PB0754 - Treatment of hepatocellular carcinoma with autologous platelets encapsulating sorafenib or lenvatinib: a novel therapy exploiting tumor-platelet interactions

Background: Hepatocellular carcinoma (HCC) activates platelets through the action of adjacent sinusoidal cells. Activated platelets bind to tumor-associated endothelial cells and release growth factors that promote tumor progression. We hypothesized that platelets encapsulated with tumor inhibitors would function as drug carriers for tumor therapy.

Aims: We propose a therapeutic strategy for HCC using autologous platelets encapsulating multiple tyrosine kinase inhibitors in a rat chemically-induced HCC model.

Methods: Sorafenib or lenvatinib was encapsulated in platelets isolated from tumor-bearing rats in vitro. The rats were divided into groups that received repeated intravenous injections (twice a week for 10 weeks) of the following materials: placebo, sorafenib (SOR), lenvatinib (LEN), autologous platelets, autologous platelets encapsulating sorafenib (SOR-PLT), and autologous platelets encapsulating lenvatinib (LEN-PLT). The therapeutic effect was then analyzed by ultrasonography (US) and histopathological analysis.

Results: Histopathological and US analysis demonstrated extensive tumor necrosis in the tumor tissue of SOR-PLT or LEN-PLT, but not in other experimental groups. By liquid chromatography-mass spectrometry, more abundant sorafenib was detected in tumor tissues after SOR-PLT administration than in surrounding normal tissues, but no such difference in sorafenib level was observed with SOR administration.

Conclusion(s): The use of autologous platelets encapsulating drugs might be a novel therapeutic strategy for HCC.