These studies suggest that the glycoprotein D vaccine has efficacy against genital herpes in women who are seronegative for both HSV-1 and HSV-2 at base line but not in those who are seropositive for HSV-1 and seronegative for HSV-2. It had no efficacy in men, regardless of their HSV serologic status.
3Time-to-event curves analyzed by Cox proportional hazards regression are commonly used to describe the outcome of drug studies. This methodology has the advantage of using all available information, including patients who fail to complete the trial, such as in cancer chemotherapy or human immunodeficiency virus antiviral treatment studies. The goal of treatment in such studies may be to prevent the development of a complication, for example, Pneumocystis carinii pneumonia, and to describe the likelihood of this complication's developing in the treatment group compared to the control group. The hazard ratio describes the relative risk of the complication based on comparison of event rates.Hazard ratios have also been used to describe the outcome of therapeutic trials where the question is to what extent treatment can shorten the duration of the illness. However, the hazard ratio, a type of relative risk, does not always accurately portray the degree of abbreviation of the illness that occurred. In these circumstances, time-based parameters available from the time-to-event curve, such as the ratio of the median times of the placebo and drug groups, should be used to describe the magnitude of the benefit to the patient. The difference between hazard-based and time-based measures is analogous to the odds of winning a race and the margin of victory. The hazard ratio is the odds of a patient's healing faster under treatment but does not convey any information about how much faster this event may occur.We have observed that there is substantial confusion among clinicians and clinical investigators about the difference between the hazard ratio and the median ratio. This report presents examples of this confusion, the exact distinction between the two statistics, and proper use of the hazard ratio and median ratio when interpreting the results of clinical trials to patients. COX PROPORTIONAL HAZARDS MODELTime-to-event analysis. Clinical trials commonly record the length of time from study entry to a disease endpoint for a treatment and a control group. These data are commonly depicted with a Kaplan-Meier curve (Fig. 1), from which the median (time at which 50% of cases are resolved) and the mean (average resolution time) can be derived. The groups are compared by a time-to-event analysis (survival analysis) (1, 7). Time-to-event analysis provides a method to include patients who fail to complete the trial or do not reach the study endpoint (censored data) by making comparisons between the number of survivors in each group at multiple points in time. The alternative approach, excluding patients who are lost to follow-up, may introduce considerable bias because the data that these patients generate prior to their exit are important to the power and validity of the study. Time-to-event analysis can also incorporate information about subjects that may change over time (time-dependent covariates). Clinically important differences in the effect of treatment may be obscured if the proportions of survivors or recovered individu...
We performed daily examination of 80 patients with recurrent herpes simplex labialis to define the course of the disease and to identify quantitative and objective measurements for use in monitoring the efficacy of antiviral chemotherapy. Pain, lesion size, mean virus titers from lesion swabs (10(5) plaque-forming units [PFU]) and frequency of virus-positive lesions (89 per cent) were maximal during the first 24 hours and decreased thereafter. Lesion punch-biopsy virus titers increased from a mean of less than 10(1) PFU in the prodromal and erythema stages to a mean of 10(4.7) in the vesicle stage. MEasurements potentially useful in monitoring antiviral efficacy include: time to loss of crust, time to complete healing, intensity and duration of lesion pain, area defined by lesion virus titer and duration of lesion virus excretion, and maximum lesion virus titer after the first visit. Early application of topical antiviral therapy should theoretically be able to alter the course of this disease.
Genital human papillomavirus infection is one of the most common sexually transmitted diseases. Imiquimod is a new agent, an immune-response modifier, that has been demonstrated to have potent in vivo antiviral and antitumor effects in animal models. The present prospective, multicenter, double-blind, randomized, vehicle-controlled trial evaluated the efficacy and safety of daily patient-applied imiquimod for up to 16 weeks for the treatment of external genital warts. Wart recurrence was investigated during a 12-week treatment-free follow-up period. In the intent-to-treat analysis, baseline warts cleared from 49 of 94 (52%) patients treated with 5% imiquimod cream, 13 of 90 (14%) patients treated with 1% imiquimod cream, and 3 of 95 (4%) vehicle-treated patients; the differences between the groups treated with vehicle and imiquimod were significant (P< 0.0001). For subjects who completed the follow-up period, recurrence rates after a complete response were 19% (9 of 48 patients) in the 5% imiquimod cream group, 17% (2 of 12) in the 1% imiquimod cream group, and 0% (0 of 3) in the vehicle-treated group. There were no systemic reactions, although local skin reactions (generally of mild or moderate severity) were common, particularly in the 5% imiquimod cream group. Local reactions caused two patients to discontinue treatment. The most frequently reported local skin reactions were erythema, excoriation or flaking, and erosion. Patient-applied 5% imiquimod cream is effective for the treatment of external genital warts and has a favorable safety profile.
Herpes simplex viruses (HSVs) can cause a variety of infections, including genital herpes. Despite effective antiviral therapy, HSV infections remain a significant worldwide public health problem. Vaccines offer the best hope for controlling spread and limiting HSV disease. This article discusses the pathogenesis and immunobiology of mucocutaneous HSV infections, summarizes the spectrum of diseases caused by HSV, and provides a review of the field of HSV vaccine research. This article also discusses what might be realistically expected of a vaccine intended for control of genital herpes and explores the question of whether a vaccine that is effective in controlling genital HSV disease might also be effective in controlling nongenital HSV disease. The efficacy of such vaccines for the full spectrum of HSV disease will eventually determine the timing and targeting of immunization, ranging from selective immunization in preadolescence to universal childhood immunization as part of the routine childhood regimen.
Acyclovir cream has been available for the treatment of herpes labialis in numerous countries outside the United States for over a decade. Evidence for its efficacy comes from a few small clinical trials conducted in the 1980s. To examine more comprehensively the efficacy and safety of this formulation, we conducted two independent, identical, parallel, randomized, double-blind, vehicle-controlled, large-scale multicenter clinical trials. Healthy adults with a history of frequent herpes labialis were recruited from the general population, screened for eligibility, randomized equally to 5% acyclovir cream or vehicle control, given study medication, and told to self-initiate treatment five times daily for 4 days beginning within 1 h of the onset of a recurrent episode. The number of patients who treated a lesion was 686 in study 1 and 699 in study 2. In study 1, the mean duration of episodes was 4.3 days for patients treated with acyclovir cream and 4.8 days for those treated with the vehicle control (hazards ratio [HR] ؍ 1.23; 95% confidence interval [CI], 1.06 to 1.44; P ؍ 0.007). In study 2, the mean duration of episodes was 4.6 days for patients treated with acyclovir cream and 5.2 days for those treated with the vehicle control (HR ؍ 1.24; 95% CI, 1.06 to 1.44; P ؍ 0.006). Efficacy was apparent whether therapy was initiated "early" (prodrome or erythema lesion stage) or "late" (papule or vesicle stage). There was a statistically significant reduction in the duration of lesion pain in both studies. Acyclovir cream did not prevent the development of classical lesions (progression to vesicles, ulcers, and/or crusts). Adverse events were mild and infrequent.Acyclovir (ACV) has been found to be efficacious in the management of herpes labialis in a variety of formulations and routes of administration. ACV (5%) ointment (Zovirax ointment) accelerated healing of herpes labialis in immunocompromised patients (22). Peroral administration of 400 mg of ACV five times/day for 5 days significantly reduced virus shedding and reduced lesion healing time and the duration of lesion pain among the subgroup of patients who started treatment "early" (in the prodrome or erythema lesion stage) (19). Peroral ACV administered as prophylaxis at 400 mg two times/day significantly reduces the frequency of recurrent episodes and prevents herpes-associated erythema multiforme (4,8,11).Demonstration of the clinical efficacy of topical formulations of antiviral drugs among immunocompetent patients has been difficult because of the marked variance in lesion severity that occurs, necessitating large numbers of subjects; the rapid natural healing of lesions; and the difficulty in finding a topical drug formulation that facilitates skin penetration without causing undue skin irritation (15,16,20). Several studies with ACV ointment in immunocompetent subjects provided sparse evidence of efficacy in this population (1,6,13,17). ACV was shown to penetrate human skin more effectively in a cream than in an ointment formulation (3). According...
Therapy with r-HuEPO can increase the mean hematocrit and decrease the mean transfusion requirement in anemic patients with AIDS who are receiving zidovudine and have endogenous low erythropoietin levels (< or equal to 500 IU/L). Such therapy is of no apparent benefit in patients whose endogenous erythropoietin levels are higher than 500 IU/L.
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