What does the drug do?

Inflammation in the brain and spinal cord is thought to contribute to MND progression. Studies on animals and humans have shown that Interleukin-2 (IL-2) can control a type of immune cell called a Regulatory T Cell (Treg). Tregs play a role in the immune system (fight diseases, infection and help control inflammation) but are dependent on IL-2 for survival and function. At low doses IL-2 has been shown in increase number of Treg cells and function in the blood.

Trial Outcome

The Phase 2 trial (MIROCALS) investigated the use of IL-2 in people living with MND over 18 months. IL-2 was found to be safe and well tolerated. 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 (a biological signal of damage to neurones) they found a larger and statistically significant effect on survival for those who 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. Further analysis is still ongoing and we will update this page once we have more information. You can read more here.  

Clinical Trials

Phase 2 - IMODALS

The Phase 2 trial (IMODALS) enrolled 36 participants into 2 different dosing regimens or placebo over 3 months. The trial showed that the number of circulating Tregs was increased with improved ability to control other immune cell responses that contribute to nerve cell death. This results are promising but the results need to be validated across a longer and larger trial. You can find out more about the trial here.

Phase 2 - MIROCALS

The Phase 2 trial (MIROCALS) evaluated the efficacy of IL-2 over 18 months in 304 participants. This phase 2 trial looked at a larger cohort of participants over a longer time period compared to IMODALS. You can find out more about the trial here.

The top-line results were announced at the 33rd International Symposium on ALS/MND on 6 December 2022. 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 (a biological signal of damage to neurones) they found a larger and statistically significant effect on survival for those who 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.

Further analysis of the results is being conducted to understand how IL-2 affects the underlying biology of the disease. The lead researchers on the trial are prioritising discussions with drug regulatory bodies to determine next steps for IL-2 in the treatment of ALS. We look forward to reporting on further analysis once we have it.

Latest News

2023

Sept 2023 - The trial data is now being collated and analysed and we are awaiting publication of the full results. The MND Association has submitted an application for the repurposing of aldesleukin (also known as interleukin-2 or by its brand name Proleukin) to NHS England's Medicines Repurposing Programme. 

2022

Dec 2022 - Topline results were announced at the 33rd International Symposium on ALS/MND. You can find out more here.

Jan 2022  - Topline results are expected in 2022.

2021

June 2021  - MIROCALS completed recruitment.

Last updated: 26/09/2023