A Study to Assess Safety, Pharmacokinetics, and Pharmacodynamics of mRNA-3705 in Participants With Isolated Methylmalonic Acidemia

Description

This study comprises 2 parts: Dose Optimization part (Part 1) followed by a Dose Expansion part (Part 2). The study is designed to evaluate multiple doses and dosing intervals of mRNA-3705.

In both parts, after confirmation of eligibility, participants will enter an Observation Period (48 to 72 hours pre-dose) in Part 1 and 24 hours before dose 1 in Part 2), followed by the Treatment Period. Participants who complete the Treatment Period, including the End of Treatment (EOT) Visit, are offered participation in the mRNA-3705 extension study. If the participant chooses to participate and meets eligibility criteria, they will be enrolled in the extension study; otherwise, they will transition to the follow-up part of the study (approximately 2-year follow-up in Part 1 and 6-months follow-up in Part 2).