Argenx shares plunge 16% after Sjögren’s drug trial halted
Argenx shares dropped 16% after halting a Phase 3 trial of efgartigimod for Sjögren’s disease due to unlikely success. The independent committee recommended stopping the study as it wouldn't meet the primary endpoint. The company plans to analyze the data further. Efgartigimod is approved for other conditions in Japan.
How this was made
The 30-second read
Why it matters
The announcement triggered a sharp sell‑off, reflecting the material impact of clinical‑trial outcomes on biotech valuations.
Market read
The trial halt is a primary corporate event with immediate price impact, making it a high‑value trading signal for ARX.
What to watch
The drug remains approved for other indications, providing some revenue base and potential for future development.
Background
argenx announced the early termination of its late‑stage trial for efgartigimod in Sjögren’s disease after an interim analysis indicated low probability of meeting the primary endpoint.
Market effects
The setback may weigh on the broader autoimmune‑therapy biotech sector as investors re‑evaluate pipeline risks.
European biotech indices could see modest downside pressure given argenx’s Belgian base.
Limited to biotech investors; no broad market impact expected.
Counterpoint
If the company can pivot the asset to another indication, the stock may recover over the longer term.
Key entities
- companyargenx
Belgian biotech firm developing efgartigimod.
- drugefgartigimod
Antibody fragment being tested for Sjögren’s disease.


