As global efforts against Neglected tropical diseases (NTDs) intensify, experts believe the development of newer drugs, administered over a shorter period could put the continent on the path to eradication.
Neglected tropical diseases are considered some of the oldest, with global statistics from the World Health Organisation showing that about 1.6 billion people, mostly in Africa and Asia are currently affected by various NTDs.
Dr Monique Wasunna, the Africa regional director for Drugs for Neglected Diseases Initiative (DNDi), a not-for-profit research organisation, said for a long time, many of these diseases were not a priority for policy makers, pharmaceuticals and research and development institutions.
According to a 2011 assessment by DNDi, out of 850 new drugs and vaccines that were approved for various diseases at the time, only 37 or four per cent were for diseases that WHO classifies as neglected. This is despite the fact that these diseases contribute about 11 per cent of the global disease burden.
“The newer drugs come in to fill this unmet gap,” Dr Wasunna told delegates at a recent meeting of neglected tropical disease experts, researchers and policy makers held in Kampala. The meeting discussed some of the challenges and progress so far made in the development of new treatments for NTDs that still continue to afflict the majority of the continent’s poor people.
While some NTDs have been controlled through mass drug administration campaigns, diseases such as the African Human Trypanosomiasis, commonly known as sleeping sickness, mycetoma and Visceral Leishmaniasis or kala-azar have been too complex to treat and effectively control because patients must endure long periods of treatments, with drugs that are often toxic.
Sleeping sickness remains endemic in over 20 African countries, although about 76 per cent of all cases in 2017 were reported in the Democratic Republic of Congo alone.
The Central African Republic, Guinea and Chad also have a disproportionately high burden of the disease. Without early diagnosis and treatment, sleeping sickness becomes fatal as the parasites invade the nervous system.
Dr Wilfred Mutombo, the coordinator of the Sleeping Sickness Clinical Trial Project in the Democratic Republic of Congo, noted that the old treatment involved patients being administered of painful injections, with drugs that were highly toxic.
“At the time, these old drugs came with considerable side effects, to a point where up to five per cent of patients who were receiving treatment died,” he said. Most patients were also presenting at the hospital with stage two of the disease, which is more difficult to treat.
This prompted scientists to find a short term solution to this problem by developing a combination therapy using two old drugs — nifurtimox and eflornithine combination therapy (NECT) — as a way of offering better treatment to patients.
Dr Mutombo noted that although this was an improvement from the old treatment, patients are still required to be hospitalised to receive the intravenous infusions and undergo lumber puncture to determine the stage of the disease.
However, with the improved drugs, Dr Mutombo said the country has been able to reduce new cases of the disease in the last decade, from 25,000 to an estimated 1,500 cases annually by 2017.
But for better treatment outcomes, scientists are pinning their hope on Fexinidazole, a drug that once approved for use, will be administered to patients orally.
Clinical trials of the drug conducted in the DRC and CAR between 2012 and 2017 that concluded that was safe for use.
The drug will consist of one daily pill that a patient can take for 10 days, irrespective of the stage of the disease.
Developed by DNDi in partnership with pharmaceutical company Sanofi, it is currently awaiting regulatory approval from the European Medicines Agency.
Another drug under trial, Acoziborol, to be administered as a single dose, is also being lined up as a potential game changer in fighting sleeping sickness.
NTD research experts say if Acoziborol proves to be safe and effective, it could be key to sleeping sickness elimination beyond 2020, the target date set by WHO.
A phase III clinical trial for a new treatment for Visceral Leishmaniasis, another deadly but neglected parasitic disease commonly found in the East African region is also underway in Kenya, Sudan, Ethiopia and Uganda.
The trial under the Leishmaniasis East Africa Platform seeks to assess the efficacy of a combination of two drugs — miltefosine and paromomycin — in treating VL in the East African.
Uganda, Kenya, Sudan and Ethiopia jointly contribute between 30,000 and 40,000 new cases of Visceral Leishmaniasis every year, out of the estimated 90,000 cases globally, making it the region with the highest burden of the disease on the continent.