Betaseron (interferon beta 1b)
Drug identification number (DIN): 02169649
Bayer Inc.

Betaseron (interferon beta-1b) is a beta-interferon that is produced from bacterial cells using recombinant DNA techniques (a series of procedures used to join together DNA segments). Beta-interferon is a protein that occurs naturally in the human body in response to initiating factors such as viruses.

Indications and use

Betaseron is indicated for the treatment of:

  1. people with relapsing-remitting MS who are ambulatory (able to walk) to reduce the frequency of attacks.
  2. people with secondary-progressive MS (with relapses) to slow the progression of disability and to reduce the frequency of MS attacks.
  3. people at risk of developing clinically definite MS (CDMS) accompanied by at least two lesions on MRI to delay the progression to clinically definite MS. Before Betaseron is initiated, alternative diagnoses must be ruled out.

    Betaseron is contraindicated in; people with a history of hypersensitivity to natural or recombinant interferon beta, albumin human or to any other ingredient in the formulation, pregnant women and people with decompensated liver disease.

Administration and dose

Betaseron is self-injected every other day under the skin (subcutaneously). Betaseron is available in a diluent (diluting agent) pre-filled syringe. The syringes are pre-filled with a salt-water solution to mix with the active medication, which is in a powder form. The recommended dose of Betaseron is 250 mcg every other day.

Mechanism of action (MOA)

The main effects of Betaseron are to block the activity of certain immune system cells and to reduce the passage of these immune cells into the central nervous system, where they cause inflammation and damage to myelin (the insulating material that protects nerves and helps them work properly).

Side effects*

The most common side effects of Betaseron therapy include flu-like symptoms (fatigue, chills, fever, muscle aches, and sweating) and injection site reactions (swelling, redness, discolouration, and pain). Most of these symptoms tend to improve over time.

This is not a comprehensive list of all possible side effects of Betaseron. Please see the Betaseron product monograph for a list of other potentially serious side effects.It is important that those with MS discuss side effects about any medication they are considering with their physician. (*Health Canada, product monograph for Betaseron.)

Neutralizing antibodies

Some people taking a beta-interferon therapy develop neutralizing anti- bodies (NAb). It is not known if NAbs completely “neutralize” the clinical benefits of therapy. Some research has found that a higher NAb level may be associated with a lesser treatment effect. Studies are continuing in this area, as is the development of a standardized NAb test.

Clinical trials

Clinical Trials in Relapsing-Remitting MS

Interferon Beta Multiple Sclerosis Study Group
In this clinical trial, 372 people with relapsing-remitting MS received Betaseron at a dose of either 1.6 MIU or 8 MIU, or placebo (a treatment that has no active medication) for 2 years. Compared to placebo, Betaseron reduced the annual attack rate by about 30%.1 Betaseron also reduced disease activity, as measured by magnetic resonance imaging (MRI), by 80% compared to placebo.2 MRI is a powerful tool that provides images of the brain, spinal cord, or other areas of the body. It is often used in MS to identify areas of inflammation.

Clinical Trials in Secondary-Progressive MS

European Study in Secondary-Progressive MS
In this study, 718 people with secondary-progressive MS received either Betaseron or placebo for up to 3 years. Compared to placebo, Betaseron delayed progression of disability for 9-12 months. Betaseron also reduced the attack rate by 31%.3 In another analysis, MRI scans showed that Betaseron reduced the number of new lesions compared to placebo.4 [Miller et al. Ann Neurol 1999; 46: 850–859]
The final analysis (mean 35 month follow-up) of this study confirmed the benefits of Betaseron over placebo with respect to progression and relapses.5 [Kappos et al. Neurology 2001; 57: 1969-1975]

North American Study in Secondary-Progressive MS
The North American study of Betaseron involved 939 individuals with secondary-progressive MS. In this trial, treatment with Betaseron failed to show a significant difference in the time to progression compared to placebo, although there were improvements in relapses and MRI brain lesions.6

Clinical Trials: Single Event Suggestive of MS

BENEFIT trial: Betaferon in Newly Emerging Multiple Sclerosis for Initial Treatment
This study examined whether Betaseron could reduce conversion to clinically definite MS in people who had a first clinical event suggestive of MS (an event involving the optic nerve, brain stem/cerebellum, or spinal cord) and at least two clinically silent brain lesions on MRI. A total of 468 were treated with Betaseron or placebo for up to 2 years. The probability of developing clinically definite MS over 2 years was 45% with placebo compared to 28% with Betaseron, for an absolute risk reduction of 17% and a relative risk reduction of 38%.7

Cost reimbursement

The price of Betaseron is approximately $20,000 per year. Much of the cost can be reimbursed through private and group health plans for people who meet the prescribing criteria, and through provincial drug programs for individuals who meet the prescribing criteria.

Drug support program

Betaplus at 1-800 977-2770. Please discuss any other questions about treatment options with your physician.


  1. The IFNB Multiple Sclerosis Study Group. Interferon beta-1b is effective in relapsing-remitting multiple sclerosis. I. Clinical results of a multicenter, randomized, double-blind, placebo-controlled trial. Neurology 1993; 43: 641-643.
  2. Paty DW, Li DK. Interferon beta-1b is effective in relapsing-remitting multiple sclerosis. II. MRI analysis results of a multicenter, randomized, double-blind, placebo-controlled trial. UBC MS/MRI Study Group and the IFNB Multiple Sclerosis Study Group. Neurology 1993; 43: 662-667.
  3. European Study Group on Interferon Beta-1b in Secondary-Progressive MS. Placebo-controlled multicentre randomised trial of interferon beta-1b in treatment of secondary-progressive multiple sclerosis. Lancet 1998; 352: 1491-1497.
  4. Miller DH, Molyneux PD, Barker GJ, et al. Effect of interferon-beta1b on magnetic resonance imaging outcomes in secondary progressive multiple sclerosis: results of a European multicenter, randomized, double-blind, placebo-controlled trial. Ann Neurol 1999; 46: 850–859.
  5. Kappos L, Polman C, Pozzilli C, et al. Final analysis of the European multicenter trial on IFNbeta-1b in secondary-progressive MS. Neurology 2001; 57: 1969-1975.
  6. North American Study Group on Interferon Beta-1b in Secondary Progressive MS. Interferon beta-1b in secondary progressive MS: results from a 3-year controlled study. Neurology 2004; 63: 1788-1795
  7. Kappos L, Polman CH, Freedman MS, et al. Treatment with interferon beta-1b delays conversion to clinically definite and McDonald MS in patients with clinical isolated syndromes. Neurology 2006; 67: 1242-1249.

Betaseron® is a registered trademark of Bayer Inc.