Sentinel site active surveillance of safety of first-line antiretroviral medicines in Namibia

Protocol for active safety monitoring of a cohort of patients using a dolutegravir-based antiretroviral regimen in Mozambique

INTRODUCTION

Dolutegravir-based antiretroviral therapy (ART) is increasingly being used as the preferred first-line regimen for the treatment of HIV in low-income and middle-income countries. The National Program for the Control of STI/HIV/AIDS in Mozambique has planned a phased introduction of the tenofovir/lamivudine/dolutegravir (TLD) regimen. In 2019, concerns about a potential safety signal identified with dolutegravir identified in the results of the Tsepamo study, conducted in Botswana, led the National Directorate of Pharmacy and the National Program for the Control of STI/HIV/AIDS to establish an active pharmacovigilance surveillance system among newly placed patients on a TLD regimen. This activity aims to establish an active pharmacovigilance system to monitor adverse events in patients on a TLD regimen to support the effectiveness of Mozambique's public health programmes in improving the process of care and treatment outcomes for people with HIV/AIDS.

METHODS AND ANALYSIS

This is a prospective, non-interventional, descriptive cohort study to monitor HIV patients managed with TLD at 10 sentinel health centres in Mozambique. The cohort consists of HIV-infected patients commencing treatment with TLD, either as treatment naïve patients or switched from other ART regimens. Patients have monthly routine follow-up visits for the first 3 months after starting HIV treatment with TLD, and subsequently every 3 months for a total period of 1 year. Patients are monitored to identify possible adverse events during the follow-up period. The intended size of the cohort is 3000 patients.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the National Commission on Bioethics in Health in Mozambique. Written informed consent is obtained from each participant who agrees to participate to have their information collected, analysed and stored. Findings will be reported to the Ministry of Health and participating health centres to inform policy and practice as well as disseminated by peer-review publications.

Routine data underestimates the incidence of first-line antiretroviral drug discontinuations due to adverse drug reactions: Observational study in two South African cohorts

Introduction

Estimating the incidence of antiretroviral discontinuations due to adverse drug reactions (ADRs) is important to inform antiretroviral treatment (ART) regimen recommendations, and to guide prescribing and monitoring policies. Routinely collected clinical data is a useful source of pharmacovigilance data. We estimated the incidences of first-line antiretroviral discontinuations due to ADRs using routine clinical data, and compared them with incidences estimated using data enhanced by folder review, in two South African cohorts.

Methods

We included patients 16 years and older on first-line ART. We selected a stratified random sample of 25% for checking of ART prescription data and reasons for antiretroviral discontinuations retrospectively, including folders reviews where required (enhanced-data sample). We estimated the incidence of antiretroviral discontinuations using Kaplan-Meier and competing risk analyses.

Results

In 15396 patients, 40% had a first-line antiretroviral discontinuation by three years on ART. We could determine the reason for 65% of discontinuations using routine data only, and 84% of discontinuations, in the enhanced-data sample of 3837 patients. ADR was the most common reason for discontinuations. In the enhanced-data sample, the cumulative incidence of discontinuations due to ADRs by three years was 30.4% (95% CI: 24.4–36.6) for stavudine; 2.0% (95% CI: 1.5–2.6) for tenofovir, and 1.3% (95% CI: 0.8–2.1) for efavirenz. Using routine data only, the cumulative incidences of discontinuations due to ADRs by three years for stavudine, tenofovir, and efavirenz respectively were 23.9% (95% CI: 20.3–27.7), 1.2% (95% CI: 0.9–1.4) and 0.5% (95% CI: 0.3–0.7).

Conclusions

Although the relative rankings were similar using routine or enhanced data, lack of checking for missing reasons for discontinuation resulted in underestimates of the incidence of antiretroviral discontinuations due to ADRs. Systems to improve data collection of reasons for regimen changes prospectively would increase the capacity of routine data to answer pharmacovigilance questions.

Active Surveillance versus Spontaneous Reporting for First-Line Antiretroviral Medicines in Namibia: A Cost-Utility Analysis

INTRODUCTION

Active surveillance pharmacovigilance is a systematic approach to medicine safety assessment and health systems strengthening, but has not been widely implemented in low- and middle-income countries. This study aimed to assess the cost effectiveness of a national active surveillance pharmacovigilance system for highly active antiretroviral therapy (HAART) compared with the existing spontaneous reporting system in Namibia.

METHODS

A cost-utility analysis from a governmental perspective compared active surveillance pharmacovigilance to spontaneous reporting. Data from a sentinel site active surveillance program in Namibia from August 2012 to April 2013 was projected to all HIV-infected adults initiating HAART in Namibia. Costs (pharmacovigilance program, HAART, adverse event [AE] treatment), quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs, dollars/QALY) were evaluated. Analysis was completed for (i) cohort analysis: a single cohort beginning HAART in 1 year in Namibia followed over their remaining lifetime, and (ii) population analysis: patients continued to enter and leave care and treatment over 10 years.

RESULTS

For the cohort analysis, totals were US$21,267,902 (2015 US dollars) and 116,224 QALYs for care and treatment under active surveillance pharmacovigilance versus US$15,257,381 and 116,122 QALYs for care and treatment under spontaneous reporting pharmacovigilance, resulting in an ICER of US$58,867/QALY for active surveillance compared with spontaneous reporting pharmacovigilance. The population analysis ICER was US$4989/QALY. Results were sensitive to quality of life associated with AEs.

CONCLUSION

Active surveillance pharmacovigilance was projected to be highly cost effective to improve treatment for HIV in Namibia. Active surveillance pharmacovigilance may be valuable to improve lives of HIV patients and more efficiently allocate health resources in Namibia.