Tolerability, treatment satisfaction and quality of life outcomes in stable multiple sclerosis patients switched from injectable therapies to auto injected intramuscular interferon beta 1a: The SFERA study.

Background: Interferon beta (IFNB) and Glatiramer acetate, long-term first line disease modifying treatments (DMTs) for multiple sclerosis (MS), have different injection frequencies crucial for injection site related side effects. We aimed at investigating whether switching to intramuscular IFNB-1a injected once/week with the Avonex®Pen™ device improves treatment tolerability and quality of life in stable MS patients.

Methods: Clinically stable MS patients, whom their treating neurologist switched from high frequency injectable DMTs to weekly intramuscular IFNB-1a because of bothersome injection site reactions, were included. Injection site and systemic tolerability were measured by a composite 100 mm visual analogue scale at screening, months 4 and 12. Treatment satisfaction, quality of life, relapses and EDSS progression were also recorded. The primary endpoint was change in injection site tolerability from screening to Month 4. Descriptive statistics and Wilcoxon paired signed-rank tests were applied.

Results: The median injection site tolerability and systemic tolerability were significantly improved at months 4 (n = 36) and 12 (n = 33) [change -51.60 (IQR: -60.13, -39.60) mm (p < 0.0001); -26.00 (-54.00, 2.25) mm (p = 0.002)]. Median treatment satisfaction was significantly improved at month 12 [change of 18.00 (2.00, 47.50) mm (p = 0.0003)]. Physical and mental components of the SF-36 did not change significantly, and 30/33 (90.9%) and 33/33 (100%) patients were free from relapses and EDSS progression at month 12.

Conclusions: Weekly intramuscular IFNB-1a may represent an alternative treatment option for clinically stable MS patients suffering from intolerable injection-related side effects under treatment with high frequency injectable DMTs.