Inclusion Body Myositis – Clinical Trials

Clinical trials for inclusion body myositis are research studies that investigate the effectiveness of new treatments, medical tests, or devices. Trials are carefully designed and follow strict procedures to help provide reliable results.

Clinical Trials – General Considerations

• Phase I: Initial studies of new drugs in humans are small, short studies designed primarily to see if the medication is safe.
• Phase II: If a medication seems safe, a larger and longer study will be done to begin to learn if the drug actually works, and to obtain more safety data. Sometimes studies are designated as either Phase IIa or Phase IIb. Phase IIa studies are more exploratory in nature. Although they are designed to reveal information about the efficacy of the drug, the primary endpoint may be to determine the optimal frequency of dosing, the type of patient most suitable for future testing, or other aspects of safety and efficacy. Phase IIb studies are more advanced, and are generally designed with efficacy as the primary endpoint.
• Phase III: The final phase involves research studies of large groups of patients.

Each trial has eligibility criteria that specify which patients are allowed to participate. This can be frustrating if you are a patient who does not meet the criteria, especially for diseases like inclusion body myositis that do not have currently approved treatments. The purpose of the criteria is to ensure that all the patients in the trial have the same disease, and that they can participate in all aspects of the treatment and testing. This increases the likelihood that a successful treatment will be identified. If the treatment eventually does receive FDA approval, the treatment might then be given to patients who did not meet the eligibility criteria for the study.

Clinical trials for Rare Diseases are Challenging:

• It can be difficult to recruit adequate numbers of patients.
• Clinical trials are expensive, and funding can be hard to obtain.
• The natural history of the disease may be poorly known.

Natural History Studies

The natural history of a chronic disease refers to how the disease affects people, from the time the disease begins until the patient dies, without treatment. Accurate knowledge of how the disease progresses is crucial to the design and implementation of clinical trials. How do you test if a drug works if you don’t know what happens in the disease without the drug? Cure IBM encourages all inclusion body myositis patients to participate in natural history studies.

The ClinicalTrials.gov online registry

ClinicalTrials.gov is an online registry of clinical trials, and is the place to go if you would like to search for clinical trials for inclusion body myositis. The site is managed by the United States National Library of Medicine and the National Institutes of Health. Although it is a US government website, some studies offered outside the United States are listed on the website. After entering inclusion body myositis as the name of the condition/disease, clicking the “Search all studies” button will bring up a list not only of active studies that are currently recruiting new patients, but also recently concluded studies and studies which are about to begin.

Inclusion Body Myositis Clinical Trials of Current Interest

Arimoclomol

A Phase 2/3 inclusion body myositis clinical trial is now taking place. The trial is fully enrolled; no additional patients will be accepted. Arimoclomol is a “protein-folding” drug. People with IBM have abnormally folded and clumped proteins in their muscle cells, and these protein clumps may be involved in causing the muscle damage. Arimoclomol helps maintain proper folding of the proteins, and helps clear away the abnormal clumps. It is the first drug of this type to be studied in inclusion body myositis. The study is being conducted at University College London, in England, and at multiple sites in the United States. Participants take two pills 3 times a day for 20 months.

Orphazyme A/S, the Danish biopharmaceutical company conducting the arimoclomol clinical trial, has received Fast Track designation from the US Food and Drug Administration (FDA) for arimoclomol as a potential treatment for inclusion body myositis.

Pioglitazone

An open-label pilot study of pioglitazone (brand name Actos) in sporadic inclusion body myositis is currently underway at Johns Hopkins University. Pioglitazone was approved by the FDA in 1999 for treating diabetes, and is available as generic tablets. Research has shown that skeletal muscle in IBM patients have defective mitochondria, which are energy-producing structures inside our cells. One of the known effects of pioglitazone is to increase the production of certain enzymes which improve the health and function of mitochondria in the skeletal muscles of diabetic patients, and the researchers hope the same effect will be found in IBM. The current trial of pioglitazone is a preliminary study involving only 15 patients, and the primary goal is to see if pioglitazone increases the production of an enzyme known as PGC-1α in the skeletal muscles of IBM patients. Other biochemical changes will also be studied, and the effect of pioglitazone on mitochondrial health will be investigated. The study will determine if pioglitazone increases muscle strength.

Rapamycin

Rapamycin is an established, FDA-approved drug that has been used for many years to prevent kidney transplant rejection. A Phase IIb clinical trial of rapamycin in inclusion body myositis has been completed in France, and results were reported in November, 2017. Based on the primary endpoint, changes in quadriceps muscle strength, the drug failed to show efficacy. However, encouraging results were obtained from several secondary endpoints, such as the distance walked in 6 minutes, composite muscle strength and function, tests of breathing, and muscle changes seen on MRI scans. The results were promising enough to spur interest in further study. Detailed information can be found in The Cure IBM Blog article on Rapamycin and Inclusion Body Myositis.

Follistatin Gene Transfer

A Phase I clinical trial of follistatin gene transfer in sporadic inclusion body myositis has been completed and the results have been published. Six patients received injections directly into the quadriceps muscle of both legs. A benign virus, rAAV1 (recombinant adeno-associated virus 1) was used to carry the follistatin gene into the muscles. Follistatin blocks a protein called myostatin, which inhibits muscle growth. Blocking myostatin allows the muscles to grow. No adverse effects were detected, and patients who received the therapy improved in a 6-minute walk test, while control patients worsened. Much work needs to be done, and this is not a therapy that will be approved quickly. Gene therapy is new and has potential risks. Unlike medications, which can be stopped if adverse effects develop, once the gene is injected it cannot be removed or stopped. However, gene therapy is a rapidly evolving field, and it does have great potential.

by Kevin Dooley, MD

Revised December 18, 2019