Real-world data show Enspryng reduces NMOSD relapses over 2.5 years
Most patients In Japan were relapse-free with approved injection therapy
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Treatment with Enspryng (satralizumab) for more than two years was shown to prevent relapses in most people with neuromyelitis optica spectrum disorder (NMOSD) in Japan.
That’s according to a new study that tracked outcomes from Japanese NMOSD patients given the approved injection therapy in real-world practice.
“Overall, most patients remained relapse-free on [Enspryng],” the researchers wrote, noting that “no new safety issues were identified.”
The team concluded that the available medical data “[support] the relapse-preventive effect” of Enspryng use.
The study, “Long-term effectiveness and safety of satralizumab for neuromyelitis optica spectrum disorder in a real-world clinical setting in Japan: A 2.5-year final analysis of a multicenter medical chart review (The SAkuraBeyond Study),” was published in the Multiple Sclerosis Journal. The work was funded by Enspryng’s developer Chugai Pharmaceutical, a Roche company.
An autoimmune disorder, NMOSD is marked by self-reactive antibodies that target aquaporin-4 (AQP4), a protein present on neuron-supporting cells in the brain and spinal cord. The disease is characterized by relapses or flares in which inflammation damages nervous system tissue, which leads symptoms to suddenly worsen.
Symptoms usually ease somewhat after a relapse is managed. However, it’s common for some symptoms to become long-term even once the initial relapse is over. As such, preventing relapses is a key goal of NMOSD treatment.
Enspryng approved for use in US and EU as well as Japan
Enspryng is approved in Japan to treat NMOSD patients positive for anti-AQP4 antibodies; the therapy is also approved in the U.S. and the European Union, though its use in those two regions is restricted to patients ages 12 and older.
The therapy is administered by subcutaneous, or under-the-skin, injections every other week for the first three doses, and every four weeks thereafter. Its use works to block the activity of a signaling molecule that helps drive inflammation in NMOSD.
While the treatment’s long-term safety and efficacy have been confirmed in clinical trials, “long-term real-world evidence on the nature of NMOSD relapse in patients treated with [Enspryng] is limited,” the researchers wrote.
SAkuraBeyond (UMIN000050027), launched in 2023, “was designed to evaluate, in detail, relapse over 2.5 years among [Enspryng-treated] patients with [AQP4-related] NMOSD in a real-world clinical setting in Japan,” the team wrote.
An interim analysis published last year showed nearly all patients were free from relapses in the first six months after starting Enspryng.
Now, the research team is reporting SAkuraBeyond’s final outcomes. Of the 124 patients who started the study, 92 completed a full 2.5 years of follow-up while consistently taking Enspryng, according to the scientists.
Over 90% of treated patients were free from relapses
The final results showed that nine relapses occurred in nine participants over the course of the study. This corresponded to an annualized rate of relapse (ARR) of 0.03, which was lower than the AAR of 0.45 observed the year prior to starting Enspryng.
At the end of the study, 91.8% of all patients and 92.4% of those who completed the 2.5 years of treatment were free from relapses, the data show.
Available data also suggested that most of the participants who experienced a relapse while on Enspryng made a full recovery afterward, with no substantial worsening of long-term clinical severity. Seven of the nine patients who relapsed continued Enspryng treatment, per the researchers.
The team also looked at patterns of use of corticosteroids, or anti-inflammatory and immunosuppressive medicines that have long been a standard component of NMOSD management.
Although these medications can help control the disease, their long-term use, especially at high doses, can lead to serious side effects, incuding weight gain, skin problems, and mental health issues. As such, clinicians generally try to minimize corticosteroid use where possible.
The average dose of oral corticosteroids dropped from 10.3 mg/day at the study’s start to 2.5 mg/day after 2.5 years, the data show. While most participants (72.6%) were also on oral corticosteroids when they started Enspryng treatment, nearly half (48.8%) had discontinued them by the end of the study, the researchers noted.
More than a third of those who were relapse-free after 2.5 years and were taking oral corticosteroids at the study’s start had discontinued them. Further, almost all patients who were still taking corticosteroids were on a low dose (5 mg/day or lower).
Use of other immunosuppressive medications also decreased with long-term Enspryng treatment. The researchers noted that patients tended to decrease corticosteroid doses before altering dosages of other meds.
However, there is no standard protocol for how to decrease other therapies after starting Enspryng. The researchers noted the importance of individualized treatment plans.
Serious adverse events reported for nearly 10% of patients
Safety data from this long-term study, which was limited to patients in Japan, did not reveal any unexpected findings.
Serious adverse events — mainly serious infections related to immunosuppressive treatment — were reported in nearly 10% of participants. One patient died of a heart attack during the study, but this was determined to be unrelated to Enspryng.
Overall, these findings are broadly consistent with data seen in the clinical trials that formed the basis for Enspryng’s approval in Japan and other countries, the researchers noted.
Enspryng is “a suitable treatment option to target inflammation in patients with [AQP4-related] NMOSD,” the team concluded.
