Patients transitioning from non-pegylated to pegylated interferon beta-1a have a low risk of new flu-like symptoms: ALLOW phase 3b trial results.

Background: Flu-like symptoms are common adverse events associated with interferon beta relapsing multiple sclerosis therapies.

Objectives: To evaluate the incidence and severity of flu-like symptoms after transitioning from non-pegylated interferons to peginterferon beta-1a and assess flu-like symptom mitigation using naproxen.

Methods: ALLOW was a phase 3b open-label study in relapsing multiple sclerosis patients.