An FDA panel decision will require some cardiovascular pump makers to submit their already-approved medical devices for review under the FDA’s more stringent premarket review pathway.
The federal watchdog agency’s Circulatory Devices Advisory panel this week acknowledged that non-roller-type cardiopulmonary bypass blood pumps are life-supporting, but recommended against shifting them to a lower-risk category for temporary ventricular support. Panelists also suggested down-classification into Class II (special controls) for cardiopulmonary and circulatory bypass therapy.
The decision sent ABMD shares spiraling downward today, dropping as low as $12 per share in morning trading before recovering completely to reach last night’s close of $12.88 by about 3:30 p.m.
The Danvers, Mass.-based cardiac devices maker said that it believes it’s well-positioned to undergo PMA review for its star line of Impella cardiovascular pumps and that the devices won’t have to come off of shelves while the company navigates the regulatory approval process.
The FDA defines non-roller-type cardiopulmonary bypass pumps (NRPs) as devices that use a method other than revolving rollers to pump the blood through the cardiopulmonary bypass circuit during bypass surgery. Although these devices are classified in the FDA’s Class III category, designating devices that pose the greatest risk to patients, they fall under a pre-1976 medtech amendment that has allowed the devices to pass through the less-stringent premarket notification 510(k) review process rather than the PMA pathway.
There are 2 types of NRPs: The 1st variety, centrifugal-type pumps, use a rotor to "to impart energy to the blood in an extracorporeal circuit through centrifugal forces," and usually contain an oxygenator, according to FDA. They are intended to provide cardiopulmonary support over a span of 6 or fewer hours during cardiopulmonary or circulatory bypass. This type of pump has been on the market for 36 years and has well-established, clinically meaningful benefits, the agency notes.
The 2nd type of NRP, catheter-based axial-type pumps, are temporarily placed within the heart or vasculature to provide ventricular support only, according to the FDA. They are not designed for use with an oxygenator, and are comprised of a pump motor, a cannula and a catheter that connects to a console. This type of pump has recently been introduced to the market and the federal watchdog agency considers it to be an evolving/new technology.
A majority of panelists on the Circulatory System Devices Panel, which convened in Gaithersburg, Md., concurred with FDA that NRPs should remain in the higher risk Class III for temporary ventricular support because of the short history of catheter-based axial-type pumps on the market, their resulting undefined risk profile and insufficient evidence of safety and effectiveness. A few panelists, however, recommended down-classifying NRPs to the lower-risk Class II for all indications.
Panelist Dr. Keith Allen of the Mid America Heart Institute in Kansas City, MO, explained why he and a majority of other panelists concurred with the FDA in recommending that NRPs remain in the higher risk Class III category for temporary ventricular support.
"As a user of these devices I can’t fathom how they can be regulated by special controls when they’re not the same devices, and to me that seems an impossibility," he said.
"To me when you have devices in a class as a whole that are very similar, are manufactured the same and do the same thing, then I think that’s an appropriate way to manage them with special controls," Allen continued. "But in this case, you’ve got different types of devices and they need to be managed differently and they need to be separated and be classified. And I think that if you did look at the data as a PMA and the Protect II trial came up to panel … a trial that was stopped prematurely and didn’t meet its primary endpoint and had a composite endpoint that had 10 pieces to it with a lot of post-hock analysis, I can’t imagine any panel approving that as a primary PMA panel.
"So, I think we need to lend credence to what the FDA is asking for, what this panel is charged with, which is: give clarity to the field of mechanical circulatory support," Allen underscored. "I don’t care how we got into this mess, but let’s not kick the can down the road, like they’re doing down the road, and let’s clean this mess up and classify devices that are the same, put those in one bucket, and devices that are different, put them in a bucket, which is all I think the FDA is asking."
The risks of NRPs intended for cardiopulmonary and circulatory bypass, according to FDA, include alteration in blood composition, inadequate tissue perfusion, embolism, problems related to duration of use, fluid leakage, adverse tissue reaction and infection. For the temporary ventricular support indication, the risks also include structural/tissue damage to the heart, local heat generation and problems with flow dynamics.
Abiomed, manufacturer of the Impella catheter-based axial-type pump says it will work to strengthen the body of clinical evidence to support the safety and effectiveness of its device. "We look forward to collaborating with the FDA on next steps and agree with the 515i Panel’s feedback that our existing data, combined with our U.S. registry, position us to work with the FDA to submit a PMA application," said Abiomed president, chairman & CEO Michael Minogue in prepared remarks.
"We welcome the opportunity for a PMA to strengthen our existing marketing clearances and expand the indications for Impella patients."