Residual HIV-1 replication may impact immune recovery in patients on first-line lopinavir/ritonavir monotherapy.

BACKGROUND: Antiretroviral combination therapy raises issues of long-term adherence and toxicity. Initial treatment simplification based on single-drug therapy was investigated in the MONARK trial, which compared first-line lopinavir/ritonavir monotherapy (arm A) with first-line lopinavir/ritonavir + zidovudine/lamivudine tritherapy (arm B). The MONARK trial is registered as a randomized trial at clinical trials.gov under identifier NCT 00234923. PATIENTS AND METHODS: Immune recovery was compared in patients with undetectable plasma virus (<50 copies/mL) after 60 weeks of treatment (arm A, n = 21; arm B, n = 13). RESULTS: The week 60 CD4 T cell count and CD4 T cell subset distribution did not differ significantly between the treatment arms. Memory CD4 T cell responses to HIV and recall antigens were better with triple therapy than with monotherapy. The frequencies of activated CD8 T cells and anti-HIV CD8 T cell effector responses were similar in the two arms. However, the repertoire of CD8 T cell effector responses was broader and persistent residual viraemia more frequent (by ultrasensitive PCR) in the monotherapy arm. CONCLUSIONS: While viral control can be achieved with first-line lopinavir/ritonavir monotherapy, the quality of immune recovery is inferior to that obtained with triple therapy, possibly owing to a higher level of residual viral replication. Thus, the benefits of first-line lopinavir/ritonavir monotherapy in terms of toxicity and adherence might be offset by an increased risk of residual viral replication, which may also fuel latent viral reservoirs.

Phenotypic characterization of virological failure following lopinavir/ritonavir monotherapy using full-length Gag-protease genes.

OBJECTIVES: Major protease mutations are rarely observed following first-line failure with PIs and interpretation of genotyping results in this context may be difficult. We performed extensive phenotyping of viruses from five patients failing lopinavir/ritonavir monotherapy in the MONARK study without major PI mutations by standard genotyping. METHODS: Phenotypic susceptibility testing and viral infectivity assessments were performed using a single-cycle assay and fold changes (FC) relative to a lopinavir-susceptible reference strain were calculated. RESULTS: >10-fold reduced baseline susceptibility to lopinavir occurred in two of five patients and >5-fold in another two. Four of five patients exhibited phylogenetic evidence of a limited viral evolution between baseline and failure, with amino acid changes at drug resistance-associated positions in one: T81A emerged in Gag with M36I in the protease gene, correlating with a reduction in lopinavir susceptibility from FC 7 (95% CI 6-8.35) to FC 13 (95% CI 8.11-17.8). Reductions in darunavir susceptibility (>5 FC) occurred in three individuals. DISCUSSION: This study suggests both baseline reduced susceptibility and evolution of resistance could be contributing factors to PI failure, despite the absence of classical PI resistance mutations by standard testing methods. Use of phenotyping also reveals lower darunavir susceptibility, warranting further study as this agent is commonly used following lopinavir failure.

Impact of lopinavir/ritonavir use on antiretroviral resistance in recent clinical practice.

OBJECTIVES: This observational study was requested by French health authorities to determine the impact of lopinavir/ritonavir (Kaletra(®)) on antiretroviral resistance in clinical practice. Virological failures of lopinavir/ritonavir and their effects on the resistance to protease inhibitors and reverse transcriptase inhibitors were evaluated in protease inhibitor-experienced patients. PATIENTS AND METHODS: Virological failure was defined as an HIV-1 plasma viral load >50 copies/mL after at least 3 months of lopinavir/ritonavir-containing antiretroviral therapy. For all patients, a resistance genotypic test was available at failure and before lopinavir/ritonavir treatment. Data from 72 patients with inclusion criteria were studied. RESULTS: The mean viral load at baseline was 4 log(10) copies/mL (1.6-6.5). Mutations in the protease gene significantly selected between baseline and failure were L10V, K20R, L33F, M36I, I47V, I54V, A71V and I85V (P < 0.05). Patients who had more than seven protease inhibitor mutations at baseline showed a significantly increased risk of occurrence of protease inhibitor mutations. The proportion of viruses susceptible to atazanavir, fosamprenavir and darunavir decreased significantly between baseline and failure (P < 0.05). Among patients with a virus susceptible to atazanavir at day 0, 26% (n = 14) exhibited a virus resistant or possibly resistant at the time of failure. This proportion was 32% (n = 16) for fosamprenavir and 16% (n = 7) for darunavir. CONCLUSIONS: A darunavir-based regimen appears to be a sequential option in the case of lopinavir/ritonavir failure. To compare and determine the best treatment sequencing, similar studies should be performed for darunavir/ritonavir and atazanavir/ritonavir.

Impact of 48 week lopinavir/ritonavir monotherapy on blood cell-associated HIV-1-DNA in the MONARK trial.

OBJECTIVES: To study the impact of protease inhibitor monotherapy on the HIV-1 blood reservoir in 72 antiretroviral-naive patients. PATIENTS AND METHODS: This was evaluated for 72 antiretroviral-naive patients included in the on-treatment analysis of the MONARK trial; 46 patients receiving lopinavir/ritonavir monotherapy and 26 patients receiving a triple therapy. HIV-DNA was quantified in whole blood, using real-time PCR. RESULTS: The decrease in HIV-DNA after 48 weeks of lopinavir/ritonavir monotherapy was similar to the decrease observed with triple therapy including lopinavir/ritonavir (-0.77 versus -0.69 log copies/10(6) leucocytes, respectively; P = 0.91). The HIV-DNA decrease was also similar in patients with a virological response in both arms (-0.69 versus -0.69 log copies/10(6) leucocytes, respectively). Interestingly, non-responders had a significantly higher baseline HIV-DNA load than responders in the monotherapy arm; 3.16 versus 2.86 log copies/10(6) leucocytes, respectively (P = 0.05). CONCLUSIONS: The MONARK data indicate that a lopinavir/ritonavir monotherapy regimen is potent against HIV blood reservoirs in antiretroviral-naive patients after 1 year of treatment, in comparison with a standard-of-care highly active antiretroviral therapy. This impact should be evaluated with other boosted protease inhibitor monotherapies.

Protease inhibitor resistance analysis in the MONARK trial comparing first-line lopinavir-ritonavir monotherapy to lopinavir-ritonavir plus zidovudine and lamivudine triple therapy.

The MONARK study was a pilot randomized trial comparing the safety and efficacy of lopinavir-ritonavir (LPV/r) monotherapy to those of LPV/r-zidovudine-lamivudine triple therapy for antiretroviral-naïve human immunodeficiency virus type 1 (HIV-1)-infected patients. Resistance testing was performed at the time of initial screening and at the time of virological failure (defined to include low-level viremia with >50 and <400 HIV-1 virus RNA copies/ml of plasma). Changes from the baseline sequences, including mutations noted on the 2008 International AIDS Society-USA list of resistance-associated protease mutations, were considered. Drug resistance testing was performed for 38 patients (5 of 53 on triple therapy and 33 of 83 on monotherapy). By week 96 (W96), virus samples from 18 of 33 patients in the monotherapy arm showed changes from baseline sequences, and 5 of these patients had viruses with major protease inhibitor (PI) resistance-associated mutations (M46I at W40, L76V at W48, M46I and L76V at W48, L10F and V82A at W72, and L76V at W84). Data on virus phenotypes detected at the time of initial screening and the time of virological failure were available for four patients in whom major PI resistance mutations developed, and these data revealed a mean increase of 2.2-fold (range, 0.75- to 4.6-fold) in the LPV 50% inhibitory concentration. All three patients in whom the L76V PI resistance mutation developed were infected with HIV-1 subtype CRF02_AG. In the triple-therapy group, no major PI resistance mutation was selected among the three patients with protease changes by W48. No association between the baseline CD4 cell count and the viral load, the W4 and final viral loads, or the final LPV trough concentration and the emergence of a major PI resistance mutation was found. Major PI resistance-associated mutations were detected in 5 (6%) of 83 patients treated with LPV/r monotherapy, suggesting that LPV/r monotherapy is an inappropriate first option. The mutation L76V may be considered in further studies of lopinavir resistance.

Prognostic factors for virological response in antiretroviral therapy-naive patients in the MONARK Trial randomized to ritonavir-boosted lopinavir alone.

BACKGROUND: MONARK is a pilot randomized trial comparing the safety and efficacy of lopinavir/ritonavir (LPV/r) monotherapy to a standard triple-drug regimen as initial therapy. The primary endpoint was virological response (VR) defined as viral load (VL)<400 copies/ml at week 24 and VL<50 copies/ml at week 48. The objective of this study was to determine prognostic factors of VR in patients receiving LPV/r monotherapy. METHODS: Baseline characteristics, including demographics, HIV type-1 (HIV-1) subtype (B versus non-B), early VR up to week 4, LPV trough concentrations and compliance were investigated as prognostic factors for VR in patients receiving LPV/r monotherapy. Logistic regression was used to search for variables significantly associated with the occurrence of VR. RESULTS: VR was achieved in 53 out of 83 patients randomized to the LPV/r arm. The on-treatment analysis, using a multivariate model, indicated that having VL<400 copies/ml at week 4 and harbouring HIV-1 subtype B were independently associated with an increased probability of VR. No difference in early VL reduction was evidenced between patients harbouring B or non-B subtypes. The latter patients had more difficulty in adherence to therapy than the former patients. The intention-to-treat analysis showed similar results. CONCLUSIONS: HIV-1 RNA measured at baseline or at week 4 and HIV-1 subtype (B versus non-B) were independent predictive factors of VR in patients starting therapy with LPV/r alone. Although based on a small sample size, results of this study showed that adherence to therapy is lower in patients harbouring non-B subtypes and appears to be a key factor of VR in the context of protease inhibitor monotherapy.

Effect of lopinavir/ritonavir monotherapy on quality of life and self-reported symptoms among antiretroviral-naive patients: results of the MONARK trial.

BACKGROUND: Standard-of-care for HIV-infected patients consists of combining three antiretroviral drugs. However, other therapeutic strategies could be beneficial given long-term toxicity and quality of life (QOL) issues associated with taking multiple antiretroviral drugs for many years. In the prospective, open label, randomized, pilot monotherapy antiretroviral Kaletra (MONARK) trial among antiretroviral-naive patients, lopinavir/ritonavir (LPV/r) monotherapy was found to be less suppressive for HIV RNA than a standard triple-drug therapy of LPV/r plus zidovudine/lamivudine (on-treatment analysis after 48 weeks). We present data from the MONARK trial concerning QOL and patient-reported symptoms. METHODS: Patient-reported symptoms were collected at baseline and at weeks 4, 12, 24 and 48 using a list of 22 symptoms. QOL was assessed at baseline, week 24 and week 48 using the six-domain World Health Organization QOL short form questionnaire for HIV-infected individuals including an evaluation of global health perception. RESULTS: Patients treated with the standard triple-drug therapy reported significantly more symptoms over 48 weeks of treatment than patients treated with LPV/r monotherapy (incidence rate ratio [95% confidence interval] 1.3 [1.1, 1.6] P=0.001 and 1.4 [1.2, 1.7] P=0.0004 for the total number of symptoms and the number of symptoms causing discomfort, respectively). No baseline differences and no significant changes were observed in the six QOL scores. The percentage of patients with a positive perception of their global health status increased significantly in the monotherapy arm from 32% at baseline to 67% at week 48 (P<0.0001). CONCLUSIONS: These results suggest that the number of self-reported symptoms could be used as a treatment-sensitive measure of patients' well-being in clinical trials.

Absence of HIV-1 shedding in male genital tract after 1 year of first-line lopinavir/ritonavir alone or in combination with zidovudine/lamivudine.

BACKGROUND: New strategies such as boosted-protease inhibitor (PI) monotherapy are being investigated. However, a concern remains regarding the efficacy of this strategy in viral sanctuaries such as the male genital tract. More than 80% of untreated HIV-infected men have detectable HIV-RNA in semen and such a strategy could favour local selection of resistant variants, given the poor penetration of most PIs in semen. OBJECTIVES: To evaluate the impact of a first-line lopinavir/ritonavir alone or standard triple combination on HIV-1 shedding in the genital tract. METHODS: HIV-1-infected men enrolled in the Monark randomized trial were eligible for the present study after 48 weeks of a first-line lopinavir/ritonavir alone or in combination with zidovudine and lamivudine. Single-paired samples of blood and semen were collected at week 48. Blood plasma HIV-RNA and seminal plasma HIV-RNA were measured at week 48. Lopinavir and ritonavir concentrations were measured in blood and in semen at week 48 by high-performance liquid chromatography. RESULTS: Ten patients were included: five of them received lopinavir/ritonavir monotherapy and five received a triple combination. At week 48, all patients had blood plasma HIV-RNA <1.7 log(10) copies/mL. Median lopinavir and ritonavir concentrations were within the expected therapeutic target range in blood plasma (4896 and 130.5 ng/mL, respectively), whereas both lopinavir and ritonavir were undetectable in all seminal plasma samples (<30 ng/mL). All 10 patients had undetectable seminal plasma HIV-RNA at week 48 (<2.3 log(10) copies/mL). CONCLUSIONS: No local viral production was evident in semen, despite the local absence of therapeutic antiretroviral drug concentrations in the five patients receiving lopinavir/ritonavir alone.

Polymorphism in Gag gene cleavage sites of HIV-1 non-B subtype and virological outcome of a first-line lopinavir/ritonavir single drug regimen.

Virological failure on a boosted-protease inhibitor (PI/r) first-line triple combination is usually not associated with the detection of resistance mutations in the protease gene. Thus, other resistance pathways are being investigated. First-line PI/r monotherapy is the best model to investigate in vivo if the presence of mutations in the cleavage sites (CS) of gag gene prior to any antiretroviral treatment might influence PI/r efficacy. 83 patients were assigned to initiate antiretroviral treatment with first-line lopinavir/r monotherapy in the randomised Monark trial. We compared baseline sequence of gag CS between patients harbouring B or non-B HIV-1 subtype, and between those who achieved viral suppression and those who experienced virological failure while on LPV/r monotherapy up to Week 96. Baseline sequence of gag CS was available for 82/83 isolates; 81/82 carried at least one substitution in gag CS compared to HXB2 sequence. At baseline, non-B subtype isolates were significantly more likely to harbour mutations in gag CS than B subtype isolates (p<0.0001). Twenty-three patients experienced virological failure while on lopinavir/r monotherapy. The presence of more than two substitutions in p2/NC site at baseline significantly predicted virological failure (p = 0.0479), non-B subtype isolates being more likely to harbour more than two substitutions in this specific site. In conclusion, gag cleavage site was highly polymorphic in antiretroviral-naive patients harbouring a non-B HIV-1 strain. We show that pre-therapy mutations in gag cleavage site sequence were significantly associated with the virological outcome of a first-line LPV/r single drug regimen in the Monark trial.

Fat tissue distribution changes in HIV-infected patients treated with lopinavir/ritonavir. Results of the MONARK trial.

Given the decline in mortality among HIV-infected patients, it has become increasingly important to consider delayed disease-related and/or anti-HIV therapy-related adverse effects, such as lipodystrophy, when choosing initial therapy. Data from the MONARK trial allowed for comparison of the potential lipodystrophic effects of lopinavir/ritonavir (LPV/r) monotherapy with those of triple therapy with LPV/r plus zidovudine (ZDV) and lamivudine (3TC). This was a randomized, open-label, multinational study that included 136 antiretroviral-naive HIV-infected patients. A portion of study patients underwent evaluations of limb and trunk fat tissue by dual-energy x-ray absorptiometry at baseline and after 48 weeks of treatment (and 96 weeks in some patients). Sixty-three patients had paired absorptiometry data at baseline and week 48 (13 patients at week 96). At week 48, median change in limb fat was -63 g on LPV/r monotherapy versus -703 g on LPV/r + ZDV/3TC triple therapy (p=0.014). The proportion of patients with fat loss (>20% loss in limb fat) was significantly lower with LPV/r monotherapy (4.9% versus 27.3%; p=0.018). Changes in trunk fat did not differ significantly between treatments. Nonetheless, limb fat and trunk fat varied in the same direction with both treatments. The decrease in arm lean mass was also significantly less in patients receiving LPV/r monotherapy. Only treatment type emerged as a significant predictor of fat loss (odds ratio, 7.06; 95% CI, 1.11-78.69). These results suggest that LPV/r, and possibly other protease inhibitors, may not be the main contributor to lipoatrophy in HIV-infected patients receiving triple therapy.

Lopinavir/ritonavir monotherapy or plus zidovudine and lamivudine in antiretroviral-naive HIV-infected patients.

BACKGROUND: Guidelines for the use of antiretroviral agents for HIV-1 infection recommend combining at least three agents. The toxicity, cost, and complexity of such regimens warrant the search for other options. METHODS: MONARK is a prospective, open-label, randomized, 96-week trial comparing the safety and efficacy of lopinavir/ritonavir monotherapy with a standard lopinavir/ritonavir plus zidovudine and lamivudine regimen as an initial treatment regimen in HIV-infected patients with HIV-RNA levels less than 100,000 copies/ml. The primary endpoint was the proportion of patients with HIV-1-RNA levels below 400 copies/ml at week 24 and below 50 copies/ml at week 48. RESULTS: Eight-three and 53 patients were randomly assigned and exposed in the monotherapy and triple-drug groups, respectively. At week 48, by an intent-to-treat analysis, 53 of 83 patients (64%) in the monotherapy group and 40 of 53 patients (75%) in the triple-drug group achieved the primary endpoint (P = 0.19). The on-treatment analysis indicates that 80 and 95% of patients reached the primary endpoint in the monotherapy and triple-drug groups, respectively (P = 0.02). In the monotherapy arm, protease inhibitor-associated resistance mutations were seen in three of the 21 patients qualifying for genotypic resistance testing, with a modest impact on lopinavir susceptibility. None of the serious reported adverse events were considered to be related to study treatment. CONCLUSION: Our results suggest that lopinavir/ritonavir monotherapy demonstrates lower rates of virological suppression when compared with lopinavir/ritonavir triple therapy and therefore should not be considered as a preferred treatment option for widespread use in antiretroviral-naive patients.

Predictive genotypic algorithm for virologic response to lopinavir-ritonavir in protease inhibitor-experienced patients.

Several genotypic resistance algorithms have been proposed for quantitation of the degree of phenotypic resistance to the human immunodeficiency virus (HIV) protease inhibitor (PI) lopinavir (LPV), including the original LPV mutation score. In this study, we retrospectively evaluated 21 codons in HIV protease known to be associated with PI resistance in a large antiretroviral agent-experienced observational patient cohort, "Autorisation Temporaire d'Utilization" (ATU), to assess whether a more optimal algorithm could be derived by using virologic response data from patients treated with LPV in combination with ritonavir (LPV/r). Five of the 11 mutations constituting the LPV mutation score were not associated with a virologic response, while 4 additional mutations not included in this score demonstrated an association. Therefore, the LPV ATU score, which includes mutations at codons 10, 20, 24, 33, 36, 47, 48, 54, 82, and 84, was constructed and shown in two different types of multivariable analyses of the ATU cohort to be a better predictor of the virologic response than the LPV mutation score. The LPV ATU score was also more strongly associated with a virologic response when it was applied to independent clinical trial populations of PI-experienced patients receiving LPV/r. This study provides the basis for a new genotypic resistance algorithm that is useful for predicting the antiviral activities of LPV/r-based regimens in PI-experienced patients. The refined algorithm may be useful in making clinical treatment decisions and in refining genetic and pharmacologic methods for assessing the activity of LPV/r.

Virological and pharmacological parameters predicting the response to lopinavir-ritonavir in heavily protease inhibitor-experienced patients.

The genotypic inhibitory quotient (GIQ) has been proposed as a way to integrate drug exposure and genotypic resistance to protease inhibitors and can be useful to enhance the predictivity of virologic response for boosted protease inhibitors. The aim of this study was to evaluate the predictivity of the GIQ in 116 protease inhibitor-experienced patients treated with lopinavir-ritonavir. The overall decrease in human immunodeficiency virus type 1 (HIV-1) RNA from baseline to month 6 was a median of -1.50 log(10) copies/ml and 40% of patients had plasma HIV-1 RNA below 400 copies/ml at month 6. The overall median lopinavir study-state C(min) concentration was 5,856 ng/ml. Using univariate linear regression analyses, both lopinavir GIQ and the number of baseline lopinavir mutations were highly associated with virologic response through 6 months. In the multivariate analysis, only lopinavir GIQ, baseline HIV RNA, and the number of prior protease inhibitors were significantly associated with response. When the analysis was limited to patients with more highly mutant viruses (three or more lopinavir mutations), only lopinavir GIQ remained significantly associated with virologic response. This study suggests that GIQ could be a better predictor of the virologic response than virological (genotype) or pharmacological (minimal plasma concentration) approaches used separately, especially among patients with at least three protease inhibitor resistance mutations. Therapeutic drug monitoring for patients treated by lopinavir-ritonavir would likely be most useful in patients with substantially resistant viruses.