Early treatment of cold sores with topical ME-609 decreases the frequency of ulcerative lesions: A randomized, double-blind, placebo-controlled, patient-initiated clinical trial

COMPARATIVE EFFICACY OF ANTIVIRAL AGENTS FOR PREVENTION AND MANAGEMENT OF HERPES LABIALIS: A SYSTEMATIC REVIEW AND NETWORK META-ANALYSIS

OBJECTIVE

To compare the relative efficacy and safety of antiviral agents used in the prevention and management of herpes labialis through a network meta-analysis of clinical trials.

METHODS

A systematic search was performed in Ovid Medline PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), Scopus and Clinicaltrials.gov for randomized controlled trials (RCTs) reporting a comparison of antiviral agents in the management and prevention of herpes labialis in healthy/immunocompetent adults. The data extracted from the selected RCTs were assessed and a network meta-analysis (NMA) was performed. The interventions were ranked according to the surface under the cumulative ranking (SUCRA).

RESULTS

A total of 52 articles were included for qualitative synthesis and for the quantitative part, 26 articles were analyzed for the primary treatment outcome and 7 studies were analyzed for the primary prevention outcome. The combination therapy of oral valacyclovir and topical clobetasol was the best ranked with a mean reduction in healing time of -3.50 (95% CI -5.22 to -1.78) followed by vidarabine monophosphate of -3.22 (95% CI -4.59 to -1.85). No significant inconsistencies, heterogeneity, and publication bias were reported for TTH outcome analysis. For primary prevention outcomes, only 7 RCTs fulfilled the inclusion criteria, and none of the interventions was shown to be superior to each other. The absence of adverse events was reported by 16 studies, whereas other studies reported mild side effects only.

CONCLUSION

NMA highlighted that several agents were effective in the management of herpes labialis among which the combination of oral valacyclovir with topical clobetasol therapy was the most effective in reducing the time to heal. However, further studies are required to determine which intervention is the most effective in preventing the recurrence of herpes labialis.

40 Years after the Registration of Acyclovir: Do We Need New Anti-Herpetic Drugs?

Herpes simplex virus types 1 and 2 HSV1 and 2, namely varicella-zoster VZV and cytomegalovirus CMV, are among the most common pathogens worldwide. They remain in the host body for life. The course of infection with these viruses is often asymptomatic or mild and self-limiting, but in immunocompromised patients, such as solid organ or bone marrow transplant recipients, the course can be very severe or even life-threatening. Unfortunately, in the latter group, the highest percentage of infections with strains resistant to routinely used drugs is observed. On the other hand, frequent recurrences of genital herpes can be a problem even in people with normal immunity. Genital herpes also increases the risk of acquiring sexually transmitted diseases, including HIV infection and, if present in pregnant women, poses a risk to the fetus and newborn. Even more frequently than herpes simplex, congenital infections can be caused by cytomegalovirus. We present the most important anti-herpesviral agents, the mechanisms of resistance to these drugs, and the associated mutations in the viral genome. Special emphasis was placed on newly introduced drugs such as maribavir and brincidofovir. We also briefly discuss the most promising substances in preclinical testing as well as immunotherapy options and vaccines currently in use and under investigation.

Increasing antigen presentation on HSV-1-infected cells increases lesion size but does not alter neural infection or latency

CD8⁺ T cells have a role in the control of acute herpes simplex virus (HSV) infection and may also be important in the maintenance of latency. In this study we have explored the consequences of boosting the efficacy of CD8⁺ T cells against HSV by increasing the amount of an MHC I-presented epitope on the surface of infected cells. To do this we used HSVs engineered to express an extra copy of the immunodominant CD8⁺ T cell epitope in C57Bl/6 mice, namely gB₄₉₈ (SSIEFARL). Despite greater presentation of gB₄₉₈ on infected cells, CD8⁺ T cell responses to these viruses in mice were similar to those elicited by a control virus. Further, the expression of extra gB₄₉₈ did not significantly alter the extent or stability of latency in our mouse model, and virus loads in skin and sensory ganglia of infected mice were not affected. Surprisingly, mice infected with these viruses developed significantly larger skin lesions than those infected with control viruses and notably, this phenotype was dependent on MHC haplotype. Therefore increasing the visibility of HSV-infected cells to CD8⁺ T cell attack did not impact neural infection or latency, but rather enhanced pathology in the skin.

Intracellular imaging of docosanol in living cells by coherent anti-Stokes Raman scattering microscopy

Docosanol is an over-the-counter topical agent that has proved to be one of the most effective therapies for treating herpes simplex labialis. However, the mechanism by which docosanol suppresses lesion formation remains poorly understood. To elucidate its mechanism of action, we investigated the uptake of docosanol in living cells using coherent anti-Stokes Raman scattering microscopy. Based on direct visualization of the deuterated docosanol, we observed highly concentrated docosanol inside living cells 24 h after drug treatment. In addition, different spatial patterns of drug accumulation were observed in different cell lines. In keratinocytes, which are the targeted cells of docosanol, the drug molecules appeared to be docking at the periphery of the cell membrane. In contrast, the drug molecules in fibroblasts appeared to accumulate in densely packed punctate regions throughout the cytoplasm. These results suggest that this molecular imaging approach is suitable for the longitudinal tracking of drug molecules in living cells to identify cell-specific trafficking and may also have implications for elucidating the mechanism by which docosanol suppresses lesion formation.

Efficacy and safety of nucleoside antiviral drugs for treatment of recurrent herpes labialis: a systematic review and meta-analysis

OBJECTIVES

To evaluate the effectiveness and safety of nucleoside antiviral drugs for the treatment of recurrent herpes labialis.

METHODS

Randomized controlled trials that examined the effectiveness and/or safety of nucleoside antiviral drugs for recurrent herpes labialis were identified via a literature search. The parameters used to measure efficacy were time to healing of classic and all lesions, time to resolution of pain, and percentage of aborted lesions. Safety was assessed by evaluating the adverse events reported during treatment. Subgroup analyses based on the mode of application (topical/systemic) and type of nucleoside antiviral drugs were performed, as were sensitivity analyses of studies with a low risk of bias.

RESULTS

Our analysis included 16 publications reporting 25 randomized controlled trials (8453 patients). Nucleoside antiviral drugs decreased the time to healing of all lesions (mean difference: -0.74 days; 95% confidence interval: -0.86, -0.62), especially classic lesions (mean difference: -1.09 days; 95% confidence interval: -1.27, -0.92). They also reduced the time to resolution of pain (mean difference: -0.38 days; 95% confidence interval: -0.58, -0.18) and increased the percentage of aborted lesions (rate ratio: 1.15; 95% confidence interval: 1.07, 1.23). Valaciclovir more effectively reduced the time to healing of all lesions and the time to resolution of pain than did aciclovir. Both nucleoside antiviral drugs increased the percentage of aborted lesions, whereas penciclovir and famciclovir did not.

CONCLUSIONS

Nucleoside antiviral drugs are safe and beneficial for the treatment of recurrent herpes labialis; both systemic and topical formulations are recommended. Valaciclovir is more effective than aciclovir, especially in reducing the time to healing of lesions.

Effectiveness of topical corticosteroids in addition to antiviral therapy in the management of recurrent herpes labialis: a systematic review and meta-analysis

BACKGROUND

Recurrent herpes labialis (RHL) is one of the most common viral infections worldwide. The available treatments have limited efficacy in preventing the recurrence of ulcerative lesions and reducing the duration of illness. The objective of this review was to identify the effectiveness of topical corticosteroids in addition to antiviral therapy in the treatment of RHL infection.

METHODS

A systematic review of randomized clinical trials comparing the efficacy of combined therapy (topical corticosteroids with antiviral) with placebo or antiviral alone in the management of RHL was conducted. MEDLINE, EMBASE, CINAHL, Web of Science, the Cochrane library, and Google Scholar databases were searched. We used RevMan software to conduct the meta-analysis. A fixed-effects model was used for mild to moderate heterogeneity, whereas a random-effects model was used for significant heterogeneity. Heterogeneity among trials was established using I(2) and chi-square test for heterogeneity.

RESULTS

Four studies that fulfilled the selection criteria were included in this review. The total number of participants across included studies was 1,891 (range, 29 to 1,443). The antiviral drugs used were acyclovir, famciclovir, and valacyclovir. Corticosteroids used were 1% hydrocortisone and 0.05% fluocinonide. Pooled results showed that patients receiving combined therapy had a significantly lower recurrence rate of ulcerative lesions compared to those in both the placebo group (OR, 0.50; 95% CI, 0.39-0.66; P < .001) and the antiviral treatment alone group (OR, 0.73, 95% CI, 0.58-0.92; P = .007). The healing time was also significantly shorter in combined therapy in comparison to placebo (P < .001). However, there were no significant differences in healing time between combined therapy and antiviral alone. The adverse reactions in combined therapy were not significantly different than the placebo group (OR, 1.09; 95% C, 0.75-1.59; P = .85).

CONCLUSION

Treatment with combined therapy is safe and more effective than placebo or antiviral alone for preventing the recurrence of ulcerative lesions in RHL infection.

Novel composite efficacy measure to demonstrate the rationale and efficacy of combination antiviral-anti-inflammatory treatment for recurrent herpes simplex labialis

Historically, the primary target for research and treatment of recurrent herpes simplex labialis (HSL) has been limited to inhibiting herpes simplex virus (HSV) replication. Antiviral monotherapy, however, has proven only marginally effective in curtailing the duration and severity of recurrent lesions. Recently, the role of inflammation in the progression and resolution of recurrences has been identified as an additional target. This was evaluated in a randomized study comparing combination topical 5% acyclovir-1% hydrocortisone cream (AHC) with 5% acyclovir alone (AC; in the AHC vehicle) and the vehicle. The efficacy of each topical therapy was evaluated for cumulative lesion size--a novel composite efficacy endpoint incorporating episode duration, lesion area, and proportion of nonulcerative lesions. In that study, cumulative lesion area was significantly decreased with AHC compared with AC (25% decrease; P<0.05) and the vehicle (50% decrease; P<0.0001). As research continues in this arena, cumulative lesion area should be included as a measure of efficacy in clinical trials of recurrent HSL therapies.

Safety and tolerability of combination acyclovir 5% and hydrocortisone 1% cream in adolescents with recurrent herpes simplex labialis

A Phase 3, open-label, multicenter study was conducted to assess the safety of the combination of 5% acyclovir and 1% hydrocortisone cream (AHC cream) in the treatment of recurrent herpes simplex labialis (HSL) in immunocompetent adolescents. Eligible subjects were aged 12 to 17 years and had a history of recurrent labial herpes with two or more episodes during the last 12 months. Subjects initiated treatment at the first signs or symptoms of a herpes recurrence-at the earliest prodromal phase and preferably before the presence of papules or vesicles. Subjects applied the cream topically five times per day for 5 days. Adverse events, categorization of recurrence (ulcerative or nonulcerative), and maximum lesion area (maximum area of an ulcerative lesion) were assessed. Of the 134 subjects analyzed for safety, 131 had data for categorization of recurrence at the post-treatment visit 3 ± 1 weeks after the last dose. Seventy-eight subjects (59.5%) had nonulcerative recurrences, and 53 (40.5%) had ulcerative recurrences. All 131 subjects reached the stage of normal skin, with no signs or symptoms, at the follow-up visit. The mean maximum lesion area in the 53 subjects with ulcerative herpes lesion was 39 mm(2). Five subjects reported five adverse events (secondary herpes labialis recurrences, n = 2; infectious rhinitis, n = 1; application site inflammation, n = 1; bronchial asthma, n = 1). All adverse events were of mild to moderate intensity. The results of this study demonstrate that the combination of AHC cream is well tolerated in the treatment of recurrent HSL in adolescents.

Current management and recommendations for access to antiviral therapy of herpes labialis

Herpes labialis is a common skin infective condition, worldwide, which is primarily caused by HSV-1. Recurrent episodes of herpes labialis, also known as cold sores, can be frequent, painful, long-lasting and disfiguring for infected patients. At present, there are two types of antivirals for the treatment of herpes labialis, topical and oral, which are available over the counter or as prescription-only. The aim of antiviral therapy is to block viral replication to enable shortening the duration of symptoms and to accelerate healing of the lesions associated with herpes labialis. This review examines the evidence for the effectiveness of current topical and oral antivirals in the management of recurrent episodes of herpes labialis. In most countries, oral antivirals for herpes labialis are available as prescription-only. However, in early 2010, the oral antiviral famciclovir was reclassified from prescription-only medicine to pharmacist-controlled status in New Zealand. The benefits and risks associated with moving an antiviral therapy for herpes labialis from prescription-only to pharmacist-controlled status are reviewed here, and the implications for patients, general physicians and pharmacists are considered.

Helicase–primase inhibitors as the potential next generation of highly active drugs against herpes simplex viruses

Since the introduction of the nucleoside analogs decades ago, treatment of herpes simplex virus (HSV) infections has not seen much innovation, except for the development of their respective prodrugs. The inhibitors of the helicase–primase complex of HSV represent a very innovative approach to the treatment of herpesvirus disease, and this article considers the development of some representatives of this class of therapeutics. The molecular and biochemical features of the helicase–primase complex are considered and the development of three inhibitors of helicase–primase, BILS 179 BS, AIC316 and ASP2151, is described. The clinical development of AIC316 is at an advanced stage and displays general safety as well as favorable, long-lasting exposures in healthy volunteers. The first efficacy data from a Phase II trial with more than 150 HSV-2-positive subjects demonstrated dose-dependent antiviral activity.