Here's Why Shares Of Vertex Pharmaceuticals Tumbled

Shares of Vertex Pharmaceuticals Incorporated VRTX tumbled by more than 6 percent on Friday after the company confirmed it has received a letter from the U.S. Food and Drug Administration for use of Kalydeco in people with cystic fibrosis.

Vertex Pharmaceuticals said that it received a Complete Response Letter from the U.S. FDA for its supplemental New Drug Application (sNDA) for the use of Kalydeco. The letter stated that the FDA cannot approve the application in its current form.

Vertex Pharmaceuticals added that it plans on meeting with the FDA to determine an appropriate path moving forward.

"Our intention with this submission was to rapidly bring KALYDECO to additional people with CF who we believe may benefit," said Vertex Executive Vice President and Chief Medical Officer, Jeffrey Chodakewitz, M.D. "We chose to pursue this approach given our strong belief in the science of CF and in the well-established safety of KALYDECO across many different groups of people with CF. We are disappointed by this decision and look forward to discussing with the FDA the next steps to bring KALYDECO to people with CF who have these residual function mutations."