Table 5Interferon beta-1b and 1a compared with placebo: Efficacy measures

Outcome measureInterferon beta-1b SC (Betaseron®)Interferon beta-1a IM (Avonex®)Interferon beta-1a SC (Rebif®) 44 μg
Disability progression
 Progressed at 2 yrs RR (95% CI) vs. placebo, NNT Absolute risk, %0.73 (0.46 to 1.15) 20.2% vs. 27.6%0.56 (0.33 to 0.97), NNT 12
11.4% vs. 20.3%
0.73 (0.54 to 0.99), NNT 11b
26.6% vs. 36.4%
 Difference in mean change in EDSS vs. placebo (95% CI)−0.28 (−0.64 to +0.08)--−0.24 (−0.48 to +0.00)b
Relapses
 Patients with ≥ 1 relapse at 2 yrsa RR (95% CI) vs. placebo, NNT Absolute risk, %0.83 (0.71 to 0.98), NNT 8
63.7% vs. 76.4%
0.75 (0.56 to 1.00), NNT 9
33.5% vs. 44.8%
0.81 (0.72 to 0.91), NNT 7b
67.9% vs. 84.0%
 Annualized/mean relapse rate, P value0.96 1.6 MIU vs. 1.12, P=0.0057
0.78 8 MIU vs.1.12, P=0.0006
0.61 vs. 0.90, P=0.0021.82
22 mcg 3/wk vs. 2.56 P<0.05 b
1.73 44 mcg 3/wk vs. 2.56, P<0.05 b
1.08 22 mcg vs. 1.08, NSc
0.87 44 mcg vs. 1.08, P=0.0069c

Abbreviations: EDSS, Expanded Disability Status Scale; IM, intramuscular; MIU, NNT, number needed to treat; NS, not significant; SC, subcutaneous; wk, week; yr, year.

a

Inverse of % relapse-free.

b

PRISMS trial data, 2 years.

c

OWIMS trial data, 48 weeks.

From: Results

Cover of Drug Class Review: Disease-modifying Drugs for Multiple Sclerosis
Drug Class Review: Disease-modifying Drugs for Multiple Sclerosis: Final Update 1 Report [Internet].
Smith B, Carson S, Fu R, et al.
Portland (OR): Oregon Health & Science University; 2010 Aug.
Copyright © 2010 by Oregon Health & Science University, Portland, Oregon 97239. All rights reserved.

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