Rationale and design of theprospective and retrospectiveobservational study of Avonexand Rebif (PROOF) for thetreatment of relapsing-remittingmultiple sclerosis

Abstract

SUMMARYPrevious studies comparing the two available interferon beta (IFNβ)-1a products, Avonex and Rebif, for the treatment of relapsing-remitting multiple sclerosis (RRMS) have been limited and of short duration. Therefore, the Prospective and Retrospective Observational Study of Avonex and Rebif (PROOF) was designed to provide long-term (up to 5 years) comparative data on the efficacy, safety, and tolerability of these two agents. Patients with RRMS receiving treatment with either Avonex 30 μg intramuscularly once weekly or Rebift 44 μg subcutaneously three times weekly from 12 to 24 months are being enrolled and will continue their respective treatments for the 36-month duration of the study. The primary efficacy endpoint will be change in brain parenchymal fraction, which will be evaluated through magnetic resonance imaging scans by blinded radiologists. Secondary endpoints will include the following: relapse rates; intravenous steroid use; the proportion of patients with an increase of >1 point on the Expanded Disability Status Scale (EDSS) and with an increase in EDSS score sustained for 6 months; mean change in EDSS score; cumulative number of new or enlarging T2 lesions; T2 and T1 lesion volumes; gadolinium-enhanced lesion number and volume; and safety and tolerability. The study design of PROOF will permit more meaningful conclusions regarding the optimal IFNβ-1 a product for the long-term treatment of patients with multiple sclerosis.* Avonex is a registered trade name of Biogen, Inc., Cambridge, MA, USA