In silico design, synthesis and anti-HIV activity of quinoline derivatives as non-nucleoside reverse transcriptase inhibitors (NNRTIs).

A series of quinoline derivatives has been designed, synthesized and screened for their anti-HIV properties. The drug-like properties of compounds were evaluated first and then molecular docking using DS v20.1.0.19295 software showed that the compounds behaved as non-nucleoside reverse transcriptase inhibitors (NNRTIs) while interacting at the allosteric site of target HIV-RT protein (PDB:3MEC). The docking results revealed that all compounds formed hydrogen bonds with Lys101, Lys103, Val179, Tyr188, Gln190, Gly190, Pro225, Phe227, and Tyr318, and showed π-interaction with Tyr188 and Tyr318. TOPKAT (Toxicity Prediction by Komputer Assisted Technology) results confirmed that the compounds were found to be less toxic than the reference drugs. Density functional theory (DFT) analysis was performed to assess the binding affinity of all compounds. Further, molecular dynamics (MD) simulations were performed on compound 6 and delavirdine with HIV-RT enzyme. Comprehensive MD analyses showed a similar pattern of conformational stability and flexibility in both the complexes suggesting alike inhibitory action. The hydrogen-bonding interactions and the binding energy of active-site residues for the compound 6 complex revealed strong inhibitory activity than the reference (delavirdine) complex. Thus, the compound 6 might act as a potential inhibitor against HIV-RT. Overall, this study revealed that compound 6 (5-hydroxy-N-(4-methyl-2-oxo-1,2-dihydroquinolin-8-yl) thiophene-2-sulfonamide) has prudent anti-HIV activity against both HIV-1 (SI = 2.65) and HIV-2 (SI = 2.32) that can further be utilised in drug discovery against HIV virus.

Prevalence of predicted resistance to doravirine in HIV-1-positive patients after exposure to non-nucleoside reverse transcriptase inhibitors.

This study investigated the prevalence of doravirine (DOR) resistance mutations in non-nucleoside reverse transcriptase inhibitor (NNRTI)-experienced patients. DOR resistance was assessed in samples from NNRTI-experienced patients who underwent genotypic testing for virological failure from the Antiretroviral Response Cohort Analysis (ARCA) database. Intermediate DOR resistance was defined as detection of any of V106A/M, Y188C/H, V108I, and K103N+P225H. High-level DOR resistance was defined as detection of any of Y188L, M230L, G190E, V106A/M+F227L, and V106A/M+L234I. Overall, 6893 patients were included in the study: 64.2% had experienced efavirenz (EFV), 54.4% nevirapine (NVP), 6.8% etravirine (ETR), 7.7% rilpivirine (RPV) and 0.7% delavirdine. Among NNRTI-experienced patients, 12.7% and 6.1% of subjects had intermediate and high-level DOR resistance, respectively. The most common DOR resistance mutation was Y188L. In multivariable analysis, previous EFV use (OR = 1.52, 95% CI 1.15-2.02) and ETR use (OR = 1.91, 95% CI 1.34-2.73) were associated with detection of high-level DOR resistance, whilst RPV use was associated with a lower probability of high-level DOR resistance (OR = 0.39, 95% CI 0.22-0.71). Moreover, EFV use (OR = 1.76, 95% CI 1.19-2.58) and ETR use (OR = 1.72, 95% CI 1.10-2.68) were associated with detection of the Y188L mutation, whereas RPV use was not (OR = 0.16, 95% CI 0.05-0.50). In Italy, DOR resistance is uncommon among NNRTI-experienced patients, confirming a distinguishing resistance pattern within NNRTIs. However, previous EFV and ETR experience poses a higher risk of DOR resistance. These results support the use of DOR in NNRTI-experienced patients.

HIV-1 drug resistance among newly HIV-1 infected individuals attending tertiary referral center in Chennai, India.

CONTEXT: In the era of free HAART, accessibility and availability of ARV has been dramatically increased in India. However, rates of treatment literacy and adherence appear to be sub-optimal. Therefore, it is essential to monitor the extent of primary drug resistance in such settings. MATERIALS AND METHODS: Between July and October 2006, 18 anti-retroviral-naοve individuals were identified as recent infected by the BED-Capture enzyme immunoassay in a VCTC clinic in Chennai. Specimens from these individuals were subjected to genotypic drug resistance testing. Phylogenetic trees were generated using MEGA for Windows version 4.0 using neighbor-joining method. The significant differences in polymorphic mutation frequencies between the study specimens and established subtype C-specific polymorphisms were examined using the Chi-square test. RESULTS: Amino acid substitution (K103N and V106MV) at drug resistance positions occurred in two (11%) isolates, conferring high-level resistance to the non-nucleoside reverse-transcriptase inhibitors nevirapine (NVP), efavirenz (EFV), delavirdine (DLV) and notably extensive genetic variations were observed. K122E (94.4%) and K49R/KR (11.1%) polymorphisms identified in this study have not been previously described in established subtype-C specific polymorphisms. The rate of polymorphisms showed marked difference at the locations V60, D121, V35, and D123 (P < 0.0001). All the sequences showed maximum homology with Indian HIV-1 subtype C reference strain C.IN.95IN21068. CONCLUSIONS: The finding of resistance to NNRTIs is of public health importance. There is an urgent need to establish surveillance for primary drug resistance in large scale. Further studies are required to determine the phenotype impact of newer polymorphic mutations in relation to drug resistance and viral fitness.

Progress of bis(heteroaryl)piperazines (BHAPs) as non-nucleoside reverse transcriptase inhibitors (NNRTIs) against human immunodeficiency virus type 1 (HIV-1).

Since the first case of acquired immunodeficiency syndrome (AIDS) was reported in 1981, AIDS, as the global disease affecting 33.2 million people in 2007, has always been an unsolved problem worldwide. Reverse transcriptase (RT) is a crucial enzyme in the life cycle of human immunodeficiency virus type 1 (HIV-1), and thereby has been the prime drugs target for antiretroviral (ARV) therapy against AIDS. To date, two classes of RT inhibitors (RTIs), e.g., nucleoside reverse transcriptase inhibitors (NRTIs) and non-nucleoside reverse transcriptase inhibitors (NNRTIs), and a lot of compounds tested as RTIs have been described. To our knowledge, bis(heteroaryl)piperazines (BHAPs) have been considered as one class of promising NNRTIs, such as structurally and chemically related NNRTI delavirdine, which was approved by the U. S. Food and Drug Administration (FDA) for the treatment of HIV-1 infection in 1997. In this mini-review, we make attempts to report the progress of synthesis and structure-activity relationship (SAR) of BHAPs, in the meantime, the synergistic inhibition of HIV-1 replication by combining delavirdine with other HIV-1 inhibitors is also discussed. It will pave the way for the design and development of BHAPs as anti-HIV-1 agents in AIDS chemotherapy in the future.

Addressing ceiling effects in health status measures: a comparison of techniques applied to measures for people with HIV disease.

OBJECTIVES: To compare different approaches to address ceiling effects when predicting EQ-5D index scores from the 10 subscales of the MOS-HIV Health Survey. STUDY DESIGN: Data were collected from an HIV treatment trial. Statistical methods included ordinary least squares (OLS) regression, the censored least absolute deviations (CLAD) approach, a standard two-part model (TPM), a TPM with a log-transformed EQ-5D index, and a latent class model (LCM). Predictive accuracy was evaluated using percentage of absolute error (R(1)) and squared error (R(2)) predicted by statistical methods. FINDINGS: A TPM with a log-transformed EQ-5D index performed best on R(1); a LCM performed best on R(2). In contrast, the CLAD was worst. Performance of the OLS and a standard TPM were intermediate. Values for R(1) ranged from 0.33 (CLAD) to 0.42 (TPM-L); R(2) ranged from 0.37 (CLAD) to 0.53 (LCM). CONCLUSIONS: The LCM and TPM with a log-transformed dependent variable are superior to other approaches in handling data with ceiling effects.

Non-nucleoside phenotypic hypersusceptibility cut-point determination from ACTG 359.

PURPOSE: Non-nucleoside reverse transcriptase inhibitor (NNRTI) hypersusceptibility (HS) improves virologic response to those agents, but phenotypic susceptibility cut-points, and methods to determine the cut-points, have not been completely defined. METHOD: Phenotypic drug susceptibility (fold change in IC50 [FC]) was determined for 96 randomly selected antiretroviral-experienced, NNRTI-naive patients who received a delavirdine (DLV)-containing regimen in ACTG 359. A weighted FC score was used to account for other regimen agents. Regression models were used to define baseline DLV HS cut-points using week 4 or week 16 responses. RESULTS: At study entry, DLV HS was present in 36% (35/96) of patients. Models explored HS cut-points from 0.2-1.0 using the week 4 virologic response. Using either a binary or continuous endpoint, DLV HS cut-points between 0.3 and 0.4 were identified. The classification and regression tree (CART) analysis identified baseline DLV FC <0.44 as a predictor of week 4 response. CONCLUSIONS: In relating drug HS to virologic response, several different analytic methods identified a DLV HS FC cut-point of 0.3-0.4. In refining phenotypic cut-points, early virologic responses (not confounded by rebound) may be better metrics than later responses, especially for drugs with low genetic barriers, such as DLV.

Emergence of NNRTI drug resistance mutations after single-dose nevirapine exposure in HIV type 1 subtype C-infected infants in India.

A feasibility study for providing single-dose nevirapine (SD-NVP) prophylaxis for prevention of mother-to-child transmission (PMTCT) of HIV infection provided an opportunity to study the emergence of nonnucleoside reverse transcriptase inhibitor (NNRTI) resistance mutations as a result of single-dose administration. The study aimed at the detection of NNRTI drug resistance mutations arising as a result of SD-NVP. A total of 19 and 13 samples collected at 48 h and 2 months postpartum, respectively, from infants that were given SD-NVP were studied for the presence of NNRTI drug resistance mutations by PCR amplification and sequencing of the HIV-1 pol gene using HIV proviral DNA. The drug resistance mutational analysis of final sequences was carried out using the Stanford University HIV Drug Resistance database (http://hivdb.stanford.edu/hiv). Mutations associated with NNRTI drug resistance were observed in two (10.5%) and six (46.15%) samples at 48 h and at 2 months, respectively. K103N, one of the most common mutations, was not observed in any of the samples. The emergence of NVP resistance must be weighed against the simplicity, efficacy, and cost effectiveness of SD-NVP prophylaxis in PMTCT settings in developing countries.

[HIV-1 genotypic resistance profiles in children failing highly active antiretroviral therapy].

OBJECTIVE: To study the genotypic resistance profiles of HIV-1 children failing highly active antiretroviral therapy (HAART) so as to provide helpful information for the treatment regime of Chinese children infected with HIV-1. METHODS: Peripheral venous blood samples were collected from 20 HIV-1 infected children of Henan province, aged 9 (3 - 14). Nested RT-PCR was used to amplify part of the RT (40 -250 aa) gene. The PCR products of RT gene underwent nucleotide sequencing, the resulting nucleotide sequences were analyzed by the HIVdb data offered by the Stanford University web site to find the drug resistance mutations. RESULTS: (1) Phylogenetic analysis revealed that 20 of the RT sequences were classified as subtype B. (2) According to the genotypic analysis, 20 , 15, and 13 children showed high level resistance to the nevirapine. (NVP), delavirdine (DLV), and efavirenz (EFV) respectively; 7 and 5 children showed high and intermediate level resistance to azidothymidine (AZT) respectively. Five children showed potential low-level and intermediate level resistance to lamivudine (3TC), and 11 showed high level resistance to 3TC; 11 showed intermediate and high level resistance to stavudine (d4T) and didanoside (ddI) respectively; and 19 and 12 children showed resistance to abacavir (ABC) and tenofovir (TDF) which had never been taken by these children. CONCLUSION: The emergence of HIV resistant strains during antiretroviral therapy is one of the main reasons for treatment failure in HIV-infected children.

Interactions between buprenorphine and antiretrovirals. I. The nonnucleoside reverse-transcriptase inhibitors efavirenz and delavirdine.

This study examined drug interactions between buprenorphine, an opioid partial agonist medication used in the treatment of opioid dependence, and the nonnucleoside reverse-transcriptase inhibitors (NNRTIs) efavirenz (EFV) and delavirdine (DLV). Opioid-dependent, buprenorphine/naloxone-maintained, human immunodeficiency virus (HIV)-negative volunteers (n=10 per NNRTI) participated in 24-h sessions to determine pharmacokinetics of buprenorphine and of buprenorphine with either EFV or DLV after administration of standard doses of either antiretroviral for 15 or 7 days, respectively. Opiate withdrawal symptoms, cognitive effects, and adverse events were determined before and after antiretroviral administration in opioid-dependent participants. The pharmacokinetics of NNRTIs in healthy control participants were used to determine the effect of buprenorphine on NNRTIs. EFV decreased the buprenorphine area under the concentration-time curve (P<.001). DLV increased buprenorphine concentrations (P<.001). Clinically significant consequences of these interactions were not observed. Buprenorphine did not alter antiretroviral pharmacokinetics. Adjustments of doses of either buprenorphine or EFV or DLV are not likely to be necessary when these drugs are administered for the treatment of opiate dependence and HIV disease.

Population pharmacokinetics of delavirdine and N-delavirdine in HIV-infected individuals.

OBJECTIVE: Delavirdine is a non-nucleoside reverse transcriptase inhibitor used in combination regimens for the treatment of HIV-1 infection. Our objective was to characterise the population pharmacokinetics of delavirdine in HIV-infected patients who participated in the adult AIDS Clinical Trials Group (ACTG) 260 and 261 studies. METHODS: ACTG 261 was a randomised, double-blind study of delavirdine 400mg three times daily, in various combination regimens; ACTG 260 was a concentration-targeted monotherapy study. Two hundred and thirty-four patients, and 1254 and 1251 plasma concentrations for delavirdine and N-delavirdine, respectively, were available for population pharmacokinetic analysis. The pharmacokinetic model (and initial parameters), based on previous studies, included two compartments for delavirdine (peripheral and central) and parallel clearance pathways (nonlinear conversion to N-delavirdine and first order clearance from the body). The model was one compartment for N-delavirdine with first order clearance. Diurnal variation of delavirdine and N-delavirdine oral clearance was modelled as a cosine function, with amplitude variation a fitted parameter. Pharmacokinetic parameter estimates were derived from iterative two-stage analysis; observed delavirdine and N-delavirdine concentrations fit with weighting by the inverse observation variance. Covariates were analysed by multiple general linear modelling. RESULTS: The mean (percent coefficient of variation [%CV]) CD4 count was 315 (109) cells/mm(3), weight 76.9 (14.7) kg, age 37 (8.5) years, and 15% of the population were women. Mean (%CV) population pharmacokinetic parameter estimates for delavirdine were: volume of distribution at steady state 67.6 (100) L, intrinsic oral clearance 19.8 (64) L/h, concentration at half the maximum velocity of metabolism (V(max)) 6.3 (69) micromol/L and first order oral clearance 0.57 (86) L/h. For N-delavirdine, the mean (%CV) apparent volume of distribution was 24.7 (75) L and apparent clearance 29.7 (42) L/h. The mean V(max) was 1376 (68) mg/day. The final model for average intrinsic clearance of delavirdine included race, sex, weight and age as significant covariates (p < 0.05); however, these covariates do not explain a significant proportion of the overall variability in the population. CONCLUSIONS: Delavirdine disposition exhibits nonlinear pharmacokinetics and large interpatient variability, and is significantly altered by time of day (impacting potential therapeutic drug monitoring and future pharmacokinetic study designs). Although race and sex appear to influence delavirdine pharmacokinetics, men and women and patients of different races should receive similar mg/kg dosage regimens. The presence of large interpatient variability supports the further investigation of the utility of therapeutic drug monitoring for delavirdine, if target drug concentrations can be better defined.

Antiretrovirals, Part II: focus on non-protease inhibitor antiretrovirals (NRTIs, NNRTIs, and fusion inhibitors).

The second in a series reviewing the HIV/AIDS antiretroviral drugs. This review summarizes the non-protease inhibitor antiretrovirals: nucleoside and nucleotide analogue reverse transcriptase inhibitors (NRTIs), the nonnucleoside reverse transcriptase inhibitors (NNRTIs), and cell membrane fusion inhibitors. In an overview format for primary care physicians and psychiatrists, this review presents the mechanism of action, side effects, toxicities, and drug interactions of these agents.

Effects of the G190A substitution of HIV reverse transcriptase on phenotypic susceptibility of patient isolates to delavirdine.

BACKGROUND: Cross resistance is common among the non-nucleoside reverse transcriptase inhibitors (NNRTIs). G190A appears in 5-15% of the patients treated with nevirapine or efavirenz who develop clinical resistance. OBJECTIVES: In this study we investigated the effect of G190A and other NNRTI substitutions on the phenotypic susceptibility to this class of drugs. STUDY DESIGN: We identified 15 individuals, who after treatment with NNRTIs (nevirapine or efavirenz; median exposure of 20 months), developed isolated G190A, G190A in combination with K103N, or K103N alone. Phenotypic and genotypic analyses of stored plasma specimens were performed before and after the mutations occurred to assess NNRTI susceptibility. RESULTS: All isolates that developed only G190A substitution became less susceptible to nevirapine (median: 125-fold) and efavirenz (median: 10-fold) but were 2.5-fold more sensitive to delavirdine (Wilcoxon P = 0.06). In the group with only K103N substitution, acquisition of resistance to all NNRTIs was observed. In the group with the double substitutions, G190A and K103N, delavirdine susceptibility decreased 13-fold, while resistance to nevirapine and efavirenz decreased by 239- and 154-folds, respectively (Kruskal-Wallis H P = 0.009). CONCLUSIONS: The data suggest that the presence of a G190A substitution attenuates the phenotypic resistance associated with a K103N substitution, although resistance is still present. The in vivo significance of the increased phenotypic susceptibility to delavirdine is not known but could be evaluated in a clinical trial.

Clinical utility of current NNRTIs and perspectives of new agents in this class under development.

Highly active antiretroviral therapy (HAART) has significantly reduced the number of deaths caused by AIDS. However, the antiviral efficacy of HAART comprising protease inhibitors (PIs) and nucleoside reverse transcriptase inhibitors (NRTIs) is frequently accompanied by a decrease in patients' quality of life. PI-based therapies often fail due to poor adherence caused by heavy pill burden, complex dosing schedules and undesirable side effects. The current trend is to switch from PI-based to PI-sparing regimens consisting of non-nucleoside reverse transcriptase inhibitors (NNRTIs) and NRTIs. Despite some encouraging results from NNRTI-containing therapies, two major concerns in using the currently available NNRTIs remain: 1) low genetic barrier to the emergence of resistance and 2) cross-resistance due to single mutations that often render the whole class of NNRTIs ineffective. Clearly, new and improved NNRTIs are needed to address these concerns.

In vivo dynamics of the 103N mutation following the withdrawal of non-nucleoside reverse transcriptase inhibitors in HIV-infected patients: preliminary results.

Due to the preferential selection of the fittest HIV mutants, drug-resistant variants are often overgrown by wild-type virus after treatment interruption. Our objective was to investigate the dynamics of the 103N mutation (which usually does not reduce HIV fitness) following the withdrawal of non-nucleoside reverse transcriptase inhibitors (NNRTIs). Patients who were found to have the 103N mutation at or after failure of a NNRTI were selected from an observational database. Two groups of patients were identified: one which continued antiretroviral treatment without NNRTIs (group A) and one which discontinued all anti-retrovirals after failure of an NNRTI (group B). Genotype was obtained by direct sequencing of the replicating plasma virus. Sixty-two subjects tested between July 1998 and December 2002 were included in the analysis, 39 in group A and 23 in group B. At the time of the first resistance test, median (IQR) CD4+ T-lymphocytes and HIV-RNA were 269 (150-449) cells/microL and 25,000 (9,600-83,300) copies/mL. In 31 (50%), 30 (48%), and one case (2%), the 103N mutation was selected by nevirapine, efavirenz, and by delavirdine, respectively. A total of 149 tests were analyzed, with a median (IQR) of 2 (2-3) tests/patient. The median (IQR) interval between failure of NNRTIs and the last resistance test was 11 (5-22) months. Overall, a reversion to wild-type at position 103 was observed in 23/62 (37%) subjects, 14/39 (36%) in group A and 9/23 (39%) in group B. In group A, 14/23 (61%) patients tested within 12 months, 10/16 (63%) of those tested between 12 and 24 months, and 12/14 (86%) of those tested beyond 24 months from NNRTI discontinuation had the 103N mutation. In group B, 14/20 (70%) patients tested within 12 months, 3/4 (75%) of those tested between 12 and 24 months, and none out of two tested beyond 24 months from NNRTI discontinuation had the 103N mutation. In conclusion, following NNRTI discontinuation, in the majority of patients HIV variants carrying the 103N mutation are not overgrown for long by wild-type quasispecies at this position. This suggests that the 103N mutation per se influences minimally the viral fitness in vivo.

Provider bias in the selection of non-nucleoside reverse transcriptase inhibitor and protease inhibitor-based highly active antiretroviral therapy and HIV treatment outcomes in observational studies.

OBJECTIVE: To compare the characteristics of patients prescribed non-nucleoside reverse transcriptase inhibitors (NNRTI) and protease inhibitors (PI), and evaluate treatment outcomes in a setting in which nevirapine has been preferentially recommended since 1998. METHODS: A population-based analysis of antiretroviral-naive adults who started highly active antiretroviral therapy (HAART) between 1 August 1996 and 31 July 2000, and who were followed until 31 March 2002. We compared baseline characteristics, and evaluated virological responses and mortality. RESULTS: Overall, 439 patients (28.8%) started HAART with NNRTI (94.1% used nevirapine), 100 (6.6%) used a double PI, and 983 (64.6%) used a single PI-based regimen. Substantial differences were observed between the baseline clinical characteristics of these populations. In adjusted analyses, in comparison with single PI therapy, only the use of NNRTI was associated with more rapid HIV-RNA suppression [relative hazard (RH) 1.42; 95% confidence interval (CI) 1.22-1.65; P < 0.001]. A total of 204 deaths were identified in the study population [42 (9.6%) NNRTI; 11 (11%) double PI; 151 (15.4%) single PI, respectively]. In adjusted analysis, NNRTI (RH 1.01; 95% CI 0.71-1.45) and double PI-based HAART (RH 0.74; 95% CI 0.40-1.39) had similar mortality rates to the single PI reference category. CONCLUSION: NNRTI use was associated with more rapid virological suppression, whereas similar rates of rebound and mortality were found. Nevertheless, major baseline differences existed between patients prescribed the various initial regimens. As such, it is likely that similar selection factors may explain why our findings contrast with several non-randomized studies showing worse clinical outcomes of patients prescribed nevirapine.

Effect of delavirdine on plasma lipids and lipoproteins in patients receiving antiretroviral therapy.

Plasma lipid and lipoprotein levels were measured at baseline and after 8 weeks of highly active antiretroviral therapy among patients receiving delavirdine with or without a protease inhibitor (PI). In patients receiving nucleoside reverse transcriptase inhibitors (NRTI) plus delavirdine, there was a statistically significant increase in cholesterol and HDL levels, whereas those receiving NRTI plus a PI had no significant change in their HDL levels. When delavirdine was combined with a PI, there was a more dramatic increase in both cholesterol and HDL concentrations.