Influence of interferon-beta therapy switching on neutralizing antibody titres: results from the Austrian Switch Study

Neutralizing antibodies against interferon-beta are associated with a reduction of the efficacy of this drug. Continuing treatment leads to a decline or even loss of neutralizing antibodies over years. No strategies are currently available to shorten the period of neutralizing antibody positivity. The objective of this study was to investigate the effect of switching between high and low immunogenic interferon-beta products on neutralising antibody titres. Twenty-four patients treated with the subcutaneously administered interferon-beta 1b or 1a and high titres of neutralizing antibodies were included. At baseline interferon-beta therapy was interrupted for 3 months and two pulses of high dose methylprednisolone were applied. Patients were then randomized to receive either the previous interferon-beta preparation or the low immunogenic intramuscular interferon-beta 1a. The primary end-point was the change of neutralizing antibody titres 12 months after randomization. Twelve patients were switched to interferon-beta 1a intramuscularly and 12 patients remained on previous treatment. Median neutralizing antibody titres were 846 NU at baseline and 196 NU at the end of the study. The median change of neutralizing antibody titres did not differ significantly between therapy switchers and non-switchers. Baseline and final neutralizing antibody titres correlated significantly. In conclusion, neither switching nor continuous therapy with any subcutaneous interferon-beta preparation significantly changed neutralizing antibody titres.

Both paracetamol and ibuprofen are equally effective in managing flu-like symptoms in relapsing-remitting multiple sclerosis patients during interferon beta-1a (AVONEX) therapy

Interferon beta-1a is an established therapy for patients with relapsing-remitting multiple sclerosis (MS). Adverse effects in the first weeks of treatment are common. This open-label, multicenter, randomized, prospective study compared treatment of flu-like symptoms (FLS) with paracetamol versus ibuprofen administered 48 h within interferon injection. The percentage of patients with FLS was comparable between both treatment groups and improved during the course of the study (baseline: paracetamol 92%, ibuprofen 90%; week 12: paracetamol 60%, ibuprofen 57%). More than 75% of patients receiving either paracetamol or ibuprofen reported no or only mild impairment of daily activities. There was no significant difference in general satisfaction or incidence of additional symptoms (weakness, nausea, headache; paracetamol 84.6% patients, ibuprofen 86.0% patients) between the two groups. A significant overall improvement from baseline to week 12 was observed for all parameters studied (paracetamol and ibuprofen groups were pooled). These results indicate that neither the paracetamol nor the ibuprofen treatment regimen is better.