The ARDAT (Accelerating Research and Development for Advanced Therapies) consortium is a collaboration between academia, small and medium-sized enterprises (SMEs) and European Federation of Pharmaceutical Industries and Association (EFPIA) members. Consequently, the unique nature of the consortium combining industry with academia, the approaches and outcomes represent a broad cross section of stakeholders, experience and innovation. The overall objective of ARDAT is to develop and provide the data and tools to address knowledge gaps in the areas of immunology and metabolism of viral gene/cell therapy to accelerate the research and development of Advanced Therapy Medicinal Products (ATMPs). As part of these objectives, the ARDAT consortium aims to address regulatory harmonisation and the requirements around the issue of immunogenicity and immunosuppression protocols using a multifaceted approach. Here we provide an update on this polyvalent approach which combines preclinical data from novel models, data from clinical studies and a biobank, as well as a systematic literature review as well as a comprehensive regulatory landscape analysis to be compiled as a whitepaper. The overall aim is to provide a comprehensive and integrated approach to assessing immunogenicity and immunosuppression requirements in order to provide data driven recommendations that would (i) improve and potentially simplify or reduce existing regulatory requirements; and (ii) provide a data-based framework for evaluating emerging issues. In addition, as part of the broader aims of the consortium, some of the other initiatives towards regulatory harmonization and interaction with regulators and patient groups are summarized with an eye to future initiatives.