Positive one-year results of TOBA clinical trial presented

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Data presented at the Leipzig Interventional Course 2015 (LINC, 27– 30 January, Leipzig, Germany) demonstrate significant improvement in dissection repair with the Tack Endovascular System (Intact Vascular).

The Tack Endovascular System is a new technology designed to repair dissections in the artery wall that frequently occur as a complication of balloon angioplasty. The system allows physicians to repair these dissections while leaving a minimal amount of foreign material in the artery, reducing mechanical stress on the artery, and preserving future treatment options.

TOBA (Tack optimized balloon angioplasty) enrolled 138 subjects at 13 sites in Europe. All study subjects were suffering from severe peripheral arterial disease in one or both legs. They were treated with the Tack Endovascular System following standard balloon angioplasty in the superficial femoral and popliteal arteries.

Marc Bosiers, head, Department of Vascular Surgery, AZ St Blasius Hospital in Belgium, a co-principal investigator of the trial, presented the data at LINC. Dierk Scheinert, University Hospital Leipzig, Leipzig, Germany, is also a co-principal investigator.

Some of the key conclusions from the TOBA study included:

  • Freedom from clinically driven target lesion revascularisation rate at 12 months was 89.5%. Clinically driven target lesion revascularisation rate accounts for repeat procedures, or re-interventions, due to recurrent symptoms related to the treated lesion.
  • One-year Kaplan-Meier patency rate was 76.4%. Most of the subjects had significant dissections, which are graded from A to F. In the study, 74% of the patients had dissections graded C or higher, and less than 5% of the patients had simple Grade A dissections, based on independent core lab adjudication.
  • Technical success rate was 98.5%.
  • There was no migration or movement of Tack implants throughout the one-year follow-up period.

Bosiers stated, “The TOBA experience demonstrates that the long-term results from angioplasty can be substantially improved if we repair arterial dissections using this new approach that minimises vessel trauma and the metal we leave behind. The Tack supports the dissection and allows the vessel to heal, while preserving future treatment options for patients.”

Patients in the study demonstrated a marked improvement in their ability to walk and a reduction in the leg pain they experienced, as measured by the Rutherford Classification system. The study saw a reduction in patients with Rutherford class 3 disease from 73.8% before treatment to 5.7% at 12 months, with a majority of the patients achieving Rutherford class 0 (no symptoms). Patients also reported significantly less pain, with no pain during exercise increasing from 5.4% before treatment to 76.2% at 12 months. In addition, ankle brachial index (ABI) improved 38% from baseline at 12 months. Equally important, no subjects had a major amputation at 12 months.

Marianne Brodmann, professor of Angiology, Medical University of Graz, Austria, who was the lead enroller in the trial, said, “This new approach of low radial force and spot treatment of dissections support our desire to leave as little metal behind as possible. I look forward to using the Tack in conjunction with drug coated balloons and conducting further research, to reduce lining the artery with stents.”

Based on these promising results, the company is pursuing an expanded study (TOBA II) that will assess the performance of the Tack Endovascular System in a larger population and will include US investigators.