FDA Approves Expansion of Edwards' PARTNER II Trial

November 7, 2011—Edwards Lifesciences Corporation (Irvine, CA) announced that the US Food and Drug Administration (FDA) conditionally approved the addition of a second treatment group to the PARTNER II trial, which is studying the company's next-generation Edwards Sapien XT transcatheter heart valve.

According to the company, this new cohort (cohort A) of PARTNER II is a noninferiority study of up to 2,000 patients with severe, symptomatic aortic valve stenosis who have an elevated risk for open heart surgery (Society of Thoracic Surgeons score > 4), which is a lower-risk profile than those who were enrolled in the PARTNER trial. Patients will be evenly randomized to receive the Edwards Sapien XT valve or surgery. Those patients undergoing transcatheter valve replacement will be treated either transfemorally or transapically. The primary endpoint to be evaluated is a composite of death and major stroke at 2 years, with secondary endpoints that include valve performance and quality-of-life indicators.

Edwards stated that it hopes to complete enrollment in the first cohort (cohort B) of the PARTNER II trial near the end of 2011. Cohort B will randomize up to 600 inoperable patients to receive either the next-generation Sapien XT or the first-generation Sapien transcatheter heart valve in a noninferiority study. Data from this cohort of inoperable patients is intended to support commercial approval of the Edwards Sapien XT valve in the United States, where it is currently an investigational device and not available on the market. The Sapien XT valve is commercially available in Europe, where it received a CE Mark in March 2010.

On November 2, as reported in Cardiac Interventions Today, the FDA approved the company's first-generation Edwards Sapien transcatheter aortic heart valve for transfemoral delivery to treat inoperable patients who have severe symptomatic aortic stenosis, who have been determined by a cardiac surgeon to be unsuitable for open aortic valve replacement and in whom existing comorbidities would not preclude the expected benefit from correction of the aortic stenosis. The device's safety and effectiveness were evaluated in the randomized controlled PARTNER pivotal study, which supported its FDA approval. Cardiac Interventions Today reported in June 2011 that the PARTNER investigators published the pivotal study's cohort A results in the The New England Journal of Medicine (2011;364:2187–2198). In September 2010, as reported in Cardiac Interventions Today, the cohort B data was published in The New England Journal of Medicine (2010;363:1597–1607).