Philips Begins Pivotal THOR Trial of Combined Device to Treat PAD

November 4, 2024—Royal Philips announced enrollment of the first patient in THOR, a United States investigational device exemption (IDE) clinical trial of the company’s combined laser atherectomy and intravascular lithotripsy catheter for the treatment of peripheral artery disease (PAD). The goal of the pivotal study is to evaluate the safety and efficacy of the device to treat complex, calcified lesions in a single procedure for patients with PAD.

According to Philips, the prospective, single-arm, multicenter THOR IDE study will enroll up to 155 patients at up to 30 sites in the United States. It will assess the system’s safety and effectiveness in achieving procedural success with a low rate of complications.

The company stated that the pivotal study’s primary endpoints include freedom from major adverse events, such as mortality, unplanned amputations, and clinically driven target lesion revascularization within 30 days of the procedure, as well as achieving ≤ 50% residual stenosis post-procedure. Patients will be followed for 12 months.

The Cardiovascular Institute of the South (CIS) in Houma, Louisiana, recently completed the first procedure using the new laser catheter. The patient, a male (age, 78 years) with peripheral vascular disease, was successfully treated using the Philips device.

“Developing and driving clinical evidence is crucial to improving care and guiding the adoption of new technologies like the Philips laser atherectomy and lithotripsy system,” commented Craig Walker, MD, Pradeep Nair, MD, and McCall Walker, MD, of CIS in Philips’ press release. “This trial will provide essential data to demonstrate how this combined approach can optimize procedural efficiency and patient outcomes in treating challenging calcified lesions.”

Philips stated that the device is intended to streamline complex interventions into a single procedure, potentially reducing the need for multiple interventions and hospital visits.

The laser catheter uses atherectomy to remove atherosclerotic plaque from the internal surface of an artery, and intravascular lithotripsy to modify calcium deposits within the artery or disrupt calcium deposits in the artery wall.

Both the atherectomy and lithotripsy are laser driven. The device’s pulsed laser instantly vaporizes fluid within the blood vessel to create bubbles that expand and then rapidly collapse, generating the required sonic waves as they do so, noted the company.

The Philips laser atherectomy and intravascular lithotripsy system is currently investigational and not yet commercially available anywhere in the world, including the United States, advised the company.

Elizabeth Anne Genovese, MD, coprincipal investigator of the THOR trial, who is a vascular surgeon at the Penn Advanced Limb Preservation at the Hospital of the University of Pennsylvania in Philadelphia, Pennsylvania, commented on the device in Philips’ press release.

“This innovative approach to vessel preparation could improve patient outcomes while minimizing the need for multiple therapies and intervention,” stated Dr. Genovese. “That makes this an exciting innovation milestone as we enroll the first patient in this important United States clinical trial.”

Dr. Genovese continued, “Integrating atherectomy and intravascular lithotripsy into a single device has the potential to revolutionize the treatment of patients with complex femoropopliteal lesions associated with moderate to severe calcifications.”