Vyvgart (Efgartigimod) Indication for CIDP vs MMN
Vyvgart (efgartigimod alfa-fcab) is FDA approved for CIDP but not for MMN. Based on the most recent evidence, efgartigimod is only indicated for the treatment of Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) and not for Multifocal Motor Neuropathy (MMN).
CIDP Indication
According to the most recent evidence from 2024, efgartigimod (Vyvgart-Hytrulo) received FDA approval specifically for the treatment of CIDP 1. This approval was based on the phase II Adhere study, which demonstrated efficacy in CIDP patients.
The treatment pathway for CIDP typically includes:
First-line treatments:
- Intravenous immunoglobulin (IVIg)
- Corticosteroids
- Plasma exchange
Newer FDA-approved option:
- Efgartigimod (Vyvgart-Hytrulo) - specifically approved for CIDP in 2024
MMN Treatment Options
For MMN, the evidence shows a different treatment approach:
- IVIg is the only proven effective treatment for MMN 2, 3
- Steroids are NOT beneficial in MMN and may worsen the condition 2
- Plasma exchange is probably not effective in MMN 2
- There is no evidence supporting efgartigimod use in MMN
Important Clinical Considerations
When considering treatment options for these conditions:
Differential response to treatments: MMN and CIDP respond differently to immunotherapy, supporting a fundamental difference between CIDP (immune attack on Schwann cells and myelin) and MMN (attack on nodes of Ranvier and axons) 4.
Transition challenges: Recent evidence suggests potential challenges when transitioning patients from IVIg to efgartigimod for CIDP. A 2025 study reported that some patients experienced severe relapse of CIDP after transitioning from IVIg to efgartigimod 1.
Alternative administration routes: For both conditions, subcutaneous immunoglobulin therapy has been explored as an alternative to IVIg with potential benefits in tolerability and patient convenience, though long-term efficacy data is still limited 5.
Clinical Implications
When treating patients with these conditions:
- Correctly distinguish between CIDP and MMN through appropriate diagnostic workup, as treatment approaches differ significantly
- For CIDP patients, efgartigimod is now an FDA-approved option
- For MMN patients, IVIg remains the standard of care, and efgartigimod is not indicated
- Monitor patients closely during any treatment transitions, particularly when switching from IVIg to efgartigimod in CIDP
The clear distinction in treatment approaches underscores the importance of accurate diagnosis between these two inflammatory neuropathies, as using the wrong treatment could potentially worsen outcomes.