Patients with ADA-SCID who require ERT will receive Revcovi on a dosage and schedule determined by the treating physician. They will be followed for safety throughout the study, and will be monitored for the efficacy markers of adenosine deaminase (ADA) activity and deoxyadenosine nucleotide (dAXP) concentration according to a suggested schedule. Some subjects will be new to ERT; some will have transitioned from Adagen, which was the ERT available before Revcovi; and some will have previously participated in an earlier Phase 3 trial of Revcovi (study STP-2279-002). Patients will be followed either until they are able to successfully undergo a stem cell transplant or stem cell gene therapy and thus no longer require ERT treatment, or until all ongoing participants have received a minimum of 24 months of Revcovi treatment.
Note: Due to the nature of this study, all analyses are descriptive and no statistical hypotheses will be tested.