The amphotericin B (AmB) is the main active ingredient in the most effective drug used to treat leishmaniasis, a disease that affects over 12 million people in developing countries, with more than 70,000 deaths per year. The cost of treating humans with AmB surpasses $5,000 per patient, the treatment is extensive (2-hour sessions every day during 21 days) and the side effects are frequent and many times patients must be hospitalised.
Researchers from the University of Miami, Florida and the Universitat Autònoma de Barcelona have developed a method which allows to drastically reduce the drug dose, as it improves its efficacy 83%, multiplies by 10 the capacity of the drug to attack cell infected by the parasite that provokes the disease and significantly reduces the toxicity of the parasite. In a paper published in The Journal of Infectious Diseases, the researchers report that the method has been successfully tested on mice models of leishmaniasis.
The complex compound acts through the action of a pan-DR-binding epitope derivatized-dendrimer (PDD) nanoparticle, a substance that measures 10 nanometres in diameter and fits into the active principle, amphotericin B, guiding it to the cells that harbor the parasite.
While the usual complete dose of the drug requires over 12 days to reduce the skin lesions caused by the disease, scientists observed that one dose of the complex compound with only 17% of the complete dose of the drug improves skin lesions in two or three days in the study. Moreover, the complex compound acts as a therapeutic vaccine which activates the immune system against the reservoir cells hosting the parasite.
The PDD substance has been used in previous trials with people with the aim of improving the response of their immune system to other diseases. Now there is a need for clinical trials with humans in order to verify its safety as an adjuvant in the treatment of leishmaniasis. If its safety in humans is confirmed, it will also reduce the cost of the treatment drastically, and this is a key element in reducing mortality rates in developing countries.
Date: November 5, 2013
Source: Universitat Autonoma de Barcelona
Filed Under: Drug Discovery