% of RPV- and 61% of EFV-treated patients maintained confirmed viral load <50 copies/ml (ITT-TLOVR algorithm). The mean changes from baseline in CD4 cell count were similar in both groups (RPV: 210 cells/mm(3) vs. EFV: 225 cells/mm(3)). No new safety concerns were noted between week 48 and 192. In the week 192 analysis, RPV compared with EFV was associated with a lower overall incidence of grade 2-4 adverse events (AEs) at least possibly related to treatment, including rash (p<0.001) and neurologic AEs (p<0.05 Fishers exact test, post hoc analyses) Incidences of serious AEs, grade 3 or 4 AEs, and discontinuations due to AEs were similar across groups. Increases in total cholesterol, LDL-cholesterol, HDL-cholesterol, and triglycerides were significantly lower with RPV than with EFV. RPV continued to show sustained efficacy similar to EFV at week 192 with a generally more favorable safety profile.