FDA provides a Complete Response Letter for Somaxon Pharmaceuticals' Silenor NDA

Dec 7 2009

Somaxon Pharmaceuticals, Inc. (Nasdaq: SOMX), a specialty pharmaceutical company focused on the in-licensing, development and commercialization of proprietary branded pharmaceutical products and late-stage product candidates for the treatment of diseases and disorders in the central nervous system therapeutic area, today announced that the company has received a Complete Response Letter from the U.S. Food and Drug Administration (FDA) for its New Drug Application (NDA) for Silenor^® (doxepin) for the treatment of insomnia. Based on its review, the FDA has determined that the NDA cannot be approved in its present form. Somaxon previously received a Complete Response Letter for the NDA in February 2009, and it resubmitted the NDA in June 2009.

In the most recent Complete Response Letter, the FDA stated that the Silenor NDA did not meet the approval standard for efficacy due to a lack of robustness of sustained subjective sleep maintenance efficacy in adults with primary insomnia.

With respect to safety, the most recent Complete Response Letter did not raise any clinical safety issues. This is consistent with the February 2009 Complete Response Letter, in which the FDA noted that there were no adverse events observed in the clinical studies included in the NDA that would preclude approval. The most recent Complete Response Letter did request that the company submit an amended Risk Evaluation and Mitigation Strategy (REMS), including a Medication Guide to be distributed with the product, in any resubmission of the NDA.

Because the most recent Complete Response Letter did not contain any specific requirement to conduct any additional clinical work or other specific guidance to address the issue raised by the FDA, Somaxon believes that a meeting with the FDA will be necessary to discuss the basis for the FDA’s decision and to seek such specific guidance. The company intends to schedule this meeting as soon as possible.

“We are disappointed in the decision because we believed that our June NDA resubmission adequately addressed the concerns raised by the FDA in its February Complete Response Letter,” said Richard W. Pascoe, Somaxon’s president and chief executive officer. “We have carefully reviewed the current Complete Response Letter and have requested a formal meeting with senior FDA leadership to discuss its conclusions.”

“In the February Complete Response Letter, the FDA acknowledged objective and subjective efficacy at the beginning and end of treatment in elderly patients, and at the beginning of treatment for non-elderly adult patients, and the most recent Complete Response Letter did not alter those conclusions,” continued Pascoe. “In addition, statistical significance on the primary endpoint and multiple secondary endpoints was achieved for all of our four Phase 3 clinical trials and both of our Phase 2 clinical trials for Silenor. We are consulting with our clinical and regulatory advisors and intend to take all steps we deem appropriate to seek approval and commercialization of this product candidate.”