The FDA expanded the indication of efgartigimod alfa and hyaluronidase-qvfc (Vyvgart Hytrulo) Friday to include treatment of adults with chronic inflammatory demyelinating polyneuropathy (CIDP), drugmaker .
The FDA's decision marked a "groundbreaking day" for CIDP treatment, said Jeffrey Allen, MD, of the University of Minnesota in Minneapolis, a principal investigator for the drug's pivotal trial.
CIDP is a rare and debilitating immune-mediated neuromuscular disorder of the peripheral nervous system. "Existing treatments have been limited to corticosteroids and plasma-derived therapies," Allen noted in a press release. "These treatments, while effective for many patients, can be challenging for some patients to receive."
The approval of the efgartigimod-hyaluronidase combination "gives doctors and patients a new, safe, and effective treatment option that may lessen the burden of treatment that some patients experience," he added.
The treatment, a weekly 30-to-90 second subcutaneous injection, is the first neonatal Fc receptor (FcRn) blocker approved for CIDP. It works by decreasing the recycling of immunoglobulin G (IgG) and reducing pathogenic IgG autoantibody levels that may play a role in CIDP. FcRn blockers first became available in 2021 with the approval of IV efgartigimod (Vyvgart) for generalized myasthenia gravis.
CIDP often results in serious cumulative disability despite some improvement in most patients with first-line therapies of corticosteroids, IV or subcutaneous immunoglobulin, or plasmapheresis.
"While CIDP patients face many daily concerns and challenges, fear of disease progression should not be one of them," noted Lisa Butler, executive director of the GBS|CIDP Foundation.
"The approval of this promising new treatment option for CIDP may provide hope to patients that they can treat their disease beyond just managing symptoms," Butler said in the press release. "CIDP patients deserve treatment options, and we look forward to a future of choices for optimal and individualized care."
The FDA based its decision on the trial of 322 CIDP patients. In Stage A of ADHERE, 214 patients (66.5%) experienced improvements with efgartigimod-hyaluronidase and were classified as treatment responders. Stage B showed that treatment responders had a compared with placebo for up to 48 weeks of weekly treatment (HR 0.39, 95% CI 0.25-0.61, P=0.000039).
Most treatment-emergent adverse events were mild to moderate. Three deaths occurred, but none were considered related to efgartigimod treatment.
Safety results were generally consistent with the known safety profile of efgartigimod in previous clinical studies and real-world use, argenx said. warned against infections, hypersensitivity reactions, and infusion-related reactions.
The open-label to assess the long-term safety and efficacy of the efgartigimod-hyaluronidase combination is ongoing.