Safety of alitretinoin for severe refractory chronic hand eczema: Clinical studies and postmarketing surveillance

Exploring the interactions of antihistamine with retinoic acid receptor beta (RARB) by molecular dynamics simulations and genome-wide meta-analysis

Kaposi sarcoma (KS) is one of the most common AIDS-related malignant neoplasms, which can leave lesions on the skin among HIV patients. These lesions can be treated with 9-cis-retinoic acid (9-cis-RA), an endogenous ligand of retinoic acid receptors that has been FDA-approved for treatment of KS. However, topical application of 9-cis-RA can induce several unpleasant side effects, like headache, hyperlipidemia, and nausea. Hence, alternative therapeutics with less side effects are desirable. There are case reports associating over-the-counter antihistamine usage with regression of KS. Antihistamines competitively bind to H1 receptor and block the action of histamine, best known for being released in response to allergens. Furthermore, there are already dozens of antihistamines that are FDA-approved with less side effects than 9-cis-RA. This led our team to conduct a series of in-silico assays to determine whether antihistamines can activate retinoic acid receptors. First, we utilized high-throughput virtual screening and molecular dynamics simulations to model high-affinity interactions between antihistamines and retinoic acid receptor beta (RARβ). We then performed systems genetics analysis to identify a genetic association between H1 receptor itself and molecular pathways involved in KS. Together, these findings advocate for exploration of antihistamines against KS, starting with our two promising hit compounds, bepotastine and hydroxyzine, for experimental validation study in the future.

Current emerging and investigational drugs for the treatment of chronic hand eczema

INTRODUCTION

: Chronic hand eczema (CHE) is a highly prevalent, burdensome condition associated with functional impairment. Currently, topical therapeutics are the mainstay of CHE management. However, many cases are refractory to existing topical therapeutics, and the few existing systemic options are often limited in efficacy and by their side effect profiles.

AREAS COVERED

: Following a brief overview of CHE pathogenesis and existing treatments, this review will outline the mechanisms and available data on emerging and investigational drugs currently being studied in clinical trials for the treatment of CHE.

EXPERT OPINION

: Immunomodulatory drugs such as topical and systemic JAK inhibitors and Th2-targeting antibodies such as dupilumab are currently under investigation for CHE treatment, with early promise. Management of CHE will likely move toward more targeted treatments through clinical trials and away from broad immunosuppressants such as cyclosporine and methotrexate, which have previously been investigated for CHE and have more side effects. In coming years, CHE patients may benefit from a wider range of both topical and systemic therapeutics that target immune pathways relevant to the various CHE subtypes.

The cardiovascular safety of oral alitretinoin: a population-based cohort study involving 19 513 patients exposed to oral alitretinoin

BACKGROUND

Oral alitretinoin is a retinoid used for severe chronic hand eczema. Although caution is recommended for patients with uncontrolled dyslipidaemia or cardiovascular risk factors, the actual atherothrombotic risk has not been investigated thus far.

OBJECTIVES

To detect any excess of atherothrombotic events among patients exposed to alitretinoin, during treatment or in the 2 years following initiation.

METHODS

Using the French Health Insurance database, we compared the number of patients who had an atherothrombotic event (coronary artery disease, ischaemic stroke or peripheral artery disease requiring revascularization) in the population exposed to oral alitretinoin vs. the general population of the same age, sex and baseline cardiovascular risk, using standardized morbidity ratios (SMRs).

RESULTS

Between 2009 and 2017, 19 513 patients were exposed to oral alitretinoin in France. Sixty-four (0·3%) patients had an atherothrombotic event while on alitretinoin. Patients receiving alitretinoin experienced no more atherothrombotic events than the general population: patients without cardiovascular risk factors or previous atherothrombotic events had a SMR of 0·65 [95% confidence interval (CI) 0·26-1·34] during alitretinoin treatment, and 1·21 (95% CI 0·90-1·59) in the 2 years following initiation; patients with cardiovascular risk factors or previous atherothrombotic events had a SMR of 0·82 (95% CI 0·60-1·08) during alitretinoin treatment and 0·95 (95% CI 0·82-1·09) in the 2 years following initiation. Taken separately, SMRs for each outcome did not increase either.

CONCLUSIONS

These data from an exhaustive nationwide population-based study do not support an increase in the incidence of atherothrombotic events with alitretinoin use, regardless of the baseline cardiovascular risk of the patient.

Guidelines for the Diagnosis, Treatment, and Prevention of Hand Eczema

Hand eczema is a common condition associated with significantly impaired quality of life and high social and occupational costs. Managing hand eczema is particularly challenging for primary care and occupational health physicians as the condition has varying causes and both disease progression and response to treatment are difficult to predict. Early diagnosis and appropriate protective measures are essential to prevent progression to chronic eczema, which is much more difficult to treat. Appropriate referral to a specialist and opportune evaluation of the need for sick leave are crucial to the good management of these patients. These guidelines cover the diagnosis, prevention, and treatment of chronic hand eczema and highlight the role that primary care and occupational health physicians can play in the early management of this disease.

Drugs for the Treatment of Chronic Hand Eczema: Successes and Key Challenges

Chronic hand eczema (CHE) is a common and burdensome inflammatory skin condition seen in up to 10% of the population, more often in high-risk occupational workers. Topical therapeutics comprise the standard of care, but up to 65% of cases do not resolve after treatment, and moderate-to-severe cases are often resistant to topical therapeutics and require systemic options instead. To date, there are no systemic therapeutics approved to treat CHE in the United States, but several drugs are under investigation as potential treatments for CHE. The primary focus of this review is on the novel therapeutics, topical and systemic, that are under investigation in recently completed or currently ongoing trials. This review also briefly outlines the existing treatments utilized for CHE, often with limited success or extensive adverse effects. CHE represents a major challenge for physicians and patients alike, and efforts to improve the minimally invasive diagnostic tools and treatment paradigms are ongoing. In the near future, CHE patients may benefit from new topical and systemic therapeutics that specifically target abnormally expressed immune markers.

Alitretinoin Compliance in Patients with Chronic Hand Eczema

Background

Oral alitretinoin is effective in the treatment of chronic hand eczema (CHE), and ≥12 weeks of alitretinoin treatment has been shown to be effective in Korean patients. However, in the real world, a considerable number of patients discontinue alitretinoin, which leads to treatment failure.

Objective

To evaluate the compliance rate of alitretinoin treatment and explore common reasons for poor compliance in patients with CHE in the real world.

Methods

We retrospectively reviewed the electronic medical records of CHE patients treated with alitretinoin. We defined ‘poor-compliance’ as subjects who were treated with alitretinoin for <12 weeks and ‘good-compliance’ as subjects who were treated with alitretinoin for ≥12 weeks. We reviewed the demographics, dose, and duration of alitretinoin usage, efficacy, and reasons for poor compliance.

Results

A total of 137 subjects were enrolled, and 77 (56.2%) did not complete the 12-week treatment with alitretinoin. Among them, the non-improvement rate was significantly higher in the poor-compliance group than in the good-compliance group (p<0.01). The main reasons for the alitretinoin cessation in the poor-compliance group were insufficient response (40.8%), followed by high cost (34.7%), and adverse events (24.5%).

Conclusion

Alitretinoin appears the preferred long-term treatment option for CHE. Although there are complaints about late efficacy, cost, and side effects, following proper explanation, these should not justify discontinuation. Physicians need to recognize the reasons for poor compliance with alitretinoin for each patient and suggest continuing alitretinoin for the successful treatment of CHE.

Management of chronic hand and foot eczema. An Australia/New Zealand Clinical narrative

Chronic hand/foot eczemas are common, but treatment is often challenging, with widespread dissatisfaction over current available options. Detailed history is important, particularly with regard to potential exposure to irritants and allergens. Patch testing should be regarded as a standard investigation. Individual treatment outcomes and targets, including systemic therapy, should be discussed early with patients, restoring function being the primary goal, with clearing the skin a secondary outcome. Each new treatment, where appropriate, should be considered additive or overlapping to any previous therapy. Management extends beyond mere pharmacological or physical treatment, and requires an encompassing approach including removal or avoidance of causative factors, behavioural changes and social support. To date, there is little evidence to guide sequences or combinations of therapies. Moderately symptomatic patients (e.g. DLQI ≥ 10) should be started on a potent/super-potent topical corticosteroid applied once or twice per day for 4 weeks, with tapering to twice weekly application. If response is inadequate, consider phototherapy, and then a 12-week trial of a retinoid (alitretinoin or acitretin). Second line systemic treatments include methotrexate, ciclosporin and azathioprine. For patients presenting with severe symptomatic disease (DLQI ≥ 15), consider predniso(lo)ne 0.5-1.0 mg/kg/day (or ciclosporin 3 - 5 mg/kg/day) for 4-6 weeks with tapering, and then treating as for moderate disease as above. In non-responders, botulinum toxin and/or iontophoresis, if associated with hyperhidrosis, may sometimes help. Some patients only respond to long-term systemic corticosteroids. The data on sequencing of newer agents, such as dupilumab or JAK inhibitors, are immature.

Alitretinoin reduces erythema in inherited ichthyosis

Background

Acitretin is the main retinoid used to treat severe inherited ichthyosis. Alternatives may be considered if it results ineffective or there are side-effects, or for women of childbearing age.

Our objective is evaluation of the effects and tolerance of alitretinoin.

An observational retrospective multicentric study was designed to analyse patients with inherited ichthyosis treated by alitretinoin.

Results

A total of 13 patients were included, 11 of whom were receiving acitretin at inclusion. The main reason for switching to alitretinoin was a desire for pregnancy, but also because of side-effects or unsatisfactory efficacy. Starting dose was 10 mg/day, increased to 20 or 30 mg/day. Alitretinoin seemed to be more effective than acitretin at reducing erythema, but was less effective at reducing scaling or hyperkeratosis. Global efficacy was considered low for two patients, moderate for nine, and high for two. Treatment was well-tolerated, except for one patient who presented with benign intracranial hypertension leading to discontinuation of treatment.

Conclusions

Alitretinoin may be suitable for hereditary ichthyosis with prominent erythema, especially for women of childbearing age.