The First 24-Month Data Release on the BTK Global Real-World Registry of the Lutonix DCB

(Leipzig, Germany) January 29, 2020 -- The prospective, single-arm multicenter Lutonix real-world registry aims to demonstrate the safety and assess the clinical use and outcomes of the Lutonix drug-coated balloon (DCB) (BD) for the treatment of stenosis or occlusion of native below-the-knee (BTK) arteries in a heterogeneous patient population in real-world clinical practice.¹

Two-year results of the Lutonix registry were presented on Wednesday by Dierk Scheinert, MD (University Hospital Leipzig), who is the study’s co-principal investigator alongside Michael Lichtenberg, MD (Klinikum Arnsberg, Germany).

“The Lutonix registry was carried out in parallel with the randomized clinical trial (RCT)²,” Professor Scheinert told audiences at LINC. “Its total enrollment was 371 subjects at 26 international sites in 11 countries.

“The inclusion and exclusion criteria were relatively closely matching those of the RCT, [including] Rutherford 3–5 patients. The requirement was that lesions could be stenotic or occlusions below the knee (BTK), but the vessel had to reconstitute at the ankle. So, below-the-ankle disease was excluded.”

Lesions were included with ≥70% stenosis, with target vessels reconstituting above or at the ankle. Exclusion criteria included neurotrophic ulcer or heel pressure ulcer or ulcer potentially involving calcaneus of the index limb.

The primary safety endpoint was a composite of freedom from BTK major adverse limb events and perioperative death at 30 days. The primary efficacy endpoint was freedom from target lesion revascularization (TLR) at six months.

Secondary endpoints included reintervention for the treatment of thrombosis of the target vessel(s), reintervention for embolization to distal vasculature, unexpected device or drug-related adverse events, change or improvement in Rutherford class of the target limb, and freedom from all-cause death.

“Baseline clinical characteristics were typical features of a challenging critical limb ischemia (CLI) cohort with BTK disease,” said Professor Scheinert, noting that 63.9% of patients were diabetic, 65.4% of patients were Rutherford 5, 10.5% were Rutherford 4, and 24.1% were Rutherford 3.

Professor Scheinert continued on to describe lesion characteristics. “Most of the treatments were carried out in the anterior tibial artery. That is something that we typically see. And then there is a spread between the posterior tibial, peroneal, and tibioperoneal trunk arteries.

“The total target lesion length was 12 cm on average, which I think is showing that this is a real-world population, far beyond the short lesions that are otherwise typically studied in RCTs. Calcification was present in 68% of lesions.

Six-month results have previously been published.³ Discussed yesterday were the 24-month results. On Kaplan Meier analysis of freedom from primary safety events, Professor Scheinert commented: “I think [these are] very respectable. There is a very high rate of freedom from such events – 98.4% at the two-year time point – reinforcing that this treatment was really safe in the hands of these operators.” 

He continued, “In terms of efficacy, freedom from TLR was 78.9% at the two-year time point. Beyond the one-year time point, there have been relatively few additional events being recorded; the curve seems to flatten quite nicely. So for those patients who didn’t have early events, a good durability is demonstrated.”

Going on to discuss secondary endpoints, he noted a rate of freedom from major amputation of 93.4% and a rate of freedom from reintervention for distal embolization of 100%. 

On the subject of all-cause death, he said, “Of course, in such a challenging CLI cohort, we have to expect a higher death rate than what we typically see when we discuss claudicants. At the two-year time point, we had a total survival rate of 80.5%, which I think is in line with previous reports of such cohorts.

“The Rutherford [category] improvement was impressive. Many patients improved by several levels of Rutherford category. In fact, 81.9% improved by at least one Rutherford category, and 59.5% improved by three or more Rutherford categories. So the fact of the treatment was, from a clinical standpoint, impressive.

“In summary, this was a safe treatment.”

References

1. Registry Investigating the Clinical Use and Safety of the Lutonix Drug Coated Balloon for Treatment of BTK Arteries (BTKRegistry). ClinicalTrials.gov. Available online at https://clinicaltrials.gov/ct2/show/NCT02554266. Accessed January 29, 2020.
2. Mustapha JA, Brodmann M, Geraghty PJ, et al; Lutonix BTK Study Investigators. Drug-coated vs uncoated percutaneous transluminal angioplasty in infrapopliteal arteries: six-month results of the Lutonix BTK trial. J Invasive Cardiol. 2019;31(8):205-211.
3. Thieme M, Lichtenberg M, Brodmann M, et al. Lutonix^® 014 DCB global Below the Knee Registry Study: interim 6-month outcomes. J Cardiovasc Surg (Torino). 2018;59(2):232-236.