6.13.Trial Description

A prospective clinical study is being conducted on subjects with chronic, stable osteoarthritis of the knee. Each study participant acts as his or her own control because subjects are heterogeneous in their degree of muscle wasting. We can use the participants as their own baseline because the degree of atrophy remains stable over time unless treated. Each subject is evaluated over a 12-week period before BIONs™ are implanted and over a 12 week period after the BIONs™ are implanted when he or she returns to the clinic to have his or her stimulus program updated. Stimulation is then stopped for 12 weeks and another evaluation takes place.

6.14.Preliminary Results

Thus far, three study participants have been implanted with BIONs™. In each participant, one BION™ was implanted near the common femoral nerve distal to the inguinal canal and a second BION™ was implanted in the vastus medialis muscle. The thresholds during percutaneous testing with the insertion tool and immediately following BION™ implantation were in the range of 2-6 mA@200µs indicating successful placement near the desired motor nerves. One of the participants reports adverse symptoms that could be related to the use of the device. All report improvement in knee pain and in their ability to use the knee. In one subject, the device injected in the region of the vastus medialis did not enter the muscle fully; this device was ineffective at stimulating the muscle, but effective muscle stimulation could be secured by stimulating the femoral nerve. We are currently considering a modification to this experimental plan for subsequent participants that would eliminate the placement of the second device in the vastus medialis.

2.5. Adverse information

Because this is a novel application of the BION™ microstimulator, there are no publications of adverse information that are relevant to an evaluation of the safety or effectiveness of the device. Adverse symptoms are typically not reported by patients even when the patients are thoroughly questioned about their possible concerns or problems. One patient in the osteoarthritis trial has reported a very modest dysaesthesia in a cutaneous field in the thigh. This dysaesthesia may relate not to the use of the device, but to the fact that the patient has a history of peripheral neural dysfunction. The patient has reported that this dysaesthsia does not interfere with activities in daily living or require medical attention or pharmaceutical intervention or management.

Any adverse events that may arise from BION™ treatment would fall into three categories: patient injury, events associated with surgical removal of the implanted device, and loss of device function. The results of our studies are consistent with risk analyses (discussed in section 5) that suggest a very low risk of any of these events occurring.

7.Investigational plan