This biotech stock is down 25% on Wednesday: find out why

Argenx SE (NASDAQ: ARGX) says a late-stage trial of its candidate drug for an autoimmune condition failed to meet the primary or secondary endpoints. Its shares are down 25% at writing.

Here's what we know so far

The said study tested its efgartigimod (subcutaneous) as a treatment of pemphigus – a disease that causes chronic blistering of the skin.

Argenx has decided in favour of not developing the drug for that autoimmune condition following today’s results. Still, Luc Truyen – its Chief Medical Officer said in a press release today:

Last month, the Netherlands-based company reported $329 million in global net product sales for its third quarter. Argenx stock is now down close to 40% versus its year-to-date high.

Analyst reacts to today's news

Note that the U.S. Food and Drug Administration (FDA) has already approved formulations of efgartigimod for myasthenia gravis.

But the biotech firm is now reviewing and may alter the design of a trial that’s testing the same drug in patients of bullous pemphigoid. Thomas Smith – a Leerink Partners analyst said in a research note this morning:

Still, Smith maintained Argenx stock at “outperform” on Wednesday. Heading into today, he expected the company’s Vyvgart Hytrulo to eventually hit $716 million in global sales as pemphigus treatment and $1.6 billion as bullous pemphigoid treatment.