Purpose: Camptothecin-11 (CPT-11) is a new semisynthetic derivative of CPT, and has been shown to inhibit DNA topoisomerase I and to have a strong antitumor activity with low toxicity in murine tumors. To evaluate the effectiveness of CPT-11 in patients with non-small-cell lung cancer (NSCLC), a phase II study was conducted between April 1989 and February 1990.
Patients and methods: Seventy-three patients were entered onto the study. All patients had had no previous therapy and had measurable disease. Their median age was 67 years (range, 34 to 75 years). Fifty-four patients had a performance status (PS) of 0 or 1 on the Eastern Cooperative Oncology Group (ECOG) scale, and 19 had a PS of 2. CPT-11 was given at a dose of 100 mg/m2 by intravenous 90-minute infusion once a week. The dose of CPT-11 was modified based on the WBC count obtained on the day of drug administration.
Results: Of 72 assessable patients, 23 (31.9%) showed a partial response (95% confidence interval, 20.2% to 43.6%). Of 40 patients with a stage IV disease, 13 (32.5%) responded. Response rates for patients with PS 0 or 1 and those with PS 2 did not differ (34.0% and 26.3%, respectively). The median duration of response in patients showing a PR was 15 weeks. The median survival time for all patients was 42 weeks. The major toxicities were leukopenia and diarrhea. Grade 3 or 4 leukopenia and diarrhea occurred in 18 patients (25%) and 15 patients (21%), respectively. These toxicities were unpredictable. Other toxicities of greater than or equal to grade 3 included nausea/vomiting (22%), anemia (15%), alopecia (4%) and pneumonitis (3%). One patient died of pulmonary toxicity (interstitial pneumonitis).
Conclusions: CPT-11 is a very active agent for NSCLC with acceptable toxicities. Further trials in combination with other agents for this disease are warranted.