Autoinjector Ease-of-Use in Patients with Multiple Sclerosis Treated with Interferon ß-1a Subcutaneously: Preliminary Data from REDEFINE

Background: Various injection devices exist for patients with multiple sclerosis (MS) to self-inject disease-modifying drugs, but information regarding the appeal of different devices is limited. For patients taking interferon beta-1a subcutaneously three times weekly (IFN β-1a SC tiw), options include a pre-assembled, single-use autoinjector and a reusable autoinjector with an adjustable injection-depth feature.

Objectives: To compare subject-assessed relative ease-of-use of two autoinjectors for administration of IFN β-1a SC tiw in preliminary results from a crossover study.

Methods: A Phase IV, randomized, prospective, US-based, multicenter study assigned patients with MS, who had been using IFN β-1a 44 µg SC tiw by manual injection for ≥12 weeks, in a crossover design: 4 weeks using a single-use autoinjector, then 4 weeks using a reusable autoinjector in one sequence, and vice versa in the other sequence. The primary endpoint is the proportion of patients rating each device as ‘easy’ or ‘very easy’ following the 4 weeks using each device. Additional endpoints include responses to other ease-of-use questions, and quality of life (as per the MusiQoL [© MusiQoL 2008]¹).

Results: Preliminary data, as of November 9, 2015, were available from 60 subjects: 28 randomized to use the single-use autoinjector followed by the reusable autoinjector and 32 to the opposite order. The respective groups were 82.1% and 53.1% female. Disability level (per questionnaire) was similar between groups: overall, 26.7% had no disability while 20.0% had a moderate level. In total, 74.5% found the reusable autoinjector easy or very easy to use, while 64.7% felt this way regarding the single-use autoinjector (p=0.3125); 45.1% felt both were easy or very easy to use. 7.8% and 9.8% found the reusable and single-use autoinjector difficult or very difficult to use, respectively. 84.3% of patients felt that both devices completed injections in a satisfactory amount of time, and 80.4% felt both required a satisfactory number of steps. 60.8% and 94.1% found storage of the single-use and reusable autoinjectors, respectively, to be convenient (p<0.001). Two MusiQoL dimensions (symptoms [Spearman’s correlation 0.3279; p=0.0155] and coping [0.2750; p=0.0484]) were correlated with ease-of-use after 4 weeks, but not 8 weeks.

Conclusions: This study’s preliminary results suggest potential differences in satisfaction regarding aspects of the two autoinjectors. Most patients found neither to be difficult to use.

Reference: 1. Simeoni M, et al. Mult Scler 2008;14:219-30.