Wednesday, October 01, 2008
By Louise Gagnon
MONTREAL -- September 24, 2008 -- Specific magnetic resonance imaging (MRI) scans can predict which patients will develop multiple sclerosis (MS), according to retrospective research presented here at the World Congress on Treatment and Research in Multiple Sclerosis (WCTRMS).
The Betaferon/Betaseron in Newly Emerging MS for Initial Treatment (BENEFIT) study is a randomised, double-blind, placebo-controlled, parallel-group clinical trial that was carried out among 468 patients whose first clinical event suggestive of MS happened within 60 days of trial entry. The study found that treatment with interferon (INF) beta-1b 250 mcg prevented the onset of clinically definite multiple sclerosis (CDMS) by 1 year.
Patients in the BENEFIT study were assigned to either early treatment, which was IFN beta-1b from the start of the trial, or delayed treatment, which was initial placebo followed by IFN beta-1b therapy after conversion to CDMS or upon completing 2-year follow-up.
Principal investigator Bastiaan Moraal, MD, VU Medical Center, Amsterdam, Netherlands, speaking at an oral session here on September 19, said that this analysis examined radiological rather than clinical endpoints.
"We were looking at which type of lesions measured at baseline would predict conversion to clinically definite multiple sclerosis or McDonald multiple sclerosis," said Dr. Moraal.
In this analysis, blinded raters assessed baseline MRI parameters using T2-weighted and postcontrast T1-weighted sequences. Statistical analysis was employed to assess the predictive value of each baseline MRI parameter and treatment interaction.
Investigators found overall conversion to CDMS was 42%, with factors such as the presence of =>9 T2 lesions and =>3 periventricular lesions demonstrating predictive value. They found that conversion rose with the cumulative number of positive criteria. No specific advantage was demonstrated for a threshold of =>3 Barkhof criteria.
"Patients whose treatment was delayed and had 4 positive Barkhof criteria had a higher chance of conversion to CDMS and McDonald MS compared to those with early treatment and fewer positive Barkhof criteria at baseline," explained Dr. Moraal.
Investigators found that prognostic value was affected by treatment (P = .002) for 4 positive Barkhof criteria. The prognostic value was not influenced by therapy for CDMS.
"We saw that, with one exception, the predictive value of MRI values was not affected by treatment," said Dr. Moraal.
Future analysis will examine the predictive value of MRI variables at 3, 6, and 9 months to assess the impact of those variables on conversion to either CDMS or McDonald MS.
[Presentation title: Baseline Magnetic Resonance Imaging Predictors for Conversion to Clinically Definite Multiple Sclerosis and McDonald Multiple Sclerosis, Based on Integrated 3-Year Data From the BENEFIT Study. Abstract 51]