Effect of dosing frequency on the safety and efficacy of imiquimod 5% cream for treatment of actinic keratosis on the forearms and hands: a phase II, randomized placebo-controlled trial

Systematic review of randomized controlled trials of topicals for actinic keratosis field therapy

Cutaneous field cancerization in dermatology describes the anatomic region of photodamaged skin with actinic keratoses (AKs) or cutaneous squamous cell carcinoma (cSCC) that is surrounded by cellular atypia, forming a dysplastic field. The concept of field cancerization is especially relevant in dermatology, as actinic keratoses and the surrounding dysplastic region can progress to carcinomas, necessitating the treatment of the field. Recent research has focused on field-directed therapy using topical agents. This study aims to systematically review randomized controlled trials on topical treatments for actinic keratosis field cancerization, following the PRISMA guidelines. Clinical recommendations were based on the Oxford Centre for Evidence-Based Medicine. We identified 20 original randomized controlled trials for topical cutaneous field therapy. 0.5% 5-Fluorouracil/salicylic acid and 0.5% 5-fluorouracil received a clinical recommendation grade of A, while diclofenac sodium received a clinical recommendation grade of B. Calcipotriol/5-fluorouracil, Imiquimod, sunscreen combination therapies, and tirbanibulin received a recommendation grade of C. This review provides a framework for clinicians when considering topical treatments for patients with field cancerization.

1% Tirbanibulin Ointment for Actinic Keratoses on Upper Extremities: A Retrospective Case Review Study

Abstract is missing (Short communication)

Imiquimod as Local Immunotherapy in the Management of Premalignant Cutaneous Conditions and Skin Cancer

Cutaneous cancers are, by far, the most common malignant neoplasms of the human being. Due to the great array of clinical conditions, their worldwide increasing incidence and the steady ageing of the population, non-invasive treatments modalities that show a good clinical response, a proper benefit-risk ratio and cosmetic results are becoming increasingly important in the clinical setting. Imiquimod is a topically applied immunomodulator which is often used in the management of several premalignant and malignant cutaneous disorders. This article is a review of the current literature on its mechanism of action, pharmacokinetics, and therapeutical effects.

Pharmacological Agents Used in the Prevention and Treatment of Actinic Keratosis: A Review

Actinic keratosis (AK) is among the most commonly diagnosed skin diseases with potentially life-threatening repercussions if left untreated. Usage of pharmacologic agents represents one of many therapeutic strategies that can be used to help manage these lesions. Ongoing research into these compounds continues to change our clinical understanding as to which agents most benefit particular patient populations. Indeed, factors such as past personal medical history, lesion location and tolerability of therapy only represent a few considerations that clinicians must account for when prescribing appropriate treatment. This review focuses on specific drugs used in either the prevention or treatment of AKs. Nicotinamide, acitretin and topical 5-fluorouracil (5-FU) continue to be used with fidelity in the chemoprevention of actinic keratosis, although some uncertainty persists in regard to which agents should be used in immunocompetent vs. immunodeficient/immunosuppressed patients. Topical 5-FU, including combination formulations with either calcipotriol or salicylic acid, as well as imiquimod, diclofenac and photodynamic light therapy are all accepted treatment strategies employed to target and eliminate AKs. Five percent of 5-FU is regarded as the most effective therapy in the condition, although the literature has conflictingly shown that lower concentrations of the drug might also be as effective. Topical diclofenac (3%) appears to be less efficacious than 5% 5-FU, 3.75-5% imiquimod and photodynamic light therapy despite its favorable side effect profile. Finally, traditional photodynamic light therapy, while painful, appears to be of higher efficacy in comparison to its more tolerable counterpart, daylight phototherapy.

Field Therapy for Actinic Keratosis: A Structured Review of the Literature on Efficacy, Cost, and Adherence

BACKGROUND

Although there are evidence-based guidelines for actinic keratosis management, selecting a cost-effective field therapy is challenging because of limited studies comparing cost, efficacy, and adherence among treatments.

OBJECTIVE

To review the literature on field-directed therapies for actinic keratosis, comparing efficacy, cost, and adherence data for topical and in-office treatments.

MATERIALS AND METHODS

PubMed, Embase, Web of Science, and Google Scholar databases were searched from October 2020 to March 2021 for articles on field therapy for actinic keratosis. Total cost per regimen was estimated using wholesale acquisition cost package prices and Medicare coverage rates for May 2021. Effective cost was approximated by dividing total cost by complete response rate.

RESULTS

Efficacy data for various field therapies range widely, and long-term follow-up is limited. Cross-study comparisons are challenging because of heterogeneity of studies. Field-directed therapy with topical 5-fluorouracil and photodynamic therapy have similar effective cost. Adherence may significantly affect real-world efficacy and long-term clearance; this would favor shorter duration topical regimens or in-office procedures.

CONCLUSION

Standardization of future studies examining efficacy of field treatments for actinic keratosis will allow comparison across treatments. In-office treatments such as photodynamic therapy represent a cost-effective alternative to topical therapies with comparable efficacy.

NCCN Guidelines® Insights: Squamous Cell Skin Cancer, Version 1.2022

The NCCN Guidelines for Squamous Cell Skin Cancer provide recommendations for diagnostic workup, clinical stage, and treatment options for patients with cutaneous squamous cell carcinoma. The NCCN panel meets annually to discuss updates to the guidelines based on comments from panel members and the Institutional Review, as well as submissions from within NCCN and external organizations. These NCCN Guidelines Insights focus on the introduction of a new surgical recommendation terminology (peripheral and deep en face margin assessment), as well as recent updates on topical prophylaxis, immunotherapy for regional and metastatic disease, and radiation therapy.

Guidelines of care for the management of actinic keratosis

BACKGROUND

Actinic keratoses (AK) are rough scaly patches that arise on chronically ultraviolet-exposed skin and can progress to keratinocyte carcinoma.

OBJECTIVE

This analysis examined the literature related to the management of AK to provide evidence-based recommendations for treatment. Grading, histologic classification, natural history, risk of progression, and dermatologic surveillance of AKs are also discussed.

METHODS

A multidisciplinary Work Group conducted a systematic review to address 5 clinical questions on the management of AKs and applied the Grading of Recommendations, Assessment, Development, and Evaluation approach for assessing the certainty of the evidence and formulating and grading clinical recommendations. Graded recommendations were voted on to achieve consensus.

RESULTS

Analysis of the evidence resulted in 18 recommendations.

LIMITATIONS

This analysis is based on the best available evidence at the time it was conducted. The pragmatic decision to limit the literature review to English language randomized trials may have excluded data published in other languages or limited identification of relevant long-term follow-up data.

CONCLUSIONS

Strong recommendations are made for using ultraviolet protection, topical imiquimod, topical 5-fluorouracil, and cryosurgery. Conditional recommendations are made for the use of photodynamic therapy and diclofenac for the treatment of AK, both individually and as part of combination therapy regimens.

Guidelines of care for the management of actinic keratosis: Executive summary

BACKGROUND

Actinic keratoses (AK) are rough scaly patches that arise on chronically ultraviolet-exposed skin and can progress to keratinocyte carcinoma. Treatment options for AK include topical medications, photodynamic therapy, cryosurgery, and laser ablation.

OBJECTIVE

This executive summary provides a synopsis of the 18 evidence-based recommendations for the treatment of AK detailed in the Guidelines of Care for the Management of Actinic Keratosis.

METHODS

A multidisciplinary workgroup conducted a systematic review to address 5 clinical questions on the management of AKs and applied the Grading of Recommendations Assessment, Development and Evaluation approach for assessing the certainty of the evidence and formulating and grading clinical recommendations. Graded recommendations were voted on to achieve consensus.

RESULTS

Analysis of the evidence resulted in 18 recommendations, suggesting there are several effective treatments available for AK.

LIMITATIONS

The analysis informing the recommendations was based on the best available evidence at the time it was conducted. The results of future studies may necessitate a revision of current recommendations.

CONCLUSIONS

Strong recommendations are presented for using ultraviolet protection, topical imiquimod, topical 5-fluorouracil, and cryosurgery. Conditional recommendations are presented for the use of photodynamic therapy and diclofenac for the treatment of AK, both individually and as part of combination therapy regimens.

Safety of topical interventions for the treatment of actinic keratosis

Introduction: Actinic keratosis (AK) are proliferations of atypical keratinocytes that may eventually progress to cutaneous squamous cell carcinoma. Therefore, AK requires consequent and early treatment. Areas covered: A variety of effective approaches is currently available for the clearance of AK. These interventions may be applied either in a lesion-directed or field-directed mode as AK can occur as single or multiple lesions. Field-directed approaches typically comprise topical drug-mediated interventions which aim at eliminating all visible lesions and also at clearing subclinical changes of the actinically damaged field. However, most treatment options are associated with local adverse events such as erythema, scaling, pain, and rarely with systemic symptoms. This expert review provides a comprehensive and up-to-date overview of the safety considerations of the commonly prescribed topical treatment agents cyclooxygenase inhibitors, 5-fluorouracil, imiquimod, ingenol mebutate, and photodynamic therapy. All these therapies have been proven efficient, yet they differ considerably regarding their safety profile. Expert opinion: In the future, safety concerns will relate to long-term and irreversible adverse drug events instead of application site reactions. In particular, the rate of treatment-associated non-melanoma skin cancers will increasingly come into focus and warrant investigation in postmarketing surveillance trials with a long-term follow-up.

Italian expert consensus paper on the management of patients with actinic keratoses

Two round tables involving experts were organized in order to reach a consensus on the management of patients with actinic keratosis (AK). In the first, seven clinical questions were selected and analyzed by a systematic literature review, using a Population, Intervention, Control, and Outcomes framework; in the second, the experts discussed relevant evidences and a consensus statement for each question was developed. Consensus was reached among experts on how to best treat AK patients with respect to different clinical scenarios and special populations. Lesion-directed treatments are preferred in patients with few AKs. Patients with multiple AKs are challenging, with more than one treatment usually needed to achieve complete lesion clearance or a high lesion response rate, therapy should be personalized, based on previous treatments, patient, and lesion characteristics. Methyl aminolevulinate-PDT, DL (day light) PDT, and imiquimod cream were demonstrated to have the lowest percentage of new AKs after post treatment follow-up. For IMQ 5% and 3.75%, a higher intensity of skin reactions is associated with higher efficacy. Photodynamic therapy (PDT) is the most studied treatment for AKs on the arms. Regular sunscreen use helps preventing new AKs. Oral nicotinamide 500 mg twice daily, systemic retinoids and regular sunscreen use were demonstrated to reduce the number of new squamous cell carcinomas in patients with AKs. Limited evidence is available for the treatment of AKs in organ transplant recipients. There is no evidence in favor or against the use of any of the available treatments in patients suffering from hematological cancer.

Transcutaneous immunization with CD40 ligation boosts cytotoxic T lymphocyte mediated antitumor immunity independent of CD4 helper cells in mice

Transcutaneous immunization (TCI) is a novel vaccination strategy that utilizes skin-associated lymphatic tissue to induce immune responses. Employing T-cell epitopes and the TLR7 agonist imiquimod onto intact skin mounts strong primary, but limited memory CTL responses. To overcome this limitation, we developed a novel imiquimod-containing vaccination platform (IMI-Sol) rendering superior primary CD8⁺ and CD4⁺ T-cell responses. However, it has been unclear whether IMI-Sol per se is restricted in terms of memory formation and tumor protection. In our present work, we demonstrate that the combined administration of IMI-Sol and CD40 ligation unleashes fullblown specific T-cell responses in the priming and memory phase, strongly enhancing antitumor protection in mice. Interestingly, these effects were entirely CD4⁺ T cell independent, bypassing the necessity of helper T cells. Moreover, blockade of CD70 in vivo abrogated the boosting effect of CD40 ligation, indicating that the adjuvant effect of CD40 in TCI is mediated via CD70 on professional APCs. Furthermore, this work highlights the so far underappreciated importance of the CD70/CD27 interaction as a promising adjuvant target in TCI. Summing up, we demonstrate that the novel formulation IMI-Sol represents a powerful vaccination platform when applied in combination with sufficient adjuvant thereby overcoming current limitations of TCI.

Investigational drugs currently in phase II clinical trials for actinic keratosis

INTRODUCTION

Actinic keratoses (AKs) are limited areas of irregular epidermal growth on a background of excessive solar exposure. The entire sun-damaged skin is considered a field of cancerization with multiple visible and subclinical lesions. AK management requires field-directed therapies to block lesion relapse and prevent squamous cell carcinoma (SCC).

AREAS COVERED

In this review, we focused on phase II clinical trials for AKs, involving well-known agents and newer molecules such as proapoptotic drugs (VDA-1102, SR-T100, oleogel-S10, ICVT, eflornithine), immunomodulants (isotretinoin, tretinoin) and chemopreventive agents (nicotinamide, perillyl alcohol, liposomal T4N5). We used the website 'ClinicalTrials.Gov' as main reference. We selected and discussed completed and ongoing trials and analysed chemical structure and mechanism of action of the investigated molecules.

EXPERT OPINION

AK therapy should be tailored on the patient's profile considering first of all the age and site of the AKs, which are relevant parameters for local immune response. The new molecules could be combined to obtain a synergic effect blocking the different steps of skin tumorigenesis. Phase II trials highlight a new therapeutic opportunity to block selectively cell proliferation regulators and work both on the field of cancerization and on the AKs currently present.

Current developments in pharmacotherapy for actinic keratosis

INTRODUCTION

Actinic keratosis (AK) is a superficial squamous cell carcinoma (SCC) where chronic sun exposure playing central role in its pathogenesis. UVB causes direct damage to DNA, producing pyrimidine dimers, and suppressing the protective role of p53. The stepwise progression of AK, with increased expression of anti-apoptotic Bcl-2, favors progression to SCC. Moreover, the dermal response characterized by inflammation and mediated by prostaglandins is a critical component of tumorigenesis that promotes tumor growth, tissue invasion, angiogenesis and metastasis. Other risk factors are represented by age, gender, phototype and drugs.

AREAS COVERED

In this review, the authors document the recent developments of different therapies used to treat AK and provide their perspectives on current and future treatment strategies.

EXPERT OPINION

The usefulness of long-term treatment with piroxicam and sun filters or diclofenac targeting the inflammation phases of skin tumorigenesis favors AK's healing and provides greater control of the cancerization field. Nonsteroidal anti-inflammatory drugs can be safely used in patients who use photosensitizing drugs and, therefore, are more at risk of developing skin tumors. Immunomodulatory therapies, which require shorter treatment, are characterized by more common local side effects, and need more attention by the dermatologist in the concern of patient education, resulting essential to improve adherence and outcomes.

Comparison of the Treatment Guidelines for Actinic Keratosis: A Critical Appraisal and Review

There are currently several reputable guidelines on the treatment of actinic keratosis (AK) from groups in Canada, the United Kingdom, and Europe. These recommendations, based on evidence or expert consensus, offer clinicians a variety of treatment options for the different clinical presentations of AKs. Although the guidelines are similar in some regards, variations exist in treatment options, duration, and strength of recommendation. Some guidelines also lack input on specific therapies and certain types of AK, such as hypertrophic or thin presentations. The purpose of this article is to review and compare guidelines published by Canadian, UK, and European groups for the management of AKs in patients.

Non-melanoma Skin Cancer in Canada Chapter 3: Management of Actinic Keratoses

Background

Actinic keratosis (AK) and cheilitis (AC) are lesions that develop on photodamaged skin and may progress to form invasive squamous cell carcinomas (SCCs).

Objective

To provide guidance to Canadian health care practitioners regarding management of AKs and ACs.

Methods

Literature searches and development of graded recommendations were carried out as discussed in the accompanying introduction (chapter 1 of the NMSC guidelines).

Results

Treatment of AKs allows for secondary prevention of skin cancer in sun-damaged skin. Because it is impossible to predict whether a given AK will regress, persist, or progress, AKs should ideally be treated. This chapter discusses options for the management of AKs and ACs.

Conclusions

Treatment options include surgical removal, topical treatment, and photodynamic therapy. Combined modalities may be used in case of inadequate response. AKs are particularly common following the longterm immunosuppression in organ transplant patients, who should be monitored frequently to identify emerging lesions that require surgery.

Etanercept: a review of its use in autoimmune inflammatory diseases

With its approval more than 15 years ago, subcutaneous etanercept (Enbrel(®)) was the first biological disease-modifying antirheumatic drug (bDMARD) and the first tumour necrosis factor inhibitor to be approved for use in rheumatic diseases. Etanercept remains an important cost-effective treatment option in adult patients with rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis or plaque psoriasis, and in paediatric patients with juvenile idiopathic arthritis or plaque psoriasis. In all of these populations, etanercept (with or without methotrexate) effectively reduced signs and symptoms, disease activity and disability, and improved health-related quality of life, with these benefits sustained during long-term treatment. The safety profile of etanercept during short- and long-term treatment was consistent with the approved product labelling, with adverse events being of a predictable and manageable nature. The introduction of etanercept and other bDMARDs as therapeutic options for patients with autoimmune rheumatic diseases and spondyloarthropathies revolutionized disease management and these agents continue to have a central role in treatment strategies. This article reviews the extensive clinical experience with etanercept in these patient populations.

Cost-utility of first-line actinic keratosis treatments in Finland

Introduction

Cost–utility assessment of first-line actinic keratosis (AK) treatments for max 25 cm² AK field.

Methods

A probabilistic, 2-year decision tree model was used to assess costs, quality-adjusted life-years (QALY), incremental cost-effectiveness ratio (ICER), cost-effectiveness efficiency frontier, cost-effectiveness acceptability frontier (CEAF), and expected value of perfect information (EVPI) of AK treatments from the Finnish health care payer perspective with 3% discounting per annum. In the model, the first-line AK treatment resulted in complete clearance (CC) or non-CC with or without local skin responses (LSR), or AK recurrence. Non-CC AK was treated with methyl aminolevulinate + photodynamic therapy (MAL + PDT), and AK recurrence was retreated with the previous effective treatment. Costs included primary and secondary health care, outpatient drugs, and LSR management. QALYs were assessed with the EuroQol (EQ-5D-3L). Result robustness was assessed with sensitivity analyses.

Results

The mean simulated per patient QALYs (costs) were 1.526 (€982) for MAL + PDT, 1.524 (€794) for ingenol mebutate gel (IngMeb) 0.015% (3 days), 1.522 (€869) for IngMeb 0.05% (2 days), 1.520 (€1062) for diclofenac 3% (12 weeks), 1.518 (€885) for imiquimod 3.75% (6 weeks), 1.517 (€781) for imiquimod 5% (4/8 weeks), and 1.514 (€1114) for cryosurgery when treating AK affecting any body part. IngMeb 0.015% was less costly and more effective (dominating) than other AK treatments indicated for face and scalp area with the exception of imiquimod 5% for which the ICER was estimated at €1933/QALY gained and MAL + PDT, which had an ICER of €82,607/QALY gained against IngMeb 0.015%. With willingness-to-pay €2526–18,809/QALY gained, IngMeb 0.015% had >50% probability for cost-effectiveness on the CEAF. IngMeb 0.05% dominated AK treatments indicated for trunk and extremities. EVPIs for face and scalp (trunk and extremities) analyses were €26 (€0), €86 (€58), and €250 (€169) per patient with the willingness-to-pay of €0, €15,000, and €30,000 per QALY gained, respectively.

Conclusion

IngMebs were cost-effective AK treatments in Finland.

Funding

LEO Pharma.

Electronic supplementary material

The online version of this article (doi:10.1007/s12325-015-0211-7) contains supplementary material, which is available to authorized users.

Toll receptor agonist therapy of skin cancer and cutaneous T-cell lymphoma

PURPOSE OF REVIEW

The use of agents which exhibit the ability to potently activate the innate immune response has gained significant interest as therapeutics to treat cancer. We will review the history and the current applications of these agents to treat skin cancer and cutaneous T-cell lymphoma.

RECENT FINDINGS

Particular attention has been focused upon Toll-like receptor (TLR) agonists, including imidazoquinolines, which can trigger TLR 7 and TLR 8, and cytosine-phosphate-guanine (CpG) oligodeoxynucleotides, which activate TLR 9-expressing cells. Imiquimod, a TLR 7 agonist, has been found to be efficacious for basal cell and squamous cell cancers, as well as cutaneous T-cell lymphoma and lentigo maligna melanoma. CpGs have demonstrated efficacy for cutaneous T-cell lymphoma. Additional more potent compounds, including resiquimod, are presently in clinical trials for several types of skin cancers.

SUMMARY

TLR agonists that can activate the innate immune response have been used to treat a variety of skin cancers including basal cell cancer, squamous cell cancer, lentigo maligna melanoma and cutaneous T-cell lymphoma. Significant clinical efficacy has been observed for all of these conditions. It is anticipated that additional members of the TLR agonist family will be available in the clinic for the future treatment of skin cancers as well as other malignancies.

Inhibition of keratinocyte proliferation by phospholipid-conjugates of a TLR7 ligand in a Myc-induced hyperplastic actinic keratosis model in the absence of systemic side effects

BACKGROUND

The Toll-like receptor 7 (TLR7) activator imiquimod (IMQ) is safe and effective in treating actinic keratosis; however, an intermittent treatment regimen is necessary because of excessive local reactions.

OBJECTIVES

To evaluate in vitro potency, pharmacodynamics/pharmacokinetics, toxicity and efficacy in vivo of the newly developed TLR7 ligand-phospholipid conjugate, TMX-202, in a gel formulation.

MATERIAL AND METHODS

The effects of TMX-202 were assessed both in vitro on a murine macrophage cell line and in primary bone marrow-derived dendritic cells and in vivo on mice (C57BL/6-wild type, Myd88(-/-) and Tlr7(-/-)).

RESULTS

TMX-202 was more potent than IMQ in vitro using murine and human cells. In contrast, in vivo it showed less systemic pro-inflammatory activity and better safety than IMQ. Moreover, the TMX-202 gel formulation exhibited at least comparable efficacy to Aldara in a mouse model for skin proliferative diseases.

CONCLUSION

TMX-202 is safe and efficacious without causing excessive adverse effects, suggesting that it may be an alternative to Aldara for the treatment of proliferative skin conditions.

Understanding efficacy end-points in studies of field-directed therapy for actinic keratosis

BACKGROUND

The rates of short-term clearance of actinic keratoses appear to be comparable in clinical trials of topical treatments used in field therapy, but direct comparisons of efficacy results can be problematic. Trials use different efficacy end points, have different study designs, involve different anatomic sites, and enroll different patient populations. In addition, because adherence in real-world clinical practice differs from that observed in clinical trials, conclusions drawn from efficacy outcomes can be misleading. The objective of this review was to examine the efficacy end points used in studies of topical therapy for actinic keratosis, address other factors influencing efficacy outcomes in these studies, and discuss the possible influence of nonadherence on effectiveness.

METHODS

Review of the available literature on topical therapy for actinic keratosis.

RESULTS

The end points used to determine efficacy of therapies for actinic keratosis include a disparate group of outcomes, which can often make comparison between studies impossible.

CONCLUSIONS

Efficacy end points of clinical studies designed to assess the treatment of actinic keratosis should be standardized to facilitate between-trial comparisons, and studies should focus on the end points that are most clinically relevant.

Network meta-analysis of the outcome 'participant complete clearance' in nonimmunosuppressed participants of eight interventions for actinic keratosis: a follow-up on a Cochrane review

The conclusions of pairwise meta-analyses of interventions for actinic keratosis (AK) are limited due to the lack of direct comparison between some interventions. Consequently, we performed a network meta-analysis for eight treatments [5-aminolaevulinic acid (ALA)-photodynamic therapy (PDT), cryotherapy, diclofenac 3% in 2·5% hyaluronic acid (DCF/HA), 5-fluorouracil (5-FU) 0·5% or 5·0%, imiquimod (IMI) 5%, ingenol mebutate (IMB) 0·015-0·05%, methyl aminolaevulinate (MAL)-PDT and placebo/vehicle (including placebo-PDT)] to determine their relative efficacies. As part of a prior Cochrane systematic review, different databases and grey literature were searched for randomized controlled trials up to April 2012. The inclusion criteria were parallel-group studies with nonimmunosuppressed participants: (i) reporting 'participant complete clearance' and (ii) comparing at least two of the interventions. Thirty-two publications met the criteria and they included the following number of individual or pooled studies (n) and total number of participants (N) for the different interventions: 5-FU 0·5% (n = 4, N = 169), 5-FU 5·0% (n = 2, N = 44), ALA-PDT (n = 6, N = 739), cryotherapy (n = 2, N = 174), DCF/HA (n = 5, N = 299), IMI (n = 14, N = 1411), IMB (n = 3, N = 560), MAL-PDT (n = 7, N = 557) and placebo (n = 32, N = 2520). Network analyses using a random-effects Bayesian model were carried out with the software ADDIS v1.16.1. The interventions were ranked as follows based on calculated probabilities and odd ratios: 5-FU > ALA-PDT ≈ IMI ≈ IMB ≈ MAL-PDT > cryotherapy > DCF/HA > placebo. This efficacy ranking was obtained based on the current available data on 'participant complete clearance' from randomized controlled trials and the analysis model used. However, several other factors should also be considered when prescribing a treatment for AK.

Ingenol Mebutate: A Promising Treatment for Actinic Keratoses and Nonmelanoma Skin Cancers

Background:

A new treatment for actinic keratoses, ingenol mebutate, was recently approved by the US Food and Drug Administration.

Objective:

To review the mechanisms of action, efficacy and safety data, and practical recommendations for ingenol mebutate.

Methods:

The PubMed and clinicaltrials.gov databases were searched in March/April 2012 using the terms PEP005, ingenol mebutate, and ingenol 3-angelate. The abstracts from the Annual Scientific Meeting of the Australian College of Dermatologists (2009–2011) and the Annual Meeting of the American Academy of Dermatology (2009–2012) were also searched.

Results:

Due to its multiple mechanisms of action, ingenol mebutate treatment resulted in short- and long-term efficacy similar to other topical treatments for actinic keratoses in a shorter period of 2 or 3 days. This short therapy would reduce the duration of adverse events. Premarketing trials for treatment of nonmelanoma skin cancers also showed promising results for ingenol mebutate.

Conclusion:

Ingenol mebutate is a convenient, safe, and effective intervention for precancerous and cancerous skin conditions.

Interventions for actinic keratoses

BACKGROUND

Actinic keratoses are a skin disease caused by long-term sun exposure, and their lesions have the potential to develop into squamous cell carcinoma. Treatments for actinic keratoses are sought for cosmetic reasons, for the relief of associated symptoms, or for the prevention of skin cancer development. Detectable lesions are often associated with alteration of the surrounding skin (field) where subclinical lesions might be present. The interventions available for the treatment of actinic keratoses include individual lesion-based (e.g. cryotherapy) or field-directed (e.g. topical) treatments. These might vary in terms of efficacy, safety, and cosmetic outcomes.

OBJECTIVES

To assess the effects of topical, oral, mechanical, and chemical interventions for actinic keratosis.

SEARCH METHODS

We searched the following databases up to March 2011: the Cochrane Skin Group Specialised Register, CENTRAL in The Cochrane Library, MEDLINE (from 2005), EMBASE (from 2010), and LILACS (from 1982). We also searched trials registers, conference proceedings, and grey literature sources.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing the treatment of actinic keratoses with either placebo, vehicle, or another active therapy.

DATA COLLECTION AND ANALYSIS

At least two authors independently abstracted data, which included adverse events, and assessed the quality of evidence. We performed meta-analysis to calculate a weighted treatment effect across trials, and we expressed the results as risk ratios (RR) and 95% confidence intervals (CI) for dichotomous outcomes (e.g. participant complete clearance rates), and mean difference (MD) and 95% CI for continuous outcomes (e.g. mean reduction in lesion counts).

MAIN RESULTS

We included 83 RCTs in this review, with a total of 10,036 participants. The RCTs covered 18 topical treatments, 1 oral treatment, 2 mechanical interventions, and 3 chemical interventions, including photodynamic therapy (PDT). Most of the studies lacked descriptions of some methodological details, such as the generation of the randomisation sequence or allocation concealment, and half of the studies had a high risk of reporting bias. Study comparison was difficult because of the multiple parameters used to report efficacy and safety outcomes, as well as statistical limitations. We found no data on the possible reduction of squamous cell carcinoma.The primary outcome 'participant complete clearance' significantly favoured four field-directed treatments compared to vehicle or placebo: 3% diclofenac in 2.5% hyaluronic acid (RR 2.46, 95% CI 1.66 to 3.66; 3 studies with 420 participants), 0.5% 5-fluorouracil (RR 8.86, 95% CI: 3.67 to 21.44; 3 studies with 522 participants), 5% imiquimod (RR 7.70, 95% CI 4.63 to 12.79; 9 studies with1871 participants), and 0.025% to 0.05% ingenol mebutate (RR 4.50, 95% CI 2.61 to 7.74; 2 studies with 456 participants).It also significantly favoured the treatment of individual lesions with photodynamic therapy (PDT) compared to placebo-PDT with the following photosensitisers: aminolevulinic acid (ALA) (blue light: RR 6.22, 95% CI 2.88 to 13.43; 1 study with 243 participants, aminolevulinic acid (ALA) (red light: RR 5.94, 95% CI 3.35 to 10.54; 3 studies with 422 participants), and methyl aminolevulinate (MAL) (red light: RR 4.46, 95% CI 3.17 to 6.28; 5 studies with 482 participants). ALA-PDT was also significantly favoured compared to cryotherapy (RR 1.31, 95% CI 1.05 to 1.64).The corresponding comparative risks in terms of number of participants completely cleared per 1000 were as follows: 313 with 3% diclofenac compared to 127 with 2.5% hyaluronic acid; 136 with 0.5% 5-fluorouracil compared to 15 with placebo; 371 with 5% imiquimod compared to 48 with placebo; 331 with ingenol mebutate compared to 73 with vehicle; 527 to 656 with ALA/MAL-PDT treatment compared to 89 to 147 for placebo-PDT; and 580 with ALA-PDT compared to 443 with cryotherapy.5% 5-fluorouracil efficacy was not compared to placebo, but it was comparable to 5% imiquimod (RR 1.85, 95% Cl 0.41 to 8.33).A significant number of participants withdrew because of adverse events with 144 participants affected out of 1000 taking 3% diclofenac in 2.5% hyaluronic acid, compared to 40 participants affected out of 1000 taking 2.5% hyaluronic acid alone, and 56 participants affected out of 1000 taking 5% imiquimod compared to 21 participants affected out of 1000 taking placebo.Based on investigator and participant evaluation, imiquimod treatment and photodynamic therapy resulted in better cosmetic outcomes than cryotherapy and 5-fluorouracil.

AUTHORS' CONCLUSIONS

For individual lesions, photodynamic therapy appears more effective and has a better cosmetic outcome than cryotherapy. For field-directed treatments, diclofenac, 5-fluorouracil, imiquimod, and ingenol mebutate had similar efficacy, but their associated adverse events and cosmetic outcomes are different. More direct comparisons between these treatments are needed to determine the best therapeutic approach.

Results of an investigator-initiated single-blind split-face comparison of photodynamic therapy and 5% imiquimod cream for the treatment of actinic keratoses

BACKGROUND

Topical photodynamic therapy (PDT) with aminolevulinic acid (ALA) and 5% imiquimod cream are effective therapies for the treatment of actinic keratoses (AKs), but no split-face studies directly comparing these treatment options are available in the literature.

OBJECTIVE

To compare the efficacy and tolerability of ALA-PDT and imiquimod 5% cream for the treatment of AKs.

RESULTS

Sixty-one patients were enrolled from the Salt Lake City Veterans Affairs Hospital; 51 completed the study and were included in the analysis. All patients were randomized to receive half of a sachet of imiquimod 5% cream twice weekly on half of their face and two sessions of PDT with 20% solution of ALA applied for 1 hour to the other side of the face. The 75% AK clearance rate was 34.6% for ALA-PDT and 25% for imiquimod 5% cream (p = .30). The mean reduction in AK count was 59.2% for ALA-PDT and 41.4% for imiquimod 5% cream (p = .002). Dermatology Life Quality Index (DLQI) scores were assessed for each treatment modality at week 4 and were 1.95 and 1.38, respectively (p = .20).

LIMITATIONS

The sample size was small, and patients applied a small amount of imiquimod 5% cream (half a sachet) to a large surface area.

CONCLUSION

There was no statistically significant difference in treatment response when the 100% or 75% clearance rate cutoff was used, but our secondary outcome suggests that two sessions of ALA-PDT is superior to imiquimod 5% cream for the treatment of AKs. There was no statistically significant difference in effect on quality of life as assessed using the DLQI.

Diclofenac gel in the treatment of actinic keratoses

Actinic keratoses are areas of intraepithelial neoplasia for which treatment is necessary. Because they arise in areas of sun damage, it is desirable to treat the entire damaged field to not only treat visible lesions, but also subclinical, emerging malignancies, ie, “field therapy”, 5-fluorouracil, imiquimod, and diclofenac are all treatment options, and are discussed and compared.

Imiquimod 3.75% cream (Zyclara) for the treatment of actinic keratoses

INTRODUCTION

actinic keratosis is a premalignant disease with a high incidence and is a strong predictor for the development of squamous cell carcinoma. Various treatment options have been established over recent years, including topical treatment with imiquimod, 5-fluorouracil, diclofenac or photodynamic therapy, cryotherapy and surgical procedures.

AREAS COVERED

this review covers basic and clinical experiences with imiquimod 3.75% for topical treatment of actinic keratosis of the face and balding scalp and its comparators with special focus on imiquimod 5%. It also covers pharmacology of imiquimod 3.5% and its contribution to the current treatment options of actinic keratoses.

EXPERT OPINION

imiquimod 3.75% is an interesting, safe and well-tolerated treatment option for actinic keratoses of the face or balding scalp especially in respect of compliance, as it is indicated for daily use for a shorter time period (2 times, 2-week cycles) and approved for use on larger areas compared with imiquimod 5%. Data from current trials indicate lower efficacy compared with imiquimod 5% cream when applied three times a week for 16 weeks or for two 4-week cycles with a 4-week no-treatment interval, but indicate similar efficacy when compared with a twice-weekly schedule for 16 weeks. An additive effect was observed when combining cryosurgery followed by imiquimod 3.75%.

Exaggerated Imiquimod Application Site Reactions in the Context of Systemic Tumor Necrosis Factor-Alpha Inhibition: More Than a Coincidental Occurrence?

Topical imiquimod and tumor necrosis factor (TNF)-α inhibitors have gained wide acceptance as safe and effective treatments for non-melanoma skin cancer (NMSC) and moderate to severe psoriasis, respectively. While mild to moderate application site reactions (ASRs) are a well-known and common phenomenon associated with imiquimod, the potential of TNF-α blockers to elicit cutaneous inflammatory reactions has only recently been recognized. We present two cases of severe, atypical ASRs which occurred during NMSC treatment with imiquimod in the context of infliximab administration for psoriasis, and consider the grounds supporting a non-fortuitous association. To date, no relation has ever been suggested between TNF-α inhibitors and increased susceptibility to developing exaggerated ASRs with imiquimod. We believe that this subject deserves further analysis; meanwhile, increased attention should be drawn to the possibility of this adverse interaction, as simultaneous treatment with TNF-α blockers and imiquimod is becoming increasingly frequent in daily practice.

Photodynamic therapy with BF-200 ALA for the treatment of actinic keratosis: results of a prospective, randomized, double-blind, placebo-controlled phase III study

BACKGROUND

Photodynamic therapy (PDT) with 5-aminolaevulinic acid (ALA) provides a therapeutic option for the treatment of actinic keratosis (AK). Different strategies are applied to overcome the chemical instability of ALA in solution and to improve skin penetration. A new stable nanoemulsion-based ALA formulation, BF-200 ALA, is currently in clinical development for PDT of AK.

OBJECTIVES

To evaluate the efficacy and safety of PDT of AK with BF-200 ALA.

METHODS

The study was performed as a randomized, multicentre, double-blind, placebo-controlled, interindividual, two-armed trial with BF-200 ALA and placebo. A total of 122 patients with four to eight mild to moderate AK lesions on the face and/or the bald scalp were included in eight German study centres. The efficacy of BF-200 ALA after one and two PDT treatments was evaluated. BF-200 ALA was used in combination with two different light sources under illumination conditions defined by European competent authorities.

RESULTS

PDT with BF-200 ALA was superior to placebo PDT with respect to patient complete clearance rate (per-protocol group: 64% vs. 11%; P < 0.0001) and lesion complete clearance rate (per-protocol group: 81% vs. 22%) after the last PDT treatment. Statistically significant differences in the patient and lesion complete clearance rates and adverse effect profiles were observed for the two light sources, Aktilite CL128 and PhotoDyn 750, at both time points of assessment. The patient and lesion complete clearance rates after illumination with the Aktilite CL128 were 96% and 99%, respectively.

CONCLUSIONS

BF-200 ALA is a very effective new formulation for the treatment of AK with PDT. Marked differences between the efficacies and adverse effects were observed for the different light sources used. Thus, PDT efficacy is dependent both on the drug and on the characteristics of the light source and the illumination conditions used.

Imiquimod 2.5% and 3.75% for the treatment of actinic keratoses: results of two placebo-controlled studies of daily application to the face and balding scalp for two 3-week cycles

BACKGROUND

Imiquimod 5% cream is approved as a 16-week regimen for the treatment of actinic keratoses involving a 25-cm(2) area of skin.

OBJECTIVE

We sought to evaluate imiquimod 2.5% and 3.75% creams for short-course treatment of the entire face and scalp.

METHODS

In two identical studies, adults with 5 to 20 lesions were randomized to placebo, or imiquimod 2.5% or 3.75% cream (1:1:1). Up to two packets (250 mg each) were applied per dose once daily for two 3-week treatment cycles, with a 3-week, no-treatment interval. Efficacy was assessed at 8 weeks posttreatment.

RESULTS

In all, 490 subjects were randomized to placebo, or imiquimod 2.5% or 3.75% cream. Median baseline lesion counts for the treatment groups were 9 to 10. Complete and partial clearance rates were 5.5% and 12.8% for placebo, 25.0% and 42.7% for imiquimod 2.5%, and 34.0% and 53.7% for imiquimod 3.75% (P < .001, each imiquimod vs placebo; P = .034, 3.75% vs 2.5% for partial clearance). Median reductions from baseline in lesion count were 23.6%, 66.7%, and 80.0% for the placebo, imiquimod 2.5%, and imiquimod 3.75% groups, respectively (P < .001 each imiquimod vs placebo). There were few treatment-related discontinuations. Temporary treatment interruption (rest) rates were 0%, 17.1%, and 27.2% for the placebo, imiquimod 2.5%, and imiquimod 3.75%, respectively.

LIMITATIONS

Local effects of imiquimod, including erythema, may have led to investigator and subject bias.

CONCLUSIONS

Both imiquimod 2.5% and 3.75% creams were more effective than placebo and had an acceptable safety profile when administered daily as a 3-week on/off/on regimen.