Inclusion body myositis has proven to be the most challenging of the myositis diseases to treat. To date, no treatments have been discovered that can effectively delay or stop the progressive muscle weakness that inevitably leads to disability.
A great deal of time, money, and effort are being invested, however, in trying to better understand this disease and develop some form of treatment and, of course, a cure. These are currently the medications that hold the most promise in this effort. Some of these are currently recruiting patients for clinical trials.
Arimoclomol is a compound that is believed to stimulate the repair of certain proteins in muscle cells, preventing these proteins from clumping. The compound showed some promise in a small initial clinical trial with inclusion body myositis patients. A larger trial, however, failed to show improved outcomes compared to placebo. Researchers are still studying the compound.
Bimagrumab (also known as BYM338) is a human monoclonal antibody developed to treat pathological muscle loss and weakness. In a clinical trial with inclusion body myositis patients, this compound showed that patients developed increase in muscle mass. Difficulties with the design of the trial, however, led to inconclusive results. This medication continues to be studied for other indications, and, if approved, may possibly be used off-label for inclusion body myositis. This is not a cure, however; it is a treatment for symptoms of muscle weakness only.
Follistatin (also known as AAV1-FS344) is a gene therapy-delivered protein that increases muscle strength and function. It has been shown to improve walking ability in patients with Becker muscular dystrophy. A study in patients with inclusion body myositis did not show effectiveness, however.
Rapamycin (also known as sirolimus) is an immunosuppressant drug that is currently used to prevent organ rejection in kidney transplant patients. A large clinical trial using this medication in patients with inclusion body myositis is currently recruiting participants and is expected to be completed in 2026.
Ulviprubart (also known as ABC008) is a first-in-class anti-KLRG1 antibody capable of selectively removing certain immune cells that damage muscle tissue in IBM. A large clinical trial to show effectiveness in IBM is no longer recruiting participants but is expected to have results by the end of 2025.