New York, May 20, 2026, 16:03 (EDT)
argenx SE’s U.S. shares inched up Wednesday, trailing the biotech sector after Immunovant released rheumatoid-arthritis data that drew new focus to the same drug class as argenx’s VYVGART franchise.
ARGX was trading at $803.67 near the end of the session, up 0.7%. The iShares Nasdaq Biotechnology ETF added 2.1% and SPDR S&P Biotech ETF climbed 3.8%. Shares of Immunovant soared 35.1%. Roivant Sciences, Immunovant’s parent, rose 14.6%, according to market data.
argenx is split out here because its price is tied to VYVGART, which blocks the FcRn protein. FcRn stands for neonatal Fc receptor, a target for lowering IgG autoantibodies—these drive some autoimmune diseases. VYVGART netted $1.3 billion in sales for the first quarter, up 63% year over year. CEO Karen Massey called it the “17th consecutive quarter of VYVGART growth.” argenx
Immunovant posted new data in the antibody-lowering space. The company reported that IMVT-1402 hit ACR20, ACR50 and ACR70 response rates of 72.7%, 54.5% and 35.8% at 16 weeks in the open-label portion of a hard-to-treat rheumatoid arthritis study. ACR20 measures at least 20% improvement in swollen and tender joint counts and other clinical markers.
David Risinger at Leerink Partners told Investor’s Business Daily the results are “highly compelling.” He said IMVT-1402 might be a blockbuster for patients who haven’t responded to other treatments. Investors
argenx holds its lead in the market. The U.S. Food and Drug Administration this month expanded the labels for VYVGART and VYVGART Hytrulo, covering all adults with generalized myasthenia gravis, or gMG, a rare autoimmune disorder linked to muscle weakness and fatigue. Chief Medical Officer Luc Truyen called the decision a way to “simplify treatment decisions” for doctors. Argenx
argenx finished up 0.8% at 690.40 euros in Brussels. Fourteen analysts polled by MarketScreener had a Buy consensus and saw an average target of 845.01 euros.
argenx shares barely moved, and timing looks like a factor. The next planned catalysts aren’t coming from today’s news. The company’s big updates are due later, with myositis data expected in the third quarter and empasiprubart results in multifocal motor neuropathy set for the fourth quarter.
But the risk goes both ways. Roivant’s investor deck called the IMVT-1402 rheumatoid-arthritis data preliminary and flagged another big update in the second half, pending more analysis and talks with the FDA. If rival data tops what’s out, argenx’s valuation premium could take a hit. A weaker next readout would leave Wednesday’s peer rally looking overdone.
ARGX didn’t trade like it was under siege but more like a typical big biotech facing a shift as the space gets more crowded. VYVGART is still its key asset. The market is focused on whether that is still enough for argenx while rivals move further into FcRn.
