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Interferon beta-1a (Rebif)

Merck KGaA, Darmstadt, Germany · FDA-approved active Small molecule ✓ Verified May 2026

Interferon beta-1a (Rebif) is a Interferon beta Small molecule drug developed by Merck KGaA, Darmstadt, Germany. It is currently FDA-approved for Relapsing-remitting multiple sclerosis, Clinically isolated syndrome with MRI features consistent with multiple sclerosis. Also known as: Rebif New Formulation, Rebif.

Interferon beta-1a activates interferon signaling pathways to modulate immune responses and reduce inflammatory activity in the central nervous system.

Interferon beta-1a (Rebif) is used to treat multiple sclerosis, specifically relapsing-remitting multiple sclerosis. It is administered as part of a treatment regimen that includes the use of RebiSmart, a device designed to improve treatment adherence.

At a glance

Generic nameInterferon beta-1a (Rebif)
Also known asRebif New Formulation, Rebif
SponsorMerck KGaA, Darmstadt, Germany
Drug classInterferon beta
TargetInterferon-beta receptor (IFNAR)
ModalitySmall molecule
Therapeutic areaImmunology / Neurology
PhaseFDA-approved

Mechanism of action

Interferon beta-1a binds to interferon-beta receptors on immune cells and oligodendrocytes, triggering JAK-STAT signaling that increases expression of anti-inflammatory genes and reduces pro-inflammatory cytokine production. This leads to decreased migration of immune cells across the blood-brain barrier and reduced demyelination in multiple sclerosis. The drug also enhances natural killer cell activity and promotes a shift toward a more regulatory immune phenotype.

Approved indications

Common side effects

Key clinical trials

Primary sources

Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.

SourceUsed for
ClinicalTrials.govTrial enrolment, design, endpoints, results

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Frequently asked questions about Interferon beta-1a (Rebif)

What is Interferon beta-1a (Rebif)?

Interferon beta-1a (Rebif) is a Interferon beta drug developed by Merck KGaA, Darmstadt, Germany, indicated for Relapsing-remitting multiple sclerosis, Clinically isolated syndrome with MRI features consistent with multiple sclerosis.

How does Interferon beta-1a (Rebif) work?

Interferon beta-1a activates interferon signaling pathways to modulate immune responses and reduce inflammatory activity in the central nervous system.

What is Interferon beta-1a (Rebif) used for?

Interferon beta-1a (Rebif) is indicated for Relapsing-remitting multiple sclerosis, Clinically isolated syndrome with MRI features consistent with multiple sclerosis.

Who makes Interferon beta-1a (Rebif)?

Interferon beta-1a (Rebif) is developed and marketed by Merck KGaA, Darmstadt, Germany (see full Merck KGaA, Darmstadt, Germany pipeline at /company/merck-kgaa-darmstadt-germany).

Is Interferon beta-1a (Rebif) also known as anything else?

Interferon beta-1a (Rebif) is also known as Rebif New Formulation, Rebif.

What drug class is Interferon beta-1a (Rebif) in?

Interferon beta-1a (Rebif) belongs to the Interferon beta class. See all Interferon beta drugs at /class/interferon-beta.

What development phase is Interferon beta-1a (Rebif) in?

Interferon beta-1a (Rebif) is FDA-approved (marketed).

What are the side effects of Interferon beta-1a (Rebif)?

Common side effects of Interferon beta-1a (Rebif) include Injection site reactions, Flu-like symptoms (fever, chills, myalgia), Headache, Fatigue, Depression, Elevated liver enzymes.

What does Interferon beta-1a (Rebif) target?

Interferon beta-1a (Rebif) targets Interferon-beta receptor (IFNAR) and is a Interferon beta.

Related

Primary sources · FDA · ClinicalTrials.gov · EMA · SEC EDGAR · ChEMBL · Wikidata · full sourcing