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FDA Approves Pre-Filled Syringe Administration for FcRn Modulator Efgartigimod
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Key Takeaways
- The FDA approved a pre-filled syringe for efgartigimod, enabling at-home administration for gMG and CIDP, enhancing patient convenience and flexibility.
- The European Union and other countries are expected to decide on approval by 2025, with an autoinjector version anticipated by 2027.
The prefilled syringe is approved as a 20-to-30-second subcutaneous injection, where patients are able to self-inject following proper instruction in subcutaneous injection technique.
Luc Truyen, MD, PhD
(Credit: Argenx)
The FDA has approved a new pre-filled syringe administration route for efgartigimod (Vyvgart; Argenx), a marketed medication for generalized myasthenia gravis (gMG) and chronic inflammatory demyelinating polyneuropathy (CIDP). With the decision, it offers patients greater convenience and flexibility, allowing in-home administration and reducing the number of time-consuming trips that typically come with intravenous (IV) infusions.1
A phase 1, randomized, open-label, parallel-group, single-dose, bioequivalence study tested the effects of SC efgartigimod, known as Vyvgart Hytrulo, via a pre-filled syringe against a vial + syringe presentation in healthy participants. Featuring 120 healthy adults aged at least 55, the study provided data supporting the efficacy, safety, and bioequivalence of the SC prefilled syringe administration route for efgartigimod.2
“Today’s FDA approval provides a new self-injection option across both approved indications in the U.S. that is designed for patients who seek more independence with their treatment,” Luc Truyen MD, PhD, chief medical officer, argenx, said in a statement.1 “We understand patients experience MG and CIDP in different ways, and our prefilled syringe is an important innovation that provides patients with more freedom and flexibility to self-administer VYVGART Hytrulo. Whether patients prefer to receive their treatment in a physician’s office, at home, or while traveling, they can experience treatment on their own terms and continue to benefit from VYVGART Hytrulo’s favorable safety profile and strong efficacy.”
To date, the Committee for Medicinal Products for Human Use (CHMP) has already given a positive recommendation for approval of the pre-filled syringe, with the European Union (EU) expected to make a decision in the first half of 2025. In addition, other countries, such as Japan and Canada, are also expected to make a decision for its approval in gMG and CIDP in the second half of 2025. Argenx is also looking into an autoinjector version of the therapy, expected to launch closer to 2027.3
“I am excited to offer my patients living with gMG and CIDP the option of the new prefilled syringe for VYVGART Hytrulo,” Beth Stein, MD, director of Neuromuscular Diseases at St. Joseph’s Health, said in a statement.1 “This new self-injection option will lead to more convenient and flexible administration for patients, empowering them to decide when and where they receive treatment. A ready-to-use option enhances patient independence and reduces the time required for treatment, making disease management and control more seamless.”
Efgartigimod, a neonatal Fc receptor (FcRn) blocker designed to reduced levels of pathogenic IgG autoantibodies by preventing their recycling in the body, received its first FDA approval in 2021 as a medication for gMG.4 Nearly 2 years later, the agency gave greenlight to a SC formulation, a more enhanced version coformulated with recombinant human hyaluronidase PH20 (rHuPH20), Halozyme's ENHANZE drug delivery technology, which further allows for SC delivery of biologics that are typically administered via infusion.5
Vyvgart Hytrulo’s approved indication is a 1008-mg fixed dosed administered over 30 to 90 seconds in cycles of once-weekly injections for 4 weeks. Patients may administer subsequent treatment cycles based on clinical evaluation, although the safety of initiating subsequent cycles sooner than 50 days from the start of a previous treatment cycle has not been established. Per the medications label, there are no contraindications for the treatment.6
The decision behind the SC approval was based on the phase 3 ADAPT-SC study (NCT04735432), which evaluated the noninferiority of the pharmacodynamic profile effect of SC efgartigimod as compared with the previously approved IV administration. ADAPT-SC, a trial that featured 110 patients with gMG, met its primary end point of change in total IgG reduction over a 29-day period. In the trial, SC efgartigimod achieved a mean IgG reduction of 66.4% by day 29–noninferior to the 62.2% seen with IV administration–with consistent results regardless of acetylcholine receptor (AChR) antibody status.7
“argenx is a trusted partner in the MG patient community, continuously innovating to meet the evolving needs of patients. This new self-injection option is a natural progression, empowering individuals to take control of their treatment and working toward achieving a greater sense of normalcy in their lives,” Samantha Masterson, president and CEO of the Myasthenia Gravis Foundation of America, said in a statement.1
Efgartigimod was then approved in June 2024 to treat patients with CIDP, becoming the first and only FcRn blocker indicated for this patient population. The approval was supported by results from the pivotal phase 3 ADHERE trial (NCT04281472), which showed that Vyvgart Hytrulo significantly reduced relapse risk by 61% compared with placebo (P = .00039), while maintaining a safety profile consistent with earlier studies. Considered the largest clinical trial of CIDP to date, ADHERE consisted of a run-in period where current treatment was stopped followed by an open-label Stage A, which responders to Vyvgart Hytrulo advanced to a randomized, placebo-controlled Stage B.8,9
The company noted that Vyvgart Hytrulo may cause serious adverse effects, including an increased risk of infection, allergic reactions, and infusion-related reactions. Signs of infection can include fever, cough, sore throat, and painful urination, whereas allergic reactions may involve rash, swelling, or difficulty breathing. Infusion-related reactions such as high blood pressure, chills, or pain may also occur. The most common adverse effects reported include respiratory tract infections, headaches, urinary tract infections, and injection site reactions.
“The daily burden of CIDP from both the symptoms of the disease and interruption to daily life creates profound unseen challenges for patients,”Butler, executive director of the GBS-CIDP Foundation, said in a statement.1 “Effective new treatments that reduce the need for frequent clinic visits are a welcome option for active patients seeking to regain time and a sense of normalcy in their daily routine. Today’s news about the approval of argenx’s prefilled syringe for at-home self-injection is a significant step forward for those patients seeking a new treatment option.”
