Clinical Research Directory

A Study of AT132 in Young Children With X-Linked Myotubular Myopathy (XLMTM)

X-linked myotubular myopathy (XLMTM) is a rare and serious condition present at birth where the muscles do not work properly. There are currently no therapies for this serious condition. The protein myotubularin is needed for muscle development and movement. A gene called MTM1 tells the body to make myotubularin. XLMTM is caused by changes, or mutations, in the MTM1 gene. Changes in the MTM1 gene causes low levels of myotubularin to be made, so the muscles do not work properly. XLMTM may also affect the liver, and in some cases, this can be dangerous and threaten the patient´s life. Gene therapy is a way of getting a healthy copy of a gene into the body. This allows the body's cells to make a normal protein that may reduce disease symptoms. AT132 is a gene therapy that gets a healthy MTM1 gene into the body to help improve muscle development and function in young children with the disease. AT132 does not treat liver disease, and because of the way the treatment works, it may make liver problems worse. AT132 was the gene therapy treatment given to children who participated in this study and is not available to the public. In this study, AT132 was given to children for the first time. Due to the occurrence of severe complications and fatalities associated with administration of AT132, the study has been stopped and no further participants will be enrolled. The main aim of the study is to check how long young children need machines to support breathing (ventilation support) after AT132. Due to the occurrence of severe complications and fatalities associated with administration of AT132, the study has been stopped and no further participants will be enrolled. This study included children with XLMTM under 5 years old who had breathing problems caused by XLMTM. They couldn't take part if they were born prematurely, recently had surgery, had liver disease or other condition or disease the study doctor thought was medically important. The study did enroll participants with medically significant liver disease. This is an open-label study. This means that young children and their caregivers, and clinic staff know that young children received AT132. This study was designed with 2 parts and is now in a long-term follow-up phase to collect information on the safety and improvements in muscle function in the children who received AT132. In Part 1, small groups of young children were given different doses of AT132, with one group receiving a lower dose and one group receiving a higher dose of AT132. The purpose of giving the two doses was to determine which dose was best for treating the muscle disease. After receiving AT132, a medical panel of experts reviewed each child for safety and for how their muscles responded. AT132 did not demonstrate appropriate safety at either dose. Administration of AT132 was stopped. Children who received AT132 are being monitored for 10 years for safety and to understand how their muscles function over time.

A Study to Check Liver Health in Boys With XLMTM, a Serious Genetic Muscle Condition

XLMTM (X-linked myotubular myopathy) is a serious genetic muscle condition. It is caused by changes in the MTM1 gene which stops or slows down normal muscle development, causing severe muscle weakness. There is currently no cure for XLMTM. Ongoing care is needed to manage symptoms and prevent further medical problems from this condition. Recent research shows that individuals with XLMTM often have reduced bile flow which can affect liver and gallbladder health. Bile is a liquid made in the liver that helps digest fat. Ongoing liver health checks may help with the routine care of people with XLMTM. There is a need to understand liver problems that develop in individuals with XLMTM over time. The main aim of the study is to learn how many boys with XLMTM have new cases of liver problems during the study. This study is about collecting information only. This is known as an observational study. The individual's doctor decides on treatment, not the study sponsor (Astellas). In this study, boys under 18 diagnosed with XLMTM will be followed for about 1 year. The health of their liver and gallbladder will be checked about every 6 weeks. This can be done at home, if preferred. A scan called a Fibroscan (also known as transient elastography) will check for signs of scarring in the liver (fibrosis) and the build-up of lipids. It is suggested that each boy will have a Fibroscan when they start the study and another scan when they complete the study. This study will help understand liver, gallbladder, and bile duct issues in individuals with XLMTM over time. The goal is to improve their care and provide information to use in future clinical studies.

Study of ASP2957 in Male Participants With X-linked Myotubular Myopathy Who Need Ventilators

X-linked myotubular myopathy (XLMTM) is a rare and serious condition present at birth where the muscles do not work properly. There are currently no approved therapies for XLMTM. The protein myotubularin is needed for muscle development, movement and breathing. A gene called MTM1 tells the body to make myotubularin. XLMTM is caused by changes, or mutations, in the MTM1 gene. Changes in the MTM1 gene cause low or no levels of myotubularin to be made, so the muscles do not work properly. Gene therapy is a way of getting a healthy copy of a gene into the body. This allows the body's cells to make a normal protein that may reduce disease symptoms. Researchers have developed ASP2957 to get a healthy MTM1 gene into the body. This could help improve muscle development and function in young children with XLMTM. In this study, ASP2957 will be given to humans for the first time. ASP2957 has the healthy MTM1 gene inside a type of empty (killed) virus. The virus delivers the healthy MTM1 gene directly into cells in the body. It's possible that some boys may have antibodies to the virus if they have previously been infected with a similar virus. The antibodies could stop ASP2957 from working properly and cause an immune reaction to ASP2957. To prevent this, the boys will also be given medicines to lower the immune system. The main aims of this study are to check the safety of ASP2957, how well it is tolerated, and to find a suitable dose of ASP2957. The study was designed in 2 phases. In Phase 1, different small groups of boys will receive lower to higher doses of ASP2957. Each boy will receive a single infusion of ASP2957. Any medical problems will be recorded for each dose. This is done to find a suitable dose of ASP2957 to use in Phase 2. In Phase 2, another small group of young boys will receive a single infusion of ASP2957. The most suitable dose of ASP2957 worked out from Phase 1 will be used. The boys will be checked for up to 1 year after their single infusion of ASP2957. After this, there will be the option for the boys to join another study so they will continue to be checked longer term.