St. Jude Medical announces results of Genesis neurostimulator trial on chronic migraine

St. Jude Medical, Inc.Jun 23 2011

St. Jude Medical, Inc. (NYSE:STJ), a global medical device company, today announced study results on the safety and efficacy of peripheral nerve stimulation (PNS) of the occipital nerve for the management of pain and disability associated with chronic migraine, a debilitating condition that affects millions worldwide. Presented at the 15^th International Headache Congress in Berlin, Germany, the study shows statistically significant improvement across multiple measures including a reduction in the number of headache days per month and improvement in quality of life. This is the largest clinical study to date evaluating the use of PNS via an implanted medical device for the treatment of chronic migraine.

The study followed 157 participants who, on average, suffered from headache 26 days per month. Study participants were implanted with the St. Jude Medical Genesis™ neurostimulator and randomly assigned to an active or control group for 12 weeks. The active group received stimulation immediately upon implant, while patients in the control group did not receive stimulation until after the first 12 weeks. All patients were followed for one year. At one year, 66 percent of patients reported excellent or good pain relief.

At 12 weeks, the study demonstrated the following statistically significant results:

• Patients who received stimulation reported a 28-percent decrease in their number of headache days (seven less days a month) compared to the placebo group which reported a 4-percent decrease (one less day per month).
• Overall disability as measured by the Migraine Disability Assessment questionnaire (MIDAS) indicated participants in the active group had a 41-percent improvement compared to a 13-percent improvement in the placebo group.
• Zung Pain and Disability Index (PAD) scores improved in the active group by 20 percent compared to an 8-percent improvement in the placebo group.
• In addition to the standardized scales (MIDAS and PAD), patients were asked to subjectively assess their pain relief. The active group reported 42-percent pain relief compared to 17 percent in the placebo group.
• Patients in the study were asked to define their headache relief as excellent, good, fair, uncertain, or poor. At the 12-week end point, 53 percent of patients in the active group ranked their relief as excellent or good compared to 17 percent in the placebo group.
• When asked to rate the effect on their quality of life, 67 percent of the active group reported improvement compared to 17 percent in the placebo group.
• The active group reported 51-percent satisfaction with headache relief compared to 19 percent in the placebo group.

Statistical significance was demonstrated across most measures. It was not however observed in the primary endpoint as established by the U.S. Food and Drug Administration. This was defined as a significant difference between active and placebo groups who reported a 50-percent reduction in pain as measured on a visual analog scale and a minimum 10-percent point difference between the 95-percent confidence intervals comparing the active and placebo groups. A statistically significant difference between the active and placebo groups was observed at the 40-percent reduction in pain level.

"Many migraine patients have exhausted all current treatment options and often are disabled by the pain and frequency of migraine attacks," said Stephen D. Silberstein, M.D., past president of the American Headache Society, director of the Jefferson Headache Center, and the principal investigator in the study. "Achieving a reduction in the number of days they suffer from headache and a significant improvement in their quality of life may be even more important than pain reduction alone. This research demonstrates that peripheral nerve stimulation can ease the suffering of chronic migraine patients."