Long Term Study of Avonex Therapy Following a First Attack of Multiple Sclerosis

Overview

The current study is a continuation of the 5 year extension study of the phase III CHAMPS study (see reference). This study was designed to determine if immediate initiation of therapy with Interferon Beta-1a (AVONEX) after a first attack of multiple sclerosis (MS) continues to delay the development of further attacks (CDMS) and the development of neurological disability over a 10 year period of observation. The initial 5 year extension study, called CHAMPIONS5, reported that immediate initiation of interferon Beta-1a (AVONEX) after a first attack of MS continued to delay the development of CDMS and lowered relapse rates compared to delayed initiation of disease modifying treatment (usually with AVONEX) either at the time of a second attack or at the end of the phase III study (24 months). The study was extended to 10 years to determine if these effects are sustained and result in less long term permanent disability.

The CHAMPS study determined that immediate initiation of interferon beta 1a therapy (AVONEX) immediately following a first clinical demyelinating event in high risk patients (i.e. those with at least 2 asymptomatic white matter lesions on cranial MR imaging \> 3 mm in diameter or ovoid) delayed the development of clinical definite Multiple Sclerosis (CDMS)(as defined by a second, clinically verifiable attack involving another part of the central nervous system) over 2 years of observation and significantly decreased the development of new or enlarging white matter lesions on MRI over 18 months (see reference). The current study is a long term extension of a cohort of CHAMPS study site and participants. The three main aims of the study are as follows: 1. To determine the long term neurological outcome in patients treated with interferon beta 1a (AVONEX) from onset of a first clinical demyelinating event 2. To determine if immediate initiation of AVONEX therapy (the CHAMPS Avonex treatment group) confers long term benefits compared to delayed initiation of therapy (the CHAMPS placebo group) on the rate of development of CDMS, annualized relapse rates, the development of permanent disability and MR measures of disease activity and progression. 3. To determine predictors of long term disease activity and disability in patients following a first clinical demyelinating event