Phase 1 and pharmacokinetic study of intravenous irinotecan in refractory solid tumor patients with hepatic...

To determine the recommended starting doses and pharmacokinetics of irinotecan in cancer patients with impaired liver function treated on a weekly schedule.

Patients with solid tumors who had impaired liver function were enrolled into four groups based on baseline serum total bilirubin and aspartate aminotransferase (AST)/alanine aminotransferase (ALT): Group 1 (n = 19): total bilirubin 1.5 to 3.0 x institutional upper limit of normal (IULN) and ALT/AST

Forty-two patients were treated. Among the most frequent adverse events were neutropenia (41%, grades 3/4), diarrhea (15%, grades 3/4), nausea (10%, grade 3), and vomiting (5%, grades 3/4). Two patients died from drug-induced neutropenic sepsis. Two patients had objective tumor responses (complete response, liver metastases from unknown primary; partial response, colon cancer). Hepatic dysfunction reduced irinotecan clearance while increasing relative exposure to the active metabolite, 7-ethyl-10-hydroxycamptothecin (SN-38). SN-38 exposures in patients receiving doses of 40 to 75 mg/m(2) were comparable to exposures in patients with normal liver function treated with a starting dose of 125 mg/m(2).

Irinotecan starting doses that seem to be safe for hepatically impaired patients treated with the weekly schedule are 60, 50, 60, and 40 mg/m(2) for groups 1 to 4, respectively. At these starting doses, exposure to SN-38 and the adverse event profile are similar to that observed in patients with normal liver function and antitumor activity can be observed.