Here's Why Vertex Pharmaceuticals Fell 23.4% in October
Shares of Vertex Pharmaceuticals (NASDAQ: VRTX) fell 23.4% in October, according to data from S&P Global Market Intelligence after the biotech discontinued development of a drug for alpha-1 antitrypsin deficiency (AATD).
Some patients in a midstage clinical trial of VX-814 developed elevated levels of liver enzymes, which is a sign that the drug is causing liver damage. The patients didn't have any symptoms, but Vertex would need to increase to dose further, which could cause real harm, so the biotech decided to discontinue development of VX-814.
Liver damage is one of the most common reasons companies stop development of drugs for safety concerns. It's a little surprising Vertex didn't discover the safety signal in the early sage clinical trial, but perhaps the first study wasn't large enough to discover the issue.
Source Fool.com
