Enspryng stops relapses, helps some end glucocorticoid use: Study
Real-world study looks at data from 131 NMOSD patients
Most neuromyelitis optica spectrum disorder (NMOSD) patients who start taking Enspryng (satralizumab) remain free of relapses for at least a year, with some being able to stop treatment with oral glucocorticoids, according to a study of real-world data.
The findings are consistent with those of SAkuraStar (NCT02073279) and SAkuraSky (NCT02028884), the two Phase 3 clinical trials that backed Enspryng’s approvals for NMOSD patients who are positive for disease-driving antibodies against the aquaporin-4 (AQP4) protein.
The study, “Real-world management of patients with neuromyelitis optica spectrum disorder using satralizumab: Results from a Japanese claims database,” was published in Multiple Sclerosis and Related Disorders. It was funded by Roche subsidiary Chugai Pharmaceutical, Enspryng’s developer.
In NMOSD, self-reactive antibodies, most commonly those targeting AQP4, drive inflammatory attacks that damage the eye nerves and the spinal cord, leading to problems with vision and movement. IL-6, a signaling molecule that primes the production of antibodies, is linked to a greater risk for NMOSD relapses.
Enspryng works by blocking IL-6, which is expected to reduce production of anti-AQP4 antibodies, ultimately easing symptoms of NMOSD. The medication is given via under-the-skin injections every four weeks, and can be used on its own or with corticosteroids.
Glucocorticoid side effects make tapering key
In the placebo-controlled parts of SAkuraSky and SAkuraStar trials, Enspryng, when used alone or with standard immunosuppressive therapies, was shown to safely and significantly lower the risk of relapses for up to nearly two years relative to a placebo.
However, “there is an unmet need to understand the real-world management of NMOSD using [Enspryng],” the researchers wrote. “Especially, how to safely taper concomitant [simultaneous] therapy such as oral glucocorticoids and [immunosuppressant therapy] without relapse are highly relevant questions.”
Tapering off glucocorticoids is particularly important as these can have serious side effects when taken for long periods or at a high dose.
With this in mind, the team of researchers in Japan reviewed data from 131 NMOSD patients who began taking the medication in the real-world setting after it was approved in the country in 2020.
Most patients were female (90.8%), and only two (1.5%) were younger than 18. Before starting Enspryng, nearly all (93.1%) were taking oral corticosteroids; many (83.2%) took a dose greater than 5 mg a day. Nearly half (42%) were taking immunosuppressants such as azathioprine and tacrolimus.
Patients were treated with Enspryng for a median of nearly 6.5 months. A total of 31 patients continued treatment for more than a year.
After starting Enspryng, most patients (95.4%) remained free of relapses. These were defined as a worsening of symptoms requiring standard acute-phase treatment: high-dose glucocorticoids for three days or longer, plasma exchange, or immunoglobulin therapy.
Plasma exchange is a blood-cleaning procedure, while immunoglobulin therapy involves administering healthy antibodies that are meant to neutralize NMOSD-driving antibodies.
All six patients (4.6%) experiencing relapses while on Enspryng did so within three months of being prescribed therapy, two of them within a week. All were female and were on oral glucocorticoids at Enspryng start, and all but one were also on immunosuppressants. Two patients experienced two relapses each while under continuous prescription of Enspryng.
Among the 30 patients with available data for at least one year before and after Enspryng treatment initiation, the annualized relapse rate, a measure of the number of relapses adjusted to a one-year time window, dropped about four times from 0.7 to 0.17.
Of the 21 patients who had prescriptions for Enspryng for one year or longer, six (28.6%) were free from both relapses and glucocorticoids after a year. Two were already off glucocorticoids at the time they were first prescribed Enspryng.
Nine of these 21 patients were prescribed immunosuppressants at Enspryng initiation, and three of them (33.3%) were free from immunosuppressants and relapses by one year.
Among the 18 patients who used oral glucocorticoids at Enspryng treatment start and reduced their glucocorticoid dosage during the following year, oral glucocorticoid dose dropped substantially, from a mean of 11.7 mg/day to 4.6 mg/day.
Of 34 patients on immunosuppressants, either alone or combined with oral glucocorticoids, at Enspryng initiation, 14 (41.2%) remained relapse-free for a mean of eight months and up to about 1.5 years despite having reduced their immunosuppressant dose.
The findings suggest that Enspryng is effective in preventing NMOSD relapses in a real-world setting, consistent with previously reported data in a clinical trial setting. The researchers also noted that the longer patients stayed on the therapy, the more likely they were to remain relapse-free and to reduce their need for glucocorticoids.
“This is possibly the first study describing the use of [Enspryng], in more than 100 patients from real-world clinical practice, since its approval in Japan in 2020,” the researchers wrote. “Further studies are needed to confirm these findings in a larger dataset,” they added.