B-cell blocker used for MS reduces NMOSD relapses: Study
Results provide 'real-world evidence' for ofatumumab, researchers say
Ofatumumab, a medication approved for multiple sclerosis (MS), may effectively prevent relapses and disability in people with neuromyelitis optica spectrum disorder (NMOSD), according to a study in China.
At their last follow-up, about 80% of the 112 patients analyzed were free from relapses, and more than 60% experienced significant reductions in their disability levels.
“These results provide real-world evidence for the application of ofatumumab in NMOSD,” the researchers wrote, adding that ofatumumab, administered through under-the-skin injections, may be “a convenient and effective option for relapsing NMOSD.”
The study, “Ofatumumab treatment in patients with neuromyelitis optica spectrum disorder: a retrospective multicenter cohort study,” was published in the Journal of Neurology.
NMOSD is an autoimmune disease marked by inflammation of the spinal cord and optic nerve, which relays signals between the eyes and the brain. Most cases are associated with elevated levels of self-reactive antibodies that target the aquaporin-4 (AQP4) protein, which is found on the surface of nerve-supporting cells.
Blocking protein activity
Ofatumumab is an antibody-based therapy sold by Novartis as Kesimpta and approved for adults with relapsing forms of MS. It blocks the activity of CD20, a protein found on the surface of B-cells, the immune cells that produce the self-reactive antibodies that drive NMOSD and MS. CD20 targeting promotes the death of B-cells.
Although some case reports have described the off-label use of ofatumumab to treat people with NMOSD, data on the treatment’s use in a large population have not been available.
The researchers retrospectively analyzed data from 112 people with NMOSD who were treated with ofatumumab across 15 specialized hospitals in China.
Most participants (88%) were female and had a median age of 44 when they received the first ofatumumab injection. Nearly all (93%) had anti-AQP4 antibodies, and 24.1% had other coexistent autoimmune conditions.
The most commonly used treatments before ofatumumab were oral corticosteroids, a type of anti-inflammatory and immunosuppressive treatment.
Participants received ofatumumab at a dose of 20 mg for a median of 1.7 years. The therapy was administered via under-the-skin injections, once monthly, after three initial weekly doses.
After starting ofatumumab, 22 people (19.6%) experienced at least one relapse, with a relapse rate of 16% in the first year and 8% in the second year. Most relapses (76%) were considered minor, while six were severe.
Nearly all participants (95%) experienced a significant reduction in the annualized relapse rate (ARR) within three years after ofatumumab initiation. The median ARR was two before ofatumumab treatment and zero after treatment. The ARR remained unchanged in two participants (1.8%), and increased in four (3.6%).
Available data from 99 participants showed a significant reduction in scores on the Expanded Disability Status Scale (EDSS), from 3.5 at treatment initiation to 2 at the last follow-up, indicating less severe disability. Most of these participants (62%) experienced an EDSS score reduction, while 34% showed stable scores. In four patients, disability worsened.
Most participants also saw easing or stabilization of walking problems, visual disability, sensory disturbance, and urinary issues.
Data from 94 people showed that 76% of them saw a reduction in their anti-AQP4 antibody levels, with 36% testing negative for the antibodies at the last follow-up.
The most frequently reported adverse events were infections (18%), particularly in the respiratory and urinary tracts, low antibody levels (14%), and injection-related reactions (12%).
During follow-up, 15% of the participants discontinued the therapy, mainly due to relapses, noncoverage of medical insurance, and poor compliance.
The study demonstrates that “ofatumumab can reduce the ARR in NMOSD, with manageable safety and good tolerability,” the researchers wrote. However, they added, further research is needed to “explore the sustained clinical response of ofatumumab in NMOSD.”
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