Argenx's Vyvgart sales surge after rare neuro disorder launch

Argenx's drug Vyvgart has once again surpassed sales expectations for the eleventh consecutive quarter, bolstered by the successful adoption of its subcutaneous version in its latest indication.

In the third quarter, Vyvgart generated $573 million in revenue, exceeding market expectations of $531 million. This impressive performance was largely driven by patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) beginning treatment with the subcutaneous form, Vyvgart Hytrulo, following its FDA approval in June.

The announcement of these results saw Argenx's shares ($ARGX) rise by approximately 5% at the start of trading on Thursday.

By the end of the third quarter, over 300 CIDP patients were prescribed Vyvgart Hytrulo, a number significantly higher than the 122 patients estimated by analysts from William Blair. The analysts also noted that a quarter of the prescribers were new to the Vyvgart franchise, and they anticipate further access expansion in the coming quarters.

Vyvgart initially gained FDA approval in 2021 for use in certain patients with generalized myasthenia gravis (gMG), with the subcutaneous version receiving approval in June of the previous year. Argenx has also filed for approval of a pre-filled syringe formulation, which would enable gMG and CIDP patients to self-administer the drug. The decision on this submission is expected by April 10.

In other developments, Argenx has decided to discontinue the development of Vyvgart for membranous nephropathy. However, the company remains committed to achieving approvals for 10 indications by 2030. Vyvgart is currently undergoing registrational development for thyroid eye disease, seronegative gMG, and ocular myasthenia gravis. Additionally, a pivotal trial for Sjögren’s disease is set to commence by the end of the year.

Despite these advancements, competition in the myasthenia gravis space is intensifying. UCB's Rystiggo received FDA approval in June 2023, making it the first treatment approved for both anti-acetylcholine receptor and anti-muscle-specific tyrosine kinase antibody-positive patients.