A Study of mRNA-3745 in Adult and Pediatric Participants With Glycogen Storage Disease Type 1a (GSD1a)

A Phase 1/2, Adaptive, Open-label, Single Ascending Dose to Multiple Ascending Dose Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of mRNA-3745 in Participants With Glycogen Storage Disease Type 1a (GSD1a), Followed by an Open-label Extension

The main goal of this trial is to evaluate the safety and tolerability of mRNA-3745 via intravenous (IV) administration in adult and pediatric participants with GSD1a.

The study includes a single ascending dose (SAD) stage and a multiple ascending dose (MAD) stage. Participants enrolled in the MAD stage have the option to continue treatment in an open-label extension (OLE) period that will assess long-term safety and clinical activity of mRNA-3745.

Inclusion Criteria:

• Documented GSD1a with confirmation of biallelic gene encoding glucose-6-phosphatase-α (G6PC) mutations by genetic testing.
• Absence of hospitalization for hypoglycemia in the 4 weeks prior to Screening

Exclusion Criteria:

• Solid organ transplant
• Received gene therapy for GSD1a
• Presence of liver adenoma >5 centimeters (cm) in size
• Diagnosis of type 1 or type 2 diabetes mellitus
• Presence of liver adenoma with growth of >2 cm or >5 newly diagnosed liver adenomas, in the previous 2 years

Note: Additional inclusion/exclusion criteria may apply, per protocol.