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| Red blood cell infected with malaria parasites (blue)--Courtesy of the National Institute of Allergy and Infectious Diseases |
Scientists have developed what could be the next big thing in malaria treatment, a drug that has a triple aim--cure patients, prevent infection and block transmission of the disease in mosquitos.
The drug, called ELQ-300 and created by researchers at Oregon Health & Science University (OHSU) and the Portland VA Medical Center, is made to target the malaria-causing parasite at an earlier stage in the process than current drugs do. Scientists also think it could be better at fighting drug-resistant strains of malaria that have cropped up.
Most of the drugs in clinical use today target a form of the parasite after it has released waves of merozoites into the bloodstream, which infect red blood cells. But researchers say ELQ-300 goes after the parasite earlier, when it is in the liver, before it has had time to spill into the bloodstream.
"One of the unique and desirable features of ELQ-300 targets multiple stages of the parasite's life cycle," principal investigator Michael Riscoe, professor of molecular microbiology and immunology at OHSU and director of the Experimental Chemotherapy Lab at the Portland VA Medical Center, said in an interview with FierceBiotechResearch.
When tested in mice infected with malaria, ELQ-300 hit the parasite at each of its major life stages--first in the liver, then in the bloodstream and lastly an active stage that causes symptoms and a reproductive stage that can be transmitted via mosquitoes to others. In animal tests, the parasite did not develop resistance to ELQ-300. The study appears in Science Translational Medicine.
Malaria infects more than 200 million people per year and is responsible for more than one million deaths, many of which are children in Africa, where the disease is endemic. Malaria remains a hindrance to economic progression in developing countries, and some drug-resistant strains--called Plasmodium--are becoming increasingly resistant to current therapies.
Two drugs, quinine and chloroquine, have been the go-to methods of treatment over the last several decades, but they have become less effective over time. Now, doctors typically have to prescribe patients multiple doses of a drug or two drugs at once to increase the odds of killing off the parasite and prevent a resistant form from emerging. Riscoe said that these drugs must be taken several times a day over the course of a few weeks, but because patients often feel better after a few days on the medication, they sometimes stop taking it.
"What [we] would like to achieve is to have a drug combination that could be formulated in a single pill that could be given to an infected person," Riscoe said. "With one pill it could cure the disease and provide a long-term protection against another malaria infection."
Scientists hope the drug can be ready for human clinical trials in one to two years. Riscoe said the next step is to identify partner drugs that could work with ELQ-300 in a single-dose regimen.
Along with OHSU and the VA, the National Institutes of Health and the Swiss nonprofit Medicines for Malaria Venture funded the research.
- here's the press release
- read the scientific study (sub. req.)
- check out the ScienceNews story
Editor's Note: This story has been updated to include an interview from one of the study's main authors.