EncompaSSc: Evaluation of MTX-474 in Participants With Diffuse Cutaneous Systemic Sclerosis (dcSSc)

To join this study, you need to be at least 18 years old and have a clear diagnosis of diffuse cutaneous systemic sclerosis (dcSSc). The timing of your symptoms and how much your skin is affected are important factors. For example, if you've had symptoms for a short time, your skin thickening needs to be above a certain level. If your symptoms started a bit longer ago, there are specific requirements for your skin thickening and certain blood test results.

It's important that you haven't had previous major improvements in your skin thickening on its own. Also, your lung function needs to be within a certain range, as checked by specific breathing tests. You must be able to understand the study information and agree to take part by signing a consent form.

There are also some reasons why you might not be able to join. For instance, if you have other serious health problems that might interfere with the study or make taking the new medicine unsafe. If you're a woman who could become pregnant, you'll need to have a negative pregnancy test and agree to use effective birth control throughout the study and for a period afterwards.

If you decide to take part, you'll be assigned by chance (like flipping a coin, but more carefully) to either receive the new medicine, MTX-474, or a dummy medicine called a placebo. You won't know which one you're getting, and neither will your study doctor, until the study is over. You'll receive the study medicine or placebo through an intravenous (IV) drip every four weeks, starting on your first day, and this will continue for about 20 weeks.

Throughout the study, you'll have several visits to the clinic. These visits will involve various health checks, such as physical exams, blood tests (to check your general health and levels of a specific protein called Ephrin receptor), and sometimes skin biopsies (small samples of skin). You'll also have special tests to check your lung health, including breathing tests (spirometry) and scans (HRCT and DLCO). The total treatment period is 20 weeks, with a final check-up around Week 24, and a safety follow-up visit at Week 28, which is 8 weeks after your last infusion.

It's important to know that you might be able to continue taking some of your existing dcSSc medications while in the study, if your doctor agrees. The study team will explain everything in detail, including the exact schedule of visits and what each test involves. The total duration of active participation, including follow-up, will be around 28 weeks.