Effects of topical treatment with the raft modulator miltefosine and clobetasol in cutaneous mastocytosis: a randomized, double-blind, placebo-controlled trial

Cutaneous mastocytosis: A dermatological perspective

Mastocytosis is a rare disease characterised by expansion and collection of clonal mast cells in various organs including the skin, bone marrow, spleen, lymph nodes and gastrointestinal tract. The prevalence of mastocytosis has been estimated to be one in 10 000, while the estimated incidence is one per 100 000 people per year. Cutaneous mastocytosis is classified into (i) maculopapular cutaneous mastocytosis, also known as urticaria pigmentosa; (ii) diffuse cutaneous mastocytosis; and (iii) mastocytoma of the skin. In adults, cutaneous lesions are usually associated with indolent systemic mastocytosis and have a chronic evolution. Paediatric patients, on the contrary, have often cutaneous manifestations without systemic involvement and usually experience a spontaneous regression. Diagnosis of cutaneous mastocytosis may be challenging due to the rarity of the disease and the overlap of cutaneous manifestations. This short review describes pathogenesis and clinical aspects of cutaneous mastocytosis with a focus on diagnosis and currently available therapies.

Cutaneous mastocytosis treatment: strategies, limitations and perspectives

Mastocytosis is a rare myeloproliferative disease, characterized by excessive proliferation and accumulation of mast cells in the tissues. In cutaneous mastocytosis (CM), mast cells infiltration is limited to the skin, whereas in systemic mastocytosis (SM) internal organs are involved. The first-line treatment in CM is antimediator therapy (mainly H1 and H2 antihistamines) and short-term topical corticosteroids. Phototherapy is the second-line therapy which may be considered when antihistamines do not produce the expected improvement. New therapeutic options include omalizumab and KIT-targeting agents. Although the disappearance of skin lesions has been reported as a result of cytoreductive therapies in SM, the use of potentially toxic drugs in CM is not recommended. In all adults with mastocytosis and in pediatric patients with severe CM, a persistently elevated serum tryptase level and anaphylaxis in medical history, equipping with epinephrine autoinjector for use in case of anaphylaxis is recommended.

Mast Cell Activation and Microtubule Organization Are Modulated by Miltefosine Through Protein Kinase C Inhibition

Mast cells play an effector role in innate immunity, allergy, and inflammation. Antigen-mediated activation of mast cells initiates signaling events leading to Ca²⁺ response and the release of inflammatory and allergic mediators from granules. Diseases associated with deregulated mast cell functions are hard to treat and there is an increasing demand for new therapeutic strategies. Miltefosine (hexadecylphosphocholine) is a new candidate for treatment of mast cell-driven diseases as it inhibits activation of mast cells. It has been proposed that miltefosine acts as a lipid raft modulator through its interference with the structural organization of surface receptors in the cell membrane. However, molecular mechanisms of its action are not fully understood. Here, we report that in antigen-activated bone marrow-derived mast cells (BMMCs), miltefosine inhibits degranulation, reorganization of microtubules, as well as antigen-induced chemotaxis. While aggregation and tyrosine phosphorylation of IgE receptors were suppressed in activated cells pre-treated with miltefosine, overall tyrosine phosphorylation levels of Lyn and Syk kinases, and Ca²⁺ influx were not inhibited. In contrast, lipid raft disruptor methyl-β-cyclodextrin attenuated the Ca²⁺ influx. Tagged-miltefosine rapidly localized into the cell interior, and live-cell imaging of BMMCs with labeled intracellular granules disclosed that miltefosine inhibited movement of some granules. Immunoprecipitation and in vitro kinase assays revealed that miltefosine inhibited Ca²⁺- and diacylglycerol-regulated conventional protein kinase C (cPKC) isoforms that are important for mast cell degranulation. Inhibition of cPKCs by specific inhibitor Ly333531 affected activation of BMMCs in the same way as miltefosine. Collectively, our data suggest that miltefosine modulates mast cells both at the plasma membrane and in the cytosol by inhibition of cPKCs. This alters intracellular signaling pathway(s) directed to microtubules, degranulation, and migration.

Topical corticosteroids versus "wait and see" in the management of solitary mastocytoma in pediatric patients: a long-term follow-up

Management of patients affected by mastocytoma (MS) includes avoiding triggering factors of mast cell degranulation, and administration of symptomatic treatment. We evaluated topical steroid treatment efficiency on the clinical course of MS in a group of patients, comparing the results with another untreated group.We retrospectively evaluated clinical data of 176 patients under 15 years of age, affected by MS and referred to our Dermatological Pediatric Service from 1996 to 2010. Ninety-one of 176 children were treated with topical steroids. Follow-up was possible in 130 of 176 patients and lasted for 56.3 months on average. We compared 62 treated and 68 untreated patients. There was not statistic difference between the two groups: (i) in the number of healed or partially improved cases; and (ii) in the time of partial regression, although it is quicker with therapy. The time of healing is 16.4 months (on average) with treatment, and 34.7 months (on average, p = 0.001) without any treatment. The resolution of MS is independent of therapy administration, but the time of healing is statistically faster using the local steroids. An appropriate treatment with them is effective and safe, considering the long time needed for spontaneous resolution.

Bullous mastocytosis in a 3-month-old infant

Mastocytosis is a rare myeloid neoplasm characterized by abnormal proliferation and accumulation of mast cells in one or more organ systems including the skin, bone marrow, liver, spleen, lymph nodes and gastrointestinal tract. An infant presenting with bullous lesions is an even rarer clinical presentation of cutaneous mastocytosis. The symptoms and complications are mostly in proportion to the mast cell degranulation in tissues. Management is focused on preventing and treating this event. We report a three-month-old infant with bullous mastocytosis to enhance awareness about this rare diagnosis.

Update and insights into treatment options for chronic spontaneous urticaria

Chronic spontaneous urticaria (CSU) is defined as itchy weals, angio-oedema, or both, arising spontaneously without external physical stimuli. Symptoms of the disease continue to develop for more than 6 weeks. It carries a high socioeconomic burden with considerable health care costs. Second generation H1-antihistamines are the mainstay of urticaria treatment and are the only licensed option. However, many patients are resistant to H1-antihistamine therapy. Omalizumab has proven to be an effective therapeutic option in patients with recalcitrant chronic urticaria. Ciclosporin appears to be more beneficial in patients with functional histamine releasing autoantibodies as a cause of their disease. This review article will highlight the major therapeutic options available today for the management of CSU knowing that good quality evidence for efficacy of many agents is scarce except for H1-antihistamines and omalizumab.

Repurposing miltefosine for the treatment of immune-mediated disease?

Miltefosine is an ether lipid that was initially developed for cancer treatment in the early 1980s. Miltefosine largely failed development for oncology, although it was approved for the topical treatment of breast cancer metastasis. It was subsequently discovered that miltefosine is a highly effective treatment of visceral Leishmaniasis, a parasitic disease that affects millions worldwide and causes an estimated 30,000 fatalities each year. Oral treatment with miltefosine is generally well tolerated and has relatively few adverse effects. The exact mechanism of action of miltefosine treatment is still under investigation. Its close resemblance to phospholipids allows it to be quickly taken up by cell membranes and affect related processes, such as lipid metabolism and signaling through lipid rafts. These processes play an important role in the immune response and it comes as no surprise that miltefosine has been successfully tested for the treatment of a number of immune-mediated diseases in preclinical models of disease. Drug repurposing of miltefosine for immune-mediated diseases may provide an opportunity to expand the limited number of drugs that are currently available for therapeutic use.

Treatment strategies in mastocytosis

Treatment recommendations for mastocytosis are based mostly on expert opinion rather than evidence obtained from controlled clinical trials. In this article, treatment options for mastocytosis are presented, with a focus on the control of mediator-related symptoms in patients with indolent disease.

Rupatadine improves quality of life in mastocytosis: a randomized, double-blind, placebo-controlled trial

BACKGROUND

Mastocytosis is frequently associated with mast cell-mediated symptoms which require relieving medication. While second generation antihistamines (sgAHs) are the first line therapeutic strategy to treat mast cell mediator-related symptoms, controlled clinical trials on how they improve quality of life have not been performed.

METHODS

This randomized, double-blind, placebo-controlled, cross-over trial assessed rupatadine 20 mg daily in the treatment of mastocytosis symptoms in 30 adult patients. Symptoms were assessed by a visual analogue scale (VAS) and symptom specific quality of life questionnaire (ItchyQoL).

RESULTS

The mean ItchyQoL total score and VAS symptom score were significantly improved in the rupatadine treatment phase compared with placebo. There were also significant reductions from placebo in the severity of itch, wheal and flare, flushing, tachycardia and headache but not gastrointestinal symptoms.

CONCLUSIONS

In this first comprehensive trial of a sgAH in mastocytosis, rupatadine 20 mg daily for 4 weeks significantly controlled symptoms and improved patients' quality of life.

Randomized, double-blind, placebo-controlled study of safety and efficacy of miltefosine in antihistamine-resistant chronic spontaneous urticaria

BACKGROUND

Chronic spontaneous urticaria (CSU), a mast cell-driven condition, is debilitating, common, and hard to treat. Miltefosine, a lipid raft modulator, can inhibit mast cell responses in vivo.

OBJECTIVE

To study the safety and efficacy of systemic miltefosine treatment in CSU patients resistant to standard-dosed antihistamines.

METHODS

In this investigator-initiated multicentre, randomized, double-blind, placebo-controlled study, CSU patients were treated for 4 weeks with daily doses of up to 150-mg miltefosine (n = 47) or placebo (n = 26). Disease activity was assessed using the urticaria activity score. Safety and tolerability of miltefosine were also assessed.

RESULTS

After 4 weeks of treatment, Urticaria Activity Score (UAS7) levels were substantially more reduced in miltefosine-treated patients (-6.3 vs. -3.5 in placebo-treated patients; P = 0.05). Also, the number of weals, but not the intensity of pruritus, was significantly reduced in miltefosine-treated patients vs. placebo-treated patients (P = 0.02). In general, adverse events were frequent in both groups (miltefosine: 88%, placebo: 65% of patients) but mostly mild to moderate in severity. We did not observe any serious adverse events.

CONCLUSIONS

The results of this study indicate that miltefosine is an effective and safe treatment option for CSU patients who do not respond to standard-dosed antihistamines.

Miltefosine: a novel treatment option for mast cell-mediated diseases

Mast cell-mediated diseases such as urticaria, mastocytosis and atopic dermatitis are common, disabling and hard to treat. Recently, the lipid raft modulator miltefosine has been shown to inhibit mast cell activation in vitro and in vivo. Moreover, three randomized and placebo-controlled trials have assessed the effects of miltefosine in mast cell-driven conditions. Here, we review the experimental and clinical evidence in support of miltefosine as a novel treatment option for mast cell-mediated diseases and we discuss the most imminent questions and issues that need to be addressed by future research and clinical trials.

Miltefosine: a review of its pharmacology and therapeutic efficacy in the treatment of leishmaniasis

Miltefosine is an alkylphosphocholine drug with demonstrated activity against various parasite species and cancer cells as well as some pathogenic bacteria and fungi. For 10 years it has been licensed in India for the treatment of visceral leishmaniasis (VL), a fatal neglected parasitic disease. It is the first and still the only oral drug that can be used to treat VL and cutaneous leishmaniasis (CL). The standard 28 day miltefosine monotherapy regimen is well tolerated, except for mild gastrointestinal side effects, although its teratogenic potential severely hampers its general use in the clinic and roll-out in national elimination programmes. The pharmacokinetics of miltefosine are mainly characterized by its long residence time in the body, resulting in extensive drug accumulation during treatment and long elimination half-lives. At the moment, different combination therapy strategies encompassing miltefosine are being tested in multiple controlled clinical trials in various geographical areas of endemicity, both in South Asia and East Africa. We here review the most salient pre-clinical and clinical pharmacological aspects of miltefosine, its mechanism of action against Leishmania parasites and other pathogens, and provide a systematic overview of the efficacy and safety data from all clinical trials of miltefosine, either alone or in combination, in the treatment of VL and CL.

Mastocytosis in children and adults: clinical disease heterogeneity

Mastocytosis is a clonal disease of the hematopoietic stem cell. The condition consists of a heterogeneous group of disorders characterized by a pathological accumulation of mast cells in tissues including the skin, bone marrow, liver, spleen and the lymph nodes. Mastocytosis is a rare disease which occurs both in children and adults. Childhood onset mastocytosis is usually cutaneous and transient while in adults the condition commonly progresses to a systemic form. The heterogeneity of clinical presentation of mastocytosis is typically related to the tissue mast cell burden, symptoms due to the release of mast cell mediators, the type of skin lesions, the patient's age at the onset and associated haematological disorders. Therefore, a multidisciplinary approach is recommended. The present article provides an overview of clinical symptoms, diagnostic criteria and treatment of mastocytosis to facilitate the diagnosis and management of mastocytosis patients in clinical practice.

Update on diagnosis and treatment of mastocytosis

Mastocytosis is a disorder characterized by increased numbers of mast cells in tissues. Recent clinical observations highlight the association of mastocytosis with an increased risk of anaphylaxis and underline the diversity of this disease. At the molecular level, recent studies have attempted to unravel specific gene expression profiles for activating c-kit mutations in the etiology of mastocytosis. The diagnosis may be facilitated by surrogate markers and detection of aberrant immunophenotypic surface markers. New therapeutic strategies are in development based on intracellular signal pathways, or on application of topical treatments, as are novel forms of cytoreductive therapy, including tyrosine kinase inhibitors.