argenx wins EU approval for subcutaneous VYVGART in CIDP, ending 30-year innovation drought in treatment

argenx SE, the Netherlands-based global immunology firm traded on Euronext and Nasdaq under the ticker ARGX, announced on June 20, 2025, that it has received European Commission approval for VYVGART (efgartigimod alfa) 1000mg subcutaneous injection as a monotherapy for chronic inflammatory demyelinating polyneuropathy (CIDP). The approval marks a watershed moment for patients across the European Union living with this rare neuromuscular disease and is expected to significantly impact argenx’s commercial expansion within autoimmune neurology.

The European approval represents the second regional greenlight for subcutaneous VYVGART in CIDP after prior clearance in the United States and builds on the drug’s first global approval in generalized myasthenia gravis (gMG). This milestone comes on the heels of pivotal ADHERE trial data and signals a critical expansion of the FcRn inhibitor’s therapeutic footprint.

Why is the European Commission approval of VYVGART SC for CIDP considered a landmark for autoimmune neurology in 2025?

The European Commission’s decision applies across all 27 EU member states, as well as to Iceland, Liechtenstein, and Norway. The approval positions argenx’s VYVGART SC as the first and only approved neonatal Fc receptor (FcRn) antagonist for CIDP—a serious and progressive autoimmune disease characterized by muscle weakness, numbness, and mobility issues. The drug will be offered in both vial and prefilled syringe formats, with administration options that include self-injection by the patient or delivery by a caregiver or healthcare provider.

Treatment is initiated weekly and may transition to biweekly dosing depending on patient response. For those living with chronic peripheral nerve disorders requiring long-term therapy, the availability of a targeted, convenient subcutaneous biologic is viewed by clinical experts as a transformative advancement.

The subcutaneous format provides patients with the flexibility of home-based care and reduces the dependence on infusion centers—an especially relevant benefit for rural populations or mobility-impaired patients. Experts across Europe have welcomed the new treatment paradigm, noting that CIDP care has seen little innovation in the past three decades.

What is chronic inflammatory demyelinating polyneuropathy (CIDP) and why is new treatment innovation long overdue?

CIDP is a debilitating and often underdiagnosed autoimmune disease of the peripheral nervous system. Its hallmark symptoms include symmetrical limb weakness, impaired balance, fatigue, pain, and sensory loss. Disease progression may lead to substantial physical disability, with up to one-third of patients eventually requiring a wheelchair if untreated. Despite the availability of corticosteroids and intravenous immunoglobulins, approximately 85% of CIDP patients require ongoing therapy, and nearly 88% continue to experience residual impairments.

Until now, the clinical toolkit for managing CIDP remained largely unchanged for over 30 years. The approval of a targeted FcRn antagonist is therefore regarded by institutional stakeholders and advocacy groups as a long-awaited breakthrough, particularly as CIDP continues to pose a quality-of-life burden for patients across Europe.

What did the ADHERE trial reveal about VYVGART SC’s clinical efficacy and safety in treating CIDP?

argenx’s European approval was underpinned by results from the ADHERE trial, the largest clinical study ever conducted in CIDP. This global, double-blind, placebo-controlled trial enrolled 322 adult CIDP patients, including 130 from Europe. It was designed with a two-stage format: an open-label Stage A to assess initial clinical improvement, followed by a randomized Stage B where participants were assigned to either VYVGART SC or placebo for up to 48 weeks.

The trial’s primary endpoint demonstrated a 61% reduction in risk of relapse (hazard ratio: 0.39; p<0.0001) in patients receiving VYVGART SC compared to placebo. Additionally, 66.5% of treated patients showed functional improvement across key metrics such as INCAT, I-RODS, and grip strength. Notably, clinical benefit was seen irrespective of prior treatment with corticosteroids or immunoglobulins.

ADHERE’s design also included a run-in phase to assess active disease, with independent expert confirmation of CIDP diagnosis—a feature that added rigor to the trial’s eligibility criteria. The overwhelming majority of participants (99%) opted into the long-term open-label extension, signaling high treatment satisfaction and acceptance. Safety outcomes remained consistent with VYVGART’s previously established profile.

How does the mechanism of action for efgartigimod SC differentiate it from conventional CIDP therapies?

VYVGART SC, which contains the engineered IgG1 antibody fragment efgartigimod alfa, is the first approved therapy to leverage FcRn antagonism for the treatment of CIDP. The drug functions by binding to the neonatal Fc receptor and disrupting the recycling of pathogenic IgG antibodies, which are increasingly recognized as key drivers of autoimmune-mediated nerve damage in CIDP.

Conventional therapies such as steroids and immunoglobulins suppress inflammation broadly or replace antibodies non-specifically, often requiring infusions and lengthy clinic visits. In contrast, efgartigimod offers targeted immunomodulation with the potential for fewer systemic side effects. The precision of the FcRn approach is seen by analysts as a strategic differentiator in the evolving autoimmune neurology space.

argenx is actively advancing efgartigimod across more than 15 autoimmune disease indications, signaling long-term commitment to platform expansion. Other indications under investigation include pemphigus vulgaris, lupus nephritis, and immune thrombocytopenia (ITP), with several late-stage trials ongoing.

What are institutional investors and analysts expecting next from argenx’s commercial and pipeline trajectory in Europe?

Institutional sentiment around argenx remains broadly positive following the EC approval, with expectations centered on pricing decisions, local reimbursement approvals, and uptake velocity. The subcutaneous format is particularly well-positioned to benefit from evolving European healthcare preferences favoring self-administered biologics, especially in chronic conditions requiring long-term therapy.

Analysts believe argenx will now move rapidly to engage with national health agencies and reimbursement bodies, beginning with key markets such as Germany, France, and the Nordics. Given that efgartigimod is already approved in Europe for generalized myasthenia gravis, market access pathways for VYVGART SC in CIDP could be accelerated via existing infrastructure.

The broader pipeline remains a focal point for investors, particularly as efgartigimod’s unique mechanism is under evaluation in multiple autoimmune neurology and hematology indications. Future readouts from these trials are expected to play a key role in argenx’s valuation trajectory over the next 12–24 months.

How does argenx’s latest approval position it against competitors in the FcRn and autoimmune neurology space?

With this approval, argenx consolidates its early lead in the FcRn therapeutic class, where competition is steadily intensifying. Several pharmaceutical and biotech developers are working on FcRn inhibitors, some of which are in Phase 2 or 3 trials targeting various autoimmune indications. However, argenx’s VYVGART remains the only FcRn-targeting biologic approved in multiple regions for both CIDP and gMG.

This first-mover advantage gives argenx considerable leverage in shaping clinical practice and health system protocols, particularly in Europe, where payers and providers are increasingly focused on value-based care and real-world outcomes.

Experts believe that expanding physician familiarity with FcRn biology, coupled with growing patient demand for targeted, at-home therapies, will continue to support VYVGART’s adoption. As additional real-world evidence is collected, argenx is expected to reinforce its leadership via post-marketing studies and broader indication filings.