Framework Outlines Genomic Testing Strategy for Safer Drug Dosing in Africa

Many dosing recommendations for essential medicines are derived from European cohorts, creating risks of toxicity or treatment failure elsewhere. Clinicians in Africa face this gap across human immunodeficiency virus (HIV), malaria, oncology, transplantation, and pain care. Researchers now outline a framework to integrate pharmacogenomic testing into drug policy and clinical decision-making across the continent.

Wits University (Johannesburg, South Africa), through the Target Policy Profile Framework to Leverage African Genomic Heterogeneity (TALAGH), led the creation of the policy brief “Integrating Genomic Testing into African Drug Policies” to guide regulators, procurement bodies, manufacturers, and clinicians. The initiative focuses on pharmacogenomics, the study of how inherited genetic variation influences medication response, and indicates that more than 10% of essential medicines may require pharmacogenomic guidance. The brief highlights implications for product labeling, clinical guidelines, pharmacovigilance, workforce training, and secure data systems.

Examples cited in the brief include efavirenz (EFV), an antiretroviral medication for which CYP2B6 variants common in African populations can increase overexposure and neuropsychiatric risk; tamoxifen, used in breast cancer treatment, whose efficacy may be reduced by CYP2D6-related differences in metabolism; and primaquine, used in malaria treatment, which can trigger hemolytic anemia in people with glucose-6-phosphate dehydrogenase (G6PD) deficiency.

In transplantation, dosing protocols developed largely from European cohorts may underdose some patients of African ancestry, with potential consequences for graft survival. Taken together, these examples position pharmacogenomics (PGx) as a medicines-policy and patient-safety issue, rather than a niche research topic.

Evidence-to-policy translation is already illustrated by efavirenz (EFV). Adverse effects associated with the standard 600 mg/day dose were observed in patients across multiple African countries, contributing to a national shift in Botswana toward dolutegravir and to a World Health Organization (WHO) recommendation reducing EFV dosing to 400 mg/day.

Despite this progress, adverse drug reaction reporting from the continent remains limited: only 1% of submissions to VigiBase originate from African countries, even though Africans account for up to 50% of global EFV-associated adverse reactions. TALAGH subsequently convened regulators from more than 10 countries, the South African Health Products Regulatory Authority (SAHPRA), and other stakeholders to share pharmacogenomic evidence.

The policy brief recommends PGx-informed labeling through expert working groups within regulatory agencies, along with capacity strengthening through education, research addressing African-enriched and African-specific variants, and the development of secure genomic data infrastructure. It also calls for a pan-African independent technical working group, through the Consortium for Clinical Pharmacogenetics in Africa, to guide priority implementation.

The authors note opportunities for collaboration with the African Medicines Agency and suggest that local generic manufacturers could align formulations with African pharmacogenomic evidence and clinical needs.

“TALAGH's work asserts that pharmacogenomics is a medicines policy issue, with implications for regulation, procurement, manufacturing, clinical care and patient advocacy,” said Distinguished Professor Collen Masimirembwa, principal investigator and senior scientist at the Sydney Brenner Institute for Molecular Bioscience (SBIMB).

“My dream is that our work becomes the beginning of something larger: a continental pharmacogenomics consortium that can carry African data all the way from the laboratory to the patient. Regulators, laboratory scientists, clinicians, pharmacists, Africa CDC-linked testing networks, patient advocates, and social, ethical and legal experts would work together to decide which medicines need new guidance, which tests are practical, which formulations are needed, and how patients can be protected from avoidable harm,” said Masimirembwa.

Related Links
SBIMB