The UK has significant experience in first-in-human (FIH) clinical trials and has performed almost a quarter of the total of 2,206 FIH studies in the EU between 2005 and 2017 (Figure 1 ). Furthermore, the number of FIH trials conducted in the UK continues to increase; 69 out of 143 (48%) Phase 1 trials in 2016 were FIH, whereas, in 2017, this number grew to 105 out of 167 (63%) (1 ). The collective experience of regulators, clinical Phase 1 units, and FIH principal investigators in the last couple of decades has played a significant role in the development of guidelines for FIH/early phase clinical trials. However, two events come to the forefront of any early clinical developer’s mind in relation to the guidance issued by the EMA in this area.
