ZURICH (Reuters) - Shares in Santhera (SANN.S: Quote, Profile, Research) plummeted on Friday after it failed to secure a positive recommendation from the European Medicines Agency (EMEA) for the use of its Friedreich's Ataxia drug idebenone.

EMEA formally advised Santhera it would not support a positive opinion for the marketing authorisation application (MAA) for idebenone, Santhera said in a statement.

By 0915 GMT, shares in the Swiss biotech group had fallen nearly 14 percent to 82 Swiss francs, erasing the gains made so far this year.

"The CHMP (Committee for Medicinal Products for Human Use) concluded that Santhera had not submitted a sufficient set of data demonstrating a clear positive risk/benefit balance for approval under the Committee's standard clinical review guidelines," the group said.

The additional data that must be submitted will result in a delay of around two years for the drug, said Vontobel analyst Andrew Weiss.

"We have adjusted our sales forecast for idebenone in the treatment of Friedreich's Ataxia in Europe accordingly," Weiss said.

Friedreich's Ataxia is a rare genetic neuromuscular disease that causes the degeneration of an individual's nerve and muscle tissue and results in a loss of muscle control, uncoordinated movements, muscle wasting and thickening of heart walls.

(Reporting by Katie Reid, editing by Will Waterman)