Please ensure Javascript is enabled for purposes of website accessibility
Free Article Join Over 1 Million Premium Members And Get More In-Depth Stock Guidance and Research

Here's Why AnaptysBio Shares Are Sliding Today

By Cory Renauer - Jun 21, 2019 at 2:47PM

You’re reading a free article with opinions that may differ from The Motley Fool’s Premium Investing Services. Become a Motley Fool member today to get instant access to our top analyst recommendations, in-depth research, investing resources, and more. Learn More

A potential competitor stumbled in a midstage asthma trial.

What happened

Shares of AnaptysBio ( ANAB -4.64% ), a clinical-stage biotechnology company, are sliding in response to results recently posted by Regeneron ( REGN 0.18% ) for REGN3500. Investors, worried that mediocre results for Regeneron's IL-33 antibody mean trouble for AnaptysBio's lead candidate, pushed the stock 10.9% lower as of 2:46 p.m. EDT on Friday.

So what 

AnaptysBio's lead candidate, etokimab, reduces inflammation by inhibiting IL-33, which is the same target REGN3500 aims for. Regeneron didn't share all the details from a recently completed midstage study with REGN3500 as a treatment for eosinophilic asthma, but the biotech did share something disturbing. Patients dosed with Dupixent, an IL-4 antagonist approved to treat eczema and asthma, showed that the drug outperformed REGN3500 on its own.

Guy in a suit drawing a downward sloping chart.

Image source: Getty Images.

The purpose of the study was to test REGN3500 plus Dupixent against Dupixent monotherapy, but investigators also treated a group of patients with REGN3500 on its own. Patients receiving Regeneron's IL-33 drug on its own underperformed the Dupixent-only group. Also, patients given REGN3500 in combination with Dupixent didn't perform any better than those treated with Dupixent as a monotherapy.

Now what

This outcome is troubling because there's little chance that AnaptysBio will record significant sales of etokimab if it can't clearly outperform Dupixent. But don't assume AnaptysBio's candidate will fizzle until you get a closer look.

So far, all we know is that a handful of patients treated with an IL-33 candidate that Regeneron had on the back burner didn't perform significantly better than those given available care in one of three indications AnaptysBio is pursuing with etokimab. Before assuming that AnaptysBio's IL-33 candidate is doomed, it's important to realize that Regeneron's study split just 38 asthma patients up into five different groups, so an outlier or two could have made its IL-33 drug look much worse than it really was.

We'll know more about etokimab's chances of outperforming Dupixent as a treatment for eczema when the company reports results from a phase 2 study in the second half of the year.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis – even one of our own – helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.

Invest Smarter with The Motley Fool

Join Over 1 Million Premium Members Receiving…

  • New Stock Picks Each Month
  • Detailed Analysis of Companies
  • Model Portfolios
  • Live Streaming During Market Hours
  • And Much More
Get Started Now

Stocks Mentioned

AnaptysBio Stock Quote
$30.20 (-4.64%) $-1.47
Regeneron Pharmaceuticals, Inc. Stock Quote
Regeneron Pharmaceuticals, Inc.
$635.16 (0.18%) $1.16

*Average returns of all recommendations since inception. Cost basis and return based on previous market day close.

Related Articles

Motley Fool Returns

Motley Fool Stock Advisor

Market-beating stocks from our award-winning service.

Stock Advisor Returns
S&P 500 Returns

Calculated by average return of all stock recommendations since inception of the Stock Advisor service in February of 2002. Returns as of 12/05/2021.

Discounted offers are only available to new members. Stock Advisor list price is $199 per year.

Our Most Popular Articles

Premium Investing Services

Invest better with the Motley Fool. Get stock recommendations, portfolio guidance, and more from the Motley Fool's premium services.