The prevalence of injection-site reactions with disease-modifying therapies and their effect on adherence in patients with multiple sclerosis: an observational study.

BACKGROUND: Interferon beta (IFNß) and glatiramer acetate (GA) are administered by subcutaneous (SC) or intramuscular (IM) injection. Patients with multiple sclerosis (MS) often report injection-site reactions (ISRs) as a reason for noncompliance or switching therapies. The aim of this study was to compare the proportion of patients on different formulations of IFNß or GA who experienced ISRs and who switched or discontinued therapy because of ISRs. METHODS: The Swiss MS Skin Project was an observational multicenter study. Patients with MS or clinically isolated syndrome who were on the same therapy for at least 2 years were enrolled. A skin examination was conducted at the first study visit and 1 year later. RESULTS: The 412 patients enrolled were on 1 of 4 disease-modifying therapies for at least 2 years: IM IFNß-1a (n = 82), SC IFNß-1b (n = 123), SC IFNß-1a (n = 184), or SC GA (n = 23). At first evaluation, ISRs were reported by fewer patients on IM IFNß-1a (13.4%) than on SC IFNß-1b (57.7%; P < 0.0001), SC IFNß-1a (67.9%; P < 0.0001), or SC GA (30.4%; P = not significant [NS]). No patient on IM IFNß-1a missed a dose in the previous 4 weeks because of ISRs, compared with 5.7% of patients on SC IFNß-1b (P = 0.044), 7.1% of patients on SC IFNß-1a (P = 0.011), and 4.3% of patients on SC GA (P = NS). Primary reasons for discontinuing or switching therapy were ISRs or lack of efficacy. Similar patterns were observed at 1 year. CONCLUSIONS: Patients on IM IFNß-1a had fewer ISRs and were less likely to switch therapies than patients on other therapies. This study may have implications in selecting initial therapy or, for patients considering switching or discontinuing therapy because of ISRs, selecting an alternative option.

Natalizumab reduces clinical and MRI activity in multiple sclerosis patients with high disease activity: results from a multicenter study in Switzerland.

BACKGROUND: Natalizumab has been recommended for the treatment of relapsing-remitting multiple sclerosis (RRMS) in patients with insufficient response to interferon-beta or glatiramer acetate (disease-modifying treatments-DMT) or in aggressive MS. The pivotal trials were not designed to investigate natalizumab monotherapy in these patient populations. AIM: To investigate the efficacy of natalizumab after treatment failure of previous DMT and in highly active MS. METHODS: A retrospective, multicenter study in Switzerland. Three major MS centers reported all RRMS patients who initiated natalizumab>or=12 months prior to study conduction. RESULTS: 85 RRMS patients were included (72% female, mean age 37.3 years, mean Expanded Disability Status Scale 3.1; 88.2% were pretreated with DMT), and mean treatment duration with natalizumab was 18.4+/-2.6 months. 79% of the patients were relapse-free during the observational period. The annualized relapse rate decreased from 2.0+/-0.6 to 0.27+/-0.2, and 92.9% were progression-free after 12 months (p<0.001). The mean number of gadolinium-enhancing lesions decreased from 1.2+/-1.2 to 0.1+/-0.1 at 12 months' follow-up (91.7% reduction).Discontinuation rate was 11.8% (7.1% for antibody positivity). CONCLUSIONS: Patients who initiate natalizumab after previous high disease activity experience a marked reduction of clinical and MRI disease activity.