This week, senior officials, and national regulatory authorities from across the Asia Pacific region will come together in Singapore for the Indo-Pacific Regulatory Strengthening Program (RSP) Forum (4-5 May 2022). The 2022 RSP Forum provides an opportunity to acknowledge recent successes, outline challenges and priorities whilst promoting cooperation between participating countries and partner organisations. Whilst remaining focused on responding to the COVID-19 pandemic and working to increase future preparedness will be key, the forum will also shed light on other infectious diseases like tuberculosis, HIV and malaria. These diseases continue to be a major concern for health authorities and present an ongoing threat to countless lives in the region. 

Globally the prevention and treatment landscape for malaria continues to evolve, and new products offer more practical options. But what’s on the horizon for Asia Pacific? While there are new treatment options in the pipeline, providing timely access to potentially lifesaving treatments remains a regulatory challenge as does delivery and access to remote and hard to reach communities. 

One such relatively new anti-malaria drug is tafenoquine, recently approved for paediatric use by authorities in Australia. This is a significant advance in efforts to eliminate malaria from the Asia-Pacific region, particularly given the lower investments in R&D for diseases like malaria, compared to other infectious diseases like HIV. The relatively short time between tafenoquine’s approval in 2018 for adults and now for children is testament to what the private sector, civil society organisations, donors, governments and product development partnerships (PDPs) like Medicines for Malaria Venture (MMV) can achieve when they put children’s needs first. Now begins the even more challenging task of getting tafenoquine to the children with malaria who need it. 

In the past decade, countries in the Asia Pacific region have almost halved the number of malaria infections and made impressive gains towards the goal of eliminating malaria by 2030. Yet 2 billion people in the region remain at risk of contracting it, a number likely to grow as climate change expands the habitat of the mosquitos that carry it. 

Last year the World Health Organization (WHO) recommended a vaccine for the deadliest of the parasite’s two most prevalent species, P. falciparum. But we still have limited tools to combat malaria’s most prevalent species, P. vivax. Once considered a relatively non-threatening infection, vivax is now accepted to be an important public health threat, capable of causing life-threatening disease complications, debilitating recurrent infections, miscarriage, and chronic infections. Vivax is an insidious foe: after infecting its victim, the parasite hides in the liver, where it can re-emerge to trigger a new bout of malaria months or years after the original infection. This makes diagnosing and treating vivax malaria more complex and makes elimination more challenging in areas with a high vivax prevalence. 

More than half of all global vivax infections are in the Asia Pacific, with 800,000 reported cases in 2020. Almost 90% of those were in just five countries: Afghanistan, Indonesia, India, Pakistan, and Papua New Guinea (PNG). Vivax malaria is also a challenge in countries nearing elimination like Bhutan, as complete elimination of malaria from the body (radical cure) requires long duration treatment and patient compliance is a major issue. Globally, vivax poses a particularly high risk to children aged 2-6 years, who are four times as likely to be infected as adults. Frequent relapses in children are particularly dangerous as they can lead to severe anemia and poorer health outcomes. 

Tafenoquine’s single dose represents a breakthrough in the treatment of vivax. The existing drug recommended by the WHO for treating recurring vivax, primaquine, is currently recommended to be taken over 14 days, posing significant adherence challenges. Tafenoquine is taken in a single dose, making it much simpler to administer. To make it easier for children, the newly approved formulation can be mixed with water and taken as a drink. 

But tafenoquine hasn’t made curing vivax as simple as taking a single pill. Like primaquine, tafenoquine can cause potentially fatal red blood cell damage or severe haemolytic anemia in people deficient in a particular enzyme known as G6PD. Tafenoquine’s single dose means patients need to be tested for the enzyme deficiency before taking the drug.  

That isn’t easy. The communities most vulnerable to malaria in Asia tend to live in remote forests, hard to reach border areas, tribal districts and are often migratory. They don’t always have easy access to healthcare facilities that can properly maintain and administer the tests. And the tests themselves are relatively new and still scarce in these parts. Studies are underway though to identify whether health systems and community workers closest to these communities could use the tests and make an impact. 

Some countries in Asia such as Thailand, Cambodia, Vietnam, and Laos have taken steps to incorporate the tests, new tools, and approaches to treat vivax, thereby enabling access and accelerating the work of vivax elimination in these countries. But this is not the case in Afghanistan, Indonesia, India, Pakistan, and PNG, where malaria’s burden in remote and tribal communities is an uphill challenge. Many national malaria programs also prefer to wait for a recommendation of the single dose drug and associated tests from the WHO, before incorporating new innovations and tests into national treatment guidelines. Inevitably, until this happens children with vivax malaria where the burden of malaria is troubling and extremely remote are unlikely to have access to this treatment any time soon. 

To completely rid the region of vivax malaria, treatment with tafenoquine or primaquine, accompanied by enzyme deficiency testing will need to go hand in hand, along with tailored national and sub-national solutions. It will take a multi-stakeholder push and collaboration to ensure standard guidance is in place, in-country registrations are accelerated, and access and appropriate trainings are enabled to ensure that tafenoquine reaches and spares Asia’s most vulnerable and children from the misery of malaria. 

Dr Karma Lhazeen is the Director of the Department of Medical Services, Ministry of Health, Royal Government of Bhutan and Chair of the Asia Pacific Malaria Elimination Network (APMEN) Vivax Working Group  

Amita Chebbi is the Senior Director of the Asia Pacific Leaders Malaria Alliance (APLMA) & Asia Pacific Malaria Elimination Network.