Switch to rituximab shows anti-inflammatory effect in relapsing–remitting MS
medwireNews: Rituximab may be an attractive treatment option for patients with relapsing–remitting multiple sclerosis (MS), suggest phase II study findings showing its efficacy in controlling inflammatory activity.
“We provide Class IV evidence for equal or superior inflammatory control measured by MRI [magnetic resonance imaging] parameters and CSF-NFL [cerebrospinal fluid neurofilament light chain] during the first year when rituximab was used as an alternative to first-line injectable therapies in a realistic, real-life setting”, say the researchers.
The drug, an anti-CD20 monoclonal antibody that depletes B lymphocytes, is generally well tolerated and no unexpected adverse events were seen in the current study.
Three of six serious adverse effects were considered drug related – two cases of pyelonephritis and one case of influenza – but these resolved following hospitalisation.
The 75 patients with clinically stable relapsing–remitting MS were switched to rituximab from the first-line injectables interferon (IFN)-β and glatiramer acetate (GA).
Following a 3-month run-in period, two 1000 mg intravenous doses of the anti-CD20 therapy were given 2 weeks apart.
Only one of the 75 patients reported a clinical relapse during the first year of treatment and changed to a different therapy. Ten of 72 patients with MRI data available had gadolinium-enhancing lesions detected during the run-in period, but these were no longer present after treatment.
Indeed, the overall number of gadolinium-enhancing lesions fell from an average of 0.37 before treatment switch to 0.03 after 6 months of rituximab, while the number of new or enlarged T2 lesions dropped from 0.28 to 0.01 after 12 months.
Lumbar punctures from 70 patients showed a significant 21% reduction in CSF-NFL levels, dropping from 491 ng/L before initiating rituximab to 387 ng/L 12 months after.
CSF-NFL levels tend to increase with age, note Pierre de Flon (Östersund Hospital, Sweden) and colleagues in Neurology, and so this change is unlikely to represent a natural evolution of this marker. It indicates that “rituximab treatment may yield a better protection from irreversible [central nervous system] damage than IFN/GA”, they add.
The effect of rituximab started to wane after 2 years, with clinical recurrence of activity in four patients fulfilling the criteria for treatment failure.
“This, together with an increase, although not statistically significant, in both MRI activity and CSF-NFL levels, indicates that the protective effect from a single course of 2 x 1,000 mg rituximab lasts for more than 1, but less than, 2 years”, say the researchers.
“This agrees with data that describe recurrence of B cells occurring 6–12 months after depletion with rituximab. The optimal dose and dosing frequency, as well as whether repeated doses over time may induce long-term remission in MS, need to be studied further.”
By Lucy Piper
medwireNews is an independent medical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2016