Barbara A. da Silva

Loss of bone mineral density after antiretroviral therapy initiation, independent of antiretroviral regimen

Background:Decreased bone mineral density (BMD) has been described in HIV-infected patients initiating antiretroviral therapy (ART), but the contributions of ART and immunologic and/or virologic factors remain unclear. Methods:We compared total BMD changes over 96 weeks in 106 ART-naive HIV-infected subjects who were randomized to receive efavirenz (EFV) + zidovudine/lamivudine (n = 32) or lopinavir/ritonavir (LPV/r) + zidovudine/lamivudine induction (n = 74) for 24-48 weeks followed by LPV/r monotherapy. We also sought to identify factors associated with BMD loss, including markers of systemic inflammation [soluble tumor necrosis factor-α receptors (sTNFR I and II)]. Results:After 96 weeks, the mean percent change from baseline in total BMD was −2.5% (LPV/r) and −2.3% (EFV) (P < 0.01 for within-group changes in either arm; P = 0.86 for between-group differences). No alteration in the rate of BMD change was observed upon simplification to LPV/r monotherapy. Although soluble tumor necrosis factor-α receptor II concentrations at baseline and 24 weeks were at least marginally associated with subsequent changes in BMD (P = 0.06 and P = 0.028, respectively), these associations were no longer significant after adjustment for CD4+ T cell count. Subjects with lower baseline CD4+ T cell count, non-black race, and higher baseline glucose demonstrated a higher risk for >5% decrease in BMD. Conclusions:Similar decreases in BMD over 96 weeks occurred in ART-naive subjects receiving either EFV-based regimen or LPV/r-based regimen, which was not altered by simplification to LPV/r monotherapy and was unrelated to markers of tumor necrosis factor-α activity.

Serum immune activation markers are persistently increased in patients with HIV infection after 6 years of antiretroviral therapy despite suppression of viral replication and reconstitution of CD4+ T cells.

The effect of long-term antiretroviral therapy on serum immune activation markers was assessed in a cohort of 63 patients before and after 6 years of boosted lopinavir-based antiretroviral therapy. High levels of most markers were associated with lower CD4(+) T cell counts at baseline and at year 6, with the exception of soluble cytotoxic T lymphocyte antigen-4 (sCTLA-4); high levels of sCTLA-4 were associated with higher CD4(+) T cell counts at year 6. Abnormalities of serum immune activation markers persisted after 6 years of ART but probably had different causes. Further investigation of the clinical usefulness of assaying immunoglobulin A, neopterin, and sCTLA-4 levels to assess the effectiveness of treatments for human immunodeficiency virus (HIV) disease are warranted.

A 96-Week Comparison of Lopinavir-Ritonavir Combination Therapy Followed by Lopinavir-Ritonavir Monotherapy versus Efavirenz Combination Therapy

Antiretroviral-naive HIV-1-infected volunteers received zidovudine/lamivudine plus either lopinavir/ritonavir (n=104) or efavirenz (n=51). Lopinavir/ritonavir-treated subjects demonstrating 3 consecutive monthly HIV-1 RNA levels <50 copies/mL started lopinavir/ritonavir monotherapy. In previous-failure=failure analysis, 48% (lopinavir/ritonavir) and 61% (efavirenz) maintained HIV-1 RNA at <50 copies/mL through week 96, (P= .17; 95% confidence interval [CI] for the difference, -29% to 4%); in noncompletion=failure analysis, 60% (lopinavir/ritonavir) and 63% (efavirenz) maintained HIV-1 RNA at <50 copies/mL at week 96 (P= .73; 95% CI for the difference, -19% to 13%). Significant sparing of peripheral lipoatrophy was noted in the lopinavir/ritonavir simplification strategy. This study has provided important information for future studies using treatment simplified to lopinavir/ritonavir monotherapy.

A Once-Daily Lopinavir/Ritonavir-Based Regimen Is Noninferior to Twice-Daily Dosing and Results in Similar Safety and Tolerability in Antiretroviral-Naive Subjects Through 48 Weeks

Background:Lopinavir/ritonavir (LPV/r)-dosed twice daily has demonstrated durable efficacy in antiretroviral-naive and protease inhibitor (PI) -experienced patients. Study M05-730 compared LPV/r tablets dosed once daily vs. twice daily in antiretroviral-naive subjects. Methods:Six hundred sixty-four subjects were randomized to LPV/r soft gel capsules (SGCs) once daily, SGC twice daily, tablets once daily, and tablets twice daily, all with tenofovir and emtricitabine once daily. At week 8, all SGC-treated subjects were switched to tablets, maintaining randomized dose frequency. The primary efficacy analysis used an intent-to-treat, noncompleter = failure approach to assess noninferiority of the LPV/r once-daily group compared with the twice-daily group. Results:At week 48, 77% of once-daily-dosed subjects vs. 76% of twice-daily-dosed subjects had HIV-1 RNA <50 copies per milliliter (P = 0.715; 95% confidence interval for difference: 5% to 8%). Response rates were numerically similar between the once-daily and twice-daily groups among subjects with baseline HIV-1 RNA ≥100,000 copies per milliliter (75% once daily vs. 74.6% twice daily; P > 0.999) or when analyzed by baseline CD4+ T-cell count (<50, 50 to <200, and ≥200 cells/mm3). Rates of discontinuation and adverse events, including diarrhea, were similar between arms. Among subjects with protocol-defined virologic rebound through week 48, no new PI resistance mutations were detected. Conclusions:At 48 weeks, the antiviral response in the LPV/r once-daily group was noninferior to the twice-daily group when coadministered with tenofovir and emtricitabine in antiretroviral-naive subjects. Efficacy was comparable between the once-daily and twice-daily groups regardless of baseline HIV-1 RNA or CD4+ T-cell count. Safety and tolerability of once-daily and twice-daily dosing was also comparable. No new PI resistance mutations were detected upon virologic rebound.

Seven-Year Efficacy of a Lopinavir/Ritonavir- Based Regimen in Antiretroviral-Naïve HIV-1-Infected Patients

Abstract Objective: Evaluate efficacy and tolerability of lopinavir/ritonavir (LPV/r) plus stavudine and lamivudine long term in antiretroviral-naïve patients. Design: Open-label follow-up of prospective, randomized, multicenter trial. Method: Antiretroviral-naïve HIV—infected subjects (N = 00) received of 3 doses of LPV/r plus stavudine and lamivudine for 48 weeks then received LPV/r soft-gel capsules 400/00 mg plus stavudine and lamivudine. After 6 years, subjects replaced stavudine with tenofovir. Results: At 7 years, by intent-to-treat analysis, 61 % had plasma HIV-RNA <400 copies/mL and 59% had < 50 copies/mL. Thirty-nine subjects discontinued treatment due to adverse events (n = 6), personal/other reasons (0), loss to follow-up (9), and noncompliance (4). Among 28 subjects qualifying for drug resistance testing, no protease inhibitor or stavudine resistance was observed and 4 showed lamivudine resistance. Most common drug-related moderate or severe adverse events were diarrhea (28%), nausea (6%), and abdominal pain (11 %). Subjects who received stavudine (median 6.6 years) and switched to tenofovir demonstrated significant improvements in total cholesterol (p = .009), triglycerides (p = .023), apolipoprotein C-III (p < .001 ), adiponectin (p = .008), fasting insulin (p = .04), and leptin (p = .03). Conclusion: LPV/r-based therapy demonstrated sustained efficacy with no protease inhibitor or stavudine resistance through 7 years in antiretroviral-naïve patients. Switching from stavudine to tenofovir resulted in significant improvements in multiple metabolic parameters.

Mitochondrial function, morphology and metabolic parameters improve after switching from stavudine to a tenofovir-containing regimen

OBJECTIVES HIV-associated lipoatrophy has been associated with mitochondrial dysfunction induced by nucleoside reverse transcriptase inhibitor therapy. We hypothesize that lipid profiles and markers of mitochondrial function will improve in HIV-lipoatrophic patients switched to the nucleotide analogue tenofovir. METHODS Ten patients receiving stavudine, lamivudine and lopinavir/ritonavir (Kaletra(R)) for over 6 years were switched from stavudine to tenofovir for 48 weeks. Subcutaneous fat tissue biopsies, fasting metabolic tests, HIV RNA, CD4 cell count and whole body dual energy X-ray absorptiometry (DEXA) scans were obtained at study entry and week 48. Mitochondrial DNA (mtDNA) copies/cell and mitochondrial morphology were assessed in adipose tissue biopsies, mtDNA 8-oxo-deoxyguanine in peripheral blood mononuclear cells, and glutathione (GSH) and F2-isoprostane in plasma. RESULTS There was no change in limb fat mass by DEXA; however, trunk fat mass increased by 18.9% (P = 0.01). Fasting total cholesterol decreased by 33 mg/dL (P = 0.005) and serum glucose decreased by 4 mg/dL (P = 0.039). mtDNA copies/cell increased from 386 to 1537 (P < 0.001). Transmission electron microscopy showed that mitochondrial cristae were lacking or poorly defined at study entry, whereas mitochondrial inner structures were more well defined and outer membranes were intact at 48 weeks. Oxidative damage decreased in 8/10 patients, GSH increased and F2-isoprostane decreased. CONCLUSIONS The results from this study demonstrate that systemic and peripheral fat mitochondria improve in patients switched to tenofovir following long-term exposure to stavudine, while continuing protease inhibitor therapy.

Evidence of Ongoing Immune Reconstitution in Subjects with Sustained Viral Suppression following 6 Years of Lopinavir-Ritonavir Treatment

BACKGROUND We evaluated the immunologic impact of highly active antiretroviral therapy in subjects who maintained human immunodeficiency virus type 1 (HIV-1) suppression through 6 years of receiving a lopinavir-ritonavir-based regimen. METHODS A total of 100 antiretroviral-naive subjects with any CD4+ T cell count initiated therapy with lopinavir-ritonavir, stavudine, and lamivudine. Sixty-three subjects who remained in the study for 6 years were assessed. Laboratory measurements included plasma HIV-1 RNA levels, multiparameter flow cytometry of immune cells, and markers of maturation and activation. RESULTS After 6 years, 62 of 63 subjects had plasma HIV-1 RNA levels <50 copies/mL. The mean increase in CD4+ T cell count was 528 cells/microL (P<.001), and 81% of subjects had CD4+ T cell counts >500 cells/microL, compared with 21% of subjects at baseline. The mean ratio of CD4+ T cell count to CD8+ T cell count increased from 0.38 at baseline to 0.96 at year 6 (P<.001). The percentage of subjects with cell counts below the lower limit of normal at year 6, compared with at baseline, was significantly decreased for total T cells, B cells, and natural killer cells. At year 6, the median CD4+ T cell activation level was 3.4%, and the median CD8+ T cell activation level was 5.8%. CONCLUSIONS The receipt of a lopinavir-ritonavir-based regimen resulted in ongoing immune reconstitution through 6 years of therapy in a cohort of HIV-1-infected, antiretroviral-naive subjects with suppressed HIV-1 RNA levels. Normalization of activation marker expression on CD4+ and CD8+ T cell subsets was demonstrated.

Liver Injury and Changes in Hepatitis C Virus (HCV) RNA Load Associated with Protease Inhibitor–Based Antiretroviral Therapy for Treatment-Naive HCV-HIV–Coinfected Patients: Lopinavir-Ritonavir versus Nelfinavir

BACKGROUND Highly active antiretroviral therapy (HAART) initiation in patients coinfected with human immunodeficiency virus type 1 (HIV-1) and hepatitis C virus (HCV) has been associated with transaminase and HCV viral load flares. Previous studies have included highly variable antiretroviral regimens. We compared effects of 2 protease inhibitor-based regimens on alanine aminotransferase (ALT) levels and HCV loads in HCV-HIV-coinfected patients initiating HAART. METHODS Seventy HIV-infected patients with positive baseline results of HCV enzyme-linked immunosorbant assay from a treatment trial comparing lopinavir-ritonavir with nelfinavir were evaluated during a 48-week period. HCV and HIV titers were analyzed at baseline, at weeks 24 and 48 of treatment, and during flares in the ALT level of >5 times the upper limit of normal. RESULTS A total of 57 of 70 patients tested positive for HCV RNA at baseline. HCV titers for patients in lopinavir-ritonavir and nelfinavir groups, respectively, were as follows: baseline, 6.07 and 6.22 log IU/mL; week 24 of treatment, 6.68 and 6.48 log IU/mL; and week 48 of treatment, 6.32 and 6.44 log IU/mL. Of patients with a CD4+ cell count of <100 cells/mm3 at baseline, 5 of 11 in the nelfinavir group and 0 of 10 in the lopinavir-ritonavir group had an increase in the HCV load of >0.5 log IU/mL from baseline to week 48. The mean ALT level increased by 45 U/L at 24 weeks and 18 U/L at 48 weeks in the nelfinavir group but decreased by 18 U/L at 24 weeks and 7 U/L at 48 weeks in the lopinavir-ritonavir group. Eight patients in the nelfinavir group and 2 patients in the lopinavir-ritonavir group had grade 3 or 4 flares in the ALT level. CONCLUSIONS HAART initiation is associated with increased HCV loads and ALT levels. A low baseline CD4+ cell count is associated with persistent increases in the HCV RNA load in nelfinavir-treated patients. These results warrant careful interpretation of abnormalities in the ALT load after HAART initiation in HCV-HIV-coinfected patients to prevent premature discontinuation of treatment.

Geographic and temporal trends of transmitted HIV-1 drug resistance among antiretroviral-naïve subjects screening for two clinical trials in North America and Western Europe.

Abstract Purpose: To determine the prevalence of transmitted drug resistance (TDR) in antiretroviral (ARV)-naïve HIV-1-infected subjects who were screened for two clinical trials by geographic region and time. Methods: Studies M03-613 and M05-730 screened ARV-naïve subjects in 2004 and 2005–2006, respectively. Screening drug resistance genotype assays were performed using population sequencing, and prevalence of drug resistance mutations (DRMs) was assessed at 39 amino acid positions in HIV-1 protease and reverse transcriptase (RT) and compared between geographic regions and calendar years. Results: In 913 subjects, the prevalence of DRMs was higher in North America than in Western Europe, including any DRM (13.6% vs. 6.8%, p < .001), non-nucleoside reverse transcriptase inhibitor (NNRTI) DRMs (7.3% vs. 3.2%, p = .006), protease inhibitor (PI) DRMs (3.6% vs. 0.8%, p = .004), and nucleoside reverse transcriptase inhibitor (NRTI) DRMs (6.1% vs. 3.8%, p = ns). The prevalence of TDR to NNRTIs was higher compared to PIs within each region (p = .031 for North America, and p = .011 for Western Europe). Logistic regression analysis suggested a higher prevalence of DRMs in 2005–2006 compared to 2004 for NNRTIs (p = .03) and, to a lesser extent, for PIs (p = .07). Conclusion: TDR to NNRTIs was more frequent than to PIs in both geographic regions, increased over time, and was highest in North America.

Predictors of Loss of Virologic Response in Subjects Who Simplified to Lopinavir/Ritonavir Monotherapy from Lopinavir/Ritonavir Plus Zidovudine/Lamivudine

Previous studies have demonstrated that lopinavir/ritonavir monotherapy maintained plasma HIV-1 RNA suppression in a large proportion of antiretroviral naive subjects. However, more subjects receiving lopinavir/ritonavir monotherapy experienced confirmed virologic rebound >50 copies/ml compared to a standard three-drug HAART regimen. In this study, we sought to determine the factors associated with maintenance of virologic suppression in subjects receiving lopinavir/ritonavir monotherapy. Antiretroviral-naive HIV-1-infected volunteers were randomized 2:1 to initiate a lopinavir/ritonavir-based combination regimen followed by simplification to lopinavir/ritonavir monotherapy or an efavirenz-based triple combination therapy and followed for 96 weeks. Potential predictors of time to loss of virologic response included baseline demographics, baseline HIV-1 RNA levels, baseline CD4(+) T cell counts, adherence as determined by 4-day subject recall, duration of HIV-1 RNA <50 copies/ml prior to simplification, and lopinavir concentrations. By the Cox proportional hazards model, higher reported adherence levels and higher baseline CD4(+) T cell counts were associated with a greater likelihood of maintaining virologic suppression while receiving lopinavir/ritonavir monotherapy. Lopinavir concentrations, including trough concentrations, were not significantly associated with virologic outcomes. This analysis suggests that adherence and higher baseline CD4(+) T cell counts may help to predict who will sustain virologic suppression with lopinavir/ritonavir monotherapy. The data also suggest that measuring lopinavir concentrations is not useful in predicting virologic response in these patients.