Background: SM-11355 is a platinum complex developed to treat hepatocellular carcinoma (HCC) via administration into the hepatic artery as a sustained-release suspension in iodized oil. We conducted a multicenter phase II trial in patients with HCC to evaluate the efficacy and safety of SM-11355, using a Zinostatin stimalamer suspension in iodized oil as a reference.
Methods: Patients with unresectable HCC were randomized 2:1 to receive administration of the SM-11355 or Zinostatin stimalamer suspension into the hepatic artery. A second injection was given 4-12 weeks later. Efficacy was evaluated by CT 3 months after treatment and categorized as therapeutic effect (TE) V to I, where TE V was defined as disappearance or 100% necrosis of all treated tumors.
Results: A total of 122 patients were evaluated for efficacy and toxicity (SM-11355, n = 83; Zinostatin stimalamer, n = 39). Baseline characteristics were similar in the two groups. The TE V rates were 26.5% (22/83) and 17.9% (7/39) in the SM-11355 and Zinostatin stimalamer groups, respectively. In the SM-11355 group,the most frequent drug-related adverse events (AEs) of ≥ grade 3 were elevated AST, elevated ALT, thrombocytopenia, and hyperbilirubinemia. The AEs with the largest difference between the two groups (SM-11355 vs. Zinostatin stimalamer) were hepatic vascular injury (0 vs. 48.4%) and eosinophilia (84.3 vs. 41.0%). The 2-year and 3-year survival rates were 75.9% vs. 70.3% and 58.4% vs. 48.7%, respectively.
Conclusions: The results suggest that SM-11355 in iodized oil has similar efficacy to Zinostatin stimalamer and that repeated dosing of SM-11355 is possible without hepatic vascular injury in cases of relapse.