The 13th revision of the Guidance for Applicants seeking scientific advice and protocol assistance has been recently published by the European Medicines Agency.
This guidance document addresses questions that users of the scientific advice or protocol assistance procedures may have and provides an overview of the procedure to obtain scientific advice or protocol assistance. It also explains the scope and nature of such procedures and gives guidance to applicants in preparing their request. It aims to enable applicants to submit requests which are in line with Scientific Advice Working Party (SAWP) requirements and which can be validated and evaluated quickly and efficiently.

Source: EMA website (https://www.ema.europa.eu/en/human-regulatory/research-development/scientific-advice-protocol-assistance#protocol-assistance-section)
Furthermore, applicants will be guided through the different steps of the procedure and receive useful information on the preparation of a possible discussion meeting with the SAWP.
This guidance document is updated regularly to reflect new developments and include accumulated experience. In particular, this version was amended to modify the submission process.
You can find further details by reading the guidance here.