Multidrug-resistant tuberculosis (MDR-TB) is an urgent public health challenge in Namibia, with profound socioeconomic consequences. The high burden of both tuberculosis and HIV complicates treatment and underscores the need for optimised drug therapies. Precision medicine, which leverages patient-specific genetic and molecular information, offers promise for improving MDR-TB outcomes. However, its effective application relies on population-specific data, particularly understanding how individuals metabolise tuberculosis drugs and how genetic diversity drives variability in treatment response. Currently, no pharmacokinetic (PK) or pharmacogenetic (PG) data on TB treatment exist for Namibian populations. This gap is particularly concerning, given the country’s genetic diversity, environmental factors and comorbidities that may uniquely influence drug metabolism. This study aims to generate PK and PG data to inform dose optimisation and support personalised treatment strategies for MDR-TB in Namibia. The findings will contribute to improved patient care and inform health system strengthening based on locally relevant evidence.
This cross-sectional study will consist of 100 Namibian participants with matched human DNA and PK data of MDR-TB cases receiving isoniazid, clofazimine, bedaquiline and the fluoroquinolones (levofloxacin or moxifloxacin). PK sampling will be divided as follows: 30 individuals will undergo intensive PK sampling, while the remaining (n=70) will undergo sparse PK sampling. DNA will be extracted at Stellenbosch University (SU), and samples will be genotyped using the H3Africa microarray. Sequences will be aligned to the human reference genome, hg38 (GRCh38p13), using the freely available Burrows-Wheeler Aligner. A subset of the samples (n=20–30) will undergo whole genome sequencing (WGS) to verify imputation results and identify novel genetic variants potentially affecting PK in this population.
Quality control and variant call format file generation will be performed using the Genome Analysis Toolkit best practices (V.3.5). Intensive and sparse PK data will be pooled for the development of a population PK (popPK) model using a non-linear mixed-effects modelling approach. The popPK model will characterise the relationship between TB drug dose and exposure, including quantifying covariates, including genetic variation, explaining PK variability, providing a foundation for dose optimisation and personalised treatment strategies.
Ethics approval was obtained from the University of Namibia Human Research Ethics Committee for Health (Ref. SOM18/2024), the Ministry of Health and Social Services (Ref. 22/4/2/3), the SU Health Research Ethics Committee (Ref. N21/11/136) and the University of Cape Town Human Research Ethics Committee (Ref. 500/2022).
Pre-eclampsia and fetal growth restriction are leading causes of perinatal morbidity and mortality. A therapy that enhances maternal vascular function and promotes vasodilation to increase placental perfusion could treat both conditions.
Tissue kallikrein-1 is an endogenous enzyme that releases bradykinin to activate the bradykinin 2 receptor on endothelial cells. This induces potent vasodilation and pro-angiogenic, anti-oxidant and anti-inflammatory effects.
DM199 is a recombinant form of tissue kallikrein which can be administered intravenously or subcutaneously. Clinical trials in non-pregnant populations have demonstrated its safety. Being a protein, it is unlikely to cross the placenta. This protocol describes an early-phase trial for DM199 for pre-eclampsia and fetal growth restriction.
This phase IB/IIA open-label trial at Tygerberg Hospital, Western Cape Province, South Africa, will determine the safety and effective dose of DM199 for pre-eclampsia and/or fetal growth restriction. The trial consists of two parts. Part 1 will be an ascending dose finding study, treating women with pre-eclampsia and severe hypertension who are for planned birth within 72 hours. This will search for doses that safely lower blood pressure (n=3/dose, recruiting up to 42 participants). Part 2 is a safety and efficacy study of three cohorts of pregnant women (n=30/cohort): (1) with pre-eclampsia and severe hypertension requiring delivery within 72 hours, (2) with preterm pre-eclampsia (
The trial has ethical approval (Health Research Ethics Committee, Stellenbosch University, Protocol number M24/04/009) and is registered (Pan African Clinical Trial Registry, PACTR202404895013782) and approved by the South African Health Products Regulatory Authority (20240801). Data will be presented at international conferences and published in peer-reviewed journals.
The glucose-lowering drug metformin has shown promise in non-diabetic conditions for improving endothelial dysfunction, but the literature of metformin’s effect on endothelial dysfunction and the biomarkers used to measure endothelial dysfunction have not yet been synthesised.
We aimed to map the extent and nature of the existing research related to metformin for endothelial dysfunction in non-diabetic non-communicable diseases (NCDs). This scoping review was conducted following the methodological framework by Arksey and O’Malley and the recommendations from the Joanna Briggs Institute, and was reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews.
We considered any peer-reviewed studies in adult humans on the use of metformin for endothelial dysfunction in non-diabetic NCDs. Narrative reviews, expert opinion, preclinical studies and qualitative studies were excluded.
An unrestricted search was conducted on four electronic databases and three registries from inception to October 2024.
Data charting was performed using predetermined data extraction headings. We used a systematic charting method and narrative synthesis to organise, synthesise and report the data.
We identified 56 studies comprising 4620 participants (71.7% female). Polycystic ovarian syndrome was the most investigated NCD (57.1% of studies). 19 distinct biomarkers of endothelial dysfunction were identified, with flow-mediated dilation being the most frequently assessed (18 studies, 745 participants). Metformin showed a trend towards improvement for 7/19 (36.8%) biomarkers. Male participants were underrepresented in the literature and only five studies (9%) were conducted in the global south, potentially limiting the generalisability of repurposed metformin in diverse populations or settings. Studies with an active comparator reported a significant difference between the metformin and comparator groups in 20% (4/20), in contrast to studies without an active comparator (placebo or pre–post studies) reporting significant results favouring metformin in 83.3% (30/36). A knowledge gap also exists for metformin use in people with HIV, given that they are known to develop cardiovascular NCDs at a twofold higher rate than their HIV-negative counterparts.
While there is a growing evidence base supporting metformin as treatment for endothelial dysfunction in non-diabetic NCDs, our scoping review highlighted knowledge gaps in optimal biomarker selection and dosing strategies, and applications in a broader range of NCDs, including in people with HIV. More primary and secondary research using robust methodologies and study designs is needed to determine the quantitative effect of metformin on endothelial dysfunction.