Cyberonics, Inc announced that the US Food and Drug Administration (FDA) has approved the company's proposal to amend the protocol of its D-21 post-approval dosing study in depression patients treated with VNS Therapy.

The company submitted a proposal in November 2008 to reduce the number of study subjects from 460 to 330 and completed enrolment of 331 study subjects in February 2009. With this decision from the FDA, the company expects to complete the follow-up on all patients enrolled in the study by March 2010.

Cyberonics is a medical technology company with core expertise in neuromodulation. The company developed and markets the Vagus Nerve Stimulation (VNS) Therapy System, which is FDA-approved for the treatments of refractory epilepsy and treatment-resistant depression.