Fig. 1

The SONIA 2 study design. 69 patients received nitisinone while 69 controls did not after screening and randomisation at baseline visit. Following the baseline visit, patients visited study sites at month 3 and then 12, 24, 36 and 48 months. Safety questionnaires were administered at 6, 18, 30 and 42 months. The inset figure of dark urine and less dark comparator indicated that patients could not be blinded to the study due to nitisinone therapy clearing the dark urine. All assessors of data were blinded to the treatment