The study will assess long-term safety and clinical activity of mRNA-3927. Participants with PA who were previously enrolled and completed the end-of-treatment (EOT) Visit of the mRNA-3927-P101 study will have the option to enroll into this extension study provided all eligibility criteria have been met.~The study will include 2 periods: 1) Treatment Period and 2) Follow-up Period (up to 2 years after the last dose of study drug). All participants will enter the study receiving mRNA-3927 at the same dose and at the same dosing interval last received in the mRNA-3927-P101 study.
The main purpose of this study is to evaluate the long-term safety of mRNA-3927 administered to participants with propionic acidemia (PA) who have previously participated in Study mRNA-3927-P101 (NCT04159103).