Shape Memory’s Impede-FX RapidFill Will Be Studied in AAA-SHAPE Pivotal Trial

September 7, 2023—Shape Memory Medical Inc., a developer of custom shape memory polymers for endovascular applications, announced that the FDA granted an investigational device exemption (IDE) for the Impede-FX RapidFill device.

The IDE allows the company to begin a prospective, multicenter, randomized, open-label trial to determine the safety and effectiveness of the device for improving abdominal aortic aneurysm (AAA) sac behavior when used with elective endovascular aneurysm repair (EVAR).

According to the company, the AAA-SHAPE pivotal trial will enroll 180 patients with infrarenal AAA at 40 sites in the United States, Europe, and New Zealand. Patients in the study will be randomized (2:1) either to EVAR plus sac management with Impede-FX RapidFill (the treatment arm) or to standard EVAR (the control arm).

Key endpoints of the trial will compare sac diameter and volume change, endoleak rates, secondary interventions, and mortality through 5 years.

Shape Memory stated that the investigational Impede-FX RapidFill device incorporates the company’s novel shape memory polymer, which is a porous polyurethane scaffold that is crimped for catheter delivery and self-expands on contact with blood.

In the AAA-SHAPE study, Impede-FX RapidFill is intended to fill the aneurysm blood lumen around a commercially available EVAR stent graft to promote aneurysm thrombosis and sac shrinkage.

Marc Schermerhorn, MD, serves as Principal Investigator of the AAA-SHAPE pivotal trial with Coprincipal Investigators Virendra Patel, MD, and Ross Milner, MD.

Dr. Schermerhorn is Chief of Vascular and Endovascular Surgery at Beth Israel Deaconess Medical Center in Boston, Massachusetts. Dr. Patel is Chief of Vascular Surgery at New York Presbyterian/Columbia University Irving Medical Center in New York, New York. Dr. Milner is Chief, Section of Vascular Surgery and Endovascular Therapy, at University of Chicago Medicine in Chicago, Illinois.

The company noted that the AAA-SHAPE pivotal trial is preceded by the AAA-SHAPE early feasibility studies (EFSs) that enrolled a combined 35 patients in New Zealand and the Netherlands.

In June 2023, the EFS experience was described by Andrew Holden, MBChB, et al in the Journal of Vascular Surgery: Cases, Innovations, and Techniques.

“The AAA-SHAPE EFSs have been key to validating the procedural techniques and best practices that we will leverage in the pivotal trial,” commented Dr. Schermerhorn, in Shape Memory’s press release. “We are excited to initiate this widely anticipated trial in the United States and abroad.”

Dr. Patel stated, “We used to consider both aneurysm regression and stability as indicators of a successful EVAR outcome. However, contemporary data reveals that stable sacs are not as benign as once thought and that any failure of the sac to regress is associated with higher long-term mortality. Shape memory polymer is a meaningful advancement in AAA repair and has the potential to address these unmet needs.”

Dr. Milner added, “I commend the company on the decision to pursue a randomized controlled trial. This head-to-head study will offer the level 1 evidence the vascular community will seek to determine the potential role of shape memory polymer in the management of AAA patients.”

Shape Memory’s peripheral embolization products, the Impede and Impede-FX embolization plugs and the Impede-FX RapidFill device, have received CE Mark approval and are indicated to obstruct or reduce the rate of blood flow in the peripheral vasculature.

In the United States, the Impede embolization plug is indicated to obstruct or reduce the rate of blood flow in the peripheral vasculature; the Impede-FX embolization plug is indicated for use with the Impede embolization plug to obstruct or reduce the rate of blood flow in the peripheral vasculature. The Impede and Impede-FX embolization plugs are approved in Japan.

The Impede-FX RapidFill device is not available in the United States or Japan, advised the company.