Long-Term Safety and Activity Study of mRNA-3705 for Methylmalonic Acidemia Patients Previously Treated with mRNA-3705

What this Trial Is About

This research aims to assess the long-term safety and clinical effects of mRNA-3705 in people with isolated methylmalonic acidemia MMA caused by methylmalonyl-coenzyme A mutase MUT deficiency who have already taken part in previous mRNA-3705 studies. The study includes participants who meet all eligibility requirements and focuses on monitoring safety and clinical activity over several years. Participants will continue receiving mRNA-3705 at the same dose and schedule as in their previous study, either every two weeks or every three weeks, unless changes are recommended by the sponsor. The study has two parts a Treatment Period that continues until certain conditions occur, such as drug approval or participant decision to stop, and a Follow-up Period lasting up to six months after the last dose. During participation, individuals will undergo regular assessments including monitoring for treatment-related side effects and measuring key biomarkers like plasma methylmalonic acid levels. Researchers will track health events, hospital visits, antibody levels, and quality of life using specialized questionnaires. Safety monitoring will continue throughout the study and follow-up, with total involvement potentially spanning more than six years.

An Extension Study to Evaluate the Long-Term Safety and Clinical Activity of mRNA-3705 in Participants Previously Enrolled in Other Clinical Studies of mRNA-3705