Virologic response and safety of the abacavir/lamivudine fixed-dose formulation as part of highly active antiretroviral therapy: analyses of six clinical studies.

OBJECTIVE: We analyzed virologic response and safety data from six recent clinical studies conducted in antiretroviral-naïve subjects treated with ABC/3TC or its components to assess the impact of baseline viral load on efficacy and safety endpoints used in the ACTG5202 protocol. METHODS: Primary endpoints were time to virologic failure (confirmed HIV-1 RNA > or = 1,000 copies/mL at 16-24 weeks or > or = 200 copies/mL at > or = 24 weeks) and time to first grade 3 or 4 adverse event or laboratory abnormality that was at least one grade higher than at baseline. The survival distributions of both endpoints were estimated using the Kaplan-Meier method overall and by baseline viral load (<100,000 vs. 100,000 copies/mL). A weighted mean of the virologic response and 95% confidence intervals (CI) were calculated by inverse-variance weighting for baseline viral load 100,000 copies/mL across studies. RESULTS: For subjects with baseline HIV-1 RNA 100,000 copies/mL, the rate of virologic survival ranged from 87% to 95% by 48 weeks. Few subjects treated with ABC/3TC developed grade 3 or 4 adverse events, laboratory toxicities, or changes in lipid levels. The weighted mean (CI) for the pooled virologic response was 91% (87%-96%). CONCLUSION: Based on the A5202 endpoints, ABC/3TC-containing regimens in this analysis had a high rate of virologic survival and were generally well tolerated in antiretroviral-naïve subjects regardless of baseline viral load. The pooled virologic response for ABC/3TC in our analysis is higher than the A5202 estimate.

Once daily valacyclovir for reducing viral shedding in subjects newly diagnosed with genital herpes.

OBJECTIVE: Genital herpes (GH) recurrences and viral shedding are more frequent in the first year after initial HSV-2 infection. The objective of this study was to provide the first evaluation of valacyclovir 1 g once daily compared to placebo in reducing viral shedding in subjects newly diagnosed with GH. METHODS: 70 subjects were randomized to receive valacyclovir 1 g daily or placebo in a crossover design for 60 days with a 7-day washout period. A daily swab of the genital/anal-rectal area was self-collected for HSV-2 detection by PCR. Subjects attended the clinic for routine study visits and GH recurrence visits. Treatment differences were assessed using a nonparametric crossover analysis. RESULTS: 52 subjects had at least one PCR measurement in both treatment periods and comprised the primary efficacy population. Valacyclovir significantly reduced HSV-2 shedding during all days compared to placebo (mean 2.9% versus 13.5% of all days (P < .01), a 78% reduction). Valacyclovir significantly reduced subclinical HSV-2 shedding during all days compared to placebo (mean 2.4% versus 11.0% of all days (P < .01), a 78% reduction). However, 79% of subjects had no GH recurrences while receiving valacyclovir compared to 52% of subjects receiving placebo (P < .01). CONCLUSION: In this study, the frequency of total and subclinical HSV-2 shedding was greater than reported in earlier studies involving subjects with a history of symptomatic genital recurrences. Our study is the first to demonstrate a significant reduction in viral shedding with valacyclovir 1 g daily compared to placebo in a population of subjects newly diagnosed with HSV-2 infection.

Investigation into the multidimensional genetic basis of drug-induced Stevens-Johnson syndrome and toxic epidermal necrolysis.

OBJECTIVE: Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare severe blistering skin diseases, which are mainly caused by drugs. The two idiosyncratic conditions are distinguished on the basis of the degree of blistering, possibly representing diseases at different ends of the same spectrum. A genetic predisposition has been postulated. METHOD: We have retrospectively identified a heterogeneous group of patients with SJS and TEN (n = 73 cases, 141 matched controls) induced by a number of marketed drugs and evaluated effector candidate genetic predisposition. We have used a multivariate genetic analysis method for the first time to handle the heterogeneity of clinical presentation, drug etiology, ethnicity and gender in these adverse events. RESULTS: Our results show that predisposition varied according to ethnicity. There was a correlation for SJS with HLA-B*44, DRB1*07 and with the MHC ancestral 57.1 haplotype (and its constituents) in subjects who self-reported as Caucasians, which did not differ with gender. The HLA-DRB and -DRQ genetic predisposition to SJS seemed to be distinct from that of TEN, but further work is needed for both conditions to identify the causal variants. No conclusion concerning correlations with different drugs could be made because of small numbers in each drug group. CONCLUSION: This study stresses the importance of accurate clinical phenotyping, exemplifies a novel analysis method to dissect complicated samples and calls for collaborative prospective studies.

The effect of daily valacyclovir suppression on herpes simplex virus type 2 viral shedding in HSV-2 seropositive subjects without a history of genital herpes.

BACKGROUND: A substantial number of HSV-2 seropositive individuals lack a history of clinically recognized genital herpes. These individuals can transmit disease during periods of asymptomatic viral shedding. The frequency of asymptomatic shedding and the efficacy of antiviral therapy in reducing shedding has not been assessed in this population. OBJECTIVE: To compare the effect of valacyclovir 1 g once daily for 60 days versus placebo on asymptomatic viral shedding in immunocompetent, HSV-2 seropositive subjects without a history of symptomatic genital herpes infection. STUDY DESIGN: Seventy-three subjects were randomized to receive valacyclovir 1 g daily or placebo for 60 days each in a 2-way crossover design. A daily swab of the genital area was self-collected for HSV-2 detection by polymerase chain reaction. RESULTS: Fifty-six subjects with at least 1 polymerase chain reaction measurement in both treatment periods comprised the primary efficacy population. Valacyclovir significantly reduced shedding during subclinical days compared to placebo [mean, 1.5% vs. 5.1% of subclinical days (P <0.001), a 71% reduction]. Eighty-four percent of subjects had no shedding while receiving valacyclovir versus 54% of subjects on placebo (P <0.001). Eighty-eight percent of patients receiving valacyclovir had no recognized signs or symptoms versus 77% for placebo (P = 0.033). Valacyclovir was not associated with any safety risk compared with placebo. CONCLUSIONS: In this study, asymptomatic viral shedding occurred in a substantial number of HSV-2 seropositive subjects without a history of genital herpes. Valacyclovir 1 g daily significantly reduced asymptomatic shedding compared with placebo in this population.