Cyberonics asks FDA approval to reduce study size

Medical device maker Cyberonics Inc. said Wednesday it has asked the Food and Drug Administration to approve reducing the number of patients involved in a post-marketing study of its VNS Therapy system for depression.

The request to trim patient enrollment to 330 from 460 follows a prior FDA amendment to data originally used to design the post-marketing study. Cyberonics said it would still be able to maintain the same study power with the lower amount of participants.

Sales of the company's VNS Therapy system have been lagging since 2007, when the Centers for Medicare and Medicaid Services rejected coverage of the device. The system is shaped like a pacemaker and is implanted in the chest, sending electrical signals to nerves in the neck to alleviate severe depression. It was approved by the FDA in 2005.

The Centers for Medicare and Medicaid Services rejected coverage, however, saying it didn't see a clear benefit after reviewing studies submitted by Cyberonics.

Cyberonics has been cutting staff in the wake of that decision.

In morning trading, shares fell 27 cents to $16.21.