Background & objective: 10-Hydroxycamptothecin (HCPT) is the inhibitor of topoisomerase I with anti-cancer effectiveness on several solid tumors. TUOXI (lyophilized HCPT) has higher purity and stability in comparison with solution for injection HCPT. The purpose of this study was to investigate the efficacy, toxicity, and proper dosage of TUOXI as single agent in treatment of advanced and recurrent solid tumors.
Methods: Sixty patients with the median age of 53 (range from 17 to 73 years) were enrolled into this multicenter phase II clinical trial. Among them, 18 patients were chemonaive and 42 were recurrent from chemotherapy; 22 patients with NSCLC, 12 nasopharyngeal carcinoma, 9 primary liver cancer, 9 colorectal carcinoma, 2 pancreatic carcinoma, and 6 miscellaneous malignancies. HCPT was given at the dosage of 6-8 mg/m(2) x d for 5-10 consecutive days based on the toxicity.
Results: Fifty-one patients were valuable for effectiveness. The objective response rate for the whole group was 15.7%. The partial remission (PR) rates were 16% for 6 mg/m(2) group and 15.4% for 8 mg/m(2) group, respectively. The PR rates were 13.7% (3/22) for NSCLC, 33.3% (3/9) for colorectal carcinoma, and 16.6% (2/12) for advanced nasopharyngeal carcinoma, respectively. The PR rate for 60 intent-to-treat patients was 13.3% (8/60). Myelosuppression was the dose-limiting toxicity and other adverse reactions included nausea/vomiting, diarrhea, and skin rash. The incidence of grade III+IV adverse events were 32%, 8%, 8%, 6%, and 4% for leucopenia, skin rash, thrombocytopenia, nausea/vomiting, and diarrhea, respectively. No renal, pulmonary, and cardiac toxicity were found.
Conclusion: TUOXI (HCPT lyophilized powder) had relatively broad- spectrum anti-cancer efficacy and was effective on advanced or recurrent NCSLC, colorectal carcinoma, and NPC. And the recommended dosage is 6-8 mg/m(2) as 4 hours infusion for 5-10 consecutive days every 3 weeks. Further clinical investigation on large number of solid tumors cases are warranted.