ARGX Stock Sinks as Argenx Scraps Late-Stage Trial

Argenx (ARGX) stock tumbled on Oct. 8 after the biotech firm discontinued a Phase 3 trial of its blockbuster drug Vyvgart in Sjögren’s disease. ARGX’s decision came after an independent data-monitoring committee determined the study was unlikely to meet its primary endpoint. 

The setback overshadowed encouraging Phase 2 trial results for FB102 in celiac disease — another experimental treatment in Argenx’s pipeline. ARGX shares are now trading nearly 24% below their year-to-date high. 

Here’s why Argenx Stock Tanked on Thursday

ARGX said it will discontinue the Phase 3 UNITY study evaluating subcutaneous efgartigimod — the active ingredient in Vyvgart — in adults with moderate-to-severe Sjögren’s disease. This triggered a selloff in the biotech stock primarily because of the lost growth opportunity. 

Sjögren’s was broadly viewed as an important potential expansion market for Vyvgart, and the trial failure removes a major catalyst from Argenx’s development pipeline.

UBS experts had previously modeled peak annual sales of as much as $3.5 billion for the indication. Vyvgart generated $4.2 billion in revenue in 2025.

Why ARGX Shares Are Worth Buying on the Dip

Today’s plunge in Argenx stock does not necessarily mean that the broader investment thesis is now broken. 

The company remains backed by a rapidly growing Vyvgart franchise and a substantial pipeline beyond Sjögren’s disease. It posted $1.5 billion in Q2 product sales, up 60% year-over-year, while holding $5.2 billion in cash, cash equivalents, and current financial assets as of June 30. 

Importantly, there was some positive pipeline news on Oct. 8 as well.

ARGX said its Phase 2 clinical trial of FB102 in celiac disease met its primary endpoint, and the firm’s management now plans on advancing FB102 into Phase 3 development.

How Wall Street Recommends Playing Argenx

Wall Street firms also currently view Argenx shares as undervalued and recommend buying them at the current price for the long term. 

According to Barchart, the consensus rating on the biotech company sits at “Strong Buy,” with the mean price target of about $1,188 indicating potential upside of roughly 30% from here. 

On the date of publication, Wajeeh Khan did not have (either directly or indirectly) positions in any of the securities mentioned in this article. All information and data in this article is solely for informational purposes. For more information please view the Barchart Disclosure Policy here.