Tocilizumab found to be effective, safe for NMOSD: Meta-analysis
Off-label anti-inflammatory medication helps to prevent relapses, ease disability
Tocilizumab, an anti-inflammatory medication used off-label for neuromyelitis optica spectrum disorder (NMOSD), can help prevent relapses (flare-ups) and ease disability while being generally safe, according to a meta-analysis.
The study, “Tocilizumab treatment in neuromyelitis optica spectrum disorders: Updated meta-analysis of efficacy and safety,” was published in the journal Multiple Sclerosis and Related Disorders.
NMOSD is caused by self-reactive antibodies that attack proteins, most commonly aquaporin-4 (AQP-4), in cells that support neurons (nerve cells). As a result, the optic (eye) nerve and spinal cord become inflamed, driving the symptoms of NMOSD.
Interleukin-6 (IL-6), a molecule that mediates inflammation, is found at increased levels in people with NMOSD, and those with more IL-6 are at a greater risk for relapses and more severe symptoms.
Tocilizumab is antibody that reduces inflammation by blocking IL-6 signaling
Like Enspryng (satralizumab-mwge), which is approved for adults with NMOSD who test positive for antibodies against AQP-4, tocilizumab is an antibody that reduces inflammation by blocking IL-6 signaling. This is expected to prevent relapses and ease disease symptoms.
Tocilizumab, given as an injection under the skin, is marketed by Genentech as Actemra or RoActemra to treat a range of diseases marked by inflammation. It is also available as a biosimilar. In NMOSD, it is used off-label and viewed as safe and effective.
To better understand how safe tocilizumab is and how well it works in NMOSD, a team of researchers in China combined data from nine studies published from 1994 to 2023, which were identified through a literature search.
The meta-analysis included a total of 153 people (139 men, 14 women) with a diagnosis of NMOSD who were from 23 to 62 years old when they started on tocilizumab. Tocilizumab was given at a dose of 6 or 8 milligrams per kilogram of body weight (mg/kg) at an interval of up to six weeks.
After treatment with tocilizumab, the annualized relapse rate dropped by a mean 1.34 relapses each year. The annualized relapse rate is a measure of the number of relapses adjusted to a one-year time window.
This meta-analysis provides sufficient evidence to support the efficacy of tocilizumab therapy in reducing relapse and improving disability in patients with NMOSD.
Disability scores dropped after treatment with tocilizumab
Scores on the Expanded Disability Status Scale, a measure of disability building up due to the disease, where higher scores indicate greater disability, also dropped by a mean 0.81 points after treatment with tocilizumab.
The team then analyzed a group of 39 patients to explore factors that affect the effectiveness of tocilizumab in NMOSD. Most (31) patients had antibodies against AQP-4. The effect on relapses and disability was statistically significant among those who had these antibodies, but not among those who tested negative.
Women responded better to tocilizumab than men, as did people from Africa versus those from Asia or of Caucasian descent. Moreover, a dose of 8 mg/kg of tocilizumab worked better than the lower dose of 6 mg/kg.
As for safety, a total of 101 (66%) patients experienced side effects, mostly mild. The most common were urinary tract and upper respiratory infections, and liver damage. One patient experienced serious facial cellulitis (a bacterial infection in the face) related to treatment with tocilizumab.
“The primary goal of NMOSD treatment is to prevent disease relapse,” the researchers wrote. “This meta-analysis provides sufficient evidence to support the efficacy of tocilizumab therapy in reducing relapse and improving disability in patients with NMOSD.”
“While also being safe,” tocilizumab’s effectiveness may depend on multiple factors, such as sex, race, and dosage, the researchers noted.