When Your Own Immune System Turns on Your Nerves
It usually starts with tingling in the feet. Then weakness in the legs. Then, sometimes, the inability to walk — or even breathe without a machine. Guillain-Barré syndrome (GBS) moves fast, and for people in its grip, every day of treatment that doesn't work is a day of real disability.
There are currently only two accepted treatments for GBS. And for many patients, neither works well enough.
A Condition With No Good Options
Guillain-Barré syndrome is a rare but serious disorder in which the immune system mistakenly attacks the peripheral nervous system — the network of nerves outside the brain and spinal cord that controls movement and sensation. Think of the peripheral nervous system as the wiring in your walls. In GBS, the body's own immune cells start stripping the insulation off that wiring, disrupting the electrical signals that tell your muscles to move.
GBS affects about 1 to 2 people per 100,000 each year. In severe cases, patients can become completely paralyzed and require mechanical ventilation to breathe.
The Two Treatments That Doctors Have Had for Decades
The current standard treatments for GBS are:
- Intravenous immunoglobulin (IVIG) — an infusion of antibodies (immune proteins) pooled from thousands of blood donors, which is thought to neutralize the rogue antibodies attacking the nerves.
- Plasma exchange — a process that physically removes harmful antibodies from the bloodstream by filtering the patient's blood.
Both have been in use for decades. Both work for many patients. But a significant portion — perhaps 20 to 40 percent — still experience poor outcomes, prolonged disability, or incomplete recovery.
How Efgartigimod Works Differently
Efgartigimod (ef-gar-TIG-i-mod) works by blocking a specific protein called FcRn (neonatal Fc receptor). This protein is like a recycling system for antibodies — it catches them before they break down and sends them back into circulation. By blocking FcRn, efgartigimod accelerates the breakdown of all circulating antibodies — including the harmful ones attacking the nerves.
Compared to IVIG, which floods the system with healthy antibodies to dilute and neutralize the bad ones, efgartigimod takes a more direct route: it speeds up the removal of the problem antibodies themselves.
Who Was Studied and How
Researchers at a single medical center in China retrospectively reviewed records from 34 GBS patients who were unable to walk independently when admitted between January 2023 and February 2025. Twelve patients received efgartigimod; 22 received IVIG.
The primary goals were straightforward: what percentage of patients could walk independently by week 4, and what percentage could run by week 12?
The results were striking.
By week 4, all 12 patients in the efgartigimod group (100%) could walk independently. In the IVIG group, only 14 of 22 patients (64%) reached that milestone.
By week 12, all 12 efgartigimod patients (100%) could run. In the IVIG group, only 55% had recovered to that level.
This doesn't mean efgartigimod is ready to replace IVIG as the standard treatment — not yet.
The researchers also noted particular improvements in patients with two severe complications: ophthalmoplegia (paralysis of the eye muscles) and respiratory insufficiency (the inability to breathe adequately without support). These have historically been among the hardest-to-treat presentations of GBS.
That's Not the Full Story
The 34-patient sample is small — small enough that chance alone could explain some of the difference between groups. The study was also retrospective, meaning the researchers analyzed data after the fact rather than designing a controlled experiment from scratch. Patients were not randomly assigned to treatments, which means there could be differences between the two groups that influenced outcomes.
The researchers are transparent about these limitations. They describe this as preliminary evidence that warrants larger, prospective trials.
If you or a family member is diagnosed with GBS, the current standard of care remains IVIG or plasma exchange. Efgartigimod is not yet approved for GBS, though it is approved for another antibody-mediated condition called myasthenia gravis (a neuromuscular disease that causes muscle weakness).
Speak with a neurologist about all available options and whether any clinical trials might be appropriate.
Limitations to Keep in Mind
Beyond the small sample, this study was conducted at a single hospital in China, and patients were not randomly assigned to treatments. The two treatment groups may have differed in disease severity or other factors that the analysis didn't fully account for. Without randomization, it is impossible to be certain that efgartigimod itself caused the better outcomes.
These results are promising enough to justify a large randomized controlled trial — the gold standard for testing a new treatment. Several research groups and the drug's manufacturer are likely watching these findings closely. If efgartigimod proves effective in a rigorous trial, it could eventually offer new hope for the subset of GBS patients who don't respond well to current therapies. That research, if initiated soon, could produce answers within the next several years.