The Medicines and Healthcare products Regulatory Agency (MHRA) has authorised a new subcutaneous (SC) formulation of argenx’s Vyvgart (efgartigimod alfa) for generalised myasthenia gravis (gMG).
The regulator has specifically licensed the SC injectable version of the FcRn blocker, co-formulated with Halozyme’s proprietary recombinant human hyaluronidase technology, for use as an add-on to standard therapy for adult gMG patients who are anti-acetylcholine receptor (AChR) antibody positive.
Vyvgart is now authorised in the UK for both intravenous (IV) and SC use, including possible SC self-administration.
The MHRA’s latest decision is supported by positive results from the late-stage ADAPT-SC study, in which SC Vyvgart was found to be as effective as the IV version at reducing anti-AChR antibody levels.
gMG is a rare and chronic autoimmune disease where IgG autoantibodies disrupt communication between nerves and muscles, causing debilitating and potentially life-threatening muscle weakness.
Patients with confirmed anti-AChR antibodies account for approximately 85% of the total gMG population.
David Knechtel, general manager of argenx UK, said: “[The] authorisation marks another important step forward for the management of gMG in the UK, offering a simpler way to administer [Vyvgart] through a SC injection.”
“Our focus now will be on ensuring seamless access to this medicine for all those who could potentially benefit, and we are working closely with authorities across the UK to make this a reality,” Knechtel added.
SC Vyvgart was approved by the European Commission and US Food and Drug Administration for the same gMG population in November and June 2023.
Commenting on the latest authorisation, Sivakumar Sathasivam, consultant neurologist and myasthenia gravis lead at the Walton Centre, said: “There is a clear unmet need for an effective therapy that can be used to manage gMG patients whose symptoms remain significantly uncontrolled despite established clinical management.
“SC [Vyvgart] provides a new and easier-to-administer treatment option for these people, with the ability to potentially impact their quality of life and disease burden.’’
Beyond gMG, argenx said it is also evaluating efgartigimod in multiple serious autoimmune diseases and advancing several earlier-stage experimental medicines.