FDA panel: not enough data to recommend AbioCor

The panel mulled humanitarian concerns, patient experiences before deciding not to recommend Humanitarian Device Exemption.

GAITHERSBURG, Md. – A Food and Drug Administration advisory panel has voted not to recommend a Humanitarian Device Exemption for AbioCor, an artificial heart device.

The Circulatory System Devices Panel took multiple votes, finally voting 7-6 with one abstention that the device did not meet the minimum standards for approvability under the Humanitarian Device Exemption.

Early patients implanted with the AbioCor artificial heart (Abiomed Inc.) were featured in national media coverage, and panel members were moved by speeches given by their family members during the open public hearing.

However, the feasibility study the panel was asked to consider included only 14 patients, which several panel members felt was far too few to make a decision.

“I voted against, but not happily. I think it’s obvious how torn we all are. The need for a device in this space is clear, but we need more assurance that we are helping more than we are hurting. I don’t think 14 patients presented nearly convincing evidence,” panel member Mitchell Krucoff, MD, at Duke University, said.

Panel members who voted in favor did not dispute the lack of data, but they reminded their fellow members that the application was for a Humanitarian Device Exemption. “I frankly think we’re treating a lot of this data like it’s a pre-market approval application,” said panel member Thomas B. Ferguson, MD, at Washington University School of Medicine.

Michael R. Minogue, Abiomed’s president and CEO, said in a written statement that the company would work to clarify its submission.

The AbioCor is a completely implantable artificial heart with an external battery pack that charges the internal lithium battery. Although smaller models are in design, the AbioCor is currently about the size of a grapefruit and weighs about two pounds.

The thoracic unit includes two artificial ventricles with their corresponding valves and a motor-driven hydraulic pumping system. An implantable electronics package monitors and controls the pumping speed of the heart based on the physiologic needs of the patient.

Energy transfer is accomplished through a transcutaneous energy transmission system, which consists of internal and external coils. Because tubes or wires do not pierce the skin, the chances of developing an infection are decreased, according to company documents.

14 patients

Abiomed had received approval from the FDA to test the device in patients who had a >80% chance of mortality within 30 days and with no other treatment options. The feasibility study of 14 patients showed a median survival of 112 days with a range of zero to 512 days.

“If we look at this in terms of probable benefit, we can see that at 30 days, 86% of these patients were alive. In the absence of intervention, there’s a reasonable assurance that 70% of them would be dead.

Simply having the chance to make a difference is meaningful to me,” said panel member Clyde Yancy, MD, at the University of Texas Southwestern Medical Center.

Some panel members were concerned, however, that no health measures were taken beyond survival and that some of the patients who died had succumbed to complications of stroke due to poor anticoagulation early in the study.

“I’m not sure that the anticoagulation regimen can be replicated in a real-world setting,” said panel chairman William H. Maisel, MD, at Brigham and Women’s Hospital.– by Jeremy Moore