Clinical Data describes the first six weeks of experience of the first patient in the CHAMPIONS study, who was treated November 13, 2017 with a dose of 5.00E+12 vg/kg of SB-913. The patient tolerated the infusion well. Mild (Grade 1) adverse events related to the study drug were reported on the fourth day after dosing as dizziness, weakness, and frequent urination, all of which resolved within one day without treatment. No other adverse events related to the study drug were observed. Liver function tests have remained within normal limits for the patient since the infusion.One serious adverse event has been reported and is classified as unrelated to SB-913. The subject developed an upper respiratory tract infection and was hospitalized for acute bronchitis. The subject, who recovered after receiving medical treatment, has chronic pulmonary disease and has previously been hospitalized for a similar respiratory illness.A second patient was treated in the study in mid-January 2018, also at a dose of 5.00E+12 vg/kg."Two patients have thus far been treated in the CHAMPIONS Study, and both have tolerated the SB-913 infusions well, with no concerning safety issues related to study drug seen to date," said Paul Harmatz, M.D., a pediatric gastroenterologist and a principal investigator for the CHAMPIONS study at the UCSF Benioff Children's Hospital Oakland, where the first subjects in the study were treated.