The board of Shanghai Bio-heart Biological Technology Co., Ltd. announced that the company's recently-developed sirolimus drug-eluting balloon product will conduct clinical trials for the treatment of in-stent restenosis (ISR) in Japan. The product is a sirolimus drug-eluting balloon catheter. The drug coating contains sirolimus, amphipathic liposomes, biodegradable polymers and dispersants in a certain ratio to achieve efficient transfer and durable release of the drug coating, which is safe and effective.

By encapsulating sirolimus in biodegradable nanoparticles to form nano drug-loaded microspheres, this method achieves an ultra-long release of about 90 days in the target vessel tissue. The final microsphere micelles are formed by the self-assembly effect resulting from the amphipathic liposome with the dispersant and the nano drug-loaded microspheres through intermolecular forces. Due to the effect of amphiphilic liposomes, the transfer ability of the microsphere micelles into the target vessel tissue is greatly improved, and finally drug transfer and long release period are achieved.

Drug-eluting balloon (DEB) is a kind of drug coated balloon (DCB), which usually has a longer drug release period. In-stent restenosis is a common complication after Percutaneous Coronary Intervention (PCI) procedures, with over 240,000 PCI procedures per year reported in Japan according to literature reports, and the incidence rate of in-stent restenosis is approximately 10%, and the Drug coated balloon (DCB) market is expected to be broad due to the increase in the number of PCI procedures and the expansion of indications. According to the consensus of Asia-Pacific experts, DCB is currently recommended as the first-line treatment for in-stent restenosis, and the indications are gradually expanded to small vessel disease, bifurcation lesions, etc.

To date, DCB products available in Japan market use paclitaxel-based drug coating. The paclitaxel drug-coated balloon still has a lot of room for improvement due to problems such as the cytotoxic mechanisms of action, long-term embolism caused by shedding of coating particles, and poor performance in calcified blood vessels. Compared with paclitaxel, sirolimus's unique cytostatic effect makes it have higher safety and wider therapeutic window and has anti-inflammatory effect.

However, due to the low lipophilic nature of sirolimus, low tissue transfer rate and difficulty in coating to the balloon surface, as a coating drug, it is technically difficult and has a higher technical barrier.