To ensure a smooth transition into Brexit, the UK Government will be converting the body of existing EU laws into UK domestic law. Until Brexit all EU IP Rights remain valid in the UK for at least two years.
However, to ensure that your IP Rights including patents, copyright, trade marks and design rights remain fully protected post-Brexit you should consider steps that you need to take now. You should protect your EU Trade Marks and Registered Community Designs to ensure they remain fully protected within the UK, as well as any IP agreements such as assignments, licences and other IP related documents.
In general copyright and patents are less likely to be effected due to the UK being signatory to international treaties and agreements.