- The Food and Drug Administration has approved the first new treatment in six decades for Plasmodium vivax malaria, a form of the mosquito-borne disease that can cause acute relapses weeks or months after an insect bite.
- GlaxoSmithKline and research partner Medicines for Malaria Venture (MMV) secured the OK for the treatment — branded as Krintafel in the U.S. — granting the pharma a valuable Priority Review Voucher that can be used to speed review of other experimental drugs.
- GSK will now make the treatment available in the U.S., and plans to seek approvals going forward in malaria-endemic countries globally. In such countries, GSK says it will market the drug at a "not-for-profit" price aimed at promoting patient access to treatment.
GSK has both won praise and come under criticism for its approach to marketing medicines for diseases most prevalent in poorer and developing countries.
During former CEO Andrew Witty's tenure in particular, the British drugmaker positioned itself as focused on bringing vaccines and other treatments to emerging markets. In 2016, the company said it would not file for patents on its drugs in low-income countries, earning some plaudits.
But critics, such as the non-profit Médecins Sans Frontières, have in the past attacked the company for keeping its prices higher for products such as its pneumococcal conjugate vaccine. GSK later took the step of reducing the price charged to charities for its Synflorix vaccine for pneumonia.
Charging a fair price for drugs crucial to public health is a balance the pharma industry at large has struggled to solve. One reason (among many) for lower investment flowing to tropical and other infectious disease research is the limited return on investment companies can realize.
The FDA has sought to counter-balance this with regulatory incentives, such as the tropical disease PRV program through which GSK was awarded a coveted regulatory review voucher. Such "fast-passes" can be used to cut review times down by months or sold to another company. Past sales have regularly fetched $100 million or more.
Development of Krintafel, or tafenoquine, has been ongoing at GSK for over 20 years. In 2008, the pharma partnered with MMV to help accelerate development of the anti-malarial treatment.
Three studies — among dozens — supported the FDA's approval decision, showing tafenoquine helped to prevent relapses of P. vivax malaria. Unlike other, more commonly found parasites that cause malaria, the P. vivax parasite can lay dormant in the liver, where it can't be as readily treated. Periodic reactivation can trigger additional acute malaria episodes.
About 8.5 million infections with P. vivax malaria are estimated to occur each year, according to the World Health Organization. The only medicine currently approved to treat relapses is primaquine, which needs to be taken consecutively for 14 days in order to be effective.
Tafenoquine is administered as a single dose.
GSK is also awaiting a regulatory decision from Australian authorities and said approvals by the FDA and in Australia (if granted) would "be informative" to other regulatory agencies in malaria-endemic countries.
There, GSK will sell tafenoquine at a "not-for-profit" price, although its not clear whether that means at the cost of producing the drug.
GSK said it expects Brazil will be the first malaria-endemic country in which it submit a regulatory application for tafenoquine.
In addition to tafenoquine, GSK is also developing a recombinant vaccine for the prevention of Plasmodium falciparum malaria.