A Phase 2/3, Randomized, Double-Blinded, Placebo-Controlled, Parallel-Group, 2-Arm, Multicenter, Operationally Seamless Study to Evaluate the Efficacy, Safety, Tolerability, Pharmacodynamics, Pharmacokinetics, and Immunogenicity of Efgartigimod PH20 SC in Participants Aged 18 Years and Older With Active Idiopathic Inflammatory Myopathy
Idiopathic inflammatory myopathies are rare autoimmune conditions that cause swollen, weak muscles and skin problems. Standard treatments often involve steroids, which can lead to difficult long-term side effects. This study is testing an investigational medicine called efgartigimod, given as an injection under the skin. It works by lowering certain proteins in the immune system that attack healthy tissue. Researchers want to find out whether efgartigimod can safely improve muscle strength and overall health compared with a dummy medicine (placebo). Participants aged 18 and older will take part for around 52 weeks. Neither the participants nor their doctors will know who receives the real medicine or the placebo. Throughout the trial, doctors will regularly check muscle power, skin symptoms, blood markers, and whether participants are able to safely reduce their steroid doses.
At a glance
What is this study about?
Idiopathic inflammatory myopathies (often called IIM or myositis) are a group of conditions where the body's immune system mistakenly attacks its own muscles. This can lead to persistent weakness, aching, fatigue, and sometimes skin rashes. Simple daily tasks like climbing stairs, carrying shopping, or lifting your arms can become difficult. While current treatments such as steroids can help, they do not always work well enough and can cause significant unwanted side effects over time.
This clinical trial is evaluating a new potential treatment called efgartigimod. The medicine is designed to target and reduce specific antibodies in the blood that are thought to drive inflammation in myositis. By lowering these antibodies, doctors hope the medicine will calm the immune attack and allow muscles to recover.
During the trial, half of the participants will receive efgartigimod and the other half will receive a dummy treatment (placebo), both given as injections under the skin. The main goal is to see if patients receiving the medicine show a meaningful improvement in their muscle strength, everyday ability, and skin health after one year.
Finding new, targeted treatments is vital for people living with myositis. If successful, this trial could provide doctors with a more effective way to control disease activity and help patients rely less on high doses of steroids, improving their long-term health and independence.
Key takeaways
- The study tests an injection called efgartigimod for active inflammatory muscle disease (myositis).
- It aims to see if the drug improves muscle strength, skin symptoms, and reduces the need for steroids.
- The trial lasts for roughly 52 weeks and compares the medicine against a dummy injection (placebo).
- Open to adults aged 18 and older who have active disease.
- Participation is entirely voluntary and you can withdraw at any time.
Who may be eligible?
This trial is open to adults aged 18 and over who have been diagnosed with an active inflammatory muscle condition (idiopathic inflammatory myopathy). Because the trial focuses on whether the treatment works when symptoms are troubling, participants must have active muscle inflammation or weakness at the start of the study.
People of all sexes may be considered. However, participants generally need to be on stable treatment for their condition and able to attend regular hospital appointments for check-ups and injections.
You may not be eligible if you have other serious medical conditions that could make taking part unsafe, such as severe infections or certain unrelated chronic illnesses. The study team will review your full medical history and perform safety tests before you can join.
Could this study suit you?
Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.
- I am aged 18 or older.
- I have a confirmed diagnosis of an inflammatory muscle condition (such as myositis or dermatomyositis).
- My muscle disease is currently active, causing weakness or other symptoms.
- I am able to attend regular clinic appointments over a 52-week period.
- I am willing to receive injections under the skin.
What does participation involve?
Taking part in this trial lasts for at least 52 weeks (around one year). You will be randomly assigned by a computer to receive either the active medicine (efgartigimod) or a dummy medicine (placebo). Neither you nor your trial doctor can choose which group you are in.
The treatment is given as an injection just under the skin at regular intervals. You will need to attend clinic appointments for your injections, health checks, and safety monitoring. During these visits, the study team will test your muscle strength, examine any skin rashes, check your blood and urine, and ask you to complete questionnaires about your daily symptoms. You will also be closely monitored to see if your usual steroid dose can be safely reduced in the later months of the trial.
Potential risks and benefits
Locations (19)
- —UnverifiedSlovakia
- —UnverifiedSweden
- —UnverifiedFrance
- —UnverifiedGermany
- —UnverifiedCzechia
- —UnverifiedNetherlands
- —UnverifiedCyprus
- —UnverifiedDenmark
- —UnverifiedHungary
- —UnverifiedIreland
- —UnverifiedBulgaria
- —UnverifiedBelgium
Common questions
What is a placebo and why is it used?
A placebo is an inactive dummy injection that looks identical to the real medicine. Comparing the real medicine against a placebo helps scientists prove that any improvements are truly caused by the study drug.
How is the study medicine given?
The medicine is given as a subcutaneous injection, which means it is injected gently into the fatty layer just under the skin.
Will I have to stop my current myositis medicines?
Not necessarily. Most participants continue taking their standard medicines, such as steroids, at stable doses. The study team will guide you on how to manage your current prescriptions safely.
Can I leave the study if I change my mind?
Yes. You can leave the trial at any time, for any reason. Your regular medical team will continue to look after your health as normal.
Does taking part cost anything?
No. The trial medication, doctor visits, and study tests are provided free of charge. Most trials also help cover reasonable travel expenses to and from hospital visits.
How to find out more
Always speak to your GP or specialist before deciding to take part in a study.
Interested in taking part?
Discussion
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