A new drug called Krintafel (tafenoquine) got the US Food and Drug Administration nod to treat P. vivax malaria, which accounts for 34% of the estimated 13 million cases in India. Developed by a non-for-profit research and industry partnership, it is the first new treatment for P. vivax malaria in more than 60 years and is all set to get fast-tracked approvals for use globally.
Krintafel is a single-dose, ‘radical cure’ treatment for ages 16 years and older that kills dormant infection in the liver to prevent relapse. The P. vivax parasite can form hypnozoites inside human liver cells that stay dormant for several months without causing symptoms or being detectable in blood tests. The parasite’s capacity to remain latent lead to continued malaria transmission and relapse in roughly 30% cases.
P. Vivax predominantly causes disease and outbreaks in urban areas, with the most cases reported between June and September, followed by a second, smaller peak in March, possibly because of relapses.
India had an estimated 1.31 million malaria cases and 23,990 deaths in India, where more than half of the population (698 million) is at risk of infection, according to the World Malaria Report 2017 by World Health Organisation (WHO). India accounted for 6% of all malaria cases in the world, 6% of the deaths, and 51% of the global P. vivax cases.
Unlike P. falciparum, which developed drug resistance in the 1990s, P. vivax is sensitive to treatment. Chloroquine combined with primaquine has been the standard radical curative course for more than half a century. Along with chloroquine, a low dose primaquine (0.25 mg/kg) course for 14 days is prescribed to clear the dormant hypnozoite stage that maintains transmission and leads to relapse.
Adherence to the two weeks curative cure is often poor because most people stop medication when the symptoms disappear. Adding to the problem are India’s large and poorly regulated private healthcare providers, who often just treat acute symptoms of malaria without prescribing primaquine to kill dormant infection.
“Making Krintafel available quickly will help reduce malaria cases globally and save millions of lives, especially in Asia and the Americas. To ultimately end this disease, we need novel tools like Krintafel, and to continue investing in a pipeline of innovation,” said Martin Edlund, CEO of Malaria No More, which works to support India’s goal to eliminate malaria by 2030.
Although malaria-control measures have lowered both P. falciparum and P. vivax cases and deaths in India, the declines have been achieved predominantly through the control of P. Falciparum. “The hypnozoite reservoir after primary infection maintains transmission potential and enables reestablishment of the parasite in areas in which it was thought eradicated,” notes a study by Dr Anupkumar R Anvikar from the National Institute of Malaria Research in American Journal of Tropical Medicine and Hygiene.
“Having Krintafel available in India could make a huge difference,” he said. Krintafel has been developed by GSK in collaboration with the not-for-profit drug research partnership, Medicines for Malaria Venture, with funding from Bill & Melinda Gates Foundation.
Under the national policy, all fever cases clinically suspected of being malaria must be confirmed by microscopy or rapid diagnostic test. Since 2013, bivalent RDTs that detect and differentiate between P. falciparum and P. vivax infections are being used.
Stopping p. vivax transmission is crucial for India to meet its target of eliminating malaria by 2030. Along with early diagnosis, treatment by accredited social health activists (ASHAs) at the community level, using artemisinin-based combination therapy, intensified control of mosquito breeding and use of long-lasting insecticidal nets (LLINs) to protect against bites, challenges such as ending hypnozoite reservoir in areas with low and seasonal transmission and improving vector and disease surveillance in urban and peri-urban areas will ensure P. vivax outbreaks do not set back India’s goal of eliminating malaria by 2030.
Follow @htlifeandstyle for more