Precision medicine is a model that goes against the one-size-fits-all approach to disease treatment. Instead, people are treated based on the uniqueness of their genetic makeup. Even though still relatively new, the approach has gained much momentum in developed countries due to the extensive focus of most genomic research and clinical trials in those geographical areas.
In April 2003, researchers concluded the final analysis of the Human Genome Project and affirmed that the 3 billion base pairs of genetic letters in humans were 99.9% indistinguishable in each individual. This discovery implies that if a drug is designed to target most of the disease-driving genetic variants common across all populations, then Africans are likely to benefit from it regardless of their exclusion during the drug’s development. However, if the drug targets a region within the 0.1% of the genome that differs between populations, Africans may end up not benefitting maximally from that drug.
Currently, less than 5% of global genomic research and drug discovery involves African data, thereby placing us at a disadvantage. There is therefore an unmet need to scale up genomics research to ensure better inclusion of under-represented populations that will lead to an improvement in medical interventions for all populations.
Humans are known to harbour genes that determine drug metabolism, and this biological characteristic affects each population’s Maximum Tolerated Dose (MTD) – a parameter that indicates the point of a drug’s efficacy. Different ethnic groups may have different MTDs to the same drug. This is why it is necessary to include as many diverse populations as possible in genomic research and clinical trials.
These differences in MTDs existent between different populations for the same drug is as a result of inherent genetic differences. Therefore, it is important to verify the efficacy of drugs in all ethnic populations during clinical trials, and not just a select few.
Clinical trials are an important process of drug development that determines which patient will benefit from a drug and which patient will not. In clinical trials, demographics whose genetic data are used to design a drug usually benefit better from access to that particular drug.
Eligibility requirements for clinical trials are typically geographic and are usually limited to the study region/area unless collaboration spans beyond their borders. As such, only those living in that country are involved. Genetic data collection, even if inclusive of people of African ancestry, will be limited to Africans abroad who are much fewer in number and may have had segments of their DNA altered due to the effects of their environmental conditions.
The sooner African countries begin to engage drug manufacturers in clinical trial partnerships, the sooner we will have access to more efficacious drugs and treatments. This also opens up new business opportunities for pharmaceutical companies, as they will be able to successfully market their products to one of the largest populations in the world.
With an established partnership, new drugs will be readily accessible to Africans as soon as approval is granted. This reduces the long waiting period before the drug gains entry into the African market, where in most cases a newer and advanced version of it has already been developed overseas.
Genetic data analysis and interpretations have to be representative of all populations and without bias. The inclusion of underrepresented demographics should start from genomic data collation and analysis during the drug discovery process, as it is essential that every ethnic group be well represented in these processes to ensure that medication is tailored and accessible to everyone, not only a certain group.
The ideal solution to data inequality would be for Africans and all other underrepresented populations to be included right from the beginning of the drug discovery cycle, but as this might take a while before becoming a reality, we can strive for increased partnerships to enable inclusion in clinical trials, so that the efficacy of newly developed drugs can be determined in Africans as well as other study participants involved in the research.
The need for equality to be established in research that drives precision medicine stems no further from the demand for the development, availability, and efficacy of medical products and diagnostics that will better serve African populations. Once we begin to address the challenges facing healthcare in Africa, such as the underrepresentation of African demographics in genomics research and exclusion of African data in drug development, then the dream to equalise precision medicine will begin to materialise.
Dr. Jumi is a Molecular Genetics scientist with over a decade of experience. She has worked at The Institute of Cancer Research and The Royal Marsden Cancer Hospital in London, in collaboration with Merck KGaA, Germany. She designed and implemented screening assays, which enabled fast tracking of drugs into clinical trials for patient benefit. At 54gene, she leads the Molecular Genetics team and is also an active participant in the global drug discovery communit