EnteroMedics (NSDQ:ETRM) got a mixed bag of support from a panel of FDA advisors yesterday, with most panelists voting that the company’s weight-loss implant is safe but raising concerns about the effectiveness of the device.
The 9-member panel voted 8-1 that EnteroMedics’ Maestro nerve-stimulation implant is safe and 6-2 with 1 abstention that the overall benefits outweigh the risks, but the panel split 4-5 on whether the device is effective. The FDA isn’t bound by the recommendations of its advisory panels, but the federal watchdog agency usually sides with them.
“Obesity is the most under-treated disease in this country, despite its increasingly well-understood role in co-morbid conditions ranging from hypertension and diabetes to cancer,” COO/CFO Greg Lea said in prepared remarks. “Where existing options are clearly failing to address the growing epidemic of obesity, we believe VBLOC therapy may offer a unique approach to treating obesity, a choice that fills this void by offering a safe, reversible option that does not alter the anatomy, allowing patients to take a positive path towards improving their overall health. We thank the committee members for their insights and look forward to a continued, productive dialogue with the FDA.”
EnteroMedics is seeking approval for its Maestro VBLOC neurostimulation system for treatment of patients with morbid obesity. The device uses mild electrical stimulation to activate the vagus nerve located between the stomach and the esophagus in order to help modify physiological cravings and help patients form better eating habits.
The Minnesota company has hit a few hurdles already on its road to the FDA advisory panel, which precedes the final vote from FDA regulators on whether or not the Maestro device will make it to the U.S. market. The FDA last year asked the company to provide more data on its device testing and clinical data, including information on user training and post-approval studies. EnteroMedics submitted its FDA application in June 2013, hoping to land indication to treat obesity, metabolic diseases and other gastrointestinal disorders. The Maestro system has been on the European market since winning CE Mark approval in 2011.
The split over effectiveness was based on the pre-set endpoints in the clinical trial backing EnteroMedics’ PMA application.
"At face value the very easy answer is no, just because of the parameters that are set," said Dr. Eric Felner of the Emory School of Medicine in Atlanta. "However, with what I deal with and what I see, I see obese kids, I see their parents who are far from thin, and the bottom line is this is a tremendous amount of weight loss. In every other study in every other committee I’ve been on looking at weight loss, this far exceeds what the bottom line is and so it definitely meets effectiveness, it just doesn’t meet the criteria that’s set out by the FDA."
"When you do a clinical trial and it doesn’t come out the way you want, it bothers me that we change the criteria," countered Dr. Gary Falk of the University of Pennsylvania Perelman School of Medicine in Philadelphia. "You have a study that’s been done, you have 2 primary effectiveness endpoints that have not been met. It’s close, it’s approaching clinical significance, but it doesn’t reach it."
Although the panel generally believed Maestro is safe, they raised concerns about a permanently implanted device that is unsafe for MRI in patients who will likely require this type of imaging for joint problems or traumatic injury as they age. Explanting the device could damage the vagus nerve, they noted.
Gender and racial imbalance in the study was marked, with a population that was 85% female and 93% Caucasian. Further, the bulk of data for Maestro is from patients who were only followed for 1 year.
"As difficult as it is to lose weight, it’s really maintenance that’s even harder," FDA patient representative Carolyn Lynn McAfee noted. "And I was disappointed to see that this was only a 12-month study. Six to 9 months of that is weight loss, drugs, behavior modification, whatever, so maintenance is a very short time. The other thing is I’m just stunned at the racial and gender imbalance. That’s just horrendous, and it makes it very difficult for me to go back to my people and say, ‘If you’re African-American you get this surgery or don’t get this surgery.’ If there is a post-approval study, there has to be an additional one to make up for that deficit."