Earlier rituximab treatment linked to less worsening over time
Association particularly seen with female patients over age 50, with severe disability
Starting treatment with off-label rituximab soon after neuromyelitis optica spectrum disorder (NMOSD) symptoms begin may prevent long-term disability worsening, a South Korean study suggests.
This approach was particularly true for patients who were younger than 50, female, and for those with a severe level of disability before starting rituximab, according to the researchers, who said NMOSD patients “who experience breakthrough relapses, especially those with early to middle-age onset, female sex and severe attacks, need to be switched to rituximab treatment in their early disease stages.”
The study, “Early rituximab treatment reduces long-term disability in aquaporin-4 antibody-positive neuromyelitis optica spectrum,” was published in the Journal of Neurology, Neurosurgery and Psychiatry.
NMOSD occurs when self-reactive antibodies mistakenly turn against healthy cells of the central nervous system, often causing recurring inflammation in the optic nerves, which carry messages from the eyes to the brain, and the spinal cord.
Left untreated, the inflammation can make symptoms come and go in phases. Attacks (relapses) usually last days and are followed by periods of recovery (remissions). Each relapse causes new damage that accumulates over time, sometimes leading to vision loss and paralysis.
Rituximab (sold as Rituxan, among others) is commonly used off-label in NMOSD to reduce the number of B-cells, a type of immune cell that make antibodies, including those believed to play a role in the disease. Earlier work has shown it can prevent relapses and ease disability in NMOSD, even at low doses.
“However, it is still unclear if earlier initiation of rituximab treatment will lead to a better long-term disability outcome for patients with NMOSD” and who will benefit from early rituximab treatment, said the researchers, who reviewed the medical records of 145 patients being treated with rituximab at different centers across South Korea who had a follow-up period of more than a year. Their mean age at disease onset was 39.5 years and most (88.3%) were female.
Starting rituximab treatment
Before starting rituximab, almost all (98.6%) were already taking other medications to suppress their immune system or oral steroids. The mean time from onset of the disease to starting rituximab was 77.1 months (about 6.4 years).
The maximum level of disability, as measured by the Expanded Disability Status Scale (EDSS), averaged 5.2 points before starting rituximab. At the last follow-up, it was 2.2 points lower. The EDSS ranges from zero to 10 points, with higher scores indicating worse disability.
Starting earlier and lower maximal EDSS scores before rituximab treatment were significantly associated with lower long-term disability, results showed.
This effect was more evident among patients who were younger than 50 at disease onset, who were female, and among those who had a severe level of disability — an EDSS score of six points or more — before starting rituximab.
“Initiating rituximab treatment sooner after symptom onset was significantly linked to better long-term disability outcomes in patients with NMOSD,” the researchers wrote. “Further studies are needed to clarify effectiveness of rituximab as first-line treatment compared with second-line treatment and to develop predictive biomarkers for the response to rituximab.”
The most common side effects related to treatment were reactions at the site of infusion, respiratory infection, and urinary tract infection.