Patients implanted with the HeartMate II for destination therapy (DT) from Thoratec (Pleasanton, California) fared better than those implanted with an earlier version of the device, according to an interim analysis of data the company reported late last week. The DT study protocol called for an interim analysis to test for overwhelming superiority when 67% of the first 200 randomized patients had reached two years of follow-up.
The HeartMate II was approved in April for bridge-to-transplant (BTT) patients. The DT indication would be for patients too ill to receive a transplant. The company's HeartMate XVE already is approved for this indication, but hasn't seen much uptake because of durability of the device, which is 18 to 24 months. The newer pump is expected to have durability out to 10 years (Medical Device Daily, April 23, 2008).
Susan Benton, a spokeswoman for Thoratec, told Medical Device Daily that the HeartMate XVE is a larger device and is still the only FDA-approved device for the DT indication. "It is still a very capable device, but it is older and larger," she said.
The HeartMate II, smaller than a D-cell battery, allowed women and smaller men to receive the device as a BTT patient. Smaller body sizes had previously been underserved because the predicate device was too large.
The DT data shows that patients implanted with the HeartMate II achieved statistically superior outcomes vs. those in the control group who were implanted with the HeartMate XVE. The primary endpoint for the trial assessed in this analysis includes patients being alive, and free of stroke and the need of reoperation for device replacement at two years.
As a result of the data, an independent safety monitoring board agreed with Thoratec that the HeartMate II DT should be used in all new patients enrolled in the trial instead of the older pump, the company said.
Thoratec said it would file an investigational device exemption (IDE) Supplement with the FDA seeking approval for this action later this month, and that it now expects to file a pre-market approval (PMA) application seeking approval of the HeartMate II for DT in the first half of 2009.
"This is tremendous news for patients suffering from advanced-stage heart failure and the clinicians who treat them," said President/CEO Gary Burbach. "The data indicate that the HeartMate II achieved statistical superiority to the control group patients by an overwhelming margin." He added that the findings complement the experience with the device in BTT patients, both in the company's pivotal trial and as a commercially available device since April.
Thoratec shares rose $2.48, or 10%, to $27.23 Friday after the study analysis was reported.
The HeartMate II is a mechanical circulatory support device intended for a broad range of advanced-stage heart failure patients. A continuous-flow device, the HeartMate II can pump up to 10 liters of blood per minute and is designed to provide long-term cardiac support, Thoratec noted. The device is implanted alongside a patient's native heart and takes over the pumping ability of the weakened heart's left ventricle.
The company says it is easier to implant than prior devices, and with only one moving part, the HeartMate II is designed to provide "exceptional reliability" and improved patient quality of life. The device is designed to have a much longer functional life than the previous generation of devices and to operate more simply and quietly, Thoratec noted.
Burbach said the company is in the process of providing the conclusions from the analysis to its clinical investigators and the FDA. He said Thoratec hopes to present the data publicly soon after it files its PMA.
Benton noted that the timing of these results is ahead of schedule. The company was expected to file for FDA approval in late summer or early fall; now it's on track to file in the first half of 2009.
"It just pushes things up a bit, which is exciting news," she said.
In May 2007, the company reported that it had achieved the required enrollment of 200 patients in the randomized portion of the trial. Since then, Thoratec has continued to enroll patients under continued-access protocols, including the most recent CAP approved by the FDA in mid-November allowing for enrollment of an additional 60 patients.
As of Oct. 24, the company had enrolled 607 patients in the trial, including 366 in the randomized portion of the study.
According to an Associated Press report, JPMorgan med-tech analyst Taylor Harris said he hadn't expected Thoratec to report this data until late 2009. The company could be as much as six months ahead of schedule, he said.
The AP also said Lazard Capital Markets analyst Sean Lavin raised his profit and revenue estimates for Thoratec due to the timing of the report and said the FDA should approve the HeartMate II for DT in the first half of 2010. He now expects the company to earn 76 cents a share that year on $416 million in revenue and 90 cents a share on $484 million in revenue in 2011.