Interferon Beta
Type I interferon for multiple sclerosis that reduces relapse rate through immunomodulatory and anti-inflammatory mechanisms.
Chemical Identity
| Property | Value |
|---|---|
| Molecular Weight | ~22.5 kDa |
| Amino Acids | 166 |
| Gene | IFNB1 |
| Receptor | IFNAR1/IFNAR2 |
| Route | SC, IM |
Structure
Interferon beta (IFN-beta) is a 166-amino acid type I interferon with one disulfide bond and one N-glycosylation site. Two forms are available: IFN-beta-1a (glycosylated, produced in CHO cells) and IFN-beta-1b (non-glycosylated, produced in E. coli). Both bind the same receptor.
Mechanism of Action
IFN-beta activates IFNAR1/IFNAR2, inducing anti-inflammatory ISGs and shifting the immune response from Th1 to Th2. It reduces T-cell migration across the blood-brain barrier (via MMP-9 inhibition), decreases MHC class II expression on antigen-presenting cells, and promotes regulatory T-cell function.
Clinical Applications
- Relapsing-remitting MS: First-line disease-modifying therapy
- Clinically isolated syndrome: Delaying conversion to definite MS
- Secondary progressive MS: Slowing disability progression
- Forms: IFN-beta-1a (Avonex, Rebif), IFN-beta-1b (Betaseron, Extavia)
Pharmacokinetics
- Half-life: 10 hours (IFN-beta-1a IM), 4 hours (SC)
- Bioavailability: 40-50% (SC)
- Frequency: Weekly (Avonex), 3x/week (Rebif), every other day (Betaseron)
- Route: IM, SC
Safety and Side Effects
Flu-like symptoms (60%), injection site reactions (30-85%), depression, hepatotoxicity, and neutralizing antibodies (reduced efficacy over time). Rotating injection sites recommended.
References
- The IFNB Multiple Sclerosis Study Group (1993). Interferon beta-1b for MS. Neurology, 43, 655-661.
- Jacobs, L.D., et al. (1996). Intramuscular interferon beta-1a for MS. Annals of Neurology, 39, 285-294.
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