The Lutonix DCB drug-coated balloon catheter is very similar to a standard angioplasty balloon, but contains a special coating consisting of paclitaxel and a proprietary drug carrier.
Paclitaxel acts to prevent restenosis by preventing the cellular proliferation that can cause arteries to re-narrow post-procedure. Lutonix DCB’s proprietary carrier facilitates the drug’s transfer to the tissue of the arterial wall upon balloon inflation.
Why carrier molecules matter
The drug carrier is a critically important component to any drug-coated balloon because it governs several safety and efficacy parameters such as:
- The total drug load required on the balloon to achieve a therapeutic dose in the arterial wall
- Drug dose delivered to the vessel wall and tissue uptake
- The durability and uniformity of the balloon coating
- The adhesion and release characteristics between the coating and the balloon
The safety and efficacy of the DCB formulation ultimately rests on the selection of the optimal drug carrier. The drug carrier is not a polymer, but a molecular entity that controls drug adherence to the balloon during transit, facilitates its release from the balloon during inflation, and perhaps most importantly, facilitates drug transfer to the blood vessel wall. The net effect of these variables is referred to as “transfer efficiency.”
The universe of potential effective carrier entities is limited and the available alternatives have different properties. For example, if the drug carrier selected facilitates fast and premature paclitaxel release from the balloon, too much drug may be lost during balloon transit from the insertion point to the lesion site. As a result, a sub-optimal dose is delivered to the target lesion. If the carrier overly slows or restricts release from the balloon, the drug dose delivered to the arterial wall will be sub-therapeutic. Finally, if the drug cannot effectively transfer to the vessel wall, a sub-optimal dose will be delivered.
If the carrier’s transfer efficiency is too low, more paclitaxel potentially could be loaded on the balloon to compensate. However, the amount of paclitaxel on the balloon also affects total systemic exposure. Consequently, the ideal DCB is one with a highly efficient carrier that in turn, allows for the lowest possible paclitaxel dose on the balloon. This way it becomes possible to deliver a therapeutic dose to the target tissue while minimizing systemic exposure.
The Lutonix DCB drug carrier
Lutonix DCB’s drug carrier is a molecular entity on the FDA IV-approved list. Lutonix selected that carrier agent after extensive testing involving over 250 different potential formulations.
The carrier selected for the Lutonix DCB balloon is designed to achieve:
- High drug retention on the balloon during transit to the target lesion
- Optimal drug release from the balloon catheter during inflation at the targeted treatment site
- High drug transfer efficiency to the vessel wall
- Minimized systemic drug exposure
The Lutonix DCB coating
Another critical aspect of DCBs is the robustness of the coating. An optimized coating is:
- Durable to minimize drug loss during catheter insertion and passage through what is often tortuous and highly diseased vascular anatomy to reach the lesion site
- Uniform to ensure that a consistent circumferential dose is delivered to the artery
The catheter formulation and manufacturing process determine coating integrity. The Lutonix DCB balloon manufacturing process is unique. The balloon is coated while it is inflated to ensure even distribution across the total length and diameter of the balloon.