FUSION: A Study to Evaluate the Efficacy, Safety, Pharmacokinetics and Pharmacodynamics of ION363 in Amyotrophic Lateral Sclerosis Participants With Fused in Sarcoma Mutations (FUS-ALS)

To join the first part of this study, you need to be at least 10 years old and have symptoms of Motor Neurone Disease (MND) that a doctor believes are consistent with the condition. Crucially, you must have a confirmed change in your FUS gene, which will have been checked by a certified laboratory.

Your breathing capacity is also a factor. If your lung function (measured by something called 'slow vital capacity') is at least 50% of what's expected for someone of your age, sex, and height, you might be eligible. If it's less than 50%, you'd need to be between 10 and 30 years old, and your MND symptoms must have started within the last 12 months. Any current MND medicines you're taking, like riluzole or edaravone, must have been at a steady dose for at least 28 days before the study begins, and you'll need to agree to continue them at that dose throughout the study, unless your doctor decides otherwise.

All participants must also have stable other medications and nutritional support for at least a month before the study starts. For women, you cannot be pregnant or breastfeeding. Both men and women must agree to use specific contraception methods if needed, or be surgically sterile, or for women, past menopause. Finally, you’ll need a close friend or family member who can provide information about your abilities, as judged by the study doctor.

If you join the FUSION study, your involvement will be split into three stages. For the first stage, lasting about 60 weeks (just over a year), you will either receive ION363 or a placebo, chosen at random. This means there's a 2 in 3 chance you'll get ION363 and a 1 in 3 chance of getting the placebo. After this first stage, you'll have the option to continue into a second stage where everyone will receive ION363 for about 84 weeks (around 1.5 years). There's also a potential third stage where you could receive ION363 for up to three more years, or until the medicine becomes available generally, or the study programme ends.

Throughout the study, you'll have regular visits to the study clinic for assessments. These will include checking your general health, how your MND symptoms are progressing, and performing various tests to see how the medicine is affecting your body. The total time you could be in the study, if you participate in all three parts, could be several years.