Guidance

Guideline V Post-marketing surveillance studies

Updated 16 December 2024

Applies to England, Scotland and Wales

1. What is a post-marketing surveillance study

A post-marketing surveillance study is any study carried out after a veterinary medicinal product (VMP) has been authorised. The aim is to:

• identify, characterise or quantify an adverse event
• confirm the safety and/or efficacy profile of a VMP
• measure the effectiveness of risk management measures

These studies can take the form of non-interventional studies, in which a VMP is prescribed in the usual manner in accordance with the marketing authorisation.

2. Why is a post-marketing surveillance study needed

Before authorisation, the number of animals exposed to the VMP is restricted, so experience of adverse events within any specific population of the target species may be limited. Post-authorisation, the number of animals exposed becomes greater, and can reveal other adverse events that were not apparent during the pre-authorisation stage.

A Marketing Authorisation Holder (MAH) may elect to carry out a study to investigate many different aspects of a VMP, including if:

• the concurrent use of a specific product with the VMP results in previously unknown adverse events
• the use of the VMP in a particular breed of animal results in previously unknown adverse events
• the incidence of a particular adverse event is dependent on the characteristics of an animal treated with a specific product, such as age or weight
• the incidence of a particular adverse event is dependent on the existence of another underlying disorder
• the long-term use of a product gives rise to an adverse event

There may be many other reasons for the need for a post-marketing surveillance study. The VMD may require an MAH to carry out such a study, if they determine that there may be signals that require further investigation.

3. How is a post-marketing surveillance study carried out

Only animals treated with a particular VMP in the manner specified in the product literature can be included in a post-marketing surveillance study. The MAH may recruit animals that fit the criteria for the study to be performed. Once recruited, the animal will be treated as it would normally be treated for the condition it has, but the veterinarian providing that treatment will be required to monitor the animal more closely throughout the treatment.

4. What happens after the study

Any adverse event following administration of an authorised VMP should be submitted to the VMD within 30 days of the point at which there is first awareness of events meeting the minimum criteria for reporting. The 30 days would therefore begin at the time the product can be identified as being the responsibility of the MAH.

MAHs must put in place appropriate arrangements to ensure that ‘blinding’ of products does not interfere with pharmacovigilance responsibilities.

At the end of the study, the MAH should provide the VMD with a report of the findings, which should include whether there is or is not evidence of any adverse events. As a result of this, further regulatory action may be required. The VMD may require the MAH to update the product literature to, for example to:

• exclude the use of the VMP in a particular age-range or group of animals
• advise prescribers and end-users to perform closer monitoring of animals in a particular age-range or group of animals
• advise that the VMP is not used at the same time as another specific product