Test your expertise on IgG autoantibody-driven neuromuscular disease. Explore FcRn biology, IgG reduction mechanisms, landmark trial data, and expanding indications in antibody-mediated disease.
5 questions
How does FcRn antagonism reduce pathogenic IgG autoantibodies in generalized myasthenia gravis?
Correct Answer: D
FcRn normally recycles IgG back to the cell surface, protecting it from degradation. FcRn antagonists block this recycling, diverting IgG to lysosomes. This reduces all IgG subclasses — including pathogenic anti-AChR and anti-MuSK autoantibodies that disrupt neuromuscular transmission in gMG.
https://www.mdpi.com/2227-9059/13/12/2975
Prospective study (N=16) of FcRn antagonist in severe gMG exacerbations requiring ventilatory or enteral support: What was the primary efficacy finding?
Correct Answer: A
This 2025 prospective single-arm study (PMID 42551446) enrolled 16 adults with impending myasthenic crisis. All 16 achieved clinically meaningful MG-ADL improvement at both weeks 4 and 8, and all were weaned from ventilatory or enteral support — providing preliminary evidence for FcRn blockade in acute, severe gMG. Because this was a small single-arm study, it does not by itself establish a new standard of care for myasthenic crisis.
https://pubmed.ncbi.nlm.nih.gov/42551446/
ADAPT-SC trial: What was the non-inferiority finding of SC vs IV FcRn antagonist administration in gMG?
Correct Answer: B
ADAPT-SC (N=110) demonstrated SC efgartigimod achieved 66.4% mean total IgG reduction by Day 29 — non-inferior to 62.2% with IV — with consistent results regardless of acetylcholine receptor antibody status.
https://www.neurologylive.com/view/fda-approves-pre-filled-syringe-administration-fcrn-modulator-efgartigimod
Which registrational programs reflect FcRn antagonism expansion beyond approved gMG?
Correct Answer: C
The FcRn antagonist platform has been expanded into multiple registrational programs: ADAPT-SERON (seronegative gMG), ADAPT-OCULUS (ocular MG), ADAPT-JUNIOR (pediatric gMG), and ADHERE (CIDP — approved June 2024).
https://reports.argenx.com/2024/argenx-group/our-products-and-product-candidates/efgartigimod-indications.html
Phase 3 and extension studies: What key immunosuppression-related benefit was shown with FcRn antagonist therapy in gMG?
Phase 3 data (ADAPT trial and extensions) and real-world evidence demonstrate rapid, sustained neuromuscular improvement with FcRn blockade, accompanied by reduced steroid requirements and decreased IVIg use — a clinically meaningful steroid-sparing and IVIg-sparing effect.
Start your journey with Neurologist Connect
