The Future of Precision Medicine in Africa, the World

Originally published in The Yuan on May 20, 2022. Republished here by the author. Read the archived original.

It has often been said that precision medicine is the future of healthcare. This is a future that we can safely say is already here, but its arrival has been unevenly distributed. The size of the global precision medicine market is expected to reach a 12.1 percent compound annual growth rate for the decade between 2020 and 2030, and reached about US$740 billion by 2020, up from US$203.5 billion in 2019. A few reasons for this are applications of artificial intelligence (AI) in precision medicine, as well as an increase in awareness about personalized treatments.

The question is, where does Africa fit into all of this?

'Drugs are like shoes; everyone needs them, but they don't always fit'

Precision medicine - a term often used interchangeably with personalized medicine - brings many benefits. It will focus more attention on variations in our genetic makeup, microbiome composition, and metabolomics, as well as considering medical histories, diets, lifestyle habits, and data collected from healthcare providers and patients.

This will not only work for treatments, but also help predict and prevent ailments in the first place. Instead of the one-size-fits-all approach provided by traditional healthcare practices, we will be able to transform how diseases are treated, thus augmenting these existing practices.

Benefits of Precision Medicine

Precision medicine comes with several benefits, some of which include:

• Usefulness in the prescription of effective drugs and the right dosages based on drug metabolisms and how these vary from patient to patient
• Reduction in cases of adverse drug reactions (i.e., unwanted effects from drug therapy) and side effects (unintended pharmacological effects)
• Predicting how susceptible a person or group of people may be to disease and focusing more on prevention
• This will result in the reduction of the time, cost, and failure rate of pharmaceutical clinical trials
• It will also help reduce trial-and-error prescriptions

Applications of Precision Medicine

Here, we will look into the applications of precision medicine in cancer treatments, drug administration, and nuclear imaging.

Precision oncology: Precision oncology's aim is to develop treatments that target the molecular characteristics of an individual tumor. This means carrying out molecular profiling on tumors to identify alterations that can be targeted.

An example of precision oncology in practice would be cancer treatments based on mutations, rather than anatomy and histology. Persons with BRAF V600E mutations can be similarly treated with a BRAF inhibitor, regardless of whether they have acute myeloid leukemia or breast cancer. Precision oncology focuses on the cancer genome and looks into the ribonucleic acid and proteins when identifying these new treatments.

Pharmacogenomics: A person's genetics is useful for selecting and figuring out the right dosage of medication to treat a particular disease, thus reducing or eliminating side effects that medicines may have. With the administration of amitriptyline - an antidepressant used to treat major depressive disorders - e.g., we can consider the genes that influence the drug's metabolism. These genes are CYP2D6 and CYP2C19. With recommended genetic testing for the two, a doctor can then decide on an appropriate dosage. If your body metabolizes amitriptyline very slowly, to avoid a negative reaction a smaller dose will be administered, or else an entirely different drug, but if your body tends to break down amitriptyline very quickly, you will need to be administered with a higher dose for it to be effective. Pharmacogenetic testing is currently being used for a few drugs as the field is growing quickly.

Nuclear medicine: In the area of nuclear medicine, therapy, and diagnostics (theranostics) plays a role in precision medicine. Theranostics is a technique that combines one radioactive drug to diagnose, and a second one to deliver therapy in the treatment of tumors. Cancers usually have complex characteristics, so combining these with genomic and proteomic profiling yields a detailed fingerprint of these tumors. Using these fingerprints, the damage can be reduced on unaffected tissues during treatment, and personalized theranostic agents can be designed.

For instance, in targeted radioligand imaging and targeted radioligand therapy, a therapeutic radioisotope with a cancer-targeting ligand is used. In this case, radioisotopes radiating gamma radiation may be used for diagnostic imaging, while radioisotopes radiating alpha and beta radiation may be used for therapy. Tumors express unique biomarkers and, with targeted radioligand therapy, therapeutic radiation is delivered specifically to these tumor cells, disrupting cell replication, triggering apoptosis, and reducing damage to non-cancerous cells.

Where Does Africa Fit Into All of This?

With the diminishing costs of sequencing a genome - fallen to US$300 from US$2.7 billion in less than 20 years, a faster rate of decrease than Moore's Law - it has become much easier for Africans to participate, although they still remain an underrepresented minority.

Studies have shown that nearly all Africans carry a mutation near the Duffy Antigen Receptor for the Chemokines gene which helps resist certain forms of malaria such as Plasmodium vivax and Plasmodium knowlesi, but also increases the susceptibility to human immunodeficiency virus by up to 40 percent.

Africans are also prone to sickle cell anemia though, on the flip side, this is known to reduce the risks of malaria. Sickle cell disease (SCD) is associated with a very high rate of childhood mortality in Africa. SCD is a disease caused by a mutation in both copies of a person's Hemoglobin Subunit Beta gene that results in an abnormal version called Hemoglobin S, or Hb S.

A study carried out by the University of Pennsylvania has shown that Africa is the most genetically diverse continent on Earth, which means there is still much to be explored. Another study in 2020 showed that a genome study of 426 continental Africans who represented 50 ethnolinguistic groups reported great genetic diversity. Three million novel variants were discovered after comparing with thousands of African genomes in public databases.

Peculiarities and variations like these are why we need more data around African genomes, in addition to the need for more Africans working on precision medicine and biotechnology in general.

What is currently being done?

A few research institutions and companies have taken up this challenge, but still not enough.

Some of these are research institutions like H3ABionet (Pan African Bioinformatics Network for the Human Heredity and Health in Africa), NCD-GHS (Non-communicable Diseases Genetic Heritage Study), companies like 54gene (Nigeria), and Artisan Biomed (South Africa), and partnerships with companies like Global Gene Corp (expanded to Namibia). All of them are doing great work, but need more support.

Genetic data is necessary for work on precision medicine, and more of it needs to be collected and researched.

Conclusion

Africa is ready to take on precision medicine, but to enable more research, more genetic data must be gathered and made accessible. With a little more work, proper education, laboratory infrastructure, and support for researchers and companies in this field, in due time, the benefits that come with precision medicine may no longer be so unevenly distributed in Africa.

References

1. Precision medicine market (Future Medicine)
2. Precision medicine market outlook (P&S Market Research)
3. Precision Medicine Initiative (Obama White House archives)
4. What is precision medicine? (The Jackson Laboratory)
5. 5 benefits of precision medicine (REPROCELL)
6. Precision oncology (ASCO Publications)
7. What precisely is precision oncology, and will it work? (The ASCO Post)
8. Pharmacogenomics: depression and amitriptyline (CDC)
9. Theranostics in precision medicine (NIH)
10. Radioligand therapy (Novartis)
11. The price of DNA sequencing dropped from $2.7 billion to $300 (OneZero, Medium)
12. Duffy antigen and HIV susceptibility (ScienceDaily)
13. Sickle cell disease in Africa (NIH)
14. Fixing the sickle cell disease gene (NIH)
15. African genetic diversity (BioNews)
16. High-depth African genomes (The Lancet eBioMedicine)