In a recent meeting of the Gastroenterology-Urology Devices Panel of the FDA’s Medical Devices Advisory Committee a vote was conducted regarding whether Maestro Rechargeable System vagal blocking therapy (VBLOC) should be considered safe for patients who are severely obese and are in need of immediate weight loss. The vote proved to be somewhat mixed in opinion with a vote of 8 to 1 that it is safe, 4 to 5 that it is an effective procedure and 6 to 2 and 1 abstention regarding whether the benefits outweigh the risks or not.
What is the Maestro System?
The Maestro system provides a device to be implanted into the lateral chest wall where the flexible leads attached are laparoscopically placed around the vagus nerve. The device delivers electrical pulses that suppress neural signals that ultimately help the patient to feel fuller and have a reduced appetite. This device is intended to be utilized only on those patients that are considered excessively obese.
The Maestro system comes complete with a mobile charger, an AC recharger, a transmit coil, a laptop with all of the program software and the programmer cables. This allows the physician to monitor the data regarding the progress of the device and keep track of changes that might need to be made. The physician can modify the therapy to better suit the changing needs of the patient. This will allow the physician to provide the patient with accurate programming that is right for their individual situation.
Those that voted against the effectiveness of the device stated that there was a lack of evidence due to an inability to meet coprimary endpoints in clinical trials. This said, some members did state that the effectiveness of the device was shown regardless of this point. The trial patients consisted of 80% women, 92% white and an average age of 47.1 years old. The participants in the trial where to be obese with a body mass index (BMI) of at minimum 40 kg or if the individual has at least one obesity related comorbidity, 35 kg. They must have been unsuccessful with at least one weight management program that was supervised within 5 years prior to the trial.
The ReCharge trial showed that the excess weight loss average in patients participating at random in using the VBLOC was 24.4% over a 12 month time period. This is compared to 15.9% that was shown as the excess weight loss for those patients that where selected to use sham implants. This 8.5% difference in loss, but the coprimary endpoint was factored as a 10% difference. Additionally, 38.4% of the patients in the trial had an excess weight loss of approximately 25% falling short of the coprimary effectiveness endpoint of 45% and 52.5% of the VBLOC patients saw an excess weight loss of 20% coming in less than the coprimary effectiveness endpoint of 55%.
The question of safety for the device use was also brought up in the meeting. The 8.6% safety rate when SAEs where in relation to treatment and surgery, short of the 15% guideline. During the meeting there was a public hearing portion allowing 12 people to speak about the device. These individuals were a mix of those that participated in the trials and other studies. All but one of them was in favor of the device.