European Phase II Data On Irinotecan

Preliminary results of Phase II studies of irinotecan (marketed in Japan by Daiichi and Yakult Honsha as Topotecin and Campto respectively, and licensed in Europe by Rhone-Poulenc Rorer), were presented at the 19th European Society for Medical Oncology last month. They suggest that the drug is effective in both untreated advanced colorectal cancer and second-line where 5-FU has failed.

The study in 49 untreated metastatic CRC patients, sponsored by R-PR, revealed one complete response and 11 partial responses, to give an overall response rate of 29.5%. The median duration of response was 8.5 months with the median time to disease progression 6.5 months.

Neutropenia and late-onset diarrhea were the major side effects: grade III/IV neutropenia occurred in 24 patients, and grade III/IV diarrhea in 17 patients. Diarrhea was most frequent and severe in patients with prior pelvic radiotherapy. Other toxicities included nausea and vomiting and fatigue. Four patients were withdrawn from therapy early because of severe diarrhea and one patient died of septic shock. The researchers conclude that better use of the therapy could be obtained through extensive use of antidiarrheal drugs.