2022 in review: Drug development milestones for tropical diseases After a pivot to studying Covid-19, several late-stage tropical disease projects picked the momentum back up in 2022.
Previously disrupted by the Covid-19 pandemic, this past year has seen a return of increased efforts and progress in the development of new treatments for tropical diseases. Spearheaded by collaborations between non-profit groups and pharma players, new treatments are edging closer to late-stage trials in malaria and neglected tropical diseases such as sleeping sickness.
Along with a slow movement towards pre-pandemic normalcy, there was significant progress in the development of novel treatments for tropical diseases, including those that have traditionally received scant attention from pharma. According to the World Health Organization (WHO), there are 20 conditions that are considered neglected tropical diseases. These include Chagas disease, chikungunya, and sleeping sickness. Although malaria is not classified as a neglected tropical disease, it is sometimes included in joint efforts to eradicate infectious diseases, such as in the WHO’s Malaria and Neglected Tropical Disease unit.
Pharmaceutical Technology lists some of the top events in the tropical disease arena in 2022.
Novel therapeutics and vaccines for malaria
This year saw great progress towards making new therapeutics for malaria available sooner rather than later, says Karen Barnes, professor at the University of Cape Town’s Division of Clinical Pharmacology. Novartis and the non-profit Medicines for Malaria Venture (MMV) announced plans to collaborate on a Phase III study of a novel ganaplacide/lumefantrine-SDF combination for adults and children.
MMV and Novartis have worked on the upcoming Phase III study’s plans over the course of this year and plan to start the study in 2023, says MMV CEO David Reddy. Barnes says that the novel combination of ganaplacide/lumefantrine for uncomplicated malaria is probably the closest novel antimalarial to a launch, in a few years, and is particularly important as malaria parasites in Africa are increasingly resistant to artemisinin. These partially resistant parasites have spread from Southeast Asia to African countries, says Reddy. In the early phases of the pandemic, there was an increase in malaria cases and deaths, he says. As per the WHO’s 2022 malaria report, 63,000 malaria deaths were attributed to Covid-19-caused disruptions to services from 2019–21. The same report estimates that there were 247 million malaria cases in 2021 across 84 endemic countries.
In September, researchers from Oxford University shared their findings from a Phase IIb study with a more efficacious malaria vaccine called R21, which met the WHO’s 75% efficacy threshold. In the same month, GSK’s malaria vaccine Mosquirix received prequalification from the WHO, bringing it closer to a rollout in children. According to the WHO’s October 2021 recommendation, the vaccine resulted in a 30% reduction of deadly severe malaria. Based on a Phase III trial featuring 16,000 children, malaria cases were reduced by almost half in children aged 5–17 months in the first 18 months after three doses. At the end of the study, four doses of Mosquirix reduced malaria by 39% over four years in children.
However, Mosquirix’s efficacy is limited, while results from a Phase III licensure trial of R21 are expected this year. Both vaccines are based on recombinant proteins and attack the parasite during the sporozoite stage.