A survival rate of 80% at one year was just one of the encouraging findings from Thoratec's (Pleasanton, California) ROADMAP (Risk Assessment and Comparative Effectiveness of Left Ventricular Assist Device and Medical Management in Ambulatory Heart Failure Patients) study that supports the HeartMate II LVAD. However, some analysts say that the data will have no significant impact on adoption rates of the device.
"Based on our conversations with physicians at the International Society for Heart and Lung Transplantation, we believe the ROADMAP data are encouraging but are unlikely to have a significant impact on the LVAD market because the study was not a randomized controlled trial (it was an observational study); and the complication rate with LVADs in the ROADMAP population is still too high for most patients and physicians to accept," Larry Biegelsen, an analyst with Wells Fargo said. "We believe that newer devices such as Thoratec's HeartMate III could further penetrate the ROADMAP population if the adverse event profile is superior to the current generation of devices."
ROADMAP is a prospective, multi-center, non-randomized, controlled, observational study designed to examine the effectiveness of HeartMate II support compared with optimal medical management for NYHA Class IIIB and IV patients categorized as INTERMACS profiles four through seven and not dependent on intravenous inotropic support. Results were released at the International Society for Heart and Lung Transplantation (ISHLT; Addison, Texas) meeting in Nice, France.
Data from the study shows that survival in the HeartMate II group was 80% at one year, compared with 64% for medically managed patients on an as-treated basis. At one year of follow-up, 39% of patients within the HeartMate II group met the primary endpoint of survival on the original therapy along with a 75 meter increase in six minute walk test distance, compared with 21% of patients on optimal medical management, representing a statistically significant difference (p=0.017).
"Although the overall outcomes in the HeartMate II group were superior to the optical medical management group, there were more adverse events in the HeartMate II group," Biegelsen said. "For example, the stroke rate and gastrointestinal bleeding rates were significantly higher."
Thoratec's HeartMate II, has been sold since 2008. HeartMate II attaches to the heart and is designed to assist, or take over, the pumping function of the patient's left ventricle, the main pumping chamber of the heart.
The device is competing head to head with HeartWare's (Framingham, Massachusetts) HVAD system. HeartWare released data from its ENDURANCE trial last week which demonstrated that the trial met its primary endpoint of non-inferiority compared to Thoratec's HeartMate II, but the stroke rate was much higher with HeartWare's HVAD than with HeartMate II (Medical Device Daily, April 20, 2015).
With ROADMAP estimated to finish up in December and additional studies ongoing for HeartMate II such as the PREVENT trial, which is a study designed to assess the incidence of pump thrombosis, the company is turning its attention toward HeartMate III.
"In April of this year, Thoratec received approval from the FDA to broaden enrollment in the U.S. IDE Clinical Trial for HeartMate III based on safety data the FDA evaluated from the first 10 HeartMate III implants," Keith Grossman, president/CEO of Thoratec said during an investors meeting at ISHLT last week. "The HeartMate III incorporates a full MagLev design which we believe will materially reduce sheer stress on the blood components, improve overall hemocompatibility and thereby improve outcomes and reduce adverse events. This is a really different technology than any other on or approaching the market and we look forward to providing updates as we move through the trial process."
Analysts of the space estimate that HeartMate III could gain CE mark approval sometime in either the late summer or early fall. But there are some concerns about the device.
"While the feedback on the HeartMate III has been generally positive, one concern we have heard from some surgeons is that the size and shape of the HeartMate III may make it difficult to implant the device using a less invasive thoracotomy approach in smaller patients although Thoratec management feels confident that HeartMate III will be able to be implanted via a thoracotomy in the majority of patients," Biegelsen said.
He added, "separately, some surgeons also continue to believe that the greater output of the HeartMate III (up to 10 liters of blood) compared to the HeartWare MVAD (up to 7 liters) may lead to the market being segmented where smaller patients receive an MVAD and larger patients receive a HeartMate III."
Jason Mills of Cannacord Genuity said in a Monday research note that upcoming developments with HeartMate III, which include enrollment of the pivotal trial and CE mark approval, would bolster the company.
"We would be buyers of Thoratec as we believe the stock will benefit through the remainder of 2015 from several positive catalysts: VAD market growth in the U.S. will accelerate this year, and continue higher for perhaps 2 to 3 years; and less market share loss perhaps than we originally anticipated for HeartMate II on the heels of a strong showing in HeartWare ENDURANCE study," Mills said.