MIROCALS trial publishes findings

A clinical trial investigating the protein molecule Interleukin-2 (IL-2) has found that the substance may have a slight positive impact on extending life in some people with the terminal illness motor neuron disease (MND).

IL-2, which is naturally produced in the body, was selected as a trial target because low doses have previously been shown to increase the number of immune cells, which could help reduce inflammation linked to MND progression.

The purpose of the trial was to establish the safety and effectiveness of prescribing IL-2 to people living with MND, with survival being the primary measurement for success.

The clinical trial recruited 220 participants living with MND at 17 centres across the UK and France. MND Scotland provided funding for a small number of people living with MND in Scotland to participate in the trial.

Participants were monitored for three months before either receiving low doses of IL-2 or receiving a placebo. This was in order to compare any differences between people receiving IL-2 compared to a dummy drug. The trial period lasted up to 21 months in total.

What were the findings of the MIROCALS trial?

IL-2 was found to be safe and well tolerated, side effects were minimal across both treatment and placebo.

When the whole trial population was analysed, treatment with IL-2 showed a modest decrease in risk of death for those on the treatment over the 21 months of the study, but this was found not to be statistically significant.

However, when the survival analysis was adjusted – as planned in advance – by subgrouping people using a particular biomarker in the cerebrospinal fluid (CSF pNFH, phosphorylated neurofilament heavy chain, a biological signal of damage to neurones) they found a larger and statistically significant effect on survival for those who had low to moderate CSF pNFH levels and received the treatment. This effect equated to an over 40% decrease in the risk of death at 21 months for a large proportion (80%) of the overall trial population who received IL-2. Those with high CSF pNFH levels showed no benefit with the IL2 treatment.

These results provide encouraging evidence, the first from a ‘gold standard’ randomised placebo-controlled drug trial, in support of immune system modification and neuroinflammation as viable targets for altering MND disease progression. There will now be more and deeper analysis of these encouraging results.

This was not a phase 3 trial – the type of trial that is designed to provide results for regulatory approval. However, it will be important to seek the advice of the drug regulatory authorities on the next steps.

Dr Jane Haley MBE, Director of Research at MND Scotland, said: “I welcome the initial results of the MIROCALS clinical trial, which targeted the immune response and suggests that such personalised treatment approaches may benefit people with MND.

“This study also demonstrates the strength of working in partnership to find treatments for this devastating condition. We are very grateful to everyone who participated in this study and all our supporters, whose dedication means we can support important clinical trials such as these.”

Together, we’re making time count

Your support is enabling MND Scotland to invest in pioneering MND research and clinical trials, bringing us a step closer to new potential treatments for motor neuron disease.

From modest investments in projects like MIROCALS, to major investments in MND-SMART, the biggest MND clinical trial in UK history, you’re making a big difference.

Find out more about our research and donate to help keep MND research going.