新型脑部刺激装置治疗抑郁症
2008-05-12
St Jude Device Helps Severe Depression For Some - Study
An early-stage study examining use of a St. Jude Medical Inc. (STJ) brain- stimulation device in severely depressed patients showed it had a positive effect in most cases, the company said.
St. Jude recently launched a major clinical study aimed at finding evidence to eventually seek regulatory approval for the invasive treatment, which involves implanting electrodes into a certain part of the brain and sending electric pulses from a pacemaker-like device. Rival Medtronic Inc. (MDT) is also pursuing this type of technology as a depression treatment, but the companies are targeting different areas of the brain.
The prospect of treating severely depressed people has generated interest in the medical devices sector, considering the potential for a market with an estimated 4 million patients in the U.S. Treatment with devices could someday open a new door for patients, meanwhile, who have failed treatment attempts with many different drugs or with electroconvulsive therapy.
In the pilot study with St. Jude's device, 20 patients were implanted with the company's Libra deep brain stimulation system. After six months, 56% of the patients had at least a 40% decrease in depressive symptoms, as measured by a standardized test.
Patients were enrolled at different times and have therefore not had the device for the same amount of time. Looking at patients during their most recent psychiatric evaluation, 78% of them experienced at least a 40% decrease in symptoms, St. Jude said.
Results from this study were set for presentation on Monday at the American Psychiatric Association meeting in Washington.
One patient in the study committed suicide, according to Rohan Hoare, vice president of research and development at St. Jude's ANS Division. But that event was considered a result of the disease, rather than the therapy, he said.
St. Jude got into the neuromodulation business, which includes the deep brain stimulation technology, by purchasing Advanced Neuromodulation Systems, or ANS, in 2005.
St. Jude does not yet have approval for its deep brain stimulation technology, although it is pursuing approval to treat Parkinson's disease and essential tremor. Medtronic's system is approved by the Food and Drug Administration for both of those problems, and has a certain kind of approval that allows a small number of device sales to treat the movement disorder dystonia.
Research with St. Jude's device is centered around treatment of an area of the brain called "Brodmann Area 25" that researchers believe is linked to severe depression. St. Jude announced last month that it has been awarded a U.S. patent for using neurostimulation in this area to treat depression.
Researchers studying use of the Medtronic device are targeting a different part of the brain. Data on 16 patients treated with Medtronic's system, recently released at a separate conference, showed that half of those patients had a 50% decrease after a year, according to a depression-measuring system. Medtronic plans to launch a major study on use of its device in depressed patients later this year.
While the bigger studies will randomize patients in treated and un-treated groups to guard against the placebo effect, patients in the early stage studies for St. Jude and Medtronic were not randomized. But researchers in both cases suggested that because symptoms are so severe for these patients, and because they have failed so many other treatments, that the likelihood of a long-lasting placebo effect is small.
Medtronic and St. Jude are not alone in the hunt to treat depression with devices. Cyberonics Inc. (CYBX) was an early mover into that market with a system that stimulates a major nerve, and is commonly used today to treat epilepsy. While it won regulatory approval for depression, Cyberonics hit a wall last year when Medicare declined to provide reimbursement backing.
Northstar Neuroscience Inc. (NSTR) is exploring a different kind of system that stimulates the outer surface of the brain, or cortex, to treat depression.
