argenx announces U.S. Food and Drug Administration approval of VYVGART Hytrulo (efgartigimod alfa and hyaluronidase-qvfc) injection for subcutaneous use in generalized myasthenia gravis

VYVGART Hytrulo is a subcutaneous product combination of efgartigimod alfa, a human IgG1 antibody fragment marketed for intravenous use as VYVGART, and recombinant human hyaluronidase PH20 (rHuPH20), Halozyme’s ENHANZE® drug delivery technology to facilitate subcutaneous delivery of biologics. The product is to be administered subcutaneously by a healthcare professional as a single injection (1,008 mg fixed dose) over 30-90 seconds in cycles of once weekly injections for four weeks.

“Today’s approval of VYVGART Hytrulo is another significant milestone on our path to redefine what well-controlled means for gMG patients. The availability of a second argenx innovation in just 18 months also underscores our longstanding commitment to the gMG community by providing more choice and flexibility in how patients receive treatment,” said Luc Truyen M.D., Ph.D., Chief Medical Officer, argenx. “With our broad gMG offering of both a first-in-class infusion and SC injection, we continue to offer an individualized treatment approach and possibility of staying symptom free, while providing patients options of how and where they want to seek treatment. We want to thank the gMG patient community and their supporters, clinical investigators, our employees and all stakeholders who have collaborated with us to advance this subcutaneous option, including our partners at Halozyme.”

“The availability of another gMG treatment option from argenx, now in a subcutaneous delivery, is a meaningful advancement for the patient community. Patients now have the opportunity to receive treatment in an infusion center, at home or at a physician’s office - providing more flexibility and freedom of choice that can make daily living easier for gMG patients and their caregivers,” said Allison Foss, Executive Director of the Myasthenia Gravis Association.

Phase 3 ADAPT-SC Bridging Study

“The clinical trials of VYVGART continue to show significant benefit to patients with a favorable safety profile and clear improvements in gMG disease scores. Now with the approval of VYVGART Hytrulo, we have a broad gMG treatment offering with both IV and SC administration options and can select based on patient needs and preference without sacrificing clinical benefit or safety,” said James F. Howard Jr., M.D., Professor of Neurology (Neuromuscular Disease), Medicine and Allied Health, Department of Neurology, The University of North Carolina at Chapel Hill School of Medicine and Principal Investigator for the ADAPT-SC trial.

This FDA approval is based on positive results from the Phase 3 ADAPT-SC study, which established the efficacy of VYVGART Hytrulo by demonstrating a reduction in anti-AChR antibody levels comparable to intravenous VYVGART in adult gMG patients. ADAPT-SC was a bridging study to the Phase 3 ADAPT study, which formed the basis for approval of intravenous VYVGART in December 2021.

In the ADAPT-SC study, the primary endpoint of noninferiority was met (p< 0.0001) and VYVGART Hytrulo demonstrated mean total IgG reduction of 66.4% from baseline at day 29, compared to 62.2% with VYVGART. Additional key secondary endpoints were met, which were consistent with efficacy measures from the ADAPT study identifying the correlation between total IgG reduction and clinical benefit in gMG.

VYVGART Hytrulo has a demonstrated safety profile, consistent with the ADAPT clinical trial with the exception of injection site reactions (ISRs), which were higher with VYVGART Hytrulo. It was generally well-tolerated with ISRs being the most frequent adverse events. All ISRs, which are commonly observed with biologics administered subcutaneously, were mild to moderate, and resolved over time.

Access to VYVGART Hytrulo

VYVGART Hytrulo is expected to be available for patients in the U.S. in July 2023. argenx is committed to supporting access for patients to its medicines and has decided to price VYVGART Hytrulo at parity to VYVGART on a net annual revenue basis.

Throughout their treatment journey, patients can access VYVGART Hytrulo in the same personalized way they access VYVGART today with support from My VYVGART Path. Program resources include disease and product education, access support and benefits verification, and financial assistance programs for eligible patients. Patients and clinicians can access more information at VYVGARTHytrulo.com.

Marketing authorization applications for SC efgartigimod are under review by the European Medicines Agency with a decision expected by the end of 2023, and Japan’s Pharmaceuticals and Medical Devices Agency (PMDA) with a decision expected by the first quarter of 2024.