Treatment of cutaneous leishmaniasis in Colombia with dapsone

The pipeline for drugs for control and elimination of neglected tropical diseases: 2. Oral anti-infective drugs and drug combinations for off-label use

In its 'Road map for neglected tropical diseases 2021-2030', the World Health Organization outlined its targets for control and elimination of neglected tropical diseases (NTDs) and research needed to achieve them. For many NTDs, this includes research for new treatment options for case management and/or preventive chemotherapy. Our review of small-molecule anti-infective drugs recently approved by a stringent regulatory authority (SRA) or in at least Phase 2 clinical development for regulatory approval showed that this pipeline cannot deliver all new treatments needed. WHO guidelines and country policies show that drugs may be recommended for control and elimination for NTDs for which they are not SRA approved (i.e. for 'off-label' use) if efficacy and safety data for the relevant NTD are considered sufficient by WHO and country authorities. Here, we are providing an overview of clinical research in the past 10 years evaluating the anti-infective efficacy of oral small-molecule drugs for NTD(s) for which they are neither SRA approved, nor included in current WHO strategies nor, considering the research sponsors, likely to be registered with a SRA for that NTD, if found to be effective and safe. No such research has been done for yaws, guinea worm, Trypanosoma brucei gambiense human African trypanosomiasis (HAT), rabies, trachoma, visceral leishmaniasis, mycetoma, T. b. rhodesiense HAT, echinococcosis, taeniasis/cysticercosis or scabies. Oral drugs evaluated include sparfloxacin and acedapsone for leprosy; rifampicin, rifapentin and moxifloxacin for onchocerciasis; imatinib and levamisole for loiasis; itraconazole, fluconazole, ketoconazole, posaconazole, ravuconazole and disulfiram for Chagas disease, doxycycline and rifampicin for lymphatic filariasis; arterolane, piperaquine, artesunate, artemether, lumefantrine and mefloquine for schistosomiasis; ivermectin, tribendimidine, pyrantel, oxantel and nitazoxanide for soil-transmitted helminths including strongyloidiasis; chloroquine, ivermectin, balapiravir, ribavirin, celgosivir, UV-4B, ivermectin and doxycycline for dengue; streptomycin, amoxicillin, clavulanate for Buruli ulcer; fluconazole and isavuconazonium for mycoses; clarithromycin and dapsone for cutaneous leishmaniasis; and tribendimidine, albendazole, mebendazole and nitazoxanide for foodborne trematodiasis. Additional paths to identification of new treatment options are needed. One promising path is exploitation of the worldwide experience with 'off-label' treatment of diseases with insufficient treatment options as pursued by the 'CURE ID' initiative.

Leishmanicidal effects of amphotericin B in combination with selenium loaded on niosome against Leishmania tropica

The strategy for improving the treatment of leishmaniasis by the World Health Organization, is the development of new drugs and combination therapy. The aim of this survey was to investigate the effect of amphotericin B (AmB) in combination with selenium, in a simple or niosomal form, on Leishmania tropica (L. tropica) by in vitro advanced assays. In this study, a niosomal formulation of AmB with selenium was prepared and characterized based on size and morphology. Using MTT assay, macrophage model, flow cytometry, and qPCR, the cytotoxicity and efficiency of the niosomal formulation and simple form of combination were evaluated. No toxicity was reported for both the niosomal and simple form of the combination. The niosomal formulation significantly showed higher inhibitory effect on the promastigote and amastigote forms of L. tropica than simple combination form. Interleukin (IL)-10 significantly decreased while the level of IL-12 and metacasoase as Th-1 activator significantly increased (P < 0.001). The findings of this study indicated that niosomes are the stable carriers for this combination, easy to produce and provide promising results as an effective formulation in the inhibition of extracellular and intracellular forms of L. tropica in compared with simple combination form.

Thermotherapy effective and safer than miltefosine in the treatment of cutaneous leishmaniasis in Colombia

In Colombia, pentavalent antimonials and miltefosine are the drugs of choice for the treatment of cutaneous leishmaniasis; however, their toxicity, treatment duration, (treatment adherence problems), cost, and decreased parasite sensitivity make the search for alternative treatments of American cutaneous leishmaniasis necessary. Based on the results found in a controlled, open, randomized, phase III clinical trial, the efficacy and safety of miltefosine was compared to that of thermotherapy for the treatment of cutaneous leishmaniasis in Colombia. Adult patients from the Colombian army participated in the study; they received either 50 mg of miltefosine three times per day for 28 days by the oral route (n = 145) or a thermotherapy (Thermomed®) application of 50 °C for 30 seconds over the lesion and surrounding area (n = 149). Both groups were comparable with respect to their sociodemographic, clinical, and parasitological characteristics. The efficacy of miltefosine by protocol and by intention to treat was 70% (85/122 patients) and 69% (85/145 patients), respectively. The adverse effects were primarily gastrointestinal for miltefosine and pain at the lesion site after treatment for thermotherapy. No statistically significant difference was found in the efficacy analysis (intention to treat and protocol) between the two treatments.

Thermotherapy. An alternative for the treatment of American cutaneous leishmaniasis

BACKGROUND

Pentavalent antimonials (Sb5) and miltefosine are the first-line drugs for treating cutaneous leishmaniasis in Colombia; however, toxicity and treatment duration negatively impact compliance and cost, justifying an active search for better therapeutic options. We compared the efficacy and safety of thermotherapy and meglumine antimoniate for the treatment of cutaneous leishmaniasis in Colombia.

METHOD

An open randomized Phase III clinical trial was performed in five military health centres. located in northwestern, central and southern Colombia. Volunteers with parasitological positive diagnosis (Giemsa-stained smears) of cutaneous leishmaniasis were included. A single thermotherapy session involving the application of 50°C at the center and active edge of each lesion. Meglumine antimoniate was administered intramuscularly at a dose of 20 mg Sb5/kg weight/day for 20 days.

RESULTS

Both groups were comparable. The efficacy of thermotherapy was 64% (86/134 patients) by protocol and 58% (86/149) by intention-to-treat. For the meglumine antimoniate group, efficacy by protocol was 85% (103/121 patients) and 72% (103/143) by intention-to-treat, The efficacy between the treatments was statistically significant (p 0.01 and < 0.001) for analysis by intention to treat and by protocol, respectively. There was no difference between the therapeutic response with either treatment regardless of the Leishmania species responsible for infection. The side effects of meglumine antimoniate included myalgia, arthralgia, headache and fever. Regarding thermotherapy, the only side effect was pain at the lesion area four days after the initiation of treatment.

CONCLUSION

Although the efficacy rate of meglumine antimoniate was greater than that of thermotherapy for the treatment of cutaneous leishmaniasis, the side effects were also greater. Those factors, added to the increased costs, the treatment adherence problems and the progressive lack of therapeutic response, make us consider thermotherapy as a first line treatment for cutaneous leishmaniasis.

Efficacy of miltefosine for the treatment of American cutaneous leishmaniasis

Miltefosine is an oral agent used for cutaneous leishmaniasis treatment. An open-label, randomized, phase III clinical trial was carried out in the Colombian army population. Miltefosine, 50 mg capsule was taken orally three times per day for 28 days (N = 145) or meglumine antimoniate, 20 mg/kg body weight per day for 20 days by intramuscular injection (N = 143). The efficacy of miltefosine by protocol was 69.8% (85/122 patients) and 58.6% (85/145 patients) by intention to treat. For meglumine antimoniate, the efficacy by protocol was 85.1% (103/121 patients) and 72% (103/143 patients) by intention to treat. No association was found between drug efficacy and L. (V.) braziliensis or L. (V.) panamensis species of Leishmania responsible for infection. Adverse gastrointestinal events were associated with the use of miltefosine, the meglumine antimoniate treatment was associated with adverse effects on the skeletal musculature, fever, cephalea, and higher toxicity in kidney, liver, pancreas, and hematological system.

New World cutaneous leishmaniasis: updated review of current and future diagnosis and treatment

BACKGROUND

Cutaneous leishmaniasis (CL) has traditionally been underrecognized and underreported. Improved awareness is warranted as the number of cases has increased as a result of increased travel to endemic countries, the HIV/AIDS pandemic, and the larger number of military and contract workers deployed overseas.

OBJECTIVE

We sought to present a systematic review of evidence from a gamut of research trials on the treatment efficacy of different regimens and aggregate this knowledge for use as a guide for clinical practice decisions.

METHODS

We performed a comprehensive search of print and electronic sources to identify the accumulated research information on New World CL.

RESULTS

Topical treatment of New World CL lesions is generally not recommended. Findings support the systemic administration of pentavalent antimonials as first-line treatment. Exception to this is infection with L guyanensis in French Guiana where systemic pentamidine is suggested as first-line treatment.

LIMITATIONS

The reliability of the findings of this review of research evidence is dependent on the individual quality and potential bias in its component principal trials. There was a conscious attempt to only include evidence derived from randomized controlled studies, with adequate randomization, adequate patient numbers, and complete follow-up information. However, because of the relatively small number of such studies on New World CL, evidence from nonrandomized studies and case series studies was also considered.

CONCLUSIONS

The pentavalent antimony compounds remain the first-line treatment choice for the treatment of New World CL. Concerns with cost, availability, poor compliance, and systemic toxicity, however, may compel clinicians to opt for alternative treatment modalities. Some advances in the development of an antileishmanial vaccine have been made but none is yet available for clinic use. The increase, over recent years, in the incidence of CL warrants an enhanced effort to increase awareness of the disease, assure timely diagnosis, and implement effective management and treatment strategies.

Tropical medicine rounds: Treatment of Old World cutaneous leishmaniasis with dapsone, itraconazole, cryotherapy, and imiquimod, alone and in combination

BACKGROUND

Cutaneous leishmaniasis (CL) is a major public health problem. The currently available therapies are expensive, not freely available, toxic, and not always curative. A simple, effective, noninvasive therapeutic approach is required for the treatment of CL.

AIMS

To determine the clinical patterns of CL and to report our experience in the management of CL.

METHODS

One hundred and ten patients with CL seen between January 2005 and December 2007 were included in this study. The diagnosis was based on clinical features, parasitologic diagnosis, histopathology, and culture. Each patient was treated according to disease severity with either topical (cryotherapy or imiquimod) or systemic (itraconazole or dapsone) monotherapy, or a combination of these modalities.

RESULTS

CL was more common in adult expatriate men, with the upper limbs as the most commonly affected site. Noduloulcerative CL was the most common presentation (84.6%). Atypical CL was found in 18 patients. Skin biopsy was the most common diagnostic technique (66.6%). Monotherapy showed an overall success rate of 56.41%, whereas combination therapy was successful in 69.56% of cases. Cryotherapy alone was successful in 68.18% of cases. Imiquimod alone was ineffective.

CONCLUSION

A stepwise approach represents a rational and practical way of confirming CL. A combination of itraconazole/dapsone and topically applied imiquimod is safe, simple, and effective for the treatment of CL. More studies are needed to establish the role of such an approach. Cryotherapy is also safe, simple and effective for the treatment of CL.

Miltefosine: oral treatment of leishmaniasis

The well-known problems of classic treatment of the leishmaniases with pentavalent antimony (reduced efficacy), difficulties of administration and increasing frequency and severity of adverse events have stimulated the search for new drugs to treat these diseases. Other injectable, oral and topical drugs have not been consistently effective, especially in the modern World. Beginning in 1998, Indian researchers conducted several trials with hexadecylphosphocholine (miltefosine) in patients with visceral leishmaniasis, and in 1999, clinical studies were initiated in Colombia for cutaneous disease. More than 2500 patients have been treated, including patients with diffuse cutaneous leishmaniasis, mucosal disease and patients coinfected with HIV. Cure rates between 91 and 100% were reached with a dose of 2.5 mg/kg/day for 28 days, with no difference between treatment-naive and relapsing patients. Mild gastrointestinal events were present in 35-60% of patients and 10-20% had mild transaminase and creatinine elevations. Miltefosine has potent leishmanicidal activity as a consequence of its interference in parasite metabolic pathways and the induction of apoptosis. Miltefosine is the first effective and safe oral agent with the potential to treat all major clinical presentations of leishmaniasis.

Cutaneous leishmaniasis in the returning traveler

Infection with protozoan parasites of the genus Leishmania leads to a wide variety of clinical disease syndromes called leishmaniasis, or more appropriately the leishmaniases. The three major clinical syndromes are cutaneous leishmaniasis, mucosal leishmaniasis, and visceral leishmaniasis. All three of these syndromes have been documented in returning travelers. This article focuses on cutaneous leishmaniasis with some comment on mucosal leishmaniasis.

Leishmaniasis cutánea

Leishmaniases are diseases caused by infection by protozoa of the genus Leishmania. Cutaneous leishmaniasis caused by Leishmania infantum is frequent in Spain, especially in certain geographic areas. Diagnosis of cutaneous leishmaniasis is difficult because of the varied symptoms and because making cultures of this parasite is complicated. There are also different therapeutic, medical and surgical options, none of which is fully satisfactory. We review the most significant agents of cutaneous leishmaniasis in Spain.

Disulone

For 60 years, dapsone has been used as a both antibacterial and anti-inflammatory agent. Dapsone (4,4'-diaminodiphenylsulfone, DDS) continues to be used successfully to treat a wide range of dermatologic disorders, notably those characterized by abnormal neutrophil and eosinophil polynuclear accumulation. A considerable number of other inflammatory as well as bullous dermatoses, of which dermatitis herpetiformis is the best known, have been shown to respond in varying degrees to dapsone, although the indication for the molecule has not been demonstrated in of them all. This article reviews current knowledge on the pharmacokinetics, mechanism of action and side effects of dapsone in dermatology. Despite the lack of controlled studies, the aim of this study is to specify and classify the pathological states in which disulone could be indicated.

Leishmaniasis

In 1903, Leishman and Donovan separately described the protozoan now called Leishmania donovani in splenic tissue from patients in India with the life-threatening disease now called visceral leishmaniasis. Almost a century later, many features of leishmaniasis and its major syndromes (ie, visceral, cutaneous, and mucosal) have remained the same; but also much has changed. As before, epidemics of this sandfly-borne disease occur periodically in India and elsewhere; but leishmaniasis has also emerged in new regions and settings, for example, as an AIDS-associated opportunistic infection. Diagnosis still typically relies on classic microbiological methods, but molecular-based approaches are being tested. Pentavalent antimony compounds have been the mainstay of antileishmanial therapy for half a century, but lipid formulations of amphotericin B (though expensive and administered parenterally) represent a major advance for treating visceral leishmaniasis. A pressing need is for the technological advances in the understanding of the immune response to leishmania and the pathogenesis of leishmaniasis to be translated into field-applicable and affordable methods for diagnosis, treatment, and prevention of this disease.