Somaxon Expects Delay for New Drug

Somaxon Pharmaceuticals (SOMX Quote) said Wednesday that its new drug application (NDA) for insomnia treatment Silenor could be held off to the first quarter of 2008 as a result of a request from the Food and Drug Administration.

The FDA requested more data to determine if Silenor could cause cancer; specifically, the agency asked that data from an ongoing 26-week study in mice be included in the company's NDA submission.

Somaxon said it plans to conduct the standard two-year carcinogenicity study and to submit the results of this study as a post-NDA approval commitment, but the request could force the company to delay its initial NDA submission until the first quarter of 2008.

According to the company, the carcinogenicity study was dependent on the outcome of two other standard studies the FDA requested in May of 2006 and regulators had indicated that the data could possibly be submitted as a post-NDA approval commitment.

Silenor has completed a phase III clinical trial for the treatment of insomnia.

Shares fell $2.33, or 13.3%, to $15.67 in recent trading Wednesday.