Table 1

Characteristics of the trials included

Study, publication year, countries (No of centres)InterventionsNo of randomised patientsInclusion criteriaAccrual periodFollow-up duration (months)Sponsor
European SG,18 1998, Europe (32)IFNβ-1b (Betaferon) 250 μg subcutaneously every other day360
  • Age 18–55 years, EDSS 3.0–6.5

  • SPMS defined as deterioration independent of relapses, sustained for at least 6 months, following initial RR course, with or without superimposed exacerbations, with either at least two relapses or at least 1 point increase in EDSS over previous 2 years

September 1994–March 199836Schering AG, Berlin, Germany
Placebo358
SPECTRIMS,19 2001, Europe, Canada and Australia (22)IFNβ-1a (Rebif) 22 μg subcutaneously 3 times/week209
  • Age 18–55 years; EDSS 3.0–6.5; pyramidal function score of at least 2.

  • SPMS defined as deterioration for at least 6 months, following initial RR course, with or without superimposed exacerbations, with at least 1 point increase in EDSS over previous 2 years (or 0.5 points between EDSS score of 6.0 and 6.5)

Not reported36Serono International SA, Geneva, Switzerland
IFNβ1a (Rebif) 44 μg subcutaneously, 3 times/week204
Placebo205
IMPACT,20 2002, US (31), Canada (4), Europe (7)IFNβ-1a (Avonex) 60 μg intramuscular injections weekly217
  • Age 18–60 years, EDSS score 3.0–6.5

  • SPMS defined as deterioration over previous year; with or without superimposed exacerbations

March 1998–September 199824Biogen Idec, Inc., Cambridge, MA, USA,
Placebo219
Nordic,21 2004, Denmark (4), Finland (6), Norway (12), Sweden (10)IFNβ-1a (Rebif) 22 μg subcutaneously weekly188
  • Age 18–65 years, EDSS <7.0

  • SPMS defined as deterioration for at least 6 months, following initial RR course, with or without superimposed exacerbations, with at least 1 point increase in EDSS over previous 4 years

Not reported36Serono International SA, Geneva, Switzerland
Placebo183
North America SG,22 2004, USA (31), Canada (4)IFNβ-1b (Betaferon) 250 μg subcutaneously every other day317
  • Age 18–65 years, EDSS 3.0–6.5

  • History of MS of at least 2 years' duration.

  • SPMS defined as deterioration sustained for at least 6 months, following at least one relapse, with at least 1 point increase in EDSS over previous 2 years.

August 1995–August 199936Berlex Laboratories, Montville, NJ, USA
IFNβ-1b (Betaferon) 160 μg/m2 body surface area (mean administered dose 220 μg) every other day314
Placebo308
  • EDSS, Expanded Disability Status Scale; IFNβ, interferon β; RR, relapsing remitting; SPMS, secondary progressive multiple sclerosis.