Soliris-to-Enspryng switch safe, effective in NMOSD: Case series
Switches rare, but important to understand, researchers say
Switching from Soliris (eculizumab) to Enspryng (satralizumab) is a safe and effective approach for neuromyelitis optica spectrum disorder (NMOSD) patients testing positive for antibodies against the AQP4 protein.
That’s according to data from five patients in the U.S. who switched treatments due to either preference for route of administration and dosing frequency or inadequate disease control. After the switch, all were free from disease relapses, and there were no reports of serious adverse events.
“Given the rarity of these switches — owing largely to the success of [Soliris] in managing the disease — we believed it was imperative to report these cases,” the researchers wrote. “This information could potentially assist treating physicians in making informed decisions.”
The case series study, “Switch from eculizumab to satralizumab in aquaporin 4 immunoglobulin G–seropositive neuromyelitis optica spectrum disorder: a case series report,” was published in Frontiers in Immunology.
NMOSD is an autoimmune disease that primarily affects the optic nerve — the nerve that relays signals between the eye and the brain — and spinal cord, leading to symptoms like vision and muscle control issues. Episodes of inflammation usually reoccur periodically, leading to disease relapse, and are separated by periods of remission.
Different targets
In most patients, NMOSD is caused by self-reactive antibodies against the AQP4 protein at the surface of nerve-supporting cells called astrocytes, and by activation of the complement cascade, a part of the body’s immune system.
There are several approved NMOSD therapies, including AstraZeneca’s Soliris and Roche’s Enspryng. While both work to suppress the abnormal immune and inflammatory responses that drive NMOSD, Soliris targets the C5 complement protein, while Enspryng suppresses the effects of the pro-inflammatory molecule IL-6.
Soliris is administered by an into-the-vein infusion once every two weeks, following five initial weekly doses. Enspryng is given via an under-the-skin injection once every four weeks, following three initial doses given two weeks apart.
“Data on NMOSD treatment transitions are limited, particularly real-world data on switches between approved therapies with different mechanisms of action, which may have clinical implications,” the researchers wrote.
With this in mind, the team described data from five adults (four women and one man) with NMOSD and anti-AQP4 antibodies who received treatment with Soliris followed by Enspryng for at least six months.
Patients’ median age was 56 (range 32-81). Four were Black, and one was white. They had been living with a confirmed diagnosis of AQP4-related NMOSD for a median of four years (range 1-14 years).
Three patients had signs of optic nerve inflammation, and two of them also showed spinal cord inflammation. The other two had spinal cord inflammation alone.
Three patients had received other immunosuppressive medications before starting on Soliris, which was administered for a median of 10 months. Treatment time ranged from five months to 22 months (nearly two years).
One patient switched to Enspryng because of a preference for self-administered therapy. Another cited a preference for less frequent therapy as a reason, and a third switched because of loss of access to blood veins to administer Soliris.
The remaining two patients chose to switch treatments due to inadequate disease control. One of them had been on Soliris for little over a year, during which the person experienced worsening right-arm impairments and a lack of appetite. The other patient had vision symptoms five months after initiating Soliris.
None of these symptoms was confirmed to be a disease relapse.
The time between Soliris discontinuation and Enspryng initiation ranged from two to 17 weeks (nearly four months), and patients were treated with Enspryng alone for a median of 25 months (about two years).
At the analysis cutoff date, all patients had been treated with Enspryng “for a duration at least as long as they had received [Soliris] (Patient 5) or longer (Patients 1-4),” the team wrote.
After the switch, all patients were free from relapses, and they experienced disease stabilization or lessening.
Adverse events associated with Enspryng were reported in two patients. One of these patients experienced low levels of neutrophils, a type of immune cell, that led to a temporary suspension of treatment. The same patient also developed contact dermatitis, an itchy skin rash caused by contact with a substance, followed by skin discoloration at the inflammation site.
The other patient developed low levels of immune cells that did not require treatment suspension.
“In this retrospective case series, [Enspryng] was effective and well tolerated in patients with NMOSD who switched from [Soliris] treatment,” the researchers wrote, though they added that the findings “should not be construed or interpreted as evidence of superiority or inferiority of either treatment in the absence of head-to-head clinical trials.”
Still, “understanding reasons for and outcomes after switching between approved therapies may aid in developing optimum treatment strategies in the clinical management of NMOSD,” they wrote.
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