In short
There are currently 4 clinical trials investigating new treatments for Glycogen Storage Disease Type I, a rare genetic disorder affecting the body's ability to break down glycogen into glucose. These studies are exploring gene therapy and mRNA-based treatments across several European countries, offering hope for improved management of this challenging condition.
Clinical trial locations
- Denmark
- France
- Germany
- Italy
- Netherlands
- Study of Pariglasgene Brecaparvovec and Prednisolone for Adults with Glycogen Storage Disease Type Ia
- Study on Long-Term Safety and Pregnancy Outcomes of Pariglasgene Brecaparvovec in Patients with Glycogen Storage Disease Type Ia (GSDIa)
- Study on the Effects of Pariglasgene Brecaparvovec for Adults with Glycogen Storage Disease Type Ia
- Study on the Safety and Effects of mRNA-3745 for Patients with Glycogen Storage Disease Type 1a (GSD1a)
- Poland
- Spain
- Study of Pariglasgene Brecaparvovec and Prednisolone for Adults with Glycogen Storage Disease Type Ia
- Study on Long-Term Safety and Pregnancy Outcomes of Pariglasgene Brecaparvovec in Patients with Glycogen Storage Disease Type Ia (GSDIa)
- Study on the Effects of Pariglasgene Brecaparvovec for Adults with Glycogen Storage Disease Type Ia
- Study on the Safety and Effects of mRNA-3745 for Patients with Glycogen Storage Disease Type 1a (GSD1a)
Study on Long-Term Safety and Pregnancy Outcomes of Pariglasgene Brecaparvovec in Patients with Glycogen Storage Disease Type Ia (GSDIa)
This long-term safety study is designed for patients who have previously received a gene therapy treatment called Pariglasgene brecaparvovec (also known as DTX401). The study will monitor participants for several years to understand the long-term effects of this one-time intravenous treatment.
Who can participate: The study is open to people of all ages, including children, teenagers, and adults, who have already received DTX401 in a previous clinical trial or as part of their regular treatment. If participants are under 18 or have cognitive limitations, a legally authorized representative must provide consent. Both males and females can participate.
Who cannot participate: People who do not have Glycogen Storage Disease Type Ia, those outside the specified age ranges for the study groups, or those who have not previously received DTX401 cannot join.
What the study focuses on: The main goal is to evaluate the long-term safety of DTX401 over many years, extending until 2036. Researchers will track any serious side effects, including those related to the liver, development of new health problems, or complications during pregnancy. The study also monitors pregnancy outcomes for participants or their partners who have received the treatment. Regular assessments will include nutritional status checks, blood tests, imaging studies, and clinical interviews to gather comprehensive health information.
Treatment being tested: The study examines DTX401, a gene therapy that delivers a functional copy of the gene responsible for producing the enzyme glucose-6-phosphatase. This enzyme is deficient in people with the condition, and the therapy aims to correct the underlying genetic defect.
Study of Pariglasgene Brecaparvovec and Prednisolone for Adults with Glycogen Storage Disease Type Ia
This Phase 3 study tests whether a gene therapy treatment can reduce or eliminate the need for patients to rely on cornstarch supplements to maintain normal blood sugar levels. The study compares the gene therapy treatment against a placebo over 48 weeks.
Who can participate: Adults and children aged 8 years and older with confirmed Glycogen Storage Disease Type Ia can participate. The diagnosis must be confirmed either by a liver biopsy showing low enzyme activity or genetic testing showing two problem-causing changes in the G6PC gene. Participants must currently be following a stable treatment plan with cornstarch or similar supplements, with no significant changes in their daily intake or blood sugar levels over the past month. They must also be willing to wear a continuous glucose monitor, keep detailed food diaries, and follow strict study requirements. Women who can become pregnant and men who are fertile must use effective birth control during the study and for 48 weeks afterward.
Who cannot participate: People under 8 years old, those without a confirmed diagnosis, or anyone unwilling to comply with the study requirements cannot participate.
What the study focuses on: The main focus is measuring how much daily cornstarch intake changes from the start of the study to week 48. The study also tracks glucose levels, episodes of low blood sugar, and overall quality of life. Participants receive either the gene therapy or a placebo through a one-time intravenous infusion, followed by a course of prednisolone tablets starting at 10 mg daily to manage any immune response to the treatment.
Treatment being tested: DTX401 uses an adeno-associated virus serotype 8 vector to deliver a functional copy of the glucose-6-phosphatase gene directly to the liver, aiming to restore normal glucose metabolism.
Study on the Effects of Pariglasgene Brecaparvovec for Adults with Glycogen Storage Disease Type Ia
This extension study follows adults who have already received DTX401 in a previous trial to monitor long-term safety and effectiveness.
Who can participate: Only adults who received a single dose of DTX401 in a previous study called Study 401GSDIA01 can participate. They must be willing to provide written informed consent and attend all scheduled study visits.
Who cannot participate: People who are not adults, those not diagnosed with the condition, or individuals who did not participate in the earlier DTX401 study cannot join.
What the study focuses on: The primary goal is evaluating the long-term safety of DTX401 after a single intravenous dose. Researchers will monitor for any adverse events or serious side effects over time. The study also measures changes in the time it takes for participants to experience low blood sugar during a controlled fasting challenge, which helps assess how well the treatment is working.
Treatment being tested: DTX401 is a gene therapy using AAV8 virus to deliver the glucose-6-phosphatase gene to help the body produce the missing enzyme naturally.
Study on the Safety and Effects of mRNA-3745 for Patients with Glycogen Storage Disease Type 1a (GSD1a)
This adaptive study investigates a novel mRNA-based treatment approach for managing the condition. Unlike gene therapy, this approach uses messenger RNA to instruct the body to produce the missing enzyme.
Who can participate: Adults aged 18 and older, as well as children and adolescents aged 6 to 17 with parental consent, can participate if they have a confirmed diagnosis of GSD1a through G6PC gene sequencing. Participants must have stable disease, meaning no hospital visits for low blood sugar in the 4 weeks before starting. They must also have a history of at least one symptomatic low blood sugar event in the past year, with liver enzyme levels less than 2.5 times normal and adequate blood cell counts. Women who can become pregnant must use highly effective birth control for 28 days before treatment through 52 weeks after the last dose and must have negative pregnancy tests. Men who are sexually active must use condoms and ensure their partners use birth control during the same period.
Who cannot participate: People with other serious health conditions, recent infections, those taking interfering medications, individuals with allergies to similar treatments, pregnant or breastfeeding women, recent participants in other trials, those with substance abuse history, mental health conditions affecting participation, or a history of non-compliance with medical treatments cannot join.
What the study focuses on: The study evaluates the safety and tolerability of mRNA-3745 delivered through intravenous injection. It begins with a single dose phase and may progress to multiple doses depending on participant responses. The study design is adaptive, allowing researchers to adjust the treatment plan based on observed results. Participants will undergo regular monitoring including vital sign checks, blood tests, and other assessments to evaluate both safety and effectiveness over time. An open-label extension phase allows long-term monitoring.
Treatment being tested: mRNA-3745 uses messenger RNA encoding the human G6Pase-α enzyme, encapsulated in protective lipid nanoparticles. This approach aims to temporarily instruct cells to produce the missing enzyme, potentially requiring repeated doses rather than being a one-time treatment like gene therapy.
Summary
Four clinical trials are currently investigating new treatment approaches for Glycogen Storage Disease Type I across multiple European countries. Three of these trials focus on Pariglasgene brecaparvovec (DTX401), a gene therapy approach, while one explores mRNA-3745, a novel mRNA-based treatment strategy.
The Netherlands and Spain show the highest concentration of available trials, with all four studies recruiting in these countries. Germany, Italy, and Denmark each host two trials, while France and Poland each have one. This geographic distribution provides multiple opportunities for European patients to access experimental treatments.
The studies represent different phases of clinical development. While some trials test the initial effectiveness of these treatments, others focus on long-term safety monitoring, extending up to 2036. One study specifically examines pregnancy outcomes, recognizing the importance of understanding how these treatments affect reproductive health.
Both treatment approaches aim to address the fundamental problem in this condition: the missing or malfunctioning glucose-6-phosphatase enzyme. Gene therapy attempts to provide a permanent solution through a one-time treatment, while the mRNA approach may require repeated doses but offers a different safety profile. Patients interested in participating should discuss these options with their healthcare providers to determine which trial might be most appropriate for their individual circumstances.
