Proven effective

Treatment goals

Rebif® (interferon beta-1a) is the only self-injected relapsing MS therapy proven to achieve 3 key treatment goals in relapsing MS.

The 2-year PRISMS* study study included 560 people to see how they responded to Rebif 22 mcg or Rebif 44 mcg versus placebo, all given under the skin 3 times a week.

Slows disability progression
Rebif 44 mcg was proven to nearly double the time to disability progression (21.3 months with Rebif vs 11.9 months with placebo).
Reduces relapse rates
Rebif 44 mcg was shown to reduce the frequency of relapses on average by 32% versus placebo (1.73 with Rebif vs 2.56 with placebo).
Reduces active brain lesions on the studied MRI measures†‡
Rebif 44 mcg was proven to reduce the median number of T2 active lesions per patient per scan by 78% versus placebo over 2 years (0.5 with Rebif vs 2.25 with placebo).

The exact correlation between MRI findings and the current or future clinical status of patients, including disability progression, is unknown.

Learn more about the PRISMS study.

Please see important safety information below and the Rebif Medication Guide and Prescribing Information in the top of this website, and speak with your health care provider for more information.

Head-to-head study

Rebif is the only relapsing MS treatment proven to work better than another in a class I clinical trial.§

This was shown in the EVIDENCE** study, which was a head-to-head trial that compared Rebif with Avonex® (interferon beta-1a) over an average of 64 weeks. Rebif 44 mcg was given to 339 people 3 times per week, at least 48 hours apart just under the skin. Avonex 30 mcg was given to 338 people once per week into the muscle.

in the EVIDENCE study, Rebif was proven to work better than Avonex in
reducing relapses and the development of brain lesions as seen on MRI.

The exact correlation between MRI findings and the current or future clinical status of patients, including disability progression, is unknown.

Learn more about the EVIDENCE study.

In the EVIDENCE study, those taking Rebif had similar side effects to those taking Avonex

Similar side effects

Compared with Avonex, side effects were generally similar with Rebif despite the higher, more frequent dosing of Rebif.

Differences included:

  • People taking Avonex had more flu-like symptoms than those taking Rebif.
  • People taking Rebif had a greater number of injection-site reactions, elevated liver enzymes, and decreased white blood cell counts.

In addition, the number of people who dropped out of the study because of adverse events was 5% with Rebif and 3% with Avonex.

Injection-site reactions and flu-like symptoms (fever, chills, sweating, muscle aches, and tiredness) are common side effects with Rebif. But there are things you can do that might help with them.

Your health care provider can help you monitor and manage side effects or adverse events if they occur.

*Prevention of Relapses and Disability by Interferon beta-1a Subcutaneously in Multiple Sclerosis.

†Refers to new lesions and total lesion burden or area as defined in the AAN and MS Council guidelines.

‡New or enlarging lesions detected with PD/T2-weighted MRI.

§According to the American Academy of Neurology, data from class I studies are collected under the highest scientific standards and are thought to be the most valid.

**EVidence for Interferon Dose-response: European North American Comparative Efficacy

Ron B.
MS LifeLines Ambassador, living with relapsing MS

Rebif infokit