UPDATE 1-Amicus' Gaucher drug fails in mid-stage trial

* Says to further evaluate the data

* Shares plunge 40 pct in extended trade

Oct 2 (Reuters) - Amicus Therapeutics Inc (FOLD.O) said preliminary data from a mid-stage trial showed its experimental treatment for Gaucher disease did not meet endpoint, sending its shares plunging 40 percent in extended trade.

Amicus' drug Plicera would have competed directly with Genzyme Corp's GENZ.O biggest product Cerezyme.

Based on the data, Amicus does not expect to advance the drug into a late-stage trial, the company said in a statement.

Clinically meaningful improvements in key measures of disease were observed in just one of the eighteen patients who completed the study, the company said.

The preliminary data suggest that treatment with Plicera was generally well tolerated, with no serious adverse events reported, it said.

In Gaucher patients, organs such as the spleen and liver become enlarged due to the lack of the enzyme needed to break down fats.

The company said it now expects to end 2009 with about $70 million to $80 million in cash.

Shares of the company fell to $5.10 in after-hours trade. They closed at $8.50 Friday on Nasdaq. (Reporting by Shailesh Kuber in Bangalore; Editing by Ratul Ray Chaudhuri)