Mechanism and Rationale Behind Imlifidase for Guillain-Barré Syndrome: Elisabeth Sonesson, PhD

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"This is a fast, targeted therapy that removes the antibodies causing nerve damage—within hours. That could be a real game-changer for patients with GBS."

Guillain-Barré syndrome (GBS) is a rare neurological disorder in which a person’s immune system mistakenly attacks part of their peripheral nervous system–the network of nerves that carries signals from the brain and spinal cord of the rest of the body. This disorder has an increased incidence with age and is more common in males, with a male-to-female ratio of about 1.5:1. Currently, there is no cure for GBS; however, some therapies may reduce its severity and shorten recovery time.

Plasma exchange (PE) and intravenous immunoglobulin therapy (IVIg) are the main go-to treatments for GBS, both considered equally effective if started within 2 weeks of symptom onset. Anti-inflammatory steroid hormones called corticosteroids have been tested in GBS, but clinical trials have shown this treatment is not effective. At the 2025 Peripheral Nerve Society (PNS) Annual Meeting, held May 17-20, in Edinburgh, Scotland, several emerging therapeutics for GBS were on display, including Hansa Biopharma’s imlifidase, an IgG-cleaving enzyme agent.

Imlifidase was studied in a single-arm phase 2 trial (NCT03943589) of 27 individuals with confirmed severe GBS who received the investigational drug along with IVIg. All told, the effects of the agent were rapid, as 37% of treated patients were able to walk independently within 1 week of treatment. In addition, participants demonstrated an improvement in muscle strength, reflected by a mean of 10.7 points in Medical Research Council (MRC) sum score. Of note, imlifidase plus IVIg led to rapid functional improvement, with a median time of 6 days to achieve at least 1-grade gain on the GBS Disability Scale.

Following the meeting, NeurologyLive^® sat down with Elisabeth Sonesson, PhD, who provided an overview of the agent and its mechanism of action. Sonesson, who serves as VP, Franchise Lead, Autoimmune at Hansa Biopharma, discussed some of the major differences between imlifidase and IVIg, including their onset of action and time to treat. In the interview, Sonesson emphasized that the speed and specificity observed with imlifidase could be especially beneficial in a disease where 25% of patients require mechanical ventilation and many experience prolonged disability.

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REFERENCE
1. Attarian S, Magy L, Echaniz-Laguna A, et al. Outcomes in Patients with Severe Guillain-Barré Syndrome Treated with Imlifidase and Standardof-Care Immunoglobulin. Presented at: 2025 PNS Annual Meeting; May 17-20; Edinburgh, Scotland. Abstract O582.