Autoinjector Ease-of-Use in Patients with MS Treated with Interferon Beta-1a Subcutaneously: Redefine Study Design

Background: In the use of injectable disease-modifying drugs, such as interferon beta-1a given subcutaneously (IFN β-1a SC), for the treatment of relapsing-remitting multiple sclerosis (RRMS), limited information is available about which device characteristics may make a particular device more desirable for self injection.

Objectives: The REDEFINE (REbif^® Rebidose^® vs. Rebiject II™ autoinjector trial DEFINing patient reported Ease-of-use) study is a crossover study designed to advance scientific knowledge of the Rebif  Rebidose and Rebiject II injection devices and demonstrate association between device characteristics and ease-of-use. The primary objective is to compare relative patient-assessed ease-of-use in a study of the two devices. Secondary objectives include patient rating of convenience of using the devices, overall satisfaction with the injection devices and level of convenience and satisfaction when traveling. The proportion of patients scoring each device as very difficult, difficult, neither easy nor difficult, easy, or very easy to use will be recorded. Changes in patient-reported quality of life (QoL) will also be measured.

Methods: Ninety (45 per study arm) male and female patients with RRMS, aged 18–65 years with experience using a manual injection technique are anticipated to be recruited over approximately 15 sites in the US. Consenting patients will undergo screening and baseline data collection. Patients will receive training to perform a total of 24 injections over the 8-week treatment period in a crossover design (12 injections via Rebif Rebidose in the first 4 weeks, crossing over to 12 injections via Rebiject II in the second 4 weeks in one study sequence and vice versa in the other study sequence). A User Trial Questionnaire will be completed by patients at the end of Weeks 4 and 8, and will include the assessment of ease-of-use. Patient-reported QoL will be assessed at Study Day 1 and at the end of Weeks 4 and 8, using the MS International QoL questionnaire. Preplanned subgroup analysis will be performed. Adverse events will also be recorded.

Results: The results are expected to increase understanding of which device characteristics are associated with ease-of-use and satisfaction with the Rebif Rebidose and Rebiject II devices.

Conclusions: Results may assist healthcare providers in determining the most suitable device for their patients for the injection of IFN β-1a SC.