by Giuliana Miglierini

Antimicrobial resistance (AMR) is the consequence of mutations that allow microbes to survive pharmacological treatment. Resistant strains can often be tackled only by a limited number of therapeutic options: according to a systematic analysis published in The Lancet, an estimated 1.27 million deaths occurred in 2019 due to unresponsiveness to available medicines.

As a part of its effort against AMR, the International Coalition of Medicines Regulatory Authorities (ICMRA) has published a report discussing successful regulatory and non-regulatory best practices in the field of AMR.

The report was drafted by ICMRA’s Work Group led by Health Canada, and inclusive also of the European Medicines Agency, UK’s MHRA, and regulators from Japan, Argentina, Nigeria, Saudi Arabia and Sweden. For each of the nine case studies, Annex 2 presents a table summarising the problem under examination, the proposed solution, results and consequent recommendations.

Regulatory flexibility

The US’ Biomedical Advanced Research and Development Authority (BARDA) focused on innovative approaches to developing supporting data packages required for regulatory review of certain non-traditional therapies. Public-private partnerships are the preferred vehicle to manage R&D projects and to reach regulatory approval by the FDA. The main targets for BARDA are new antimicrobials to treat antibiotic-resistant secondary bacterial infections and bioterrorism infections. Selected proposals shall lead to the development of candidate medical countermeasures (MCMs), based on a regulatory master plan inclusive of a tentative schedule for regulatory milestones. Partners may also benefit from BARDA’s expertise in the field of animal studies, flexible manufacturing and clinical study design. A Memorandum of Understanding was also signed with the FDA to provide a coordinated framework for the development of MCMs.

Antimicrobials for veterinary use

Antimicrobials for veterinary use include some products for human use. It is thus important to act in the animal sector to limit the selection pressure for the development and spread of resistant pathogens in both animals and humans.

The project led by Health Canada in collaboration with the Public Health Agency of Canada (PHAC) focused on the implementation of the Veterinary Antimicrobial Sales Reporting (VASR) system, aimed to collect data on the total quantity of antimicrobials sold or compounded by animal species. The activation of the system in 2018 followed some changes to Canada’s Food and Drugs Regulation (FDR): manufacturers and importers have to report annual sales of medically important antimicrobials intended for veterinary use based on active ingredients listed in List A. The acquired data are collected and screened by the Veterinary Drugs Directorate and validated and analysed by PHAC’s CIPARS.

Regulatory agilities during the Covid-19 pandemic

Regulatory flexibility has been one of the main tools used to respond to the Covid-19 pandemic. Health Canada’s main goal was to expedite the regulatory review of health products without compromising their safety, efficacy and quality standards. A temporary regulatory pathway was introduced in September 2020 by a Interim Order, and new transition measures were approved in September 2021 to allow the review, authorisation and oversight of Covid-19 medicines under the FDR. A procurement strategy for Covid vaccines, treatments and diagnostics was also adopted by the Government, based on advanced purchasing agreements with different companies. Another Interim Order allowed the activation of a temporary regulatory pathway to facilitate clinical trials of candidate Covid-19 products. Flexibilities to Drug Establishment Licensing (DEL) and GMPs were also introduced, and collaborations with other international regulatory bodies activated (including the EMA open pilot).

Non-prescription availability of antibiotics

UK’s MHRA focused on the case of tyrothricin-containing lozenges, a combination product available for sale at pharmacies since 1968, and that underwent a restriction of prescribing in 2018, following a NHS’s guidance advising prescriptions for the treatment of acute sore throats should not be routinely offered in primary care. The UK’s Commission on Human Medicine considered MHRA’s request of advice on the feasibility to remove the product from the market. As a result, the MHRA interacted with the Marketing authorisation holder to verify the possibility of a reformulation to exclude the antibiotic active ingredient. The action of impacted also on the education of the wider public towards the responsible use of antibiotics.

Reimbursement models for novel antimicrobials

The Public Health Agency of Sweden addressed the issue of antimicrobial market failure. Not all the few available antibiotics launched during the last decade are accessible in all European countries, due in some instances to unfavourable sales prospects. A pilot project was launched in 2018 to test a new, partially delinked reimbursement model based on a minimum annual guaranteed revenue at nation level for the pharmaceutical company (on the basis of estimated clinical needs). Security of supply of antibiotics within 24 hours and a security stock located in Sweden were the requests to interested companies.

Selective antibiograms to inform antimicrobial choice

The choice of the most appropriate antimicrobial is usually based on an antibiogram, a laboratory test used to evaluate the susceptibility and resistance profile of bacterial isolates to various antimicrobial active ingredients. The Swedish Medical Products Agency (SMPA) focused on the use and selective reporting of antibiograms of urinary cultures for Enterobacteriaceae from patients with symptoms of cystitis. The analysis included six different antibiotics for men and five for women, since the fluoroquinolone ciprofloxacin is no longer recommended to treat cystitis in women. This selective reporting allowed to decrease fluoroquinolone prescriptions of 46% in 15 years.

Feedback on prescriber data

SMPA also provided some feedback to prescribers on their antibiotic prescribing practices. The tool was implemented at the national, regional, local and also individual level, in order to raise knowledge and information, and influence prescription habits. Prescribers’ data at a high resolution level (prescriber identifying codes) are used to elaborate relevant trends. Statistics on antibiotic use at regional and national level are freely accessible at the National Board of Health and Welfare website.

Common infections in outpatient care

The Sweden’s Rainbow Pamphlet provides treatment recommendations for common infections in outpatient care. The initiative was launched in 2010 by the Swedish Strategic Programme for the Rational Use of Antimicrobial Agents and Surveillance of Resistance (STRAMA); it can be accessed in paper form or through the STRAMA mobile application. The use of the Rainbow pamphlet has been supported also by communication campaigns targeted both to healthcare professionals and the public.

Methods for monitoring AMR in the environment

The monitoring of antibiotics’ diffusion in the environment is relevant with respect to the One- Health approach, which focuses on the harmonised surveillance across human, veterinary and food sectors.

The SMPA launched two projects aimed to better identify indicators to be used for the monitoring of antibiotic resistance in the environment: EMBARK (Establishing a Monitoring Baseline for Antimicrobial Resistance in Key environments) and Antibiotikasmart Sverige (Antibiotic Smart Sweden). The current main gaps in knowledge include the abundance and prevalence of antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs) occurring naturally. Furthermore, antimicrobials may enter the environment at different points along the lifecycle of human and veterinary medical products, with processes still to be fully clarified.