Eli Lilly and Co said on Wednesday its experimental schizophrenia drug known as mGlu2/3 did not work in a late stage clinical trial.

The trial was intended to be the first of two late-stage tests of the drug as a stand-alone treatment in acute schizophrenia. A second trial is continuing and the company expects to conduct an interim analysis and present the results later this year.

The company is also awaiting the results of a recently concluded mid-stage study examining the drug, also known as pomaglumetad methionil, as a combination treatment with existing drugs known as atypical antipsychotics.

"Unfortunately, negative studies are common in the field of psychiatry and a reality of biopharmaceutical innovation," said Jan Lundberg, president of Lilly Research Laboratories.

Mark Schoenebaum, an analyst at ISI Group, said Wall Street expectations for the drug were low and the news should not significantly hurt the company's stock.

Even so, he said: "The long term investment case for Lilly depends mostly on the pipeline, as it does for all pharma/biotech stocks."

The schizophrenia trial failure "adds another, albeit modest, disappointment," he said.

The company had hoped to show the drug worked without some of the side affects associated with existing treatments, such as weight gain, elevation of lipids and reproductive hormone irregularity.