The recent massive growth of Advanced Therapeutics, in both the US and EU, continues in parallel with the steep learning curves of both the regulators and the industry on how to manufacture, regulate and provide effective and safe products to patients. The regulations are rapidly evolving to accommodate the variety of technologies, gene delivery modalities and target diseases. These regulations both facilitate and challenge the industry to adjust and refine how the implementation of phase appropriate cGMP's is a critical success factor for process and product development and delivery to patients. The session will address the key aspects to deliver an effective and efficient product characterization program, identifying the product Critical Quality Attributes from the earliest possible stage and the phased introduction of appropriate cGMP's that underpin a ‘Go Slow to Go Faster’ approach. Presentations will be based on two ongoing ATMP programs, one US, one EU. 1) Defining and implementing ‘phase-appropriate GMPs’ to balance quality, efficacy and speed in developing and delivering ATMPs; .2) The regulatory initiatives with respect to product development acceleration support are proactively supporting manufacturers; 3) In early stage programs, the success of practically applying QbD principles, from TPP to Control Strategy relies on organizational agility.