Drug-Loaded Microspheres for the Treatment of Liver Cancer: Review of Current Results

Transarterial chemoembolization (TACE) involves the emulsification of a chemotherapeutic agent in a viscous drug carrier, delivered intra-arterially to liver tumor for maximum effect. TACE reduces arterial inflow, diminishes washout of the chemotherapeutic agent, and decreases systemic exposure. Despite evidence of some clinical success with TACE, a new type of microspheres with drug-eluting capabilities may offer a precisely controlled and sustainable release of the chemotherapeutic agent into the tumor bed. In animal trials tumor necrosis (approaching 100%) was greatest at 7 days, with significantly lower plasma concentrations of doxorubicin than in control animals treated with doxorubicin intra-arterially. Clinically, drug-eluting microspheres loaded with doxorubicin, either at 75 mg/m² or at a fixed dose of 150 mg, were used recently and no severe disorders of the hepatic function were observed postprocedure, while a substantial reduction of the fetoprotein levels occurred. An interim analysis of the first 15 patients from the Hong Kong group at 3 months showed an objective response rate of 61.54% and 53.84% according to EASL criteria and RECIST criteria, respectively, and a survival rate of 93.3%. In this paper we present how to use microspheres loaded with doxorubicin and review their clinical value and preliminary performance for treatment of unresectable liver cancer.