title: Intramuscular interferon beta-1a therapy initiated during a first demyelinating event in multiple sclerosis. Jacobs LD,*(1) Beck RW, Simon JH, Kinkel RP, Brownscheidle CM, Murray TJ, Simonian NA, Slasor PJ, Sandrock AW, and the CHAMPS Study Group. N Engl J Med 2000;343:898-904.