John R. Eckardt

PURPOSE: Single-agent intravenous (IV) topotecan is an effective treatment for small-cell lung cancer (SCLC) after failure of first-line chemotherapy. This open-label, randomized, phase III study compared oral and IV topotecan in patients with SCLC sensitive to initial chemotherapy. PATIENTS AND METHODS: Patients with limited- or extensive-disease SCLC, documented complete or partial response to first-line therapy, Eastern Cooperative Oncology Group performance status < or = 2, and measurable recurrent disease (WHO criteria) with a treatment-free interval of > or = 90 days were assigned to treatment with either oral topotecan 2.3 mg/m2/d on days 1 through 5 or IV topotecan 1.5 mg/m2/d on days 1 through 5 every 21 days. Primary end point was response rate as confirmed by an external reviewer blinded to treatment. RESULTS: A total of 309 patients were randomly assigned. In intent-to-treat analysis, response rates were 18.3% with oral topotecan (n = 153) and 21.9% with IV topotecan (n = 151), with a difference (oral -IV) of -3.6% (95% CI, -12.6% to 5.5%). Median survival time was 33.0 weeks for oral and 35.0 weeks for IV topotecan; 1- and 2-year survival rates were 32.6% and 12.4% for oral topotecan, respectively, and 29.2% and 7.1% for IV topotecan, respectively. Third-line chemotherapy was similar for both groups (33% for oral; 35% for IV). Incidence of grade 4 toxicity in patients who received oral and IV topotecan was as follows: neutropenia in 47% and 64%, thrombocytopenia in 29% and 18%, grade 3 or 4 anemia in 23% and 31%, and sepsis in 3% and 3%, respectively. The most frequent nonhematologic adverse events (all grades) included nausea (43% oral; 42% IV), alopecia (26% oral; 30% IV), fatigue (31% oral; 36% IV), and diarrhea (36% oral; 20% IV). CONCLUSION: Oral topotecan demonstrates activity and tolerability similar to IV topotecan in chemotherapy-sensitive SCLC patients and offers patients a convenient alternative to IV therapy.

PURPOSE: To evaluate irinotecan (CPT-11; Yakult Honsha, Tokyo, Japan) in patients with metastatic colorectal carcinoma that had recurred or progressed following fluorouracil (5-FU)-based therapy. PATIENTS AND METHODS: Patients were treated with irinotecan 125 to 150 mg/m2 intravenously (IV) every week for 4 weeks, followed by a 2-week rest. Forty-eight patients were entered onto the study and all were assessable for toxicity. Forty-three patients completed one full course of therapy and were assessable for response. RESULTS: One complete and nine partial responses were observed (response rate, 23%; 95% confidence interval [CI], 10% to 36%). The median response duration was 6 months (range, 2 to 13). The median survival time was 10.4 months and the 1-year survival rate was 46% (95% CI, 39% to 53%). Grade 4 diarrhea occurred in four of the first nine patients (44%) treated on this study at the 150-mg/m2 dose level. The study was amended to reduce the starting dose of irinotecan to 125 mg/m2. At this dose, nine of 39 patients (23%) developed grade 4 diarrhea. Aggressive administration of loperamide also reduced the incidence of grade 4 diarrhea. Grade 4 neutropenia occurred in eight of 48 patients (17%), but was associated with bacteremia and sepsis in only case. CONCLUSION: Irinotecan has significant single-agent activity against colorectal cancer that has progressed during or shortly after treatment with 5-FU-based chemotherapy. The incidence of severe diarrhea is reduced by using a starting dose of irinotecan 125 mg/m2 and by initiating loperamide at the earliest signs of diarrhea. These results warrant further clinical evaluation to define the role of irinotecan in the treatment of individuals with colorectal cancer.

PURPOSE We conducted a phase I and pharmacokinetic trial of CPT-11 (irinotecan) to characterize the maximum-tolerated dose (MTD), toxicities, pharmacokinetic profile, and antitumor effects in patients with refractory solid malignancies. PATIENTS AND METHODS We treated 32 patients with CPT-11 administered as a 90-minute intravenous infusion every week for 4 consecutive weeks followed by a 2-week rest period. Dose levels ranged from 50 to 180 mg/m2/wk. We determined concentrations of the lactone (active) and total (lactone plus carboxylate) forms of CPT-11 and its metabolite, SN-38, in the plasma and urine of selected patients during and after drug infusion. RESULTS Grade 4 diarrhea was the dose-limiting toxicity (DLT) at the 180-mg/m2/wk dose level. Other toxicities attributed to CPT-11 included dehydration, nausea, vomiting, and asthenia. Hematologic toxicity was mild in most patients. The terminal plasma half-life for CPT-11 (total) was 7.9 +/- 2.8 hours, for CPT-11 (lactone) 6.3 +/- 2.2 hours, for SN-38 (total) 13.0 +/- 5.8 hours, and for SN-38 (lactone) 11.5 +/- 3.8 hours. We observed significant correlations between drug dose and peak plasma concentration (Cpmax) and between drug dose and area under the concentration curve (AUC) for CPT-11, but not for SN-38. CONCLUSION The MTD for CPT-11 in this patient population was 150 mg/m2/wk when administered on a weekly-times-four schedule repeated every 6 weeks. At dose levels greater than 150 mg/m2/wk, diarrhea is dose-limiting.

PURPOSE: To determine the toxicities, maximal-tolerated dose (MTD), pharmacokinetic profile, and potential antitumor activity of LY231514, a novel thymidylate synthase (TS) inhibitor. PATIENTS AND METHODS: Patients with advanced solid tumors were administered LY231514 intravenously over 10 minutes, weekly for 4 weeks, every 42 days. Dose escalation was based on the modified continual reassessment method (MCRM), with one patient treated at each minimally toxic dose level. Pharmacokinetic studies were performed in all patients. RESULTS: Twenty-five patients were administered 58 courses of LY231514 at doses that ranged from 10 to 40 mg/m2/wk. Reversible neutropenia was the dose-limiting toxicity. Inability to maintain the weekly treatment schedule due to neutropenia limited dose escalation on this schedule. Nonhematologic toxicities observed included mild fatigue, anorexia, and nausea. At the 40-mg/m2/wk dose level, the mean harmonic half-life, maximum plasma concentration, clearance, and apparent volume of distribution at steady-state were 2.02 hours, 11.20 micrograms/mL, 52.3 mL/min/m2, and 6.64 L/m2, respectively. No major antitumor responses were observed; however, minor responses were achieved in two patients with advanced colorectal cancer. CONCLUSION: The dose-limiting toxicity, MTD, and recommended phase II dose of LY231514 when administered weekly for 4 weeks every 42 days are neutropenia, 40 mg/m2, and 30 mg/m2, respectively.

PURPOSE: This open-label, randomized, multicenter phase III study compared oral topotecan/intravenous cisplatin (TC) with intravenous (IV) etoposide/cisplatin (PE) in patients with untreated extensive-disease small-cell lung cancer (ED-SCLC). PATIENTS AND METHODS: A total of 784 patients were randomly assigned to either oral topotecan 1.7 mg/m2/d x 5 with IV cisplatin 60 mg/m2 on day 5 (n = 389) or IV etoposide 100 mg/m2/d x 3 with IV cisplatin 80 mg/m2 on day 1 (n = 395) every 21 days. RESULTS: Overall survival (primary end point) was similar between groups (P = .48; median: TC, 39.3 weeks v PE, 40.3 weeks). One-year survival was 31% (95% CI, 27% to 36%) in both groups and the difference of -0.03 (95% CI, -6.53 to 6.47) met the predefined criteria of < or = 10% absolute difference for noninferiority of TC relative to PE. Response rates were similar between groups (TC, 63% v PE, 69%). Time to progression was slightly but statistically longer with PE (log-rank P = .02; median: TC, 24.1 weeks v PE, 25.1 weeks). The regimens were similarly tolerable. Grade 3/4 neutropenia occurred more frequently with PE (84% v 59%), whereas grade 3/4 anemia and thrombocytopenia occurred more frequently with TC (38% v 21% and 38% v 23%, respectively). Lung Cancer Symptom Scale scores were statistically better with PE, but the differences were small and of debatable clinical significance. CONCLUSION: Oral topotecan with cisplatin provides similar efficacy and tolerability to the standard (etoposide with cisplatin) in untreated ED-SCLC and may provide greater patient convenience compared with intravenous etoposide and cisplatin.