A meta-analysis demonstrated a link between treatment effects detected in MRI lesions and clinical relapse, suggesting the markers can be leveraged as a primary endpoint in future clinical trials of treatments for multiple sclerosis (MS) in specific situations, according to a study published online June 3 in Lancet Neurology.
Although previous research has suggested a strong relationship between the effect of an MS treatment on MRI markers and relapse, drug regulatory agencies have not accepted these markers as surrogate endpoints in trials assessing new therapies.
Maria Pia Sormani, MD, from the department of health sciences at University of Genoa in Italy, and colleagues aimed to validate previous research suggesting a quantitative relation between the treatment effects shown on MRI lesions and clinical MS relapse.
They mined MEDLINE for trials that evaluated MS therapies published from Sept. 1, 2008, to Oct. 31, 2012, and identified a total of 31 trials that included 18,901 patients.
The researchers determined the treatment effect on MRI lesions by calculating the average number of MRI lesions per patient in the experimental and control groups.
The results replicated the researchers’ earlier meta-analysis and validated the role of MRI markers as surrogate endpoints.
“First, our findings substantiate the strong association between the effect of a treatment on MRI lesions and its effect on the relapse rate. Second, our findings show that the accurate prediction of the effect of treatment on relapses, on the basis of the effect seen on MRI lesions, is possible by means of a simple regression equation.”
Sormani and colleagues suggested two specific instances in which MRI markers could provide a surrogate endpoint—trials that assess the efficacy of biosimilar and generic versions of interferon beta and glatiramer acetate and a phase III trial in testing efficacy of approved adults drugs for children.