The REbif® vs Glatiramer Acetate in Relapsing Multiple Sclerosis Pharmacogenetics Trial

A responder was defined as a participant with no multiple sclerosis (MS) relapse and no Expanded Disability Status Scale (EDSS) progression during 96 weeks in 24735 (NCT00078338). All responders were categorized on the basis of following six SNP markers: SNP1, SNP2, SNP3, SNP4, SNP5, and SNP6. Two types of variables were possible for each SNP marker: two-level genotype-based or three-level allele-based association variables. For the two-level genotype-based SNP markers (SNP2, SNP4, and SNP6), the absence or presence of the genotype was analyzed as the dichotomous variable as 0 (absence of the genotype) and 1 (presence of the genotype). For the three-level allele-based association SNP markers (SNP1, SNP3, and SNP5), the analysis was based on the number of copies of the allele (0, 1 and 2). Percentage of responders segregated on the basis of SNP marker variable were reported.

EDSS assesses disability in 8 functional systems. An overall score ranging from 0 (normal) to 10 (death due to MS) was calculated. EDSS progression was defined as increase by at least 1 point if last value of EDSS was equal to 5.5, and by at least 0.5 points if last EDSS was more than 5.5. SNP2 is two-level genotype-based SNP marker. The absence or presence of the genotype was analyzed as the dichotomous variable as 0 (absence of the genotype) and 1 (presence of the genotype). Number of responders segregated on the basis of SNP2 marker variable were reported.

Change in T1 Gd enhancing lesion volume was measured by using magnetic resonance imaging (MRI) scans. SNP4 is two-level genotype-based SNP marker. The absence or presence of the genotype was analyzed as the dichotomous variable as 0 (absence of the genotype) and 1 (presence of the genotype). SNP3 is a three-level allele-based association SNP markers. The analysis was based on the number of copies of the allele (0, 1 and 2). Change in T1 Gd enhancing lesion volume segregated on the basis of SNP3 and SNP4 marker variables were reported.

Change in brain volume was measured as the brain parenchymal fraction using MRI scans. SNP2 is two-level genotype-based SNP marker. The absence or presence of the genotype was analyzed as the dichotomous variable as 0 (absence of the genotype) and 1 (presence of the genotype). Change in brain volume segregated on the basis of SNP2 marker variables were reported.

Mean number of T2 active lesions was measured by using MRI scans. SNP5 is a three-level allele-based association SNP markers. The analysis was based on the number of copies of the allele (0, 1 and 2). Mean number of T2 active lesions segregated on the basis of SNP5 marker variables were reported.