Table 1.

Interferon beta therapies FDA approved for treatment of relapsing-remitting multiple sclerosis8–12

Drug	Trade name	Year of FDA approval	Route of administration	Dosing	Frequency	Pharmacokinetics
Interferon beta-1b	Betaseron	1993	Subcutaneous	0.25 mg	Every other day	t½: 5 h Tmax: 1–8 h
Interferon beta-1b	Extavia	1993	Subcutaneous	0.25 mg	Every other day	t½: 5 h Tmax : 1–8 h
Interferon beta-1a	Avonex	1996	Intramuscular	30 μg	Once weekly	t½: 10 h Tmax: 5–15 h
Interferon beta-1a	Rebif	2002	Subcutaneous	22 or 44 μg	3 times weekly	t½: 50–60 h Tmax: 8 h
Peginterferon beta-1a	Plegridy	2014	Subcutaneous	125 μg	Once every 2 wk	t½: mean ± SD 78 ± 15 h T max: 1–1.5 d

Abbreviations: FDA, US Food and Drug Administration; t_½, half-life; T_max, time to maximum concentration.