Medical Device Daily

Marking a major milestone not only for itself but also for the entire medical device sector – and most importantly, for some patients with severe end-stage heart failure — Abiomed (Danvers, Massachusetts) yesterday reported winning a Humanitarian Use Device (HUD) exemption from the FDA, thus allowing it to sell 4,000 of its AbioCor totally implanted artificial heart.

The approval marks the very first go-ahead by the agency to commercialize an artificial heart that is totally implanted within the body, differentiated from other devices that substitute for the heart, but with major components outside the body, or pumping devices that are implanted but able to assist only one part of the heart.

While the company said that that number of the AbioCor devices that are implanted each year will be far less than 4,000, the emption provides an important foothold in the artificial heart sector after at least 50 years of R&D work and an arduous struggle by Abiomed on the regulatory path.

The AbioCor hearts will be used only in patients who are considered end-stage, meaning they have only days or, at most, no more than a month to live and have run out of all other therapeutic options to keep them alive.
Susan Bro, a spokesperson for the agency said that the actual number of implants will be between 25 and 50 each year, a relatively miniscule amount compared to the number of those who might benefit from the device. The NIH has estimated about 5 million people in the U.S. with heart failure and about 300,000 deaths from heart failure each year.

In reporting the approval, the FDA said that “in clinical studies, [the AbioCor] was shown to prolong the life and improve the quality of life for critically ill patients.”

Besides meeting the clinical standards to receive the heart, patients must undergo a screening process to determine if their chest volume is large enough to hold the device. Thus far in clinical trial work, the size of the AbioCor has limited its implantation to men. However, the company has indicated that next generations of the device could be small enough for implantation in women as well.

Similar to the Orphan Drug Act, the HUD provision is designed to encourage development of innovative devices to treat rare conditions.

The agency said it based its approval on the company's laboratory and animal testing and on a clinical study of 14 patients conducted by Abiomed. The study — originally designed to enroll 15 patients, but the 15^th never implanted — showed that “the device is safe and has likely benefit for people with severe heart failure whose death is imminent and for whom no alternative treatments are available,” the FDA said

Two patients in the trial did not survive the implant. The 12 who did survive were supported by the heart for an average of about 160 days, significantly surpassing the 60 days of support stated as a key endpoint of the trial. Two patients did not reach the 60-day mark, dying after 54 and 55 days of support. In two cases, the device extended survival by 10 and 17 months respectively, and one patient was discharged from the hospital to go home.

Schultz said that the agency “recognizes that not all patients who are eligible will choose this option, but for many patients faced with death, the chance to have additional time with family and friends — however limited — is a chance they are willing to take. We believe it is important to make the latest technology available as soon as possible and give patients and families complete information about the risks and benefits so they can make an informed choice.”

A key question concerning the potential market uptake of the device must involve economics – who, and how much, will patients be willing to pay for the additional days or weeks of life that the AbioCor promises? While the device will cost upwards of $200,000, AbioMed has issued no reports concerning the costs of patient treatment and follow-up care in its clinical trial.

The FDA said it is requiring the company to provide a comprehensive patient information package to patients and families that clearly describes the risks as well as the probable benefits of the device and explains what patients should expect before, during and after surgery.

Abiomed promised the agency that it will continue to do additional laboratory studies and will also conduct a post-marketing study of 25 additional patients. The post-market study was recommended by the Circulatory Systems Devices Panel, a part of the agency's Medical Devices Advisory Committee.

That panel, in June of 2005, dodged a vote on approval of the device but rather, in a somewhat confusing action, ruled that the AbioCor had not met the criteria for a humanitarian device exemption, a move that appeared to reflect sharp divisions among panel members (Medical Device Daily, June 24, 2005).

Daniel Schultz, MD, director of the agency's Center for Devices and Radiological Health, in announcing the approval, called the AbioCor a “significant advance” for the treatment of heart failure patients who would not be able to benefit even from a heart transplant.

Elizabeth Nabel, MD, director of the National Heart, Lung and Blood Institute (NHLBI) of the National Institutes of Health (Bethesda, Maryland), haled the approval, noting the institute's heavy investment “since the 1960s” in research work leading to the artificial heart as well as ventricular assist devices.

The approval, she said, is “the culmination of years of research and testing to establish reliability, performance, and safety. It has been the life's work of teams of scientists, engineers, and designers. And now for the patients who qualify for this device, it can mean longer life — and a better quality of life.”

“This accomplishment also demonstrates the kind of long-term interdisciplinary scientific efforts needed to address increasingly complex health challenges that often seem initially insurmountable to many.”

The AbioCor weighs about two pounds, taking over for the heart that is removed during implantation. A transfer coil powers the system across the skin and recharges the internal battery from the outside; a controller and an internal battery are implanted in the patient's abdomen. The controller monitors and controls the function of the device, including its pumping rate. The internal battery allows the recipient to be free from all external connections for up to one hour. The system also includes two external batteries that allow free movement for up to two hours. During sleep and while batteries are being recharged, the system can be plugged into an electrical outlet.