Immunologic and virologic failure after first-line NNRTI-based antiretroviral therapy in Thai HIV-infected children.

BACKGROUND: There are limited data of immunologic and virologic failure in Asian HIV-infected children using non-nucleoside reverse transcriptase inhibitor (NNRTI)-based highly active antiretroviral therapy (HAART). We examined the incidence rate of immunologic failure (IF) and virologic failure (VF) and the accuracy of using IF to predict VF in Thai HIV-infected children using first-line NNRTI-based HAART. METHODS: Antiretroviral (ART)-naïve HIV-infected children from 2 prospective cohorts treated with NNRTI-based HAART during 2001-2008 were included. CD4 counts were performed every 12 weeks and plasma HIV-RNA measured every 24 weeks. Immune recovery was defined as CD4%≥25%. IF was defined as persistent decline of ≥5% in CD4% in children with CD4%<15% at baseline or decrease in CD4 count ≥30% from baseline. VF was defined as HIV-RNA>1,000 copies/ml after at least 24 weeks of HAART. Clinical and laboratory parameter changes were assessed using a paired t-test, and a time to event approach was used to assess predictors of VF. Sensitivity and specificity of IF were calculated against VF. RESULTS: 107 ART-naive HIV-infected children were included, 52% female, % CDC clinical classification N:A:B:C 4:44:30:22%. Baseline data were median (IQR) age 6.2 (4.2-8.9) years, CD4% 7 (3-15), HIV-RNA 5.0 (4.9-5.5) log10copies/ml. Nevirapine (NVP) and efavirenz (EFV)-based HAART were started in 70% and 30%, respectively.At 96 weeks, none had progressed to a CDC clinical classification of AIDS and one had died from pneumonia. Overall, significant improvement of weight for age z-score (p = 0.014), height for age z-score, hemoglobin, and CD4 were seen (all p < 0.001). The median (IQR) CD4% at 96 weeks was 25 (18-30)%. Eighty-nine percent of children had immune recovery (CD4%≥25%) and 75% of children had HIV-RNA <1.7log10copies/ml.Thirty five (32.7%) children experienced VF within 96 weeks. Of these, 24 (68.6%) and 31 (88.6%) children had VF in the first 24 and 48 weeks respectively.Only 1 (0.9%) child experienced IF within 96 weeks and the sensitivity (95%CI) of IF to VF was 4 (0.1-20.4)% and specificity was 100 (93.9-100)%. CONCLUSION: Immunologic failure, as defined here, had low sensitivity compared to VF and should not be recommended to detect treatment failure. Plasma HIV-RNA should be performed twice, at weeks 24 and 48, to detect early treatment failure. TRIAL REGISTRATION: Clinicaltrials.gov identification number NCT00476606.

Antiretroviral treatment outcome following genotyping in Thai children who failed dual nucleoside reverse transcriptase inhibitors.

OBJECTIVE: To evaluate outcomes in dual nucleoside reverse transcriptase inhibitor (NRTI) pretreated children after genotyping (GT). METHODS: We assessed CD4 and viral load (VL) in children three years after baseline GT at the time of dual NRTI failure. Baseline high grade resistance (HR) was defined as >or=4 nucleoside analogue mutations (NAMs)+/-Q151M or 69 insertion complex, and low grade resistance (LR) was defined as <4 NAMs. Genotypic susceptibility scores (GSS) were determined. The current selection of antiretrovirals (ARV) was based on physician judgment and ARV availability. RESULTS: Seventy-two children were enrolled, with a mean age of 9.3 years; 61% were female. Baseline median CD4 was 18%, VL was 1.7 log(10) with HR 37.5%, LR 56.9% and no mutation (NR, no resistance) 5.6%. Sixty-five (90.3%) switched ARV: 46.2% non-nucleoside reverse transcriptase inhibitor (NNRTI), 30.8% protease inhibitor (PI), and 23.1% PI+NNRTI based highly active antiretroviral therapy (HAART). The choice of regimen did not differ based on baseline HR, LR, and NR. The median duration from dual NRTI therapy to HAART was 5.4 years (interquartile range (IQR) 4.0-6.9 years) and the mean (SD) duration of current HAART regimen was 1.51 (1.78) years; both were similar between ARV groups. Five children continued dual NRTI, two interrupted therapy. The GSS score was significantly higher in the PI group (3.1) vs. PI+NNRTI (2.5) vs. NNRTI (2.6) groups. Sixty-three percent of the HR group used PI or PI+NNRTI-based HAART compared to 41% of the LR group, p=not significant. At follow-up, median CD4 changes from baseline were +5% and VL -2.2 log(10) (p<0.001). VL <1.7 log(10) was seen in 59.3% of HR, 58.5% of LR, and 50.0% of NR groups (no significant difference). More children on PI (75%) and PI+NNRTI (80%) based HAART had VL <50 compared to NNRTI-based HAART (50%), p=0.003. CONCLUSION: PI-based regimens showed a higher rate of undetectable VL compared with NNRTI-based regimens. Having GT may not affect second-line treatment choices in developing countries, most likely due to late VL failure and limited availability of PIs.

Therapeutic drug monitoring of lopinavir in human immunodeficiency virus-infected children receiving adult tablets.

Because of the lack of a lopinavir/ritonavir (LPV/r) pediatric formulation, 54 HIV-infected children were given generic LPV/r adult tablets. Of 54 children, 21 took cut pills to get the appropriate dose. The median (interquartile range) LPV trough serum concentration (C trough) was 6.7 (5.0-9.9) mg/L. All the children had C trough >1.0 mg/L and 96% had values >4.0 mg/L. LPV/r adult tablets can be used in children when it is necessary.

Pharmacokinetics and 48 week efficacy of low-dose lopinavir/ritonavir in HIV-infected children.

BACKGROUND: Lopinavir/ritonavir is a common protease inhibitor (PI) used for second-line regimens in children. Several studies have shown higher plasma concentrations of antiretroviral agents in Thai adults than in Caucasians, suggesting that lower doses may be used. METHODS: An open label study in 24 HIV-infected children between the age of 2 and 18 years, naive to PIs, randomized to receive either the WHO-recommended dose of lopinavir/ritonavir or a low dose (70% of the standard dose) twice daily in combination with zidovudine and lamivudine. A 12 h pharmacokinetic study was done at 4-6 weeks after starting treatment. Treatment outcomes were evaluated at week 48. The clinical trial number of the study is NCT00887120. RESULTS: The medians [interquartile ranges (IQRs)] of age, body surface area, percentage CD4 and plasma HIV RNA were 9.5 years (7.0-12.3), 0.9 m(2) (0.8-1.1), 17% (11%-24%) and 4.6 log(10) copies/mL (4.1-4.9), respectively. The median (IQR) lopinavir dose was 279 mg/m(2)/dose (263-294) and 194 mg/m(2)/dose (176-206) in the standard and low-dose arms, respectively. Median (IQR) AUC(0-12) and C(trough) of lopinavir were 117.6 mg.h/L (74.0-128.5) and 4.9 mg/L (2.7-8.0) for the standard arm and 83.8 mg.h/L (56.0-112.9) and 3.4 mg/L (2.7-5.4) for the low-dose arm. One child in the low-dose arm had a lopinavir pre-dose level of <1.0 mg/L. At week 48, the median percentage CD4 was 22% (15%-28%) and 27% (21%-31%) in the standard and low-dose arms, respectively, while 50% and 83% of children had HIV RNA <50 copies/mL, respectively (P = 0.19). CONCLUSIONS: Low-dose lopinavir displayed adequate pharmacokinetic parameters and good efficacy as compared with standard-dose lopinavir in Thai children. A larger study to investigate the efficacy of low-dose lopinavir is warranted.

Pattern and predictors of immunologic recovery in human immunodeficiency virus-infected children receiving non-nucleoside reverse transcriptase inhibitor-based highly active antiretroviral therapy.

BACKGROUND: Non-nucleoside reverse transcription inhibitor (NNRTI)-based highly active antiretroviral therapy (HAART) is the recommended first-line regimen for children in Thailand. This study was aimed to assess pattern and predictors of immune recovery in antiretroviral-naive Thai children starting NNRTI-based HAART. METHODS: Records were extracted from clinical databases of 2 treatment cohorts in Thailand. The inclusion criteria were HIV-infected naive children who initiated NNRTI-based HAART when CD4 <25%. Immune recovery was defined as achieving a target CD4% of 25. The impact of age, gender, baseline clinical category, CD4 and HIV RNA titer, and regimen on immune recovery to weeks 96 was assessed using multiple logistic regression. RESULTS: There were 274 patients (52% females) with a median baseline age of 7 (Interquartile range [IQR]: 4-9) years and a median CD4% of 5 (IQR: 1-12) who started treatment with nevirapine (66%) or efavirenz (34%) based HAART. Median duration of follow-up was 168 (IQR: 120-192) weeks. The median CD4% increase from baseline was 7% (IQR: 5-11) and 18% (IQR: 12-23) at weeks 24 and 96, respectively. The probability of reaching target CD4% was 51% (95% confidence interval: 45%-57%) by week 96. The predictors of immune recovery at week 96 were younger age, female gender, higher baseline CD4%, and sustained virologic suppression after week 24. CONCLUSION: In this cohort of children with low baseline CD4, half achieved immune recovery after 96 weeks of HAART. The predictors for immune recovery are younger children, female gender, high baseline CD4%, and long-term virologic suppression.

Safety and efficacy of a double-boosted protease inhibitor combination, saquinavir and lopinavir/ritonavir, in pretreated children at 96 weeks.

BACKGROUND: This study aimed to assess the long-term efficacy, safety and use of therapeutic drug monitoring (TDM) of a double-boosted protease inhibitor (PI) combination, saquinavir (SQV) and lopinavir/ritonavir (LPV/r), in Thai HIV type-1 (HIV-1)-infected children who had failed on reverse transcriptase inhibitors. METHODS: In total, 50 children from two sites in Thailand were treated with standard dosing of SQV and LPV/r. CD4(+) T-cell count and percentage, viral load (VL; HIV-1 RNA), minimum plasma drug concentrations (C(min)) and drug safety laboratory evaluations were monitored. Virological failure was defined as having two consecutive VL measures >400 copies/ml after week 12. An intention-to-treat analysis was performed. RESULTS: Baseline data were a median age of 9.3 years (interquartile range [IQR] 7.1-11.2), VL 4.8 log(10) copies/ml (IQR 4.5-5.1) and CD4(+) T-cell percentage 7% (IQR 3.0-9.5). CDC classifications were N=4%, A=14%, B=68% and C=14% of participants. Median CD4(+) T-cell percentage and CD4(+) T-cell count increase were 14% (IQR 7-19) and 558 cells/mm(3) (IQR 308-782), respectively (both P<0.001). Overall, 37 (74%) children achieved VL<50 copies/ml with significant differences between sites (90% versus 63%). Over 96 weeks, 10 patients had virological failure. Total cholesterol and high-density lipoprotein increased significantly over time, whereas the triglycerides and low-density lipoprotein did not. Approximately 50% of participants reported no change in body shape, and 33%, 43% and 39% reported fatter arms, face and abdomen, respectively. LPV and SQV C(min) were high and stable over time. CONCLUSIONS: Double-boosted SQV+LPV/r was an effective and safe alternative for a second-line regimen in children. Hypercholesterolaemia needs close follow-up. On the basis of the TDM results, PI dose reduction in this population should be considered.

Double boosted protease inhibitors, saquinavir, and lopinavir/ritonavir, in nucleoside pretreated children at 48 weeks.

OBJECTIVES: To assess the 48-week efficacy, safety, pharmacokinetics, and resistance of double boosted protease inhibitors (PI), saquinavir (SQV), and lopinavir/ritonavir (LPV/r), in children who have failed nucleoside reverse transcription inhibitors /non-nucleoside reverse transcription inhibitors-based regimens. METHODS: Fifty children at 2 sites in Thailand were treated with standard dosing of SQV and LPV/r. CD4, HIV-RNA viral load (VL), plasma drug concentrations and safety laboratory evaluations were monitored. Virologic failure was defined as having 2 consecutive VL >400 copies/mL after week 12 of therapy. Intention to treat analysis was performed. RESULTS: Baseline data were a median age of 9.3 years (interquartile range [IQR]: 7.1-11.2), Center for Disease Control and Prevention (CDC) classification N:A:B:C 4%:14%:68%:14%, VL 4.8 log10 (IQR: 4.5-5.1), CD4 7% (IQR: 3-9.5). At 48 weeks, 3 had died of bacterial infection but no cases had progressed CDC classification. Median CD4% rise was 9 (IQR: 5-16) and median HIV RNA reduction was -2.8 log10 (IQR: -3.2 to -1.4), both P < 0.001. Thirty-nine (78%) and 32 (64%) children had VL <400 and <50 with significant differences between the 2 sites. Five children (10%) had VL failure as a result of poor adherence to the drug regimen but no one had major PI mutations. Median serum cholesterol and triglyceride increased significantly (+35 mg/dL, +37 mg/dL, respectively, both P < 0.001). Mean minimum plasma concentrations (Cmin) of LPV and SQV were 4.6 and 1.24 mg/L, respectively. CONCLUSIONS: Double boosted SQV/LPV/r resulted in significant CD4 rise and VL decline at 48 weeks. Hyperlipidemia was common. Cmin of both PIs exceeded therapeutic concentrations. Poor adherence caused failure in 10%. No major PI mutations were found.