Is rituximab any good for stiff person syndrome?

A double blind, placebo-controlled study of rituximab in patients with stiff person syndrome.

Dalakas MC, Rakocevic G, Dambrosia JM, Alexopoulos H, McElroy B.

Ann Neurol 2017; 82:271-277.

Abstract

Objective

In Stiff-Person Syndrome (SPS), an antibody-mediated impaired GABAergic neurotransmission is believed to cause muscle stiffness and spasms. Patients improve with GABA-enhancing drugs and IVIg, but several respond poorly and remain disabled. The need for more effective therapy prompted a trial with the anti-CD20 monoclonal antibody rituximab.

Methods

This was a placebo-controlled randomized trial of rituximab (two bi-weekly infusions of 1gr each). The primary outcome was a change in stiffness scores at 6 months. Secondary outcomes were changes in heightened-sensitivity and quality of life scores. Enrolling 24 patients was calculated to detect 50% change in stiffness scores.

Results

Randomization was balanced for age, sex, disease duration and GAD autoantibody titers. No significant changes were noted at 6 months after treatment in all outcomes. Specifically, no differences were noted in the stiffness index, the primary outcome, or sensitivity scores, the secondary outcome, at 3 or 6 months. Quality of life scores improved significantly (p<0.01) at 3 months in both groups, but not at 6 months, denoting an early placebo effect. Blinded self-assessment rating of the overall stiffness for individual patients revealed improvement in four patients in each group. At 6 months, improvement persisted in one patient in the placebo group vs. three out of 4 in the rituximab group, where these meaningful improvements were also captured by video recordings.

Interpretation

This is the largest controlled trial conducted in SPS patients demonstrating no statistically significant difference in the efficacy measures between rituximab and placebo. The lack of rituximab’s efficacy could be due to a considerable placebo effect; insensitivity of scales to quantify stiffness especially in the less severely affected patients; or drug effectiveness only in a small patient subset. This article is protected by copyright.

This article is cited in the neurochecklist:

Stiff person syndrome (SPS): management

Abstract link

By Marta Rizzi et al – PLoS One, CC BY 2.5, Link
Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s