Sepracor tumbles as drugs suffer setback

The firm said its experimental depression medicine, SEP-225289, failed to reduce symptoms of depression following eight weeks of treatment in a phase 2 study involving 514 patients.

Sepracor said the levels of the drug that reached the bloodstream were lower than expected and well below those seen in earlier trials.

Moreover, side effects of the drug were inconsistent with those seen in the earlier studies, the company said.

“While we are clearly disappointed with the findings from the analysis of the preliminary study results, we are in the process of further analysis of the dose response and secondary endpoints to determine how or if we will take this novel mechanistic approach forward,’’ Mark Corrigan, Sepracor’s executive vice president of research and development, said in a release.

The depression drug is a member of a fairly new class of medicines designed to maximize the presence in the brain of three messenger chemicals: serotonin, norepinephrine, and dopamine.

The other setback involved Lunesta, the company’s top-selling medicine, with annual revenue of more than $500 million.

The company had already completed two pediatric studies of Lunesta in 2008 and 2009, aimed at winning a six-month extension of its US patent on the sleeping pill.

It began two additional pediatric studies in April at the request of the FDA, but those studies have been put on “clinical hold’’ because of FDA concerns about nonclinical data that could be relevant to use of the medicine in children, Sepracor said.

Sepracor, in its release, did not identify the issues. Company officials could not immediately be reached for comment.