Efficacy and tolerability of oleylphosphocholine (OLPC) in a laboratory model of visceral leishmaniasis
Dafra Pharma Research & Development, Slachthuislaan 30/7, B-2300 Turnhout, Belgium. Journal of Antimicrobial Chemotherapy
(Impact Factor: 5.31).
07/2012; 67(11):2707-12. DOI: 10.1093/jac/dks273
The alkylphospholipid oleylphosphocholine (OlPC) is a structural analogue of miltefosine and may represent a potential therapeutic backup for the treatment of visceral leishmaniasis (VL). This laboratory study compared the in vitro and in vivo activity profile of both OlPC and miltefosine.
The in vitro potency of OlPC was compared with that of miltefosine, amphotericin B, paromomycin and pentavalent antimony (Sb(V)) using the intracellular amastigote assay on different Old World and New World Leishmania species. The in vivo efficacy was dose titrated in the Leishmania infantum hamster model after infection with 2 × 10(7) amastigotes (day 0) and oral treatment at day 21 using an aqueous (OlPC/H(2)O) and liposomal formulation of OlPC in single and repeated (5 day) oral dosing regimens. The amastigote reductions in the liver, spleen and bone marrow were assessed (day 35).
The in vitro activity of OlPC against Leishmania donovani, L. infantum, Leishmania tropica, Leishmania mexicana and Leishmania panamensis showed mean IC(50) values <5 μM, while the IC(50) values for Leishmania major and Leishmania braziliensis were 7.7 and 13.5 μM, respectively. These results are fairly similar to those obtained for miltefosine. In the hamster model, treatment with 20 and 40 mg/kg for 5 days proved that both OlPC formulations were equipotent and showed a markedly higher efficacy compared with miltefosine. A single dosing of 100 mg/kg of OlPC/H(2)O or OlPC liposomes reduced the parasite burdens by 96.2% and 99.3% in liver, 99.8% and 99.9% in spleen, and 87.6% and 96.9% in bone marrow, respectively. No signs of toxicity or adverse drug-related effects were noted.
These data suggest that OlPC may become a promising candidate to improve and simplify current case management of VL. Additional pharmacological and pharmacokinetic studies are ongoing to assess the full potential of OlPC as a 'drug candidate'.
Available from: Martin Olivier
- "The selected drug for this proof-of-concept project is oleylphosphocholine (OlPC), an alkylphosphocholine formulated as liposomes of about 100 nm which can be directly used for tattooing. In a previous study, the OlPC active pharmaceutical ingredient showed good in vitro activity against several CL-causing strains of Leishmania (L.), including L. major, L. tropica, L. mexicana, L. panamensis and L. braziliensis4. These data prompted us to study the in vivo efficacy of this drug against CL when formulated as liposomes and delivered with a tattoo instrument while comparing to other, more classical, administration routes. "
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ABSTRACT: This study establishes a proof-of-concept that a tattoo device can target intra-dermal drug delivery against cutaneous leishmaniasis (CL). The selected drug is oleylphosphocholine (OlPC) formulated as liposomes, particles known to be prone to macrophage ingestion. We first show that treatment of cultured Leishmania-infected macrophages with OlPC-liposomes results in a direct dose-dependent killing of intracellular parasites. Based on this, in vivo efficacy is demonstrated using a 10 day tattooing-mediated treatment in mice infected with L. major and L. mexicana. In both models this regimen results in rapid clinical recovery with complete regression of skin lesions by Day 28. Parasite counts and histopathology examination confirm high treatment efficacy at the parasitic level. Low amount of drug required for tattooing combined with fast clinical recovery may have a positive impact on CL patient management. This first example of tattoo-mediated drug delivery could open to new therapeutic interventions in the treatment of skin diseases.
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ABSTRACT: The alkylphosphocholine oleylphosphocholine (OlPC) represents a potential new therapy for the treatment of canine leishmaniosis caused by Leishmania infantum. The aim of the present study was to evaluate the efficacy and safety of OlPC in a small cohort of dogs naturally infected with L. infantum and defined as clinically sick (LeishVet stages II and III). A total of eight dogs were included in the study and were treated orally with 4 mg/kg OlPC for 14 days. Dogs were assessed at the clinical and parasitological level at four time points during a total follow-up period of 90 days (before treatment and at 15, 30, and 90 days post-treatment onset). Ln-PCR, real-time quantitative PCR, antibody testing (IFAT), and culture of bone marrow aspirates were evaluated at the four time points. OlPC treatment induced a rapid and satisfactory clinical recovery in terms of clinical score reduction and weight gain, and treatment efficacy was found to be associated with a decrease in bone marrow parasitic load. Serological titers measured by IFAT were stable in any of the treated dogs at any time point after treatment. OlPC was well tolerated and no severe adverse events were noted in any of the treated dogs; even some dogs showed slight intestinal disorders. This proof-of-principle study is the first to show that short oral treatment with OlPC improves clinical signs of canine L. infantum leishmaniosis, highlighting the need to perform additional studies to optimize the dosing regimen and to assess long-term treatment efficacy of this drug.
Available from: Diana Caridha
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Cutaneous leishmaniasis (CL) represents a range of skin diseases caused by infection with Leishmania parasites and associated with tissue inflammation and skin ulceration. CL is clinically widespread in both the Old and New World but lacks treatments that are well tolerated, effective and inexpensive. Oleylphosphocholine (OlPC) is a new orally bioavailable drug of the alkylphosphocholine family with potent antileishmanial activity against a broad range of Leishmania species/strains.
The potential of OlPC against Old World CL was evaluated in a mouse model of Leishmania (L.) major infection in BALB/c mice. Initial dose-response experiments showed that an oral daily dose of 40 mg/kg of OlPC was needed to impact time to cure and lesion sizes. This dose was then used to directly compare the efficacy of OlPC to the efficacy of the antileishmanial drugs miltefosine (40 mg/kg/day), fluconazole (160 mg/kg/day) and amphotericin B (25 mg/kg/day). OlPC, miltefosine and fluconazole were given orally for 21 days while amphotericin B was administered intraperitoneally for 10 days. Ulcer sizes and animal weights were followed up on a weekly basis and parasitemia was determined by means of a real-time in vivo imaging system which detects luminescence emitted from luciferase-expressing infecting L. major parasites. Amphotericin B and OlPC showed excellent efficacy against L. major lesions in terms of reduction of parasitic loads and by inducing complete healing of established lesions. In contrast, treatment with miltefosine did not significantly affect parasitemia and lesion sizes, while fluconazole was completely ineffective at the dose regimen tested.
Given the data showing the outstanding efficacy and tolerability of OlPC, our results suggest that OlPC is a promising new drug candidate to improve and simplify current clinical management of L. major CL.
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