New Treatment for Recurring Malaria

American regulators have approved a simpler, one-dose treatment to prevent relapses of Malaria for the first time in six decades.

The new drug only targets the type of Malaria that occurs mainly in South America and South-east Asia.

Background

Malaria infects more than 200 million people a year worldwide, and kills about half a million, most of them children in Africa. It causes fever, headache, chills and other flu-like symptoms. It is caused by Plasmodium parasites that are spread to people through the bites of infected female Anopheles mosquitoes, called "malaria vectors." There are 5 parasite species that cause malaria in humans, and 2 of these – P. falciparum and P. vivax – pose the greatest threat. Malaria is preventable and curable.

In sub-Saharan Africa, which shoulders 90% of the global malaria burden, more than 663 million cases have been averted since 2001. Insecticide-treated nets have had the greatest impact, accounting for an estimated 69% of cases prevented through control tools.

The World Health Organization estimates that about 95% of the Indian population resides in malaria endemic areas. Nearly 80% of the disease reported in the country is confined to areas where 20% of population resides - in tribal, hilly, hard-to-reach or inaccessible areas. The relapse rate of vivax malaria in India is around 30%.

In 2017, the World Health Organization signaled a warning that progress in fighting malaria has stalled globally. The organization said that this was due to lack in funding and complacency that the mosquito-borne disease is less of a threat.

Analysis

The first drug to treat malaria has been approved by the Food and Drug Administration (FDA) in the United States. Scientists have describe the new medicine, called tafenoquine, as a phenomenal medical achievement.  A single dose of tafenoquine can flush the parasite out of its hiding place in the liver and stop people from getting it again. It can be taken alongside another medicine to treat the immediate infection.

Professor Ric Price of Oxford University stated: "The ability to get rid of the parasite in the liver with a single dose of tafenoquine is a phenomenal achievement and in my mind it represents one of the most significant advances in malaria treatment in the last 60 years."

It will be used to treat a recurring form of malaria that makes 8.5 million people sick each year - caused by the parasite plasmodium vivax, the most common type of malaria outside Sub-Saharan Africa.

The one-dose treatment makes tafenoquine simpler to use and more likely to succeed than the current 14 day-course of the drug primaquine. Often patients do not complete it as they begin to feel better, leaving the disease in their system. Drugs to cure the initial infection exist, but the parasite can make its way to the liver where it can remain dormant for months or years before triggering a relapse. Once it comes out of dormancy, the revived parasite can be carried to another victim, making the prevention of the spread of the disease even more challenging. Children are at high risk, getting several bouts of malaria from a single bite. As they become weaker each time they get the disease, their immune systems can be compromised.

While tafenoquine has been in existence since the 1970s, GlaxoSmithKline (GSK) working with Medicines for Malaria has repurposed the drug and it will be known by its brand name Krintafel. Tests performed with the drug showed that it had prevented relapses in about 75% of patients over the age of six months, making it about as effective as the current two-week treatment. It’s been approved for use on patients ages 16 and older. GSK will now apply for approval of the drug in Brazil and other Latin American countries, and sell it at a low cost.

Counterpoint

The FDA does not recommend the new drug for those suffering from G6PD deficiency (an enzyme problem), as it may result in severe anaemia. Testing people for the deficiency can pose a problem in poorer areas where malaria is common. There are also concerns that at higher doses the drug can be a problem for people with psychiatric illnesses.

Assessment

Our assessment is that the new drug alongside other precautionary measures might help reduce the incidence of vivax malaria in the world. We feel that this is a significant milestone for people living with relapsing malaria, and will contribute to the ongoing efforts to eradicate the disease. We believe that it must be made easily available and researchers must continue to invest in such innovative drugs.