Saad Shakir writes:
Pharmacovigilance has expanded in the last 10 to 15 years, shifting from low-level regulatory compliance to a more proactive approach. This is largely due to the 2012 EU legislation expanding the scope of pharmacovigilance to include risk management, risk minimisation and the introduction of reporting systems such as EudraVigilance in Europe and Sentinel in the US. These changes are of benefit to public health, ensuring that potential health risks or adverse events are identified quickly in conventional medicines, allowing swift action to be taken when needed.
However development of pharmacovigilance needs to keep up with introduction of novel medicinal products. For example, monitoring the safety of biological medicines and gene therapy brings special challenges. These are complex, frequently personalised, products, normally administered by a team of experts in secondary care to a small number of patients. These patients are often already very sick, with concurrent illnesses and taking concomitant medication. The type of adverse reactions associated with use of biological or gene therapy is also different: rather than adverse reactions affecting kidney, liver, cardiovascular and CNS function, seen with conventional medicines, these advanced therapies are associated with immunogenic effects that leave patients susceptible to infections and tumours. Existing pharmacovigilance methods need to be modified in order to sift out the effects of the new therapy from the effects of concurrent illness or medication, and to address the different nature and frequency of adverse events associated with these advanced therapies. In addition, burgeoning technologies such as artificial intelligence, machine learning and pharmacogenetics, will contribute to modification of the pharmacovigilance approach especially for advanced products.
The current COVID-19 pandemic presents unique challenges for pharmacovigilance too. With new vaccines and (mostly repurposed) drugs being rushed through clinical trials, it is especially important to conduct thorough post-marketing safety studies. Whilst pre-marketing activities provide important information on vaccine safety and efficacy, post-marketing data is essential in providing real-world evidence on the use, effectiveness and safety of the vaccine in larger groups of people. It is crucial to evaluate the efficiency with which a vaccine reduces the incidence of disease in natural conditions of use in the population in a vaccine already proven to have high efficacy in the controlled conditions of clinical trials. Effectiveness is dependent not only on vaccine potency but also the performance of vaccine immunisation programmes and other factors which may influence the disease risk itself, such as seasonality.
I explored the evolution of pharmacovigilance in more detail in this interview.