NeuroVoices: Beth Stein, MD, on Implications of Newly Approved Pre-Filled Syringe Option for Efgartigimod

Beth Stein, MD

Historically, myasthenia gravis (MG) and chronic inflammatory demyelinating polyneuropathy (CIDP) have been managed with broad immunosuppressive therapies aimed at dampening the autoimmune response. Efgartigimod (Vyvgart), an immunoglobulin 1 (IgG1) monoclonal antibody fragment, is one of the only therapies indicated for the treatment of both disorders, gaining FDA approval in MG and CIDP in 2021 and 2024, respectively.

In early April, the agency gave greenlight to a new a pre-filled syringe option for efgartigimod, expanding on its current intravenous and subcutaneous administration routes. The therapy may soon hit Europe as well, as the Committee for Medicinal Products for Human Use (CHMP) has already given a positive recommendation for the pre-filled syringe. Other countries such as Japan and Canada are also expected to make a decision in the second half of 2025.

To better understand how this latest approval impacts the clinical community, including those who treat patients with MG and CIDP, NeurologyLive® sat down with neuromuscular expert Beth Stein, MD, director of neuromuscular diseases at St. Josephs Health, in New Jersey. As part of new iteration of NeuroVoices, Stein provided context on the implications of this approval, and how it improves flexibility and independence for patients, as well as reducing the need for nurse-administered infusions. Backed by bioequivalence and safety data, the new option also points to the broader momentum in neuromuscular research, where more personalized, accessible treatments are reshaping disease management and quality of life.

NeurologyLive: What is the significance of this newly approved pre-filled syringe option?

Beth Stein, MD: The FDA approved the pre-filled syringe form of efgartigimod, and this is now going to enable at-home administration for both generalized myasthenia gravis (gMG) and CIDP. That can only enhance patient convenience and flexibility. We already had the option of at-home infusions, but those required a nurse. This new option eliminates that entirely, giving patients a level of freedom and flexibility they didn’t have before.

The EU and other countries are also expected to make decisions on approval later this year. There’s even discussion about a future auto-injector, which would make things even easier. Right now, we’re talking about a pre-filled syringe that takes about 20 to 30 seconds for a subcutaneous injection. Patients still need training on how and when to use it, and they must be monitored appropriately, just like with the previous subcutaneous option.

But this new modality is a game-changer for patients with these chronic, disabling, and unpredictable diseases. Being able to manage that unpredictability is phenomenal. It gives us, and our patients, a new level of control. And remember, these new medications were designed specifically for gMG and CIDP—unlike older treatments. So, this new option is really going to be a great addition.

What supportive evidence backed this approval?

There’s a lot of existing literature that supports efgartigimod in general, but specifically for the pre-filled syringe, the approval was backed by a phase 1 randomized, open-label, parallel-group, single-dose bioequivalence study. It tested subcutaneous efgartigimod—known commercially as Vyvgart Hytrulo—delivered via the pre-filled syringe, compared to a traditional vial-plus-syringe setup.

They used 120 healthy adults aged 55 and older in the study, evaluating safety, efficacy, and bioequivalence. The results showed that the pre-filled syringe was bioequivalent to the traditional method and safe to use. They also ran usability testing with laypersons, including patients with gMG and CIDP, and found that they were able to administer the drug successfully and were satisfied with the experience.

As for the broader evolution of Vyvgart: the original IV formulation was approved for gMG in 2021. About two years later, the subcutaneous formulation—Vyvgart Hytrulo—was approved. It contains hyaluronidase, which allows medications traditionally given via IV to be delivered subcutaneously. That version received approval following the ADAPT-SC phase 3 trial. Then in June 2024, Vyvgart Hytrulo was approved for the CIDP population based on the ADHERE trial. So this latest approval is just another step forward in expanding patient access.

Are there any safety considerations with this new pre-filled syringe option?

The safety profile is very similar to what we already see with the vial-plus-syringe subcutaneous version. Serious adverse reactions can include infections, allergic reactions, and infusion-related symptoms. Common side effects include fever, cough, sore throat, rash, swelling, and shortness of breath. These are all consistent across the different administration forms, whether it's IV, vial-plus-syringe, or pre-filled syringe.

For the pre-filled syringe specifically, it uses a 25-gauge, 5/8-inch thin-wall needle. The medication needs to be refrigerated but should be brought to room temperature—about 30 minutes out of the fridge—before administration. Headache and infection remain the most common side effects. Overall, it’s the same administration method, with the same safety expectations.

What has efgartigimod meant to the neuromuscular community?

New options like this have been incredible for the neuromuscular community. We’re in a truly exciting phase of R&D, with new treatments and modalities becoming available at a much faster pace—not just for gMG and CIDP, but for other neuromuscular conditions as well.

These new drugs are specifically designed to target neuromuscular diseases, which opens up a whole new level of disease control that was previously out of reach. As physicians, we can now deliver improved care with fewer side effects, which is amazing. It really feels like we’re entering a new era for these diseases.

How does this approval speak to the progress of the neuromuscular community in recent years?

I think this approval marks the beginning of a whole new wave of treatments and approaches. We need to stay flexible and evolve in how we treat these patients. More drugs and more administration routes will keep coming, and our patients will have access to an expanding toolbox of treatment options.

We need to stay aligned with the research and ensure we’re offering these options as soon as they’re available. With more choices comes a better chance at disease control. And when patients have that control, they gain stability faster—they can return to a more normal daily life more quickly.

We have to embrace this momentum. If we don’t, we can’t offer our patients the best care. With treatments like these, we’re now talking about achieving minimal symptom expression in gMG—and that’s a real, attainable goal thanks to these targeted, disease-modifying therapies. And we're doing it on the patient’s schedule, which makes a huge difference.

Transcript edited for clarity.