Argenx has filed for FDA approval of subcutaneous efgartigimod, keeping it on track to start selling the sibling of its existing intravenous generalized myasthenia gravis (gMG) treatment Vyvgart.
In March, argenx revealed a phase 3 clinical trial found the subcutaneous candidate was noninferior to the already approved Vyvgart. The subcutaneous formulation has the same active ingredient as Vyvgart but a different route of administration. Argenx created the candidate by co-formulating efgartigimod with Halozyme’s rhuPH20 enzyme, the delivery technology behind a clutch of subcutaneous products.
Now, the European biotech has submitted the phase 3 data to the FDA to support approval of the revised formulation. Argenx CEO Tim Van Hauwermeiren sees the subcutaneous and intravenous formulations coexisting.
“Our vision for the gMG program is to deliver the broadest treatment offering for people living with this debilitating, and often overlooked disease. Every individual experiences gMG differently, which is why we’re excited about the possibility of introducing multiple ways to meet the needs of patients, including with route of administration and dosing schedule,” Van Hauwermeiren said in a statement.
The subcutaneous formulation is potentially more convenient because it replaces a one-hour infusion with a one-minute shot and opens the door to home administration. Recipients of the subcutaneous formulation experienced mild to moderate injection site reactions, a common response to the route of administration, but otherwise the candidate performed comparably to its approved intravenous sibling.
The primary endpoint looked at the total IgG reduction from baseline at Day 29. Participants taking the subcutaneous formulation experienced a mean reduction of 66.4%, compared to a 62.2% decline in their peers in the Vyvgart arm.