The world's biggest insulin producer Novo Nordisk Monday had 10.7 billion euros ($14.4 billion) wiped off its market value after the company said US authorities had rejected its applications for two new insulin treatments.
Shares in the Danish company plunged by up to 15 percent after the US Food and Drug Administration (FDA) said "approvals for Tresiba and Ryzodeg cannot be granted" until the company provides additional information.
The FDA requested more cardiovascular data, which Novo Nordisk said it was unlikely to be able to provide this year.
"We are surprised and disappointed to receive this letter, but we acknowledge this decision by the FDA and will work with the agency to determine the best path forward to completing the review," chief executive Lars Rebien Soerensen said in a statement.
"We are convinced that Tresiba and Ryzodeg offer significant benefits for people who require insulin," he said.
The two new products have been approved in the EU, Japan and Mexico and are under regulatory review in several other countries, the company said.
Shares in French pharmaceutical company Sanofi rose on Monday since its diabetes treatment Lantus is considered the main rival to Tresiba.
Novo Nordisk said the announcement wouldn't "significantly impact" its full year guidance. According to its full-year outlook published on January 31, it expects revenue to rise by 8-11 percent this year, and operating profit to grow 10 percent.
Tresiba is the brand name for the company's new, long-acting insulin. Ryzodeg combines the substance with an insulin analog that acts more quickly.
Novo Nordisk controls around 49 percent of the global insulin market, which has grown rapidly in recent years following a rise in the number of people suffering from diabetes, estimated by the World Health Organisation to stand at around 347 million.
The company's net profit surged 25 percent last year to 2.9 billion euros, on sales that were up 18 percent.
Shares in the company -- a Copenhagen bourse heavyweight -- closed 13.22 percent lower on Monday to 928.5 kroner. Denmark's OMXC20 index closed down 6.56 percent.