The main purpose of the study is to evaluate the long-term safety of DTX401 in patients with GSDIa, as well as to monitor pregnancy outcomes in these patients. Participants in the study may have previously received DTX401 in an earlier clinical trial or as part of their regular treatment. The study will track any serious side effects that might occur, including those related to the infusion process or any other medications the patients might be taking, such as steroids. It will also look at any potential effects on the liver, the development of new or worsening cancers, and other health issues that might arise over time.

Throughout the study, various assessments will be conducted to gather information on the participants’ nutritional status, clinical and laboratory findings, and overall health experiences. This will help researchers understand the impact of DTX401 on patients’ lives and identify any major clinical events that occur during the study period. The study is expected to continue for several years, allowing for comprehensive monitoring and data collection.

The purpose of the study is to evaluate the long-term safety of this treatment, known by its code name DTX401, after a single dose is given. Participants in the study will receive the treatment and be monitored over time to see how their bodies respond. The study will look at any side effects that occur and how they relate to the treatment. Additionally, researchers will observe changes in the time it takes for participants to experience low blood sugar events during a controlled fasting period.

This study is part of ongoing research to better understand and manage Glycogen Storage Disease Type Ia. By participating, researchers hope to gather important information that could lead to improved treatments for this condition in the future. The study is expected to continue until 2026, allowing for comprehensive monitoring and data collection.

Participants in the study will receive either the new treatment or a placebo. The treatment is given as a solution through an infusion, which means it is delivered directly into the bloodstream. In addition to the main treatment, some participants will also take a medication called Prednisolone, which is a type of steroid that helps reduce inflammation. The study will compare the effects of the new treatment with those of the placebo over a period of time to determine its effectiveness and safety.

The study will last for several weeks, during which participants will be closely monitored. They will have regular check-ups and tests to track their health and how their bodies respond to the treatment. The goal is to gather information on how well the treatment works and any potential side effects. This research is important for finding new ways to help people with Glycogen Storage Disease Type Ia manage their condition more effectively.

The purpose of the study is to evaluate the safety and tolerability of mRNA-3745 in participants with Glycogen Storage Disease Type 1a. Participants will receive the treatment through an intravenous (IV) injection, which means it will be administered directly into a vein. The study will start with a single dose and may progress to multiple doses, depending on how participants respond. Throughout the study, participants will be closely monitored to see how their bodies react to the treatment and to check for any side effects.

This study is designed to be adaptive, meaning that the researchers may adjust the treatment plan based on the results they observe. Participants will be involved in the study for a period of time, during which they will have regular check-ups and tests to monitor their health and the effects of the treatment. The study aims to provide valuable information about the potential benefits and risks of using mRNA-3745 for treating Glycogen Storage Disease Type 1a.