Pharmacokinetics of a tri-glucoconjugated 5,10,15-(meta)-trihydroxyphenyl-20-phenyl porphyrin photosensitizer for PDT. A single dose study in the rat.

Photodynamic therapy (PDT) involves a non invasive treatment of small and superficial cancers using a photosensitive drug and light to kill tumoral cells. 5,10,15-meso-tri-(meta-O-beta-D-glucosyloxyphenyl)-20-phenylporphyrin [m-TPP(glu)3] is a new photosensitizer (PS) with more enhanced photocytotoxicity relative to 5,10,15,20-meso-tetra-(meta-hydroxyphenyl) chlorin [m-THPC] (Foscan). It was injected intravenously once to healthy rats at three different doses (0.25, 0.5 and 1 mg kg(-1)) and compared to m-THPC (0.3 mg kg(-1)). Pharmacokinetic parameters for both photosensitizers were derived from plasma concentration-time data using a non-compartmental analysis and a two-compartment pharmacokinetic model. m-TPP(glu)3 is more rapidly eliminated throughout the organism than m-THPC. Its mean plasma clearance is 19 mL h(-1) kg(-1) (6 mL h(-1) kg(-1) for m-THPC), and its mean residence time is 5h (20 h for m-THPC). The area under curve (AUC) and initial mean serum concentration (C0) were found to be proportional to the dose. As for Foscan, no metabolite of m-TPP(glu)3 was detected in plasma. The biodistribution study demonstrates that the most significant amount of m-TPP(glu)3 was concentrated in organs such as lung, liver and spleen which are rich in reticulo-endothelial cells. Maximum concentrations were reached in organs 14 h after IV administration. At 48 h, the photosensitizer was essentially eliminated from all organs. Because of its shorter elimination time, m-TPP(glu)3 is more attractive than m-THPC as a PDT agent since secondary side effects of shorter duration could be expected.

Efficacy of a twice-daily antiretroviral regimen containing 100 mg ritonavir/400 mg indinavir in HIV-infected patients.

OBJECTIVE: To evaluate the pharmacokinetics, efficacy and tolerability of a low-dose boosted indinavir (IDV)/ritonavir (RTV) regimen [100 mg RTV/400 mg IDV twice daily (bid)] in patients previously receiving a standard IDV regimen [800 mg three times a day (tid)]. METHODS: In a prospective, open-label, cross-over trial, patients with plasma HIV RNA < 200 copies/ml receiving an IDV-containing regimen (800 mg tid) were switched to an RTV/IDV (100/400 mg bid)-containing regimen. Minimal and maximal IDV plasma concentrations ( Cmin and Cmax ) were determined before the switch (day 0), at week 2 and week 4 after the switch. The CD4 cell count and plasma HIV RNA were determined at day 0, week 2 and week 4, then every 8 weeks. The primary end-point was the percentage of patients with plasma HIV RNA below 200 copies ml at week 48. RESULTS: Twenty patients were enrolled. At baseline, on IDV 800 mg tid, median IDV Cmin was 194 ng/ml and median IDV Cmax was 8449 ng/ml. On RTV/IDV (100/400 mg), median IDV Cmin increased to 536 ng/ml at week 2 and 475 ng/ml at week 4, while Cmax decreased to 2983 ng/ml at week 2 and 2997 ng/ml at week 4 ( P < 0.001). The median area under the IDV plasma concentration-time curve measured in seven patients was 25 126 ng.h/ml, and the IDV half-life (t1/2 ) was 4.4 h. All patients had plasma HIV RNA remaining < 200 copies/ml at week 48. Tolerability of RTV/IDV was excellent. CONCLUSION: RTV/IDV (100/400 mg bid) yields significantly higher IDV plasma Cmin and lower IDV Cmax values relative to the standard IDV regimen, thereby improving both tolerability and efficacy.

HIV and antiretroviral drug distribution in plasma and fat tissue of HIV-infected patients with lipodystrophy.

OBJECTIVE: To determine HIV and antiretroviral drug distribution in plasma and fat tissue of HIV-infected patients with lipodystrophy. METHODS: Twenty-three consecutive HIV-infected patients (median age, 43 years; male:female ratio, 18:5; median CD4 cell count, 419 x 10(6)/l) undergoing Coleman's lipostructure were enrolled prospectively in this study. HIV-1 RNA and plasma concentration of antiretroviral drugs were determined blindly in plasma and adipocyte lysate samples. HIV-1 proviral DNA was detected by nested PCR in fresh frozen adipocytes. RESULTS: Mean plasma HIV-1 RNA was significantly higher than that in adipocyte lysate samples (this was below the limit of detection in all patients tested). HIV-1 proviral DNA was positive in two out of 18 adipocyte samples with a level between 2 and 5 copies; the distribution seemed to be specific and comparable within each therapeutic class--protease inhibitors (PI) or non-nucleoside reverse transcriptase inhibitors (NNRTI). NNRTI concentrations in adipocyte lysates were approximately 100-fold higher than those of PI. Efavirenz may accumulate in fat tissue as a function of treatment duration. CONCLUSION: Our results suggest that HIV does not replicate and does not integrate its genome in fat tissue in patients with fat redistribution abnormalities. In patients with effective nadir plasma concentrations of PI and NNRTI, determination of concentration in adipocyte lysates suggests that PI may diffuse in fat tissue with the same pattern of distribution for all structurally related components tested. NNRTI present a high affinity for fat tissue and may accumulate in this compartment.

Phenotypic or genotypic resistance testing for choosing antiretroviral therapy after treatment failure: a randomized trial.

OBJECTIVE: To assess the respective value of phenotype versus genotype versus standard of care for choosing antiretroviral therapy in patients failing protease inhibitor-containing regimens. METHODS: Patients with plasma HIV-1 RNA exceeding 1000 copies/ml were randomly allocated to phenotyping, genotyping, or standard of care. RESULTS: Five-hundred and forty-one patients were randomized, 190 to phenotyping, 192 to genotyping and 159 to standard of care. The baseline median CD4 cell count (280 x 106 cells/l), the plasma HIV-1 RNA level (4.3 log10 copies/ml), and the number of drugs previously received (n = 6) were similar in the three arms. More patients in the standard-of-care arm received at least three new drugs (55% versus 20% in the other arms; P < 0.001) and a regimen containing drugs from the three different classes. Plasma HIV-1 RNA was < 200 copies/ml at week 12 in 35% of patients in the phenotyping arm, 44% in the genotyping arm and 36% in the standard-of-care arm (phenotyping versus standard of care, P = 0.918; genotyping versus standard of care, P = 0.120). In a secondary analysis of 179 patients experiencing a first protease inhibitor failure, the percentage of patients achieving HIV-1 RNA < 200 copies/ml was significantly higher in the genotyping arm (65%) than in the phenotyping (45%) and the standard-of-care arms (45%) (genotyping versus standard of care, P = 0.022). CONCLUSIONS: Overall, resistance assays did not demonstrate benefit over standard of care. In patients with the most limited protease inhibitor experience, a significant benefit was observed in the genotyping arm.

Once-daily dosing of saquinavir soft-gel capsules and ritonavir combination in HIV-1-infected patients (IMEA015 study).

This was a prospective pilot study evaluating a saquinavir (SQV) soft-gel capsules (SGC)/ritonavir (RTV)-containing once-daily regimen over a follow-up of 3 months. The primary end-point was to determine the number of patients both remaining on treatment at month 3 and with trough SQV plasma concentration 24 h after the last intake (C24h) exceeding the inhibition of 95% of viral replication in vitro (IC95). The secondary end-points were to investigate the immuno-virological efficacy and safety of SQV-SGC/RTV once daily, and to explore SQV concentrations in peripheral blood mononuclear cells (PBMCs). Twenty-three antiretroviral-naive and 17 protease inhibitors (PIs) experienced HIV-1-infected patients with plasma HIV-1 RNA level below 200 copies/ml were enrolled. They were assigned to SQV-SGC/RTV (1600/100 mg once daily) combined with nucleoside and/or non-nucleoside reverse transcriptase inhibitors. In a subgroup of 13 patients, both plasma and intracellular SQV concentrations were determined. By intent to treat analysis the percentage of success at month 3 was 87.5% (confidence interval: 73.2-95.8%) with 78.3% in naive and 100% in PI-experienced patients. SQV C24h and intracellular concentrations [median (range, n)] were 241 ng/ml (40-1209, 35) and 323 ng/ml (168-475, 12), respectively. Intracellular concentrations showed an accumulation of SQV in PBMCs persisting during 24 h. Neither immunological nor virological failure was observed. Clinical and biological tolerance was acceptable in all patients but three with adverse effects leading to discontinuation. These data confirmed the short-term efficacy of SQV-SGC/RTV once-daily regimen based on SQV therapeutic drug monitoring.

Indinavir plasma concentration and adherence score are codeterminant of early virologic response in HIV-infected patients of the APROCO cohort.

To study the respective roles of indinavir concentrations and treatment adherence as predictors of early virologic response, we analyzed the patients of the APROCO cohort treated by indinavir 800 mg TID during the first 4 months. Minimum (Cmin), maximum (Cmax), and the ratio of the measured to expected concentrations (CR) were estimated for each patient at M4, from a population pharmacokinetic analysis of all data. The relationship among virologic success at M4 [plasma HIV RNA (VL) <500 copies/mL], baseline characteristics, estimated indinavir concentrations, and adherence score measured by a self-administered questionnaire, was analyzed by multivariate logistic regression. In the 216 studied patients, baseline median HIV RNA was 4.4 log10 copies/mL, and CD4 cell count was 309/mm. Virologic success was achieved in 195 (90%) patients; it was independently related to baseline viral load (OR = 0.524, CI 0.29-0.93; P = 0.03), antiretroviral treatment naive status (OR = 3.89, CI 1.29-11.76; P = 0.01), and indinavir Cmin (OR = 1.06, CI 1.02-1.10; P = 0.004) when adherence score was not included in the model, whereas full adherence was the only independent related factor when included in the model (OR = 8.8, 95% CI 2.85-27.3; P < 10). In the 168 fully adherent patients, virologic success was more frequent in patients with shorter duration of antiretrovirals at baseline (P = 0.03), lower baseline HIV RNA (P = 0.03), and higher indinavir CR (P < 10); the most discriminating Cmin cut-off was 194 ng/mL. Data on the relationship between indinavir plasma concentration and virologic success are therefore misleading without a concomitant assessment of adherence. These data suggest that any strategy of therapeutic drug monitoring must imply first a combined evaluation of plasma concentrations and adherence level and second an intervention target based on the results of both assessments.

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.

Clinically relevant interpretation of genotype and relationship to plasma drug concentrations for resistance to saquinavir-ritonavir in human immunodeficiency virus type 1 protease inhibitor-experienced patients.

It has been shown that virological protease inhibitor (PI) resistance mutations present at the initiation of saquinavir (SQV) plus ritonavir (RTV) therapy in PI-experienced patients are the strongest predictors of virological response. But most of the current resistance algorithms are adapted for unboosted SQV regimens. We applied a stepwise methodology for the development and validation of a clinically relevant genotypic resistance score for an SQV (800 mg twice per day [b.i.d.]) plus RTV (100 mg b.i.d.)-containing regimen. PI-experienced patients treated by this regimen achieved a human immunodeficiency virus plasma viral load (VL) of <200 copies/ml at months 3 to 5 for 41.7% of subjects. Adjusted in a multivariate analysis, taking into account all the confounding factors, such as the nucleoside used, five mutations were combined in a resistance score associated with a reduced virological response to an SQV-plus-RTV regimen: L24I, I62V, V82A/F/T/S, I84V, and L90IM. Patients with isolates harboring 0 to 1 mutation among the score achieved -2.20 log10 and -1.23 log10 copies/ml of VL reduction, respectively, while it was -0.27 log10 copies/ml for those with at least two mutations, classifying the isolates as "no evidence of resistance" (0 or 1 mutation) or "resistance " (> or =2 mutations). The minimum concentration in plasma (Cmin) of SQV alone was not associated with the virological response. However, the combination of the SQV Cmin and the genotypic score, expressed as the genotypic inhibitory quotient, was predictive of the virological response, suggesting that the interpretation of SQV concentrations in plasma should be done only in the context of the resistance index provided by viral genotype for PI-experienced patients.

Amprenavir inhibitory quotient and virological response in human immunodeficiency virus-infected patients on an amprenavir-containing salvage regimen without or with ritonavir.

The efficacy of an amprenavir (APV)-containing therapy without (group A) or with (group B) ritonavir was assessed in patients with failure of previous protease inhibitor therapy for human immunodeficiency virus (HIV) infection. The mean minimal plasma APV concentrations in groups A and B were 58 and 1,320 ng/ml, respectively, corresponding to APV inhibitory quotients of 0.2 (range, 0.03 to 0.70) and 7.0 (range, 1.4 to 145), respectively. At week 24, 2 of 8 and 13 of 14 patients in groups A and B, respectively, had <200 HIV RNA copies/ml of plasma, including 4 of 5 patients infected with APV-resistant viruses.

Genotypic inhibitory quotient as predictor of virological response to ritonavir-amprenavir in human immunodeficiency virus type 1 protease inhibitor-experienced patients.

Forty-nine protease inhibitor (PI)-experienced but amprenavir (APV)-naïve patients experiencing virological failure were treated with ritonavir (RTV) (100 mg twice a day [b.i.d.]) plus APV (600 mg b.i.d.). Patients responded to therapy with a median viral load decrease of -1.32 log(10) by week 12. The addition of low-dose RTV enhanced the minimal APV concentration in plasma (APV C(min)) up to 10-fold compared with that obtained with APV (1,200 mg b.i.d.) without RTV. Baseline PI resistance mutations (L10F/I/V, K20M/R, E35D, R41K, I54V, L63P, V82A/F/T/S, I84V) identified by univariate analysis and included in a genotypic score and APV C(min) at week 8 were predictive of the virological response at week 12. The response to APV plus RTV was significantly reduced in patients with six or more of the resistance mutations among the ones defined above. The genotypic inhibitory quotient, calculated as the ratio of the APV C(min) to the number of human immunodeficiency virus type 1 protease mutations, was a better predictor than the virological or pharmacological variables used alone. This genotypic inhibitory quotient could be used in therapeutic drug monitoring to define the concentrations in plasma needed to control replication of viruses with different levels of PI resistance, as measured by the number of PI resistance mutations.

Resistance profiles observed in virological failures after 24 weeks of amprenavir/ritonavir containing regimen in protease inhibitor experienced patients.

Amprenavir (APV) is an HIV protease inhibitor (PI) used for the treatment of either naive or PI-experienced HIV-infected patients. Several genotypic resistance pathways in protease gene have been described to be associated to unboosted APV failure (I50V, V32I + I47V, I54L/M, or less commonly I84V, which may be accompanied by one ore more accessory mutations such as L10F, L33F, M46I/L). The aims of this study were to investigate the efficacy up to week 24 of an APV plus ritonavir containing regimen in PI experienced patients and to determine the genotypic resistance profiles emerging in patients failing to this therapy. Forty-nine, PI experienced but APV naïve patients were treated with APV (600 mg bid) plus ritonavir (100 mg bid). By intent-to-treat analysis, the median decrease in viral load (VL) was -1.32 log10 (min +0.6; max -2.8) and -1.46 log10 (min +0.5; max -2.8) 12 and 24 weeks after initiating APV plus ritonavir regimen, respectively. Twelve patients harboured a VL >200 copies/ml at week 24. Among these patients, the selection of mutations previously described with the use of APV as first PI (V32I, L33F, M46I/L, I50V, 54M/L, and I84V) was observed. However, in some cases, mutations classically described after the use of other PIs (V82F and L90M) were selected but always with APV-specific mutations. There was no relation between the resistance pathways selected with either APV or ritonavir plasma minimal concentration, but higher APV plasma minimal concentration were associated with a lower rate of resistance mutations selection.