A randomized, controlled, safety study using imiquimod for the topical treatment of anogenital warts in HIV-infected patients. Imiquimod Study Group

Trial watch: FDA-approved Toll-like receptor agonists for cancer therapy

Toll-like receptors (TLRs) have first been characterized for their capacity to detect conserved microbial components like lipopolysaccharide (LPS) and double-stranded RNA, resulting in the elicitation of potent (innate) immune responses against invading pathogens. More recently, TLRs have also been shown to promote the activation of the cognate immune system against cancer cells. Today, only three TLR agonists are approved by FDA for use in humans: the bacillus Calmette-Guérin (BCG), monophosphoryl lipid A (MPL) and imiquimod. BCG (an attenuated strain of Mycobacterium bovis) is mainly used as a vaccine against tuberculosis, but also for the immunotherapy of in situ bladder carcinoma. MPL (derived from the LPS of Salmonella minnesota) is included in the formulation of Cervarix®, a vaccine against human papillomavirus-16 and -18. Imiquimod (a synthetic imidazoquinoline) is routinely employed for actinic keratosis, superficial basal cell carcinoma, and external genital warts (condylomata acuminata). In this Trial Watch, we will summarize the results of recently completed clinical trials and discuss the progress of ongoing studies that have evaluated/are evaluating FDA-approved TLR agonists as off-label medications for cancer therapy.

Treatment of intra-anal warts with imiquimod 5% cream: A single-center prospective open study

Intra-anal warts are frequently recalcitrant to surgical removal, but imiquimod 5% cream is not formulated to use in clinical practice due to the risk of mucosal inflammation. In the present, prospective, open study examining the efficacy and safety of imiquimod 5% cream, the drug was applied to the entire inner surface of the anal canal with a cotton swab under anoscopy three times weekly for 16 weeks. If complete remission was not achieved, the treatment was continued until week 28. Electrocautery was applied once in a poorly responsive case. In total, 21 patients with intra-anal warts, of whom 16 were HIV-positive, were enrolled. Two patients withdrew before week 16, and nine more patients withdrew before week 28. The complete clearance rate was 36.8% (7/19) at week 16 and 70% (7/10) at week 28. Four patients achieved complete clearance at week 16 and maintained clearance at week 28 without further treatment. Three of four patients resistant to previous electrocautery achieved clearance with imiquimod 5% cream treatment. Adverse events occurred in 81% (17/21) of the patients mainly at the application site, but serious or previously unencountered adverse events were not observed. Imiquimod 5% cream applied to intra-anal warts was nearly as efficacious and safe as when applied to external anogenital warts. Since treatment modalities for intra-anal warts are very limited, application of imiquimod 5% cream alone with careful and frequent observation or in combination with electrocautery is a useful option for refractory cases of intra-anal wart.

Effectiveness of topical and ablative therapies in treatment of anogenital warts: a systematic review and network meta-analysis

OBJECTIVE

To generate estimates of comparative clinical effectiveness for interventions used in the treatment of anogenital warts (AGWs) through the systematic review, appraisal and synthesis of data from randomised controlled trials (RCTs).

DESIGN

Systematic review and network meta-analysis of RCTs. Search strategies were developed for MEDLINE, Embase, the Cochrane Library and the Web of Science. For electronic databases, searches were run from inception to March 2018. The systematic review was carried out following the general principles recommended in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement.

PARTICIPANTS

People aged ≥16 years with clinically diagnosed AGWs (irrespective of biopsy confirmation).

INTERVENTIONS

Topical and ablative treatments recommended by the British Association for Sexual Health and HIV for the treatment of AGWs, either as monotherapy or in combination versus each other.

OUTCOME MEASURES

Complete clearance of AGWs at the end of treatment and at other scheduled visits, and rate of recurrence.

RESULTS

Thirty-seven RCTs met inclusion criteria. Twenty studies were assessed as being at unclear risk of bias, with the remaining studies categorised as high risk of bias. Network meta-analysis indicates that, of the treatment options compared, carbon dioxide laser therapy is the most effective treatment for achieving complete clearance of AGWs at the end of treatment. Of patient-applied topical treatments, podophyllotoxin 0.5% solution was found to be the most effective at achieving complete clearance, and was associated with a statistically significant difference compared with imiquimod 5% cream and polyphenon E 10% ointment (p<0.05). Few data were available on recurrence of AGWs after complete clearance. Of the interventions evaluated, surgical excision was the most effective at minimising risk of recurrence.

CONCLUSION

Of the studies assessed, as a collective, the quality of the evidence is low. Few studies are available that evaluate treatment options versus each other.

TRIAL REGISTRATION NUMBER

CRD42013005457.

Sinecatechins 10% ointment for genital warts: Case report of a beneficial reaction in an HIV-positive woman

Patients with HIV infection are more likely to develop anogenital warts compared to HIV-negative people and are susceptible to treatment failures and recurrences. We report a case of extensive vulvar warts in an HIV-positive woman successfully treated with sinecatechins ointment. After the failure of a combination of cryotherapy and imiquimod 5% cream, we started therapy with sinecatechins 10% ointment. The patient developed an intense local inflammatory reaction after three weeks that induced the discontinuation of the therapy. After two weeks, we observed a complete regression of inflammation and a reduction of genital warts. The lesions completely regressed within a few weeks, with no relapse after eight months. Sinecatechins is a standardized extract of green tea leaves, effective in the treatment of external genital and perianal warts in immunocompetent patients, but their role has not been yet studied for immunocompromised people. Our case may represent a starting point for further studies, in order to evaluate the relation between treatment dosage, side effects, and drug response in immunocompromised patients.

Interferon-associated therapies toward HIV control: The back and forth

Human immunodeficiency virus (HIV) induces a persistent and incurable infection. However, the combined antiretroviral treatment (cART) has markedly changed the evolution of the infection and transformed a deadly disease into a manageable chronic infection. Withdrawal of cART generally leads though to resumption of the viral replication. The eradication of the virus from its cellular and anatomical reservoirs remains a goal-to-achieve for a cure. In this context, developing novel therapies contributing to this aim are an important field of research. Type I IFN has antiviral activity, which, before the presence of efficient anti-HIV drugs, has led to the testing of IFN-based therapeutic strategies during the early years of the pandemic. A historical overview of the results and its limitations that were put into light are reviewed here. In addition, several lessons could be drawn. For instance, the efficacy of the IFN-I depends on the timing of its administration and the context. Thus, the persistence of an endogenous IFN-signature, such as that generally observed in viremic patients, seems to be associated with a lower efficacy of IFN. Based on the lessons from previous trials, and in the context of cART and research for a cure, type I Interferon has regained interest and novel therapeutic approaches are currently tested in combination with cART, some with disappointing, other with encouraging results with regard to a reduction in the size of the HIV reservoir and/or delays in viral rebound after cessation of cART. Additional strategies are currently developed in addition to improve the antiviral function of the IFN-I, by using for instance other IFN subtypes than IFN-Iα2. In parallel, the development of innovative strategies aimed at counteracting the excessive activation of the IFN-pathways have been continued and their results are reviewed here as well. Altogether, the use of IFN-I in anti-HIV therapies has gone through distinct phases and many lessons could be drawn. Novel combinations are currently be tested that might provide interesting results.

A Pilot Study of the Immunologic, Virologic, and Pathologic Consequences of Intra-anal 5% Imiquimod in HIV-1-Infected Men With High-Grade Squamous Intraepithelial Lesions

BACKGROUND

Imiquimod can be used to treat internal anal high-grade squamous intraepithelial lesions. In HIV-1-infected individuals there is a theoretical concern for increased HIV replication in anorectal tissue secondary to imiquimod-induced mucosal inflammation.

OBJECTIVE

The purpose of this study was to assess local virologic, immunologic, and pathologic effects of imiquimod treatment in HIV-infected individuals.

DESIGN

This was a pilot study at a single academic center.

SETTINGS

The study was conducted at the University of Pittsburgh Anal Dysplasia Clinic.

PATIENTS

HIV-1-infected individuals with biopsy-confirmed internal anal high-grade squamous intraepithelial lesions were included.

INTERVENTION

Imiquimod cream was prescribed for intra-anal use 3 times per week for 9 weeks.

MAIN OUTCOME MEASURES

Anal human papillomavirus typing, anal and rectal tissue HIV-1 RNA and DNA quantification, cytokine gene expression, and anal histology were measured.

RESULTS

Nine evaluable participants (1 participant was lost to follow-up) were all white men with a median age of 46 years (interquartile range = 12 y) and a median CD4 T-cell count of 480 cells per cubic millimeter (interquartile range = 835). All were taking antiretroviral therapy, and 7 of 9 had HIV-1 RNA <50 copies per milliliter. The median dose of imiquimod used was 27.0 (interquartile range = 3.5), and there was a median of 11 days (interquartile range = 10 d) from last dose to assessment. There was no progression to cancer, no significant change in the number of human papillomavirus types detected, and no significant change in quantifiable cytokines/HIV-1 RNA or DNA levels in anal or rectal tissue. Seven (35%) of 20 high-grade lesions resolved to low-grade squamous intraepithelial lesions.

LIMITATIONS

The study was limited by the small number of participants and variable time to final assessment.

CONCLUSIONS

Intra-anal imiquimod showed no evidence of immune activation or increase in HIV-1 viral replication in anal and rectal tissue and confirmed efficacy for intra-anal high-grade squamous intraepithelial lesion treatment morbidity. See Video Abstract at http://links.lww.com/DCR/A498.

Anogenital warts and other HPV-associated anogenital lesions in the HIV-positive patient: a systematic review and meta-analysis of the efficacy and safety of interventions assessed in controlled clinical trials

OBJECTIVES

Anogenital warts (AGW, condylomata acuminata) and intraepithelial neoplasia (IEN) do not only impact health and social well-being, they are also associated with considerable costs for the healthcare systems. Immunocompromised and HIV-positive patients carry the highest epidemiological burden of human papillomavirus (HPV) infection and comprise a population specifically susceptible to treatment failures and recurrences. This systematic review aimed at identifying and appraising the available evidence from controlled studies of interventions for the treatment of AGW and IEN in immunocompromised patients.

METHODS

We conducted a comprehensive literature search. The Cochrane Collaboration's tool was used to assess risk of bias in included studies. Our confidence in the (pooled) effect-estimates was evaluated according to the Grading of Recommendations Assessment, Development and Evaluation approach. All evaluations were based on data independently extracted by two review authors.

RESULTS

Nine randomised controlled trials and two controlled studies were eligible, investigating external AGW, intra-anal and/or vaginal warts, and intra-anal and/or perianal IEN. The identified studies assessed imiquimod, cidofovir, fluorouracil, electrocautery, systemic interferon-α and interferon-β, and the combination of intralesional interferon-α and podophyllin. Four studies combined an ablational intervention with either imiquimod, cidofovir, intralesional or systemic interferon-α. One study investigated an experimental therapeutic vaccination (HPV 16 E7) at different concentrations.

CONCLUSIONS

The quality of the evidence ranged from 'very low' to 'moderate' and was limited by the often small samples. Evidence was available for the efficacy of electrocautery for intra-anal IEN, and imiquimod cream for external AGW. Some further interventions should be subjected to investigations in larger samples. No data on some interventions established for the treatment of AGW in immunocompetent patients such as podophyllotoxin, sinecatechins, laser ablation or trichloroacetate were available. Future trials should address these gaps and include relevant patient-reported outcomes such as health-related quality of life.

Clinical effectiveness and cost-effectiveness of interventions for the treatment of anogenital warts: systematic review and economic evaluation

BACKGROUND

Typically occurring on the external genitalia, anogenital warts (AGWs) are benign epithelial skin lesions caused by human papillomavirus infection. AGWs are usually painless but can be unsightly and physically uncomfortable, and affected people might experience psychological distress. The evidence base on the clinical effectiveness and cost-effectiveness of treatments for AGWs is limited.

OBJECTIVES

To systematically review the evidence on the clinical effectiveness of medical and surgical treatments for AGWs and to develop an economic model to estimate the cost-effectiveness of the treatments.

DATA SOURCES

Electronic databases (MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, The Cochrane Library databases and Web of Science) were searched from inception (or January 2000 for Web of Science) to September 2014. Bibliographies of relevant systematic reviews were hand-searched to identify potentially relevant studies. The World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov were searched for ongoing and planned studies.

REVIEW METHODS

A systematic review of the clinical effectiveness literature was carried out according to standard methods and a mixed-treatment comparison (MTC) undertaken. The model implemented for each outcome was that with the lowest deviance information criterion. A de novo economic model was developed to assess cost-effectiveness from the perspective of the UK NHS. The model structure was informed through a systematic review of the economic literature and in consultation with clinical experts. Effectiveness data were obtained from the MTC. Costs were obtained from the literature and standard UK sources.

RESULTS

Of 4232 titles and abstracts screened for inclusion in the review of clinical effectiveness, 60 randomised controlled trials (RCTs) evaluating 19 interventions were included. Analysis by MTC indicated that ablative techniques were typically more effective than topical interventions at completely clearing AGWs at the end of treatment. Podophyllotoxin 0.5% solution (Condyline(®), Takeda Pharmaceutical Company Ltd; Warticon(®) solution, Stiefel Laboratories Ltd) was found to be the most effective topical treatment evaluated. Networks for other outcomes included fewer treatments, which restrict conclusions on the comparative effectiveness of interventions. In total, 84 treatment strategies were assessed using the economic model. Podophyllotoxin 0.5% solution first line followed by carbon dioxide (CO2) laser therapy second line if AGWs did not clear was most likely to be considered a cost-effective use of resources at a willingness to pay of £20,000-30,000 per additional quality-adjusted life-year gained. The result was robust to most sensitivity analyses conducted.

LIMITATIONS

Limited reporting in identified studies of baseline characteristics for the enrolled population generates uncertainty around the comparability of the study populations and therefore the generalisability of the results to clinical practice. Subgroup analyses were planned based on type, number and size of AGWs, all of which are factors thought to influence treatment effect. Lack of data on clinical effectiveness based on these characteristics precluded analysis of the differential effects of treatments in the subgroups of interest. Despite identification of 60 studies, most comparisons in the MTC are informed by only one RCT. Additionally, lack of head-to-head RCTs comparing key treatments, together with minimal reporting of results in some studies, precluded comprehensive analysis of all treatments for AGWs.

CONCLUSIONS

The results generated by the MTC are in agreement with consensus opinion that ablative techniques are clinically more effective at completely clearing AGWs after treatment. However, the evidence base informing the MTC is limited. A head-to-head RCT that evaluates the comparative effectiveness of interventions used in clinical practice would help to discern the potential advantages and disadvantages of the individual treatments. The results of the economic analysis suggest that podophyllotoxin 0.5% solution is likely to represent a cost-effective first-line treatment option. More expensive effective treatments, such as CO2 laser therapy or surgery, may represent cost-effective second-line treatment options. No treatment and podophyllin are unlikely to be considered cost-effective treatment options. There is uncertainty around the cost-effectiveness of treatment with imiquimod, trichloroacetic acid and cryotherapy.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42013005457.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Imiquimod: A Review

Background and Objective:

Imiquimod (Aldara) is an immune response modifier used primarily to treat anogenital warts. Imiquimod induces cytokines and enhances cell-mediated cytolytic antiviral activity in vivo. It exhibits antiviral and antitumor effects; however, it does not exhibit direct antiviral effects in vitro. By inducing cytokines, such as interferon A, imiquimod stimulates both the innate immune response and the cellular arm of acquired immunity. Currently, imiquimod is approved for use in the treatment of external genital and perianal warts in adults.

Conclusion:

Beyond its established use, there are case reports and preliminary studies suggesting the effectiveness of imiquimod 5% cream in the treatment of nongenital human papillomavirus warts, molluscum contagiosum, actinic keratosis, basal cell carcinoma, squamous cell carcinoma, Bowen's disease, nongenital human papillomavirus infection, and vulvar intraepithelial neoplasia.

Natural products and synthetic compounds as immunomodulators

Research on immunomodulation by natural products or synthetic derivatives is of key interest for anti-infective therapy for a number of reasons. Many plant remedies well-known in traditional medicine or refined natural products in clinical use exert their anti-infective effects not only (if at all) by directly affecting the pathogen. At least part of their effect is indirect, by stimulating natural and adaptive defense mechanisms of the host. These findings have now given many empirical therapies a rationale, scientific basis and thereby a means for 'intelligent' improvement. In discovering the molecular mechanisms by which known remedies exert their effects, chosen elements further down the 'chain of command' might be synthesized and applied directly for more rapid and selective cure, omitting unwanted side effects. The direct use of recombinant cytokines, often in combination with antibiotics, is one consequence of this rationale.

Treatment of multifocal Bowen's disease in immunocompromised women with surgery and topical imiquimod

BACKGROUND

In human immunodeficiency virus (HIV)-infected women, Bowen's disease may be difficult to treat successfully with surgery alone. Imiquimod cream, effective in treating Bowen's disease in healthy women, may be a useful postsurgical treatment in immunocompromised women.

CASES

Two HIV-infected women had both Bowen's disease and severe cervical dysplasia. In both cases, Bowen's disease, but not cervical dysplasia, recurred after surgical treatment. When treated with topical 5% imiquimod cream twice weekly for 4 months, 70-80% reduction in lesions were observed in both patients. Follow-up biopsies of remaining lesions were vulvar intraepithelial neoplasia 1.

CONCLUSION

Imiquimod cream, in combination with surgical treatment, may be an appropriate strategy for treatment of Bowen's disease in HIV-infected and other immunocompromised women.

Treatment options for anal intraepithelial neoplasia and evidence for their effectiveness

There is a growing range of treatment options for anal intraepithelial neoplasia (AIN). In HIV-positive patients, sustained treatment is often required to achieve clearance. The treatments considered are topically applied fluorouracil, imiquimod, cidofovir and trichloroacetic acid, the potential treatments of topical lopinavir and photodynamic therapy with aminolevulenic acid, and the surgical methods of electrosurgery, infrared coagulation and laser. Destructive treatment methods, possibly including TCA, are more effective than self applied topical treatments. Combining or alternating different treatments should be considered.

Advances in the use of topical imiquimod to treat dermatologic disorders

Imiquimod (IQ) is an immune-response modifying agent, first approved by FDA for the topical treatment of external genital and perianal warts in 1997. It induces, through stimulation of Toll-like receptors (TLRs) localized on the surface of antigen-presenting cells, synthesis and release of several endogenous pro-inflammatory cytokines such as interferon-α (IFN-α), tumor necrosis factor-α (TNF-α) and interleukins (IL) 6 and 12, which in turn stimulate both the innate and acquired immune pathways, resulting in upregulation of natural antiviral and antitumor activity. IQ 5% cream has been used for the treatment of a wide variety of dermatologic conditions in which the immune system is thought to play a role in regression of the disease. In some disorders, such as genital and perianal warts, actinic keratoses, basal cell carcinomas, Bowen’s disease and molluscum contagiosum, relative safety and efficacy are supported by randomized controlled trials of IQ. However, it is common for patients to experience local skin reactions, which can range from mild to severe in intensity, but usually resolve 1–2 weeks after interrupting treatment. Additional randomized trials are encouraged to assess safety and efficacy of IQ in the treatment of an even wider range of cutaneous disorders.

Local applications of GM-CSF induce the recruitment of immune cells in cervical low-grade squamous intraepithelial lesions

PROBLEM

Quantitative alterations of antigen-presenting cells (APC) in (pre)neoplastic lesions of the uterine cervix associated with human papillomavirus (HPV) infection suggest a diminished capacity to capture viral antigens and to induce a protective immune response.

METHOD OF STUDY

To test whether a cervical application of GM-CSF could restore an immune response against HPV in women with cervical low-grade squamous intraepithelial lesions (LSIL), we performed two clinical trials with 11 healthy women and 15 patients with LSIL.

RESULTS

GM-CSF applications were well tolerated in all enrolled women, and no difference in toxicity between the treated and placebo groups was observed during the follow-up (until 30 months). Interestingly, in the GM-CSF treated group, a significant increase of APC and cytotoxic T-lymphocyte infiltration was observed in the cervical biopsies with no change in regulatory T cell numbers. All the HPV16(+) patients exhibited an immune response against HPV16 after GM-CSF applications, as shown by NK and/or T cells producing IFN-gamma whereas no cellular immune response was observed before the treatment. Moreover, the anti-virus-like particles antibody titers also increased after the treatment.

CONCLUSION

These encouraging results obtained from a limited number of subjects justify further study on the therapeutic effect of APC in cervical (pre)neoplastic lesions.

Topical treatment of anogenital human papillomavirus infection in male patients

Background: Human papillomavirus (HPV)-associated anogenital warts have a prevalence of up to 78% in sexually active men. Some HPV subtypes bear a considerable oncogenic potential. Materials & methods: Original papers on the treatment of external anogenital warts were included in a meta-analysis to assess the most effective topical treatment. Results: Clearance rates were 0–6.5% for placebo treatment, 76.6% for podophyllotoxin 0.15% cream administered for 4 weeks, 61.5% for podophyllotoxin 0.5% solution (2–6 weeks) and 53.7% for imiquimod 5% cream (12–16 weeks). For male patients, the intent-to-treat analysis demonstrated statistically significant superiority of podophyllotoxin preparations versus imiquimod (p < 0.0001 and p < 0.005, respectively). Clearance rates of locally ablative treatments, such as surgery, cryotherapy, electrocautery and carbon dioxide laser, differed widely without clear superiority of a specific ablative technique. In HIV-positive patients, all treatment options yielded lower clearance rates and higher recurrence rates. Conclusion: While preventive vaccines might reduce HPV-associated morbidity for future generations, those with active HPV disease still need to be treated with customary treatment options. In male patients, podophyllotoxin preparations yielded higher response rates than imiquimod.

Clinical investigations of Toll-like receptor agonists

BACKGROUND

Toll-like receptors (TLR) represent a family of surface molecules that function as primary sensors of the innate immune system to recognize microbial pathogens. Ligand binding to TLR results in activation of cellular signaling pathways that regulate expression of genes involved in inflammation and immunity.

OBJECTIVE

Use of synthetic TLR ligands (agonists) for treatment and prevention of infectious and neoplastic diseases.

METHODS

Review of literature about clinical investigations of agonists of TLR 4, 7, 8, and 9.

RESULTS/CONCLUSIONS

Imiquimod was the first TLR agonist approved for treatment of anogenital warts, actinic keratosis and superficial basal cell carcinoma in humans. Several other agonists of TLRs 4, 7, 8 and 9 were also shown to be effective for treatment of infections and cancers and, furthermore, were used as adjuvants for vaccination. Based on safety and efficacy of the TLR agonists used to date, applications are likely to increase in the future.

Evaluation of imiquimod for the therapy of external genital and anal warts in comparison with destructive therapies

External genital and anal warts (acuminate condyloma) were the first medical indication the topical immune response modifier imiquimod was approved for in 1997. Since then, many placebo controlled randomized clinical trials have demonstrated the efficacy and safety of this synthetic imidazoquinoline derivate for the treatment of different human papillomavirus infections and tumours. Treatment modalities for genital warts (5% cream, three times weekly, minimum duration 4 weeks, control of side-effects) have been optimized and assured by further clinical trials and meta-analyses. For a few years clinical studies focussed on the long-term efficacy of the immunomodulatory therapy (sustained clearance from warts) and most recent studies compared the efficacy of ablative, destructive and imiquimod monotherapy as well as combination therapies.

Topical imiquimod: a review of its use in the management of anogenital warts, actinic keratoses, basal cell carcinoma and other skin lesions

Topical imiquimod 5% cream (Aldara) is an immune response modulator that is indicated for the treatment of external anogenital warts, superficial basal cell carcinoma and actinic keratoses. The cream is applied two to five times per week for varying periods, depending on the indication. Topical imiquimod cream has also been evaluated in the treatment of several other skin conditions. Immunomodulatory therapy with topical imiquimod 5% is an effective option for the approved indications. The drug appears to be relatively well tolerated, with the option of breaks from treatment as required for local skin reactions (which are common). Systemic reactions have been reported. Treatment of human papillomavirus- and UV-associated skin lesions with topical imiquimod offers a noninvasive, tissue-sparing alternative to ablative treatment options. However, well designed trials of the sustained, long-term efficacy and tolerability of topical imiquimod versus those of common treatment approaches including surgery and other topical alternatives are required before the place of the drug in the management of these lesions can be finalised. Nonetheless, while other treatments for anogenital warts, superficial basal cell carcinoma or actinic keratoses are available, the advantages of self treatment linked with the demonstrated efficacy of topical imiquimod offer an attractive alternative for many patients.

Human papillomavirus (HPV) viral load and HPV type in the clinical outcome of HIV-positive patients treated with imiquimod for anogenital warts and anal intraepithelial neoplasia

OBJECTIVE

To evaluate the efficacy of 5% imiquimod in HIV-positive male patients with anogenital warts or anal intraepithelial neoplasia (AIN), and to elucidate whether human papillomavirus (HPV) type and viral load were important for clinical outcome and recurrences.

METHODS

Thirty-seven patients with histologically proven anogenital warts or AIN were enrolled. Topical 5% imiquimod was applied three times per week for more than 8 h overnight for 16 weeks, although patients were allowed to continue therapy for 4 more weeks if they did not have complete clearance of lesions.

RESULTS

Mean age was 34 years. The perianal area was the main lesion location. Thirty-three patients had CD4 counts of < 500 cells/mm(3). Eighteen patients had a histopathological diagnosis of AIN-1. Main HPV types detected corresponded to low-risk HPV types. At 20 weeks of therapy, 46% patients achieved total clearance whereas 14 patients had > 50% clearance. Recurrence was observed in 5 of 17 patients who cleared. Clearance was not influenced by patients' CD4 counts, wart location, HIV viral load or HPV viral load.

CONCLUSIONS

The assumption that visible perianal warts are benign lesions in HIV-positive patients has to be reevaluated since an important number of such lesions could correspond to low-grade anal disease, which in turn could progress to high-grade anal disease or cancer. In addition, our results in this preliminary study indicate that imiquimod appears to be effective in treating AIN in HIV-positive patients. Further studies are needed to document its utility to prevent high-grade dysplasia and/or anal cancer.

5% Topical Imiquimod Tolerance in Transplant Recipients

BACKGROUND

Topical imiquimod is a new immunomodulator agent approved for genital warts, actinic keratosis (AK) or carcinoma, occurring in immunocompetent patients.

OBJECTIVES

This study aimed to assess the safety and efficacy of imiquimod for the treatment of warts, AK and bowenoid papulosis (BP) in transplant patients.

METHODS

24 transplant patients (18 kidney, 4 kidney-pancreas and 2 heart) were included in this retrospective study conducted between June 2000 and February 2003 at the department of dermatology of 3 hospitals. Imiquimod cream was applied 3 times a week over a median period of 9 weeks.

RESULTS

Graft function was not altered under therapy. Local tolerance was excellent. Complete responses were observed in 1 patient (1/12) with cutaneous warts and 1 (1/6) with AK. Two patients of 3 with BP had total clearance of their lesions. Partial responses were observed in 3 of the 6 AK-treated patients, 5 of 12 patients with cutaneous warts and 1 of 2 patients with anogenital warts.

CONCLUSIONS

Imiquimod 5% cream is a promising, well-tolerated therapy for warts, AK and BP in transplant recipients.

Effect of imiquimod in anogenital warts from HIV-positive men

BACKGROUND

HIV-positive patients have unpredictable local immune responses even with severe systemic immunosuppression and data reported to date is insufficient to predict the effect of imiquimod in HIV-positive patients.

OBJECTIVE

To evaluate the efficacy of 5% topical imiquimod in HIV-positive male patients with anogenital warts (AGW) and to elucidate its effect on recurrence.

STUDY DESIGN

Open-label clinical trial.

RESULTS

Of the 43 patients enrolled, 86% completed treatment. Patients' mean age was 34 years (range: 19-50). Thirty-one patients were receiving highly active antiretroviral therapy (HAART) therapy. At week 16, 10 patients completely cleared lesions and 21 patients had a wart size reduction > or =50%. At 20 weeks of therapy, 17 patients achieved total clearance whereas 14 patients had a >50% wart reduction. Clearance was not influenced by CD4-counts, HIV-viral load, previous therapy, or wart localization. Of the patients who experienced a complete clearance, five (29%) had a recurrence. Mean time of recurrence was 14.4 weeks. Erythema, pruritus, and burning sensation were the most frequent local skin reactions.

CONCLUSIONS

Topical 5% imiquimod is safe and may benefit HIV-positive patients with anogenital warts particularly when it is used for up to 20 weeks. It is also useful to decrease wart recurrence.

Management of oral lesions in HIV-positive patients

HIV/AIDS is currently the leading cause of death in Africa and the fourth leading cause of death worldwide. This systematic review of the literature was conducted to evaluate the evidence for treatment of the most common oral lesions associated with HIV: oral candidiasis with or without oropharyngeal involvement (OPC), oral hairy leukoplakia (OHL), recurrent aphthous-like ulcerations (RAU), oral Kaposi's sarcoma (OKS), orolabial herpes simplex infection (HSV), oral herpes zoster infection (VZV), intraoral or perioral warts (HPV), and HIV-associated periodontal diseases. Treatment of HIV-associated salivary gland disease is addressed in a different section of this World Workshop. We found the largest body of evidence for treatment of OPC in HIV patients. Future trials will be needed to test drugs currently in development for treatment of Candida strains that are resistant to existing therapies. There were no double blind, placebo-controlled randomized clinical trials (RCT) for topical treatment of OHL, and only one RCT for systemic treatment of the lesion with desciclovir. Systemic thalidomide was the only drug tested in RCT for treatment or prevention of RAU. Only 1 double-blind RCT comparing vinblastine and sodium tetradecyl sulfate was identified for localized treatment of OKS. Three drugs (famciclovir, acyclovir, and valaciclovir) were shown to be effective in randomized, double-blind trials for treatment or suppression of mucocutaneous HSV lesions in HIV patients. In all 3 trials, the effects of these medications on orolabial HSV lesions were not reported separately. There were no double-blind, placebo-controlled RCT testing topical treatments for orolabial HSV lesions in HIV patients. No trials testing treatments of oral VZV were identified. There were no double-blind, placebo-controlled RCT for treatment of HIV-associated intraoral or perioral warts or periodontal diseases. In conclusion, there is a need for well-designed RCTs to assess the safety and efficacy of topical and systemic treatments of most oral mucosal and perioral lesions in HIV patients. There is also a need to develop newer drugs for treatment of resistant fungal and viral microorganisms. Finally, standardized outcome measures should be developed for future clinical trials to allow comparisons of studies using different populations.

Cutaneous Infections Associated with HIV/AIDS

With diminished and dysregulated cell-mediated immunity, HIV-infected individuals are susceptible to a myriad of skin infections. These infections include the conditions encountered in immunocompetent patients, as well as infections seen almost exclusively in the setting of HIV infection. The HIV/AIDS pandemic has made some previously rare infections more prominent. Although antiretroviral therapy has been helpful in relieving the burden of cutaneous infections in HIV-infected patients, it does not prevent all opportunistic infections in the skin and also has created new dilemmas.

Human papillomavirus: burden of illness and treatment cost considerations

The monetary and personal costs to society of human papillomavirus (HPV) infection are enormous. In order to make a comparison of different treatment methods we reviewed the entire literature on HPV treatment from January 1966 to December 2003 using MEDLINE, with particular reference to published meta-analyses, randomized controlled and comparative studies. Patient-applied therapies offer patients the possibility of convenient and, on the whole, pain-free treatment. Podofilox (podophyllotoxin) and salicylic acid for genital and extragenital warts, respectively, have the additional advantage of being the most cost-effective treatments and, on this basis, they are to be commended as appropriate first-line agents. The second-line treatment of choice for common warts is cryotherapy. For recalcitrant common warts possible options include inosine pranobex with cryotherapy or electrosurgery, imiquimod with paring and occlusion, intralesional bleomycin, or diphencyprone. Alternative first-line and second-line treatments for genital warts would be either some form of surgical removal or imiquimod. The first option may be the cheapest but this has to be balanced against a degree of post-operative morbidity. Limited data from comparative studies do not show any clear difference in efficacy between cryotherapy, trichloroacetic acid, scissor excision, electrosurgery, and laser surgery in the treatment of genital warts, and the cost effectiveness of these therapies is probably similar to that of imiquimod. Cryotherapy and trichloroacetic acid are relatively expensive and inconvenient for patients and should be reserved as third-line treatments with certain exceptions, such as cryotherapy for meatal warts. The duration of treatment is significantly related to the number of warts present, the area covered by the warts, and the length of time the warts have been present. For recalcitrant anogenital warts third-line treatment options that show promise include surgery in combination with imiquimod or cidofovir cream. For squamous intraepithelial lesions that cannot easily be excised or physically ablated current treatment options include imiquimod and fluorouracil cream. The latter is an inexpensive option but causes the greatest morbidity. It is hoped that cidofovir may be added to this list if it becomes commercially available, and that protective and therapeutic HPV vaccines will transform the management of HPV in the future.

[Effects of imiquimod on latent human papillomavirus anal infection in HIV-infected patients]

INTRODUCTION

High risk human papillomaviruses (HPV) have emerged as risk factors for anal carcinoma particularly in HIV-infected patients who demonstrate a high rate of anal HPV infection. Considering the relationship between the presence of anal infection and the development of neoplastic lesions, we wished to assess the capacity of imiquimod to eradicate latent HPV infection in HIV-infected patients.

PATIENTS AND METHODS

We conducted a prospective, randomized, double-blind and vehicle controlled study. Two consecutive anal swabs were taken at 2 month intervals and only patients with two consecutive tests positive for the detection of HPV-DNA (Hybrid Capture II) were included. Patients with persistent latent HPV infection were divided into 2 groups who applied imiquimod versus vehicle during 6 weeks. HPV-DNA presence was then investigated 2 and 4 months following the onset of treatment.

RESULTS

Among the 80 HIV-infected patients, 26 (32.5 p. 100) had 2 positive consecutive assays, and 19 patients were included in the study. After randomization, 9 patients received imiquimod and 10 vehicle. There was no significant difference between treatment groups according to the following criteria: gender, route of HIV transmission, CDC stage, prior medical history of sexually transmitted diseases or anogenital warts. 33.3 p. 100 (3/9) of patients treated with imiquimod were negative at M2, whereas 100 p. 100 (10/10) vehicle treated-patients remained positive (p=0.08). Similar results were observed at the M4 visit.

DISCUSSION

Our study confirmed the increased prevalence of latent HPV-DNA infection in HIV-infected patients. In spite of the low number of treated patients, we did not observe a statistically significant decrease in HPV-DNA in anal swabs from imiquimod-treated patients as compared to placebo-treated patients.

Therapy of cutaneous human Papillomavirus infections

Human Papillomaviruses (HPV) are double-stranded DNA viruses, which result in a variety of clinical manifestations according to type. The most common cutaneous lesions include warts located on the skin and genitalia. Because there is currently no cure for HPV infection, treatment focuses on the alleviation of signs and symptoms. Unfortunately, therapy has not been proved to affect transmissibility. Traditional treatment modalities have focused on the destruction of infected tissue through a variety of techniques. These include podophyllin resin, podophyllotoxin, salicylic acid, trichloroacetic acid, bichloroacetic acid, cryotherapy, laser, and surgical techniques. None of these modalities have been proved to be superior. More recently, immunomodulatory compounds with antiviral properties have demonstrated superior efficacy with clearance rates up to 77% and low recurrence rates. Most importantly, clinical trials of vaccines to prevent acquisition of oncogenic HPV are demonstrating marked safety and efficacy.

Topical Immunomodulation in Dermatology: Potential of Toll-like Receptor Agonists

BACKGROUND

Topical immunomodulators include both immunostimulatory and immunosuppressive agents. If successful, topical immunotherapy may represent an important improvement in the therapy of inflammatory dermatoses, viral infections, and cancers of the skin and genital mucosa. Topical immunotherapy using obligate contact sensitizers such as diphencyprone or dinitrochlorobenzene has been used against viral (e.g., common warts) and autoimmune diseases (e.g., alopecia areata).

RESULTS

Newer agents such imidazoquinolines (imiquimod and resiquimod) act by cytokine secretion from monocytes/macrophages (interferon-alpha, interleukin-12, tumor-necrosis factor-alpha). The locally generated immune milieu leads to a Th1-dominance and cell-mediated immunity that have been clinically used to treat viral infections such as human papillomavirus, herpes simplex virus, and mollusca. Although these agents improve antigen presentation by dendritic cells, they also act on B cells leading to the synthesis of antibodies such as IgG2a. We have also introduced this treatment against cancerous lesions including initial squamous cell and basal cell carcinoma in immunocompetent and immunosuppressed patients. We provide examples of successful treatment of squamous cell cancer using topical imiquimod.

CONCLUSION

The available and additional Toll-like receptor agonists will help to improve the specific dermatologic therapy. Topical immunotherapy with both immunostimulatory and immunosuppressive agents bears potential for effective and patient friendly treatment of inflammatory, infectious, and cancerous skin diseases. Long-term evaluation will define the tolerability and safety profile of these novel topical agents.

Imiquimod: potential risk of an immunostimulant

A 19-year-old woman with severe HLA B27 spondyloarthropathy whose disease was controlled on cyclosporin, methotrexate and prednisolone had human papillomavirus infection and developed cervical dysplasia and a large number of cutaneous and vulval warts. These were not responsive to cryotherapy, salicylic acid or cimetidine, so she was treated with topical imiquimod 5% cream. Two weeks after starting this treatment she had a significant flare of her spondyloarthropathy. She was so ill that she stopped using the imiquimod cream. She had full resolution of her warts after 3 weeks' treatment with imiquimod cream, but her spondyloarthropathy took more than 3 months to improve, despite significant augmentation of her immunosuppression. This case highlights the potential risk of using imiquimod cream (an immunostimulant) in a patient who has a condition requiring immunosuppression, such as autoimmune disease or an organ transplant.

Closing the feedback loop: an audit of the use of imiquimod for the treatment of genital warts

A retrospective case-note audit of 74 patients with 81 treatment episodes of anogenital warts with imiquimod from April 1999 until July 2000 was performed. The majority of patients had failed to clear their warts with other treatments, had recurrences after other treatments, or had other medical problems complicating their genital wart treatment. The overall clinically confirmed complete clearance rate was 33%. This is lower than other published data, but may be so because it includes patients with immunosuppression and difficult-to-treat warts. The complete clearance rate in immunocompetent patients was 37%. In addition, in this audit of clinical practice 17% of the patients did not return for full response to be assessed. The complete clearance rate in those who were able to tolerate treatment and who returned for follow-up was 45%. Based on the results of the audit we have extended the indications for the use of imiquimod in the clinic treatment guidelines. Patients are now offered imiquimod if six or more episodes of other treatments fail to give a good response. Earlier treatment with imiquimod is also offered to those patients with recurrent anogenital warts, and it is recommended as a first-line therapy for patients with multiple keratinized warts.

Therapy of external anogenital warts and molluscum contagiosum: a literature review

Anogenital warts and mollusca contagiosum are virally induced, benign skin tumors for which there is no single preferable therapy. Treatments include physical and chemical destruction, surgical removal, and biological response modifiers to enhance the natural immune response. The choice of therapy is an art, and depends upon patient preference, finances, number of lesions, and lesional morphology. However, the therapy of these lesions can sometimes be very painful and expensive, and therapy should not be worse than the disease.

Topical immunomodulators for the treatment of external genital warts, cutaneous warts and molluscum contagiosum

Topical immunomodulators (TIMs) include both immunostimulatory and immunosuppressive agents. Newer immunostimulatory compounds such as imidazoquinolines (e.g. imiquimod) act by cytokine secretion from monocytes/macrophages (interferon-alpha, interleukin-12, tumour-necrosis factor-alpha), leading to a Th1-dominance and cell-mediated immunity. This immune milieu has been clinically used to treat viral infections such as human papillomavirus (condyloma and common warts), herpes simplex virus and mollusca in immunocompetent and immunosuppressed patients.

Topical treatment of common warts in an HIV-positive patient with imiquimod 5% cream

Human immunodeficiency virus (HIV) infects and destroys crucial components of the immune system, leaving patients susceptible to a number of viral, bacterial and fungal diseases. Viral warts are caused by human papillomavirus infection and are a common skin disease that afflicts HIV-infected patients. Treatment modalities currently rely on destruction of the infected tissue or interruption of cell division; however, frequent recurrence is a particular challenge in HIV-infected patients. We report the case of a 41-year-old HIV-positive man with multiple common warts located on his hands and feet. Following 5 months of treatment with imiquimod, an immune response modifier, as a 5% cream, complete clearance of all warts was achieved. Mild erythma, itching and burning at the application site was observed in the early stages of treatment. The patient showed no relapse of warts at the 30-month follow-up visit.

[Topical immunomodulators in dermatology]

Immunomodulators include both immunostimulatory and immunosuppressive agents. Obligate contact sensitizers such as diphencyprone or dinitrochlorobenzene have been used against viral and autoimmune diseases. Newer agents such as the toll-like receptor agonists imiquimod and resiquimod have been clinically used to treat viral infections and skin cancers in immunocompetent and immunosuppressed patients. On the other hand, the topical immunosuppressive agents tacrolimus and pimecrolimus have been used with great success in the treatment of chronic inflammatory diseases in children and adults. The introduction of this new class of drugs (i.e. Calcineurin inhibitors) marked the beginning of the post-cortisone era in clinical dermatology. Toll-like receptor agonists and calcineurin antagonists will supplement corticosteroids to improve specific dermatological therapy. Topical immunotherapy with both immunostimulatory and immunosuppressive agents show potential for effective and patient-friendly treatment of inflammatory, infectious and neoplastic skin diseases. Long-term evaluation will define the tolerability and the safety profile.

Imiquimod

Imiquimod is the first of the immune response modifiers to stimulate a localized immune response to treat infectious skin conditions. The reported TLR-7 activation to provoke an immune response suggests that imiquimod might mimic a microbial antigen. The immune response initiated by induced production of IFN-alpha and TFN-alpha is specifically aimed at an infectious antigen and appears mediated (in part) by enhanced migration of Langerhans' cells to regional lymph nodes. The approved indication for imiquimod is for treatment of genital warts. The drug has demonstrated a 50% to 60% clearance rate and a 12% to 20% recurrence rate for this indication (Table 1). This recurrence rate is the lowest reported among the currently recommended treatment modalities. The self-applied treatment avoids costly and painful office-based procedures. Case reports and open-label studies have demonstrated the efficacy of imiquimod in treating some cases of common, plantar, and flat warts, as well as molluscum contagiosum and leishmaniasis. Common and plantar warts respond better to imiquimod in combination with cryosurgery, occlusion, and keratolytics. Reports of successful imiquimod treatment of granuloma annulare, alopecia areata, and vitiligo might suggest an infectious etiology to those conditions, although this hypothesis is highly speculative.

Imiquimod

PURPOSE OF REVIEW

Imiquimod is the first member of a new class of immune response modifiers; it was first approved in 1997 for the topical treatment of external genital and perianal warts. It is an imidazoquinoline, a novel synthetic compound which is an immune response stimulator, enhancing both the innate and acquired immune pathways (particularly T helper cell type 1-mediated immune responses) resulting in antiviral, antitumour and immunoregulatory activities. The mechanism of action of imiquimod involves cytokine induction in the skin, which then triggers the host's immune system to recognize the presence of a viral infection or tumour, ultimately to eradicate the associated lesion.

RECENT FINDINGS

Imiquimod, a patient-applied topical 5% cream is clinically efficacious and safe in the management of condylomata acuminata and other warty manifestations of human papillomavirus infections. Although not licensed for use against other viral skin infections, preliminary data suggest imiquimod's success against molluscum contagiosum, caused by a poxvirus. Initial studies with imiquimod for the management of HPV-related intraepithelial dysplasias (bowenoid papulosis/vulvar intraepithelial neoplasia) as well as for ultraviolet-induced skin lesions such as actinic keratoses, Bowen's disease, and basal cell carcinomas show great promise in immunocompetent and immunosuppressed patients.

SUMMARY

In the future, imiquimod and newer generations of imidazoquinolines (resiquimod) require further investigation for potential clinical utility in treating other cutaneous and mucosal viral infections, dysplasias and neoplasia, as well as potential vaccine adjuvants.

Imiquimod; an international update on therapeutic uses in dermatology

Imiquimod, the first member of a new class of immune response modifiers, is approved for the treatment of external genital and perianal warts. The clinical effect of imiquimod stems from cytokine-induced activation of the immune system. Topical application of imiquimod elevates the production of cytokines, including the principal cytokine for antiviral activity, interferon-alpha. This is the initial event in an immunological cascade resulting in the stimulation of the innate immune response as well as the cell-mediated pathway of acquired immunity. This immune modification mediates the indirect antiviral, antiproliferative and antitumor activity of imiquimod in vivo. These properties highlight the potential of imiquimod not only as an effective treatment for genital warts, but also as a treatment for other cutaneous viral infections and cutaneous neoplasms.

Human papillomavirus: a review

Human papillomavirus infection remains a great source of morbidity and mortality. Progress in understanding the structure of HPV and its pathogenesis has led to a wide variety of possible new treatment modalities to combat HPV-related disease. Most HPV infections (whether high risk or low risk) resolve without any medical intervention. Persistent or progressive disease, however, remains difficult to treat. Although currently available therapies have proved efficacious and tolerable in the treatment of nongenital and genital warts, no single therapy is uniformly effective in eradicating persistent HPV infection. Cytodestructive methods, such as cryotherapy, remain the primary treatment modality for nongenital warts. Immune response modifiers, such as imiquimod, currently show the greatest promise in treating HPV-induced anogenital lesions, both with respect to complete response and in preventing recurrence. Human papillomavirus infection is one of the most common sexually transmitted diseases in the world, and cervical cancer still causes significant morbidity and mortality. Pap smear tests have greatly reduced the incidence and mortality of cervical cancer in developed countries. Additional research will focus on primary and secondary prevention strategies. Vaccines against high-risk HPV types are promising modalities currently under investigation to prevent HPV infections and possibly to treat them.

Immunotherapy for nonmelanoma skin cancer: does it have a future?

BACKGROUND

Basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) of the skin are the most common malignancies in the white human population, accounting for greater than 95% of nonmelanoma skin cancers (NMSCs). Current data show an increasing incidence of NMSC in recent decades. Although the mortality is low, this cancer group is associated with substantial morbidity. Multiple treatment modalities are available for NMSC, with surgery being a "cornerstone" of current therapy approaches. However, in patients with multiple lesions or in cases of tumors on critical locations, disfigurement and the disease recurrence may represent a serious problem associated with the surgical treatment. The purpose of this study was to review and analyze whether NMSC could represent a target for immune therapy, evaluating the aspects of the availability of tumor antigens and the existence of tumor specific immune response, including a summary of the major clinical studies dealing with immunotherapy for NMSC.

METHODS

The authors have reviewed the available medical literature on NMSC, with a focus on tumor immunology and associated abnormalities, as well as immunotherapy-based treatment trials.

RESULTS

The major advantage of NMSCs is that they arise from the skin, which makes them easily detectable and treatable. Furthermore, these tumors posses all the prerequisites, i.e., the presence of tumor-associated antigens as well as the tumor specific immune response, needed for immune intervention. This also was confirmed in various studies demonstrating clinical efficacy of cytokines and other immune response modifiers.

CONCLUSIONS

In addition to clinical cure, by activating and stimulating patient's immune resources this therapeutic option may be a "silver bullet," providing a long-term protective immunity against initial tumor.

Resolution of recurrent perianal condylomata acuminata by topical cidofovir in patients with HIV infection

Anogenital condylomata acuminata are the most frequent clinical manifestation of genital human papillomavirus (HPV) infection. Association between human immunodeficiency virus (HIV) and HPV infections is frequent (range: 26-60% in males). Topical cidofovir (a nucleotide analogue antiviral drug active against a broad range of DNA viruses) is a potential treatment for anogenital warts in immunocompromised patients. We treated three HIV-infected patients with HPV perianal condylomas with topical 1% cidofovir in flexible collodion once a day for 2 weeks. The treatment resulted in complete clearance of the HPV lesions. The patients experienced mild transient erythema without any other side-effects. None of the patients relapsed during the 10-14-month follow-up period.

Topical immunomodulators--progress towards treating inflammation, infection, and cancer

Immunomodulators include both immunostimulatory and immunosuppressive agents. Only recently have the basic mechanisms of topical immunotherapy been elucidated. Besides topical contact sensitisers (eg, diphencyprone or dinitrochlorobenzene), newer agents of the imidazoquinoline family such as imiquimod and resiquimod act by inducing cytokine secretion from monocytes or macrophages (interferon-alpha, interleukin-12, tumour-necrosis factor-alpha). The locally generated immune milieu leads to a Th1-dominance and cell-mediated immunity that have been used clinically to treat viral infections such as human papillomavirus (HPV), herpes simplex virus (HSV), mollusca, and cancerous lesions including initial squamous cell and basal cell carcinoma in immunocompetent and immunosuppressed patients. While these agents improve antigen-presentation by dendritic cells, they also act on B cells and lead to the synthesis of antibodies such as IgG2a much like the recently discovered immunostimulatory CpG-sequences that stimulate innate immunity. These sequences act as "danger signals" since they occur in bacterial and viral DNA, but are selectively methylated and inactivated in the mammalian genome. They share the induction of the same cytokines as imidazoquinolines but they show different magnitudes and kinetics of response. Topical immunotherapy with immunostimulatory agents shows potential for effective and patient-friendly treatment of inflammatory, infectious, and cancerous skin diseases. Immunoenhancers such as imdazoquinolines and CpG-sequences also have adjuvant properties that could improve conventional (protein) and DNA vaccination against cancer, atopy, and allergies.

The treatment of human papillomavirus lesions of the lower genital tract

Anogenital warts are caused by human papillomavirus types 6 and 11 infection, and are the most common clinical manifestation of lower genital tract human papillomavirus infection. They are the most frequently recognized sexually transmitted disease in the developed world, occurring at an incidence rate of 0.5-1.2% in young men and women aged 18-25 years. Many therapies for genital warts have been described, none being ideal in that all therapeutic modalities fail to clear the warts in a proportion of patients, and the recurrence of warts after successful treatment is seen with all treatments. The current knowledge base of the therapy of genital warts is flawed by a lack of good natural history data either with treatment or without treatment over longer periods of time, in that most trials report comparisons of monotherapies over a short time and there is a lack of structured trials addressing consecutive therapies over longer durations, as occurs in real-life clinical situations.

Imiquimod for the treatment of genital warts: a quantitative systematic review

OBJECTIVE

To review published randomised controlled trials to assess the benefit and harm of imiquimod in the treatment of external genital warts.

DATA SOURCES

MEDLINE (1966 - December 2000), Cochrane Library (Issue 3, 2000) and PubMed (December 15, 2000), review articles and reference lists.

REVIEW METHODS

Included studies had to be randomised trials of imiquimod, to be full published papers, and to have a comparison group. Quality of trial reporting was assessed. Relative benefit and number needed to treat were calculated for the main outcomes of wart clearance at the end of therapy, of at least 50% reduction in wart area, and of complete clearance at the end of treatment and no recurrence of warts during a follow-up period, as well as for adverse effect withdrawal or lack of efficacy withdrawal.

RESULTS

There were six trials, all with quality scores of 3 (out of 5) or greater. In five trials with HIV-negative patients complete clearance of warts at the end of treatment occurred in 51% of patients treated with imiquimod 2% or 5% cream and 6% of placebo treated patients. The number needed to treat was 2.2 (95% confidence interval 2.0 to 2.6). In four trials at least 50% wart area reduction occurred with 72% of patients treated with imiquimod 5% cream and 20% of placebo treated patients. The number needed to treat was 1.9 (1.7 to 2.2). In three trials complete clearance of warts at the end of treatment plus no recurrence occurred in 37% of patients treated with imiquimod 5% cream and 4% of those treated with placebo. The number needed to treat was 3.0 (2.5 to 3.8). Adverse event withdrawal was rare and no more likely with imiquimod than with placebo. Imiquimod was not effective in one trial in HIV-positive patients.

CONCLUSION

The evidence base for imiquimod in treating genital warts is of high quality and the necessary size from which to draw useful conclusions. Imiquimod is effective in home application, though not in patients with HIV infection with the evidence presently available.

Efficacy and tolerability of topical 1% cidofovir cream for the treatment of external anogenital warts in HIV-infected persons

BACKGROUND

Treatment options for anogenital warts in patients with HIV-1 are unsatisfactory because they fail to eradicate latent human papillomavirus.

GOAL

To determine tolerability and efficacy of topical 1% cidofovir cream for the treatment of external anogenital warts in HIV-infected patients.

STUDY DESIGN

A randomized, placebo-controlled, single-blind, crossover pilot study of either 1% cidofovir cream or placebo applied once daily 5 days a week for 2 weeks followed by 2 weeks of observation was performed.

RESULTS

Six patients were randomized to 1% cidofovir cream and six to placebo. The latter patients eventually received 1% cidofovir cream. Thus, 12 treatment rounds of cidofovir were compared with six rounds of placebo. A reduction of more than 50% in the total wart area achieved by seven cidofovir treatments (58%), as compared with no placebo regimen (P = 0.02). Local reactions occurred in 10 of the 12 patients treated with cidofovir, as compared with 0 of the 6 subjects in the placebo group (P < 0.001).

CONCLUSIONS

For the initial clearance of anogenital warts in HIV-infected patients, 1% cidofovir cream is significantly more effective than vehicle cream. Local mucosal erosion is a common side effect.