Tab. 4:

Challenges regulatory agencies are currently facing in the context of using MPS-based assay data for risk assessment and solutions to overcome hurdles

Challenges	Solutions
New technology lacking in-house experience regarding the evaluation and assessment of the MPS data acquired	Develop performance standards, acquire in-house experience via external training or in-house experimental setup
Time lag between use and first appearance of data at regulatory agencies	Encourage industry to submit compiled data outside a clinical trial or a marketing authorization application in order to characterize MPS-based assays. There is, for example, an evaluation of data outside regulatory decision-making as described in the Guideline on the principles of regulatory acceptance of 3Rs testing approaches (EMA, 2016)
Cultural reluctance to the adoption of new approaches	Strive for global harmonization regarding the use and assessment of MPS-based assay data
	Hold workshops regarding MPS-based assay data use and assessment in a regulatory context
	Collect and disseminate survey data on the use of MPS-based assays in the regulatory context
	Define context-of-use jointly with applicant and/or technology provider
	Define unmet needs of current regulatory approach (e.g., lacking concordance of animal study data with human outcome) as a first step towards regulatory acceptance