Please ensure Javascript is enabled for purposes of website accessibility

Here's Why Solid Biosciences Fell as Much as 40.9% Today

By Maxx Chatsko – May 14, 2019 at 12:26PM

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

The gene therapy developer appears to be struggling to find a safe and effective dose of its experimental Duchenne muscular dystrophy treatment.

What happened

Shares of Solid Biosciences (SLDB -0.89%) fell nearly 41% today after the company announced first-quarter 2019 operating results and provided a business update. The clinical-stage biopharma reported that its lead drug candidate, an experimental gene therapy for Duchenne muscular dystrophy (DMD), started to be administered to a second cohort of patients in its ongoing phase 1/2 clinical trial. A serious adverse event related to the treatment was observed in the first patient dosed. 

While the issues were resolved and reported to the U.S. Food and Drug Administration, Solid Biosciences is just one of several companies and universities developing gene therapies aimed at boosting the expression of microdystrophin in DMD patients. That makes it easy for Wall Street to sell the news, especially in context of the business update from February.

As of 11:52 a.m. EDT, the stock had settled to a 27.8% loss.

A scientist in the lab with a disappointed look on his face.

Image source: Getty Images.

So what

Solid Biosciences reported that the first patient in the new dosing cohort was diagnosed with a gastrointestinal infection, but that was classified as a serious adverse event unrelated to the gene therapy candidate, SGT-001. That same patient also experienced a reduction in platelet count, which was a serious adverse event attributed to the experimental treatment. Additionally, the patient had a spike in transaminases and bilirubin -- biomarkers related to liver function -- that had to be brought back to normal ranges with additional drugs.

The development follows an update from February in which preliminary data showed the starting dose of SGT-001 had little effect on microdystrophin expression. Shares of Solid Biosciences fell more than 73% on that news.

In other words, the lowest dose tested doesn't appear to be effective, while the next-highest dose studied caused safety issues in the first patient receiving it.

Now what

To be blunt, this could prove to be an existential blow to Solid Biosciences. Advances in gene therapy delivery and manufacturing have led to a highly competitive landscape. For instance, Sarepta Therapeutics is racing ahead with its own microdystrophin gene therapy, which has delivered an increase of more than 81% in protein expression and no signs of adverse effects in early studies. While Solid Biosciences exited March with about $95 million in cash on hand, the latest clinical development suggests it may need to go back to the drawing board. 

Maxx Chatsko has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.

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

Solid Biosciences Inc. Stock Quote
Solid Biosciences Inc.
$6.67 (-0.89%) $0.06
Sarepta Therapeutics Stock Quote
Sarepta Therapeutics
$114.57 (-0.15%) $0.17

*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 analyst team.

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 11/26/2022.

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

Premium Investing Services

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