At present, riluzole is the only drug licensed in the UK to treat MND so it is very important that new treatments are found. Clinical trials are research studies using human volunteers that determine whether potential treatments are safe and effective. They are difficult to design because of the varied range of symptoms and progression seen in people with MND. Trials take many years and, in the end, the trial drug may never be approved; for MND, the likelihood that a drug will make it from pre-clinical stages to approval is less than 1%.
Trials must be conducted in such a way that the experimental drug undergoes the most rigorous testing possible. This is by ensuring that the clinical trials are placebo controlled, randomised, and double-blind.
Some of the trial participants are given a ‘dummy drug’ (placebo) instead of the trial drug. A trial of a new treatment must ensure that any beneficial effects seen are entirely down to the trial drug and not due to the power of positive thinking, the extra attention from medical staff that comes with participating in a trial, or any other factor. The group of patients taking the placebo are known as the control group and are used for comparison to give a true picture of the effects of the trial treatment.
Participants in trials are often assigned to a treatment group (trial drug or placebo) at random. This is usually done by computer, and is similar to drawing numbers from a hat. It prevents bias occurring in choosing which patients get which treatment.
In a double blind trial, neither the researchers nor the patients know who is taking the trial drug and who is taking the placebo. This prevents unintentional bias creeping in when participants are reporting how they feel or when researchers are looking at data from the trial. However, a central trial co-ordinating centre does know who is taking the trial drug and can make this information available very quickly if a patient suffers a possible side effect.
Edaravone is a drug developed by Mitsubishi Tanabe Pharma that has recently been approved to treat MND in the USA (it is also licensed in Japan and South Korea).
Edaravone is an antioxidant drug that works by mopping up ‘free radicals’ in the body. Our cells have quite effective ways of dealing with free radicals, but these ‘cellular defences’ become less and less efficient with age.
The latest clinical trial was designed to see statistically significant changes in ALSFRS scores. At the end of the 6 months of treatment, those receiving edaravone had not lost quite so much function as those that were on placebo (difference of 2.5 ALSFRS points).
Analyses of the latest Phase 3 clinical trial will be presented at the Symposium.
The following presentation will discuss edaravone at the Symposium. Find the abstract using the code below in Abstracts online:
- C26: Towards more efficient clinical trial designs in ALS: Lessons from the Edaravone Development Programme
A recently-completed Phase 3 clinical trial looked at the effectiveness of the drug masitinib when taken with riluzole.
Masitinib inactivates an enzyme, called tyrosine kinase, believed to be involved in tissue inflammation and thought to play a role in the speed of MND progression. Masitinib may reduce inflammation in the brain which could reduce the damage to motor neurones.
To reflect the range of symptoms and progression, participants were split into two groups depending on their clinical progression assessed by ALSFRS. Based on these ratings, patients who had a progression rate of less than 1.1 points per month (‘normal progression’), and who were given masitinib at a higher dose for up to 48 weeks together with riluzole, showed benefits compared to control groups.
Results of their final analyses will be presented at the Symposium.
The following presentation will discuss masitinib at the Symposium. Find the abstract using the code below in Abstracts online:
- C22: Masitinib as an add-on therapy to riluzole is safe and effective in the treatment of ALS
Clinical trials of tirasemtiv assessed the effect of the drug on respiratory function in people with MND. Tirasemtiv increases force and power of skeletal muscles and therefore delays fatigue. This drug aims to increase quality of life in people with MND by increasing muscle strength.
Randomised groups were given different daily doses of tirasemtiv, or a placebo. The primary aim of this trial was to assess slow vital capacity (SVC; a measure of respiratory capacity) after 24 weeks of treatment.
In November 2017, Cytokinetics Inc., the company behind tirasemtiv, announced that they will not continue in the development of tirasemtiv. This is because, although there was a small increase in SVC in people taking tirasemtiv compared to those on placebo, the results were not found to be significant.
The results of their Phase 3 clinical trial will be presented in full at the Symposium.
The following presentation will discuss tirasemtiv at the Symposium. Find the abstract using the code below in Abstracts online:
- C23: VITALITY-ALS: Results of a phase 3 trial of tirasemtiv, a fast skeletal muscle troponin activator, as a potential treatment for patients with ALS
More abstracts relating to clinical trials can be found in session 4B.