Medtronic just picked up a meaningful win from the FDA. The agency granted Breakthrough Device Designation to the company’s IN.PACT BTK drug-coated balloon, a tool designed specifically for peripheral artery disease in the arteries below the knee.

That matters because treating PAD in those smaller vessels has long been a headache for doctors. While drug-coated balloons are already approved and widely used for blockages higher up in the leg, none currently carry a U.S. indication for the below-the-knee area. Patients with advanced disease in this region face a real risk of repeated procedures or even amputation when blood flow stays restricted.

The IN.PACT BTK balloon is coated with paclitaxel, the same drug used in Medtronic’s earlier IN.PACT Admiral device that won FDA approval back in 2015 for upper-leg PAD. The idea is simple: open the artery and leave behind a bit of medication that helps keep it from narrowing again.

Medtronic plans to test the new balloon in a randomized pivotal trial called IN.PACT BTK DELTA. The study should enroll about 400 patients with below-the-knee lesions. Interventional cardiologist Dr. Eric Secemsky of Beth Israel Deaconess Medical Center will serve as principal investigator. He’s called effective treatment for these advanced cases one of the biggest unmet needs in endovascular care right now.

The breakthrough designation is meant to speed the device through the regulatory process. Medtronic says it’s working closely with the FDA and study investigators to lock down the final trial design over the next few months.

Other companies—Boston Scientific, BD, and Philips—already offer drug-coated balloons for above-the-knee PAD, but the below-knee space remains largely open. If the upcoming trial delivers positive results, Medtronic’s balloon could become the first of its kind available to U.S. patients who need better options for this stubborn form of the disease.