Despite continuous work by the scientific community, malaria remains one of the largest and deadliest diseases on the planet. The disease, which is spread via the bites of female Anopheles mosquitoes, was responsible for 627,000 deaths in 2020, with 95% of those occurring in Africa.
The disease largely affects at-risk groups such as infants, children under five years of age, pregnant women and patients with HIV/AIDS. And whilst over half of the world is at-risk of malaria, communities in Africa and South America bear the brunt of this disease’s burden.
Fortunately, malaria is a preventable disease and strategies to control its spread have included new diagnostic tools, antimalarial drugs and products that help effectively stop Mosquitos from reaching people.
Here, we look at some of the latest advancements from the pharmaceutical industry which are helping combat Malaria.
Kozenis – a child-friendly malaria treatment
With children especially at-risk of Malaria, the approval of Medicines for Malaria Venture (MMV) and GSK’s Kozenis (tafenoquine) was welcomed in April this year. The Australian Therapeutic Goods Administration (TGA) approved the drug for children aged two years and above in combination with chloroquine for the radical cure (prevention of relapse) of Plasmodium vivax (P. vivax) malaria.
The drug is dispersed in water and comes after the current standard of care for prevention of P. vivax required a one or two-week course of treatment.
Speaking then about the approval, Dr David Reddy, Chief Executive Officer of MMV said: “We are proud to have worked with GSK to develop this child-friendly treatment and are thrilled by today’s announcement. P. vivax malaria is particularly dangerous for young children for whom repeated relapses can lead to cumulative severe anaemia and, in some cases, be fatal. Today, we have a tool to put a stop to the relentless relapse both for adults and children – we are one step closer to defeating this disease.”
P. vivax malaria is a specific parasite which causes the disease and is most commonly found in recurring cases of malaria. It’s estimated to cause between 4.1 and 5.1 million clinical infections every year and poses a disproportionate burden for children aged two to six years who are four times as likely as adults to be infected.
GSK’s malaria vaccine for children at-risk
Last year, the World Health Organisation (WHO) recommended GSK’s RTS,S malaria vaccine for children living in sub-Saharan Africa.
The vaccine is supported by long-term clinical trials data showing a significant reduction in malaria in children. It was the first vaccine to receive a broad-use recommendation in children by the WHO. After its approval, GSK said it would donate up to 10 million doses for use in pilots and to supply 15 million doses annually.
Thomas Breuer, Chief Global Health Officer, GSK, said: “GSK is proud that RTS,S, our groundbreaking malaria vaccine, developed over decades by our teams and partners, can now be made available to children in sub-Saharan Africa and other regions with moderate to high malaria transmission. This long-awaited landmark decision can reinvigorate the fight against malaria in the region at a time when progress on malaria control has stalled. Both real world evidence and clinical trial data show that RTS,S, alongside other malaria prevention measures, has the potential to save hundreds of thousands of lives.”
Malaria vaccine hits WHO-target
In 2021, Researchers from the University of Oxford alongside the Serum Institute of India Private and Novavax announced that the malaria vaccine they were working on had achieved an efficacy level set out by the WHO.
A Phase IIB trial of the candidate malaria vaccine, R21/Matrix-M showed it demonstrated an efficacy level of 77%, making the researchers the first to meet the WHO’s Malaria Vaccine Technology Roadmap goal of a vaccine with at least 75% efficacy.
The vaccine is now being investigated in a Phase III trial which will assess the safety and efficacy of R21/Matrix-M in 4,800 children across four Africa countries.
Halidou Tinto, Professor in Parasitology, Regional Director of IRSS in Nanoro, and the trial Principal Investigator said: “These are very exciting results showing unprecedented efficacy levels from a vaccine that has been well tolerated in our trial programme. We look forward to the upcoming Phase III trial to demonstrate large-scale safety and efficacy data for a vaccine that is greatly needed in this region.”
Drug compound stops Malaria
A drug compound being developed by teams at the Francis Crick Institute and the Latvian Institute of Organic Synthesis effectively blocks a critical step in the malaria parasite life cycle.
The compound works by blocking an enzyme called SUB1, which enables malaria to burst out of red blood cells. Existing antimalarials work by killing the parasite within the cell, so the researchers hope this alternative drug action will overcome and kind of drug resistance. Importantly, the compound can also pass through the membranes of the red blood cell and the compartment within the cell where the parasites reside.
Chrislaine Withers-Martinez, author and researcher in the Malaria Biochemistry Laboratory, said: “This approach, which has already been highly successful at finding new treatments for diseases including HIV and Hepatitis C, could be key to sustained and effective malaria control for many years to come.”
Lasting protection found in vaccine
In the US, two Phase I clinical trials of a candidate malaria vaccine found that it offered unprecedentedly high levels of durable protection when volunteers were later exposed to disease-causing malaria parasites.
The Sanaria vaccine, (PfSP), was being investigated by researchers at the National Institutes of Health (NIH) Clinical Center in Maryland.
The vaccine is composed of sporozoites, the form of the malaria parasite transmitted to people by mosquito bites and is combined with either of two widely used antimalarial drugs—an approach termed chemoprophylaxis vaccination.
Data from trials show that the lowest PfSPZ dosage provided modest protection but when combined with specific antimalarials at higher doses patients were protected from homologous or heterologous challenge. The high protection shown in the trials present the vaccine as a possible therapy to be used for those travelling to countries highly affected by malaria.
