This research group from Italy looked at the relation between the treatment effects detected on MRI lesions and clinical relapses, using data from a large and independent set of clinical trials in MS. They extracted data from 31 clinical trials for the treatment effects on MRI lesions and on relapse for each trial, which provided data for 18,901 people with relapsing-remitting MS.
Using a weighted linear regression analysis, they showed a relation between the concurrent treatment effects on MRI lesions and relapses. Also, they found that on analysis of trials that tested the same drugs in phase 2 and 3 studies, that the effects on MRI lesions over short follow-up periods (6-9 months) can also predict the effects on relapse over longer follow-up (12-24 months). The reported effects on relapses were within the 95% prediction intervals in eight of the nine trials. This demonstrates that the effect of a treatment on relapses can be accurately predicted by the effect of that therapy on MRI lesions.
Based on this, the use of MRI markers as primary endpoints in future clinical trials of treatments for MS can be considered, in certain situations, for example, in trials testing generics with a well known mechanism of action or even in paediatric trials testing drugs already approved for adults.
Authors: Sormani MP, Bruzzi P.
Source: Lancet Neurol. 2013 Jun 3. [Epub ahead of print]
Read the abstract