LimFlow System’s PROMISE II Pivotal Trial Results Published

March 30, 2023—LimFlow SA, a developer of minimally invasive technology for the treatment of chronic limb-threatening ischemia (CLTI), announced the publication of results from the PROMISE II United States pivotal trial that demonstrated the LimFlow system achieved a 66% rate of amputation-free survival at 6 months. This exceeded the FDA’s performance goal with statistical significance, noted the company.

According to the company, the LimFlow system for transcatheter arterialization of deep veins (TADV) is designed to reestablish blood flow in deep veins for “no-option” CLTI patients who have exhausted all other treatment methods and face major amputation of their lower limb. The therapy is designed to prevent amputation.

The results were published by Mehdi Shishehbor, DO, et al in The New England Journal of Medicine. In November 2022, Daniel Clair, MD, presented the 6-month findings during the Late-Breaking Clinical Trials sessions at the VIVA22 conference held by the VIVA Foundation on October 31 to November 3 in Las Vegas, Nevada.

Drs. Shishehbor and Clair serve as Coprincipal Investigators of PROMISE II. Dr. Shishehbor is President of the Harrington Heart and Vascular Institute, University Hospitals, in Cleveland, Ohio. Dr. Clair is Professor and Chair of the Department of Vascular Surgery at Vanderbilt University Medical Center Section of Surgical Sciences in Nashville, Tennessee.

“The publication of PROMISE II in The New England Journal of Medicine reinforces the transformational value of TADV for a patient population in great need,” commented Dr. Shishehbor in the company’s press release. “The introduction of this therapy provides the possibility of limb salvage for a no-option CLTI population previously consigned to primary amputation, potentially reducing the suffering, mortality, and economic burden in this ever-growing segment of patients.”

Dr. Clair added, “These results establish TADV as a real alternative to major amputation for patients facing inevitable limb loss from no-option CLTI. This therapy will enable us to redefine the concept of a ‘no-option’ CLTI patient by giving us a treatment that offers patients limb salvage and hope.”

LimFlow stated that PROMISE II is a landmark trial of severe CLTI patients including 100% of patients with end-stage peripheral artery disease (Rutherford class 5 or 6), 77% with diabetes, and 57% with chronic kidney disease, many of whom were on dialysis.

The multicenter, prospective, single-arm study enrolled 105 no-option CLTI patients treated at 20 sites in the United States. The company noted that PROMISE II was designed to be representative of a broad patient population: 43% of patients are Black, Hispanic, or Latino, and 31% are female. Patients will be followed to 3 years.

The no-option patients treated in PROMISE II were determined by an independent physician committee to be no longer eligible for conventional endovascular or surgical therapy to treat their CLTI, advised LimFLow.

As summarized in the company press release, the PROMISE II trial demonstrated the following:

• 76% limb salvage rate
• 76% of patients had wounds that were completely healed (25%) or in the process of healing (51%)
• Patient pain was substantially reduced, with average pain scores dropping from 5.3/10 before treatment to 3.0/10 at 6 months after treatment
• 99% technical success of the procedure, indicating a reproducible procedure across diverse sites and investigators

In November 2016, the company announced that the LimFlow system received CE Mark approval. It is currently available commercially in Europe. In the United States, the LimFlow technology is approved for investigational use only. The LimFlow system has not been approved for sale in the United States, Canada, or Japan, advised the company.