Foundation response to Clinical Studies Group MIROCALS statement

15 May 2025

Following on from last week's publication of the MIROCALS trial in The Lancet, clinicians who make up the UK MND Clinical Studies Group (CSG), have issued a statement giving their opinion on the necessary next steps. The trial tested a repurposed drug called aldesleukin, a chemical form of interleukin-2 (IL-2), an immune modulator found in all of us.

Although it is a Phase 2 study, this is a substantial trial looking at a treatment for the vast majority of people living with motor neuron disease (MND), and potentially one of the most important trials for patients to be published in decades.

The investigators trialled a low dose version of IL-2 in 220 patients, with half receiving the drug and the other half a placebo. When researchers looked at results for all patients, they found only a modest improvement in those taking IL-2, but this wasn't statistically significant. 

However, in a pre-planned adjusted analysis, results for certain patients appeared more promising. For those with lower neurofilament levels (a biomarker of disease activity, making up around 70% of trial participants) the risk of death in the IL-2 arm was reduced by up to 48% over the length of the trial observation time of 21 months. This was statistically significant and highly encouraging.

The UK MND Clinical Studies Group (CSG) has suggested that a Phase 3 trial, led by industry, could be undertaken to confirm these results. The Foundation will discuss this with researchers, other charities, patient groups and ILTOO Pharma, the company in question. This is a regulatory pathway for a future licence for the drug and is the sole responsibility of regulators (e.g. MHRA in the UK) along with ILTOO. We recognise that the results of a Phase 3 trial will be years away and strongly recommend that an alternative or complementary approach should be adopted in the meantime. This is in line with the CSG’s statement and could take the form of what is known as a ‘managed access programme’ (MAP) with the company, or a real-world evidence study. Either of these approaches could collect the desired additional data, while allowing suitable people living with MND access to the drug. This could happen in parallel to the medicine going through the Phase 3 regulatory requirements.

My Name’5 Doddie Foundation will discuss these options with all stakeholders in the coming weeks and comment further when we have more information. As always, we will work collaboratively with researchers, clinicians, patient groups, policy makers and other charities towards a world free of MND.