By Geoffrey Kamadi

I had the privilege of sitting through a scientific lecture delivered by the late Professor Calestous Juma of the Harvard Kennedy School in Nairobi in 2013, at the Kenyatta International Conference Centre (now the Kenyatta International Convention Centre).

The esteemed professor spoke passionately of a promising new research approach in the biomedical and pharmaceutical world. Scientists were looking at new ways of using affordable, existing drugs to treat various types of cancer.

But even more interesting was the fact that this treatment was administered using very low-cost, available drugs that are off patent.

Professor Calestous Juma.

“But even more interesting,” pointed out the Professor “was the fact that this treatment was administered using very low-cost, available drugs that are off patent.”

At the time, the Professor was exploring the extent to which a mechanism could be established with the Harvard Medical School, not only to test these drugs in Kenya, but move ahead and manufacture them locally.

One of his colleagues had 24 promising cures for cancer. So, he was seeking collaboration with the Jomo Kenyatta University of Agriculture and Technology (JKUAT) and the Kenya Medical Research Institute (KEMRI) to see how these drugs can be repurposed in Africa.

According to the Professor Juma at the time, some of the drugs in question were everyday medication we take for anti-acid control, which cost next to nothing, but work against certain kinds of cancer.

Chemogenetics

An ongoing research by the KEMRI-Walter Reed Project in Kisumu has evaluated 23 out of 28 existing drugs for reuse against malaria, through a research process known as chemogenetics.

The application of chemistry and genetics is helping evaluate treatment against malaria using “drugs designed for a specific disease but is now being tested to treat another disease,” explained Douglas Ochora, a researcher at KEMRI during the 10^th KEMRI Annual Scientific & Health Conference held in February in Nairobi.

In other words, drugs act by targeting proteins of parasites, thereby either enhancing or inhibiting their activity, the end result of which is that the parasite cannot survive. It eventually dies.

Databases

These proteins, against which most of the already approved drugs act, are listed in various databases and are therefore well known to scientists and researchers. These databases online list what these drugs treat and the protein they target in either humans or parasites.

It is by use of these databases that researchers are able to identify existing drugs that might contain active ingredients against a protein of a malaria-transmitting parasite such as the Plasmodium Falciparum. The parasite is responsible for over 90 per cent of all malaria transmission.

Scientists have first to look through the National Council for Biotechnology Information (NCBI) database, which has a list of all parasite proteins.

Then, they will look for a drug that is active against an amino acid (the building blocks of proteins) sequence that corresponds to a particular parasite – Plasmodium Falciparum – in this case. These drugs are listed in the Therapeutic Target Database, Drug Bank and STITCH databases.

Drugs Show Promise

A number of already approved drugs show some efficaciousness against malaria. This includes the HIV drug, Zidovudine, the anti-cancer drugs Oxaliplatin and the antibiotic Moxifloxacin.

Repurposing or repositioning of existing drugs is a more cost-effective way of research and development.

“Simply put, safety and other research considerations surrounding drug development will not be an issue, when re-positioning drugs,” says Reagan Mogire, a research scientist at KEMRI involved in this research.

Mogire adds that the time taken to develop a new drug, up until its introduction into the market takes no less than a dozen years. And, it is an expensive affair whose cost is approximated to be between $100-800 million.

93 % of the 228 million malaria cases recorded in 2018 were in Sub Sahara Africa. Of the 405,000 deaths that occurred, 94 % took place in the same region.

WHO.

In any case, it should be noted that many active compounds under research fail to progress to the treatment phase because of safety concerns.

Re-purposing of drugs to treat malaria will no doubt help fast-track the development and later deployment of treatment. This is especially important in Africa which continues to bear the brunt of malaria infection in the World.

According to the WHO, 93 per cent of the 228 million malaria cases recorded in 2018 were in Sub Sahara Africa. And of the 405,000 deaths that occurred, 94 per cent took place in the same region.