Safety of Dietary Guanidinoacetic Acid: A Villain of a Good Guy?

Guanidinoacetic acid (GAA) is a natural amino acid derivative that is well-recognized for its central role in the biosynthesis of creatine, an essential compound involved in cellular energy metabolism. GAA (also known as glycocyamine or betacyamine) has been investigated as an energy-boosting dietary supplement in humans for more than 70 years. GAA is suggested to effectively increase low levels of tissue creatine and improve clinical features of cardiometabolic and neurological diseases, with GAA often outcompeting traditional bioenergetics agents in maintaining ATP status during stress. This perhaps happens due to a favorable delivery of GAA through specific membrane transporters (such as SLC6A6 and SLC6A13), previously dismissed as un-targetable carriers by other therapeutics, including creatine. The promising effects of dietary GAA might be countered by side-effects and possible toxicity. Animal studies reported neurotoxic and pro-oxidant effects of GAA accumulation, with exogenous GAA also appearing to increase methylation demand and circulating homocysteine, implying a possible metabolic burden of GAA intervention. This mini-review summarizes GAA toxicity evidence in human nutrition and outlines functional GAA safety through benefit-risk assessment and multi-criteria decision analysis.

An introduction of the Accelerated Development of VAccine beNefit-risk Collaboration in Europe (ADVANCE) Project

The vaccine benefit-risk assessment entails comprehensive and systematic evaluation of the major benefits and risks of vaccine based on information after a marketing authorization. In 2009, the influenza A (H1N1) pandemic led to the licensing of new H1N1 vaccines in many countries including Europe. The post-marketing evaluation and monitoring of H1N1 vaccines was carried out based on a project previously conducted in Europe. In 2013, the Accelerated Development of VAccine beNefit-risk Collaboration in Europe (ADVANCE) project was launched with the support of Innovative Medicines Initiative (IMI) to address the limitations reported in the previous project. ADVANCE consisted of seven Work Packages (WPs), each indicating the vaccine benefitrisk monitoring readiness across four areas: Governance, Data source, Methods, and Study. First, a model for vaccine surveillance and governance with various functions such as decision making, quality management, execution, and financial administration was established. Also, the project developed a tool to identify, collect, and link the data sources available for vaccine surveillance. In addition, various methodologies were reviewed to assess the infectious disease burden, vaccine coverage, and benefit-risk based on linked data sources in Europe. Guidelines were proposed for real-world vaccine surveillance studies. Accordingly, a variety of tools and programs were developed, including a code of conduct related to the benefit-risk assessment of vaccines, ADVANCE International Research Readiness (AIRR), CodeMapper, and VaccO. Since the end of the ADVANCE project in 2019, the Vaccine Monitoring Collaboration for Europe (VAC4EU) has been conducting effective and sustainable vaccine benefit-risk monitoring programs based on the vision and ideology of ADVANCE. This study explains the contents and findings of ADVANCE with emphasis on WPs and proposes directions for establishing a vaccine benefit-risk assessment system in Korea.

Dosing interval strategies for two-dose COVID-19 vaccination in 13 low- and middle-income countries of Europe: health impact modelling and benefit-risk analysis

Background: In settings where the COVID-19 vaccine supply is constrained, extending the intervals between the first and second doses of the COVID-19 vaccine could let more people receive their first doses earlier. Our aim is to estimate the health impact of COVID-19 vaccination alongside benefit-risk assessment of different dosing intervals for low- and middle-income countries of Europe. Methods: We fitted a dynamic transmission model to country-level daily reported COVID-19 mortality in 13 low- and middle-income countries in the World Health Organization European Region (Albania, Armenia, Azerbaijan, Belarus, Bosnia and Herzegovina, Bulgaria, Georgia, Republic of Moldova, Russian Federation, Serbia, North Macedonia, Turkey, and Ukraine). A vaccine product with characteristics similar to the Oxford/AstraZeneca COVID-19 (AZD1222) vaccine was used in the base case scenario and was complemented by sensitivity analyses around efficacies related to other COVID-19 vaccines. Both fixed dosing intervals at 4, 8, 12, 16, and 20 weeks and dose-specific intervals that prioritise specific doses for certain age groups were tested. Optimal intervals minimise COVID-19 mortality between March 2021 and December 2022. We incorporated the emergence of variants of concern into the model, and also conducted a benefit-risk assessment to quantify the trade-off between health benefits versus adverse events following immunisation. Findings: In 12 of the 13 countries, optimal strategies are those that prioritise the first doses among older adults (60+ years) or adults (20-59 years). These strategies lead to dosing intervals longer than six months. In comparison, a four-week fixed dosing interval may incur 10.2% [range: 4.0% - 22.5%; n = 13 (countries)] more deaths. There is generally a negative association between dosing interval and COVID-19 mortality within the range we investigated. Assuming a shorter first dose waning duration of 120 days, as opposed to 360 days in the base case, led to shorter optimal dosing intervals of 8-12 weeks. Benefit-risk ratios were the highest for fixed dosing intervals of 8-12 weeks. Interpretation: We infer that longer dosing intervals of over six months, which are substantially longer than the current label recommendation for most vaccine products, could reduce COVID-19 mortality in low- and middle-income countries of WHO/Europe. Certain vaccine features, such as fast waning of first doses, significantly shorten the optimal dosing intervals.

Preparation of a Nonclinical Overview Based on Scientific Literature

Current requirements for the registration dossier include submission of a preclinical (nonclinical) overview, including scientific literature data on preclinical studies and actual preclinical data on the medicinal product. For some groups of medicines, scientific literature data may be used instead of actual preclinical data, which may be redundant. One of the important functions of the scientific literature review is the analysis of updated preclinical information on the medicinal product, which reflects the product’s characteristics, supports conclusions on its efficacy or safety, and may affect the results of the benefit/risk assessment. The aim of the study was to determine the optimal format for presenting scientific literature data in a nonclinical overview that would reflect the methodological aspects of preclinical pharmacology and toxicology studies of medicines. The authors analysed the regulations of the Russian Federation and the Eurasian Economic Union containing requirements for the scientific literature review submitted instead of actual preclinical data as part of the registration dossier for a medicinal product. The authors also considered potential difficulties in preparing a nonclinical overview based on scientific literature. In order to systematise scientific literature data, it is recommended to provide pharmacodynamic, pharmacokinetic, and toxicological data using a format consistent with the common technical document. The proposed recommendations help to harmonise the process of preparation and design of a nonclinical overview which should contain data and facts enabling a reasoned assessment of the benefit/risk ratio. The standardised format of literature data presentation will help the developer prepare an adequate nonclinical overview and will speed up assessment of clinical trial or marketing authorisation applications.