Rebif® (interferon beta-1a)

Parent company: EMD Serono, Inc. and Pfizer Inc

• Administered by subcutaneous injection three times weekly; dosage is 22 or 44 mcg. The 44 mcg dose appears significantly more effective than 22 mcg, and 44 mcg is the dose most often used in the United States.
  
  
• Approved for relapsing types of MS. Rebif reduces the frequency of relapses and slows the progression of disability. It has also been shown to reduce MRI lesion area and activity compared to placebo.
  
  
• Interferons appear to reduce inflammation by modulating a favorable balance between cells that increase inflammation and cells that decrease inflammation. They also prevent the transport of damaging lymphocytes into the brain. Lymphocytes are immune-system cells produced to fight infection and disease.
  
  
• The REFLEX study of 517 patients is comparing the efficacy of two dosing frequencies (once or three times per week) of Rebif versus placebo. The effect studied is the conversion to definite MS in patients with clinically isolated syndrome (CIS), which is also referred to as a "first demyelinating event." The primary endpoint was the time to confirmed MS using the McDonald criteria, which is a set of guidelines used to confirm a diagnosis ofMS. The secondary endpoint was time to clinically definiteMS (CDMS). Rebif significantly delayed development ofMS as compared with placebo. This conversion was more pronounced with the higher dose (44 mcg three times weekly).
  
  
• The Phase IV SKORE study continues to evaluate cognition and fatigue in people with RRMS treated with Rebif. Its primary outcome measure is the percentage of patients with stable or altered cognition status; secondary outcome measures include the proportion of relapse-free subjects and the proportion with defined EDSS changes. "EDSS" refers to the Kurtzke Expanded Disability Status Scale, which uses numbers from one to 10 to measure degree of disability, largely in terms of mobility. The study has 300 participants; it was initiated in June 2009 and is scheduled for completion in November 2013.
  
  
• A Phase IV observational study is ongoing but is not recruiting participants. It is evaluating the effectiveness of Rebif therapy on quality of life, using two health-related, quality-of-life measures.
  
  
• A multi-center, observational, 96-week Phase IV study is evaluating whether the use of the RebiSmart™ self-injection system improves compliance with Rebif in subjects with relapsing forms of multiple sclerosis.

A German study looked at the effects of interferons and Copaxone on pregnancy and relapse rate. This study re-confirmed the reduced MS relapse rate during pregnancy and the increased relapse rate after birth. Exclusive breastfeeding seemed to have beneficial effects on postpartum relapse-rate reduction. While these data also support previous findings that the interferons and Copaxone do not present a major risk for birth defects, anyone who is pregnant or plans on becoming pregnant should discuss the risks and the benefits with her doctor before starting or continuing any disease-modifying therapy.