Vertex Pharma shares surge 21% after cystic fibrosis study results leaves Wall Street 'speechless'
Shares of Vertex Pharmaceuticals surged more than 21 percent during midday trading Wednesday, as the drugmaker crushed Wall Street's expectations when it reported an improved response in patients suffering from cystic fibrosis.

The biotech company told CNBC on Tuesday that its three-drug cocktails boosted a measure of lung function in patients with cystic fibrosis by 9.6 percentage points or more. The response was better than what Wall Street expected for the drug combination, and prepares Vertex to advance a medicine which could treat thousands more people suffering from the disease.

The "initial triple combo data does leave us speechless," JPMorgan analyst Cory Kasimov wrote in a note. "This series [of updates] is highly impressive across the board."

Anything more than 2.5 percentage points would have been considered a success by Wall Street, according to Michael Yee, an analyst at Jefferies. He wrote in a July 10 research note that results of that magnitude could drive Vertex's shares above $150 (from $130 at that time; they closed Tuesday at $132.16).

The new results are from studies aiming to expand treatment options to 90 percent of cystic fibrosis patients, as the majority of patients today do not have approved treatment options to target the cause of the disease.