Dr David Reddy
CEO, Medicines for Malaria Venture
Early markers of drug resistance have been identified in Africa, threatening the long-term efficacy of first line treatments in the continent, which bears around 93% of the global burden of the disease.
The total malaria deaths in Africa almost halved between 2000 and 2019, with the fight against the disease focused on three key elements.
Firstly, improvements in vector control, such as the use of mosquito nets and repellents; secondly, improvements in and more routine use of diagnostics; and thirdly, better medicines. Between 2010 and 2019, around 3.1 billion courses of artemisinin combination therapies (ACTs) were used.
Dr David Reddy, CEO of Medicines for Malaria Venture (MMV), explains, “ACTs are the gold standard. They have a massive impact with greater than 95% efficacy and it would be a tragedy if we lost them.”
The dangers of ACT resistance
Nonetheless, artemisinin resistance has been identified, initially in South-East Asia but now in Africa too.
Dr Reddy explains, “What we are seeing in Africa is not frank resistance, but slower parasite clearance and resistance markers. ACTs are combination treatments, and resistance either to the artemisinin component or the partner drug is a cause for concern. The identification of these resistance markers in Africa is a worrisome sign that could undermine all artemisinin-based combination medicines.”
The WHO has named antimicrobial resistance as one of the top 10 global health threats, estimated to kill 10 million people a year by 2050.
With the threat of other diseases, including COVID-19, also prevalent, Dr Reddy warns the dangers of ACT-resistant malaria are manifold.
We cannot afford to take our focus off malaria even amid a viral pandemic. Malaria kills over 400,000 people every year and it’s mostly children under five that lose their lives.
Beyond that, Dr Reddy says, is the challenge of overwhelming healthcare systems, which are weakened already by COVID-19. “When you face a collision of multiple diseases and the complexity of getting the resources needed, plus the challenge of people delaying treatment for fear of catching a disease like Ebola or COVID, you get a snowball effect where diseases feed off each other and everything becomes worse in terms of infrastructure, treatment and, eventually, outcomes.”
“On the other hand, if you can push malaria down, you create more capacity to manage other diseases and have a far better chance of detecting new threats on the horizon, which is critically important.”
Fighting ACT resistance
In response, MMV is focused on understanding the molecular basis of resistance, developing alternative treatments as resistance thresholds are reached and making new treatments available as quickly as possible, shares Dr Reddy.
“We have to keep ACTs alive for as long as we can. MMV and partners are exploring several strategies with this end in mind. For example, deploying multiple first line therapies simultaneously may slow the development of resistance,” says Dr Reddy.
Other approaches might include combining existing medicines into triple combination therapies Dr Reddy suggests. Regardless of specific approaches, quality drugs are key throughout because counterfeit or suboptimal drugs with inadequate amounts of active substance are a recipe for disaster. “They just poke the parasite and give it the time and opportunity to develop a mechanism to escape.”
MMV is also considering the long game when ACT resistance could become widespread in Africa. “While we hope this day doesn’t come, we must be prepared and that’s why we are focused on developing the next generation of malaria treatments. We plan to be ready within five years to help bring new non-artemisinin combination therapies to the field. We screen every compound we develop against resistant parasites and look for ones with low potential for resistance that will last for the long haul.”
“They say malaria is one of humans’ oldest foes, which is absolutely true, but the face of that foe is changing daily. We need to stay one step ahead,” concludes Dr Reddy.