New long-term data support the importance of early treatment with high dose, high frequency Rebif® (interferon beta-1a) 44 mcg in reducing the long-term accumulation of brain lesion volume in patients with relapsing remitting multiple sclerosis (MS). These findings, presented at the 56th Annual Meeting of the American Academy of Neurology, provide a comprehensive long-term evaluation of MS brain lesion volume as measured by magnetic resonance imaging (MRI) and show the sustained effects of Rebif 44 mcg (three times weekly, subcutaneously).
“This is good news for people with relapsing remitting multiple sclerosis as it shows that earlier initiation of high dose, high frequency interferon beta-1a therapy with Rebif®, compared to a two-year delay, is associated with a greater likelihood of reduction in total lesion accumulation over time,” said Dr. David Li of the University of British Columbia in Vancouver, British Columbia, Canada.
The findings show that Rebif® 44 mcg continued to have an impact in reducing the accumulation of MS lesion volume, as measured on MRI, in patients with relapsing remitting MS (RRMS) after 7-8 years of follow up. MRI lesions provide one of the most sensitive measures of MS disease activity for many patients. The poster reports the results of long-term changes in the accumulation of MRI T2 lesion volume among RRMS patients, who were initially randomized to receive Rebif® 44 mcg, Rebif® 22 mcg (three times weekly subcutaneously) or placebo, in the PRISMS long term follow up (LTFU) study. After the initial two-year time frame, placebo patients commenced therapy with Rebif® for subsequent years.
The PRISMS LTFU MRI evaluation compared lesion volume change from baseline to the LTFU visit (an average of 7.4 years later). In the PRISMS LTFU study, patients initially randomized to Rebif® 44 mcg were less likely to have increased lesion area than those initially given Rebif® 22 mcg or placebo for two years followed by Rebif® for up to 5.5 years. The proportion of patients showing an increase in total lesion burden over an average of 7.4 years was lowest for Rebif® 44 mcg (54%), followed by Rebif® 22 mcg (66%) compared to the placebo/Rebif® patients (73%). This represents a 26% relative reduction in the risk of lesion accumulation for Rebif 44 mcg (three times weekly) initiated early compared to delayed initiation of treatment. The exact relationship between MRI findings and the clinical status of patients is unknown.