Prevalence of TMC278 (rilpivirine) associated mutations in the Frankfurt Resistance Database

Rilpivirine resistance and the dangerous liaisons with substitutions at position 184 among patients infected with HIV-1: analysis from a national drug-resistance database (ARCA)

Rilpivirine (RPV) is a novel NNRTI with a mutational pattern different from first-generation drugs of the same class: 16 resistance-associated mutations (RAM) are listed, but the combination E138K + M184I seems to be the most important. Aims of the present study were to evaluate the prevalence of these RAMs in Italian HIV-1 infected patients and to assess if previous drug history could represent a risk to develop RPV-related RAMs. The analysis was performed using the ARCA database, which contains data on resistance and therapy from subjects throughout Italy. Prevalence of RPV-associated and first-generation NNRTI-associated RAMs was evaluated. Linear regression model, odds ratio and 95% Confidence Interval were used to assess factors associated with the development of RPV RAMs, substitutions at position 184 and their combinations. A total of 8,067 tests were selected within the database. In Italian HIV-positive HAART-naïve patients, prevalence of the main RAMs for RPV is low except for E138A (present in 5.1% of subjects). The combination E138K + M184I is absent in both naïve and experienced subjects. A previous exposure to NVP might increase the risk to develop RPV-associated RAMs. TDF, EFV, and possibly FTC may predispose to the selection for M184I. Among Italian patients the susceptibility to RPV is widespread since some severe substitutions (e.g., E138K are rare), whereas issues exist for others (i.e., E138A, Y181C) which are more frequent. Appropriate use of RPV within a therapeutic sequencing might be controversial.

Transmitted drug resistance to rilpivirine among antiretroviral-naïve patients living with HIV from northern Poland

Introduction

Rilpivirine (RPV) is a second-generation non-nucleoside reverse transcriptase inhibitor (NNRTI) that was recently approved for the treatment of antiretroviral-naïve individuals with HIV-1 viral load of <100,000 copies/ml. As transmission of the drug resistance mutations to this NNRTI may affect treatment outcomes, the frequency of primary, RPV-associated drug resistance mutations was assessed in this study.

Methods

For the study, 244 viral genome sequences from antiretroviral-naïve individuals were obtained by bulk sequencing. RPV-associated mutations were divided into RPV resistance mutations (K101E/P, E138A/G/K/Q/R, V179L, Y181C/I/V, Y188L, H221Y, F227C and M230I/L) according to the International AIDS Society-USA (IAS-USA) mutation list and variants potentially affecting RPV susceptibility (L100I, K101H/T, E138S, V179F/D/G/T, G190A/E/S, F227L and M230V) based on the in vitro and in vivo data.

Results

IAS-USA RPV drug resistance mutations were found in 5.3% sequences, with E138A and E138G being the most common (3.7 and 0.8%, respectively), followed by K101E (0.4%) and Y181C (0.4%), with no significant differences in the frequency between subtype B and non-B clades. Mutations potentially reducing RPV susceptibility were found in 2.5% of sequences, and they included V179D (1.6%) and G190A (0.8%), with equal distribution among non-B (n=2, 2.5%) and subtype B (n=4, 2.5%) clades. Clustering of RPV mutations was infrequent.

Conclusions

Prevalence of RPV-associated drug resistance mutations was low in the analysed sample and did not vary across the subtypes. The frequency of variants with potential influence on RPV susceptibility was similar among non-B variants if compared to B clades. Transmitted drug resistance to RPV is uncommon, which makes this a good option for the treatment of ARV-naïve patients; however, genotype resistance testing should remain compulsory before starting an RPV-based regimen.

Prevalence in the USA of rilpivirine resistance-associated mutations in clinical samples and effects on phenotypic susceptibility to rilpivirine and etravirine

BACKGROUND

The prevalence of rilpivirine resistance-associated mutations (RAMs) in the USA, and their effect on phenotypic susceptibility to rilpivirine and etravirine, was evaluated in clinical samples from HIV-1-infected patients.

METHODS

In total, 15,991 samples submitted to Monogram Biosciences (South San Francisco, CA, USA) for routine resistance testing between January 2010 and June 2011 were assessed for the presence of known rilpivirine RAMs K101E/P, E138A/G/K/Q/R, V179L, Y181C/I/V, Y188L, H221Y, F227C and M230I/L; non-nucleoside reverse transcriptase inhibitor (NNRTI) RAMs K103N, L100I and L100I+K103N; and the nucleoside reverse transcriptase inhibitor (NRTI) RAMs M184I/V and their combinations with rilpivirine RAMs. Phenotypic susceptibility (PhenoSenseGT(®) assay; Monogram Biosciences) was evaluated, with reduced susceptibility defined as fold change (FC) in 50% inhibitory concentration (IC50)>2.0 for rilpivirine and FC>2.9 for etravirine.

RESULTS

Of the 15,991 samples, 17% harboured ≥1 rilpivirine RAMs. The prevalence of most rilpivirine RAMs and combinations of NNRTI RAMs of interest was low (≤3%), except for Y181C (7%). Rilpivirine RAMs were often associated with reduced rilpivirine phenotypic susceptibility. Median FC values >2.0 were observed for clinical isolates with rilpivirine RAMs K101P, E138Q/R, Y181C/I/V, Y188L or M230L, and for the combination of E138K with M184I/V, and K101E with M184I. Most rilpivirine FC values >2.0 were associated with etravirine FC values >2.9 for individual rilpivirine RAMs and those combined with M184I/V. There was no relationship between the presence of K103N and rilpivirine FC. However, the L100I+K103N combination (without rilpivirine RAMs), at <2% prevalence, was associated with a rilpivirine FC>2.0.

CONCLUSIONS

Based on 15,991 US clinical samples from HIV-1-infected patients, the frequency of most known rilpivirine RAMs apart from Y181C was low.

Rilpivirine resistance mutations in HIV patients failing non-nucleoside reverse transcriptase inhibitor-based therapies

OBJECTIVE

Rilpivirine (RPV) is the latest approved nonnucleoside reverse transcriptase inhibitor (NNRTI). It displays in-vitro activity extending over other NNRTI-resistant HIV strains. There is scarce information about the rate of RPV resistance-associated mutations (RAMs) in patients failing other NNRTIs.

METHODS

RPV RAMs were examined in plasma samples collected from HIV patients that had recently failed NNRTI-based regimens at 22 clinics in Spain.

RESULTS

Resistance tests from a total of 1064 patients failing efavirenz (EFV) (54.5%), nevirapine (NVP) (40%) or etravirine (ETR) (5.5%) were examined. The prevalence of RPV RAMs was K101E (9.1%), K101P (1.4%), E138A (3.9%), E138G (0.3%), E138K (0.3%), E138Q (0.8%), V179L (0.2%), Y181C (21.8%), Y181I (0.5%), Y181V (0.2%), H221Y (8.3%), F227C (0.1%) and M230L (1.5%). K101E/M184I was seen in 1%. E138K/M184I were absent. Mutations L100I and V108I were significantly more frequent in patients failing EFV than NVP (7.9 vs. 0.2 and 12.2 vs. 7.3%, respectively). Conversely, Y181C, Y181I, V106A, H221Y and F227L were more prevalent following NVP than EFV failures. Using the Spanish resistance interpretation algorithm, 206 genotypes (19.3%) from patients failing NNRTI (NVP 52%, EFV 40.8% and ETR 7.8%) were considered as RPV resistant. In patients with ETR failure, cross-resistance to RPV was seen in 27.6%, mainly as result of Y181C (81.3%), V179I (43.8%), V90I (31.3%) and V108I (18.8%).

CONCLUSION

RPV resistance is overall recognized in nearly 20% of patients failing other NNRTIs. It is more common following ETR (27.6%) or NVP (25%) failures than EFV (14.5%). E138 mutants are rarely seen in this context.