NEW YORK (TheStreet) -- Celladon (CLDN) shares have lost more than 80% of their value in trading on Monday, down 80.35% to $2.69, after the San Diego-based company said that Mydicar, its experimental gene therapy for heart failure, failed to the show any improvement over a placebo in its CUPID2 trials.

The announcement was met with consternation as Wedbush analysts downgraded the company's stock to "neutral" from "outperform" today, while also slashing its price target by 90% to $3 from $29.

Celladon shares traded as high as $13.68 as recently at the close of trading on Friday and as high as $27.26 per share on March 19 before the release of the test results yesterday.

Separately, analysts at Roth Capital also downgraded to company's stock to "neutral" from "buy" today.

TheStreet has further coverage of Celladon's test results here.

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