A Phase I Trial to Evaluate the Multiple-Dose Safety and Antitumor Activity of Ursolic Acid Liposomes in Subjects with Advanced Solid Tumors

Ursolic acid liposome (UAL), a new antitumor drug, has potential therapeutic value. However, limited clinical data exists regarding multiple-dose safety, antitumor activity, and the recommended dose (RD) of UAL for subjects with advanced solid tumors. All subjects were intravenously administered UAL for 14 consecutive days of a 21-day treatment cycle. Twenty-one subjects were enrolled in 1 of 3 sequential cohorts (56, 74, and 98 mg/m(2)) to evaluate multiple-dose tolerability and efficacy. Eight additional subjects were treated with UAL (74 mg/m(2)) to evaluate multiple-dose pharmacokinetics. No ≥grade 3 adverse events (NCI-CTC) were observed. Sixty percent subjects achieved stable disease after 2 treatment cycles. Multiple-dose pharmacokinetic analysis suggested UAL does not accumulate in the body. This trial demonstrates that UAL was tolerable, had manageable toxicity, and could potentially improve patient remission rates. A large phase II study is recommended to confirm these results (i.e., RD of 98 mg/m(2)).