argenx 1H25 conference call feedback

argenx reported 1H25 results today, with Vyvgart sales showing a solid CSS beat. In this note you can find our main takeaways from the conference call.
ARGX-119 phase 3 in CMS - argenx emphasized that they currently have 3 assets in phase 3 development with the advancement of ARGX-119 to phase 3 in Congenital Myasthenic Syndrome (CMS). ARGX-119 targets MuSK in the neuromuscular junction and is advanced in CMS, an ultra-rare disease. This allows for a small trial with dense monitoring of patients so argenx will understand the biology well before advancing it to broader trials in ALS and SMA. The company believes that ARGX-119 has pipeline-in-a-product potential in diseases caused by issues at the neuromuscular junction.
Gross to net outlook – Gross to net is expected to remain at ~20%, and even when increased, the net revenue per patient remains constant due to other variables like number of cycles per patient per year, higher convenience of PFS and dosing differences. Overall, growth will offset gross to net increases.
Competition? - Competition is heating up, argenx is raising the bar on what patients can expect and has more data on safety and efficacy. They welcome innovation because it is great for patients, but they will keep the lead. However, they do expect some impact in the following quarters from JnJ, not because it is a better drug but because JnJ is a marketing machine.
gMG/CIDP opportunity? – argenx is still growing strong Q/Q after 14 quarters and the TAM is still large. MG: Biologics is still only 10% of whole market, PFS expands access, seronegative and ocular will lead to broadest label for Vyvgart. CIDP: 2,500 patients treated, 85-90% of patients come from IVIg and are uncontrolled, earlier line should come in future and depends on insurance firms but we are still early on the growth curve. argenx will apply the same playbook as in MG.