Recent pieces published in the international neurology journal, Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration, have sparked debate in the ALS community. 

In ALS Action Canada’s paper (Darke and Orsulak 2025), “How Effective Does a New Drug for Amyotrophic Lateral Sclerosis Need To Be – The Patient Perspective”, we argued against the proposal of Boddy et al (2025). The Boddy et al paper proposed that a new drug for ALS should only be considered effective if it showed a difference of almost 4 points from placebo on the ALS Functional Rating Scale, within three months of the start of the clinical trial. 

For example, if the average ALSFRS score was 36 at the start of the trial, a difference of 4 points would be a 40% slowing of the disease compared with placebo. It was Boddy et al’s position that this was the minimum important difference (MID) that would be considered meaningful by patients. 

In our paper, we showed that such a difference had not been demonstrated for recent ALS drugs, and that this requirement would not be met by many drugs now in the clinical trial pipeline. Our concern was that new drugs would not be approved by regulatory agencies if they adopted this proposal as policy. 

Now, in a paper by Meyer et al (2026) published in the same journal, over 500 patients were asked what they would regard as the minimum important slowing (MIS) of disease progression for a new ALS drug.

The results:

• 37% of patients thought that a 5 – 10% slowing would be important; 
• 34% said 20 – 40% slowing would be important; 
• and 29% said 50% slowing would be important. 

The authors concluded that regulatory authorities should regard modest slowing of ALS progression – even as low as 5-10% – as relevant to many patients, a significant difference from the 40% slowing proposed by Boddy et al.

This new paper reinforces our advocacy for the essential nature of ALS patient and caregiver voices as part of these public and policy debates.