Clinical evidence for topotecan-paclitaxel non--cross-resistance in ovarian cancer. Novel doublets in extensive-stage small-cell lung cancer: a randomized phase II study of topotecan plus cisplatin or paclitaxel (CALGB 9430). Topotecan versus paclitaxel for the treatment of recurrent epithelial ovarian cancer. Topotecan compared with no therapy after response to surgery and carboplatin/paclitaxel in patients with ovarian cancer: Multicenter Italian Trials in Ovarian Cancer (MITO-1) randomized study. Paclitaxel/carboplatin/etoposide versus paclitaxel/topotecan for extensive-stage small cell lung cancer: a Minnie Pearl Cancer Research Network randomized, prospective phase II trial. Recurrent epithelial ovarian carcinoma: a randomized phase III study of pegylated liposomal doxorubicin versus topotecan.
A large, randomized study comparing the efficacy and safety of topotecan versus paclitaxel in patients with relapsed epithelial ovarian cancer showed that these two compounds have similar activity. In this study, a number of patients crossed over to the alternative drug as third-line therapy, ie, from paclitaxel to topotecan and vice versa. We therefore were able to assess the degree of non-cross-resistance between these two compounds.
                Patients who had progressed after one platinum-based regimen were randomized to either topotecan (1.5 mg/m(2)/d) x 5 every 21 days (n = 112) or paclitaxel (175 mg/m(2) over 3 hours) every 21 days (n = 114). A total of 110 patients received cross-over therapy with the alternative drug (61 topotecan, 49 paclitaxel) as third-line therapy.
                Response rates to third-line cross-over therapy were 13.1% (8 of 61 topotecan) and 10.2% (5 of 49 paclitaxel; P =.638). Seven patients who responded to third-line topotecan and four patients who responded to paclitaxel had failed to respond to their second-line treatment. Median time to progression (from the start of third-line therapy) was 9 weeks in both groups, and median survival was 40 and 48 weeks for patients who were receiving topotecan or paclitaxel, respectively. The principal toxicity was myelosuppression; grade 4 neutropenia was more frequent with topotecan (81.4% of patients) than with paclitaxel (22.9% of patients).
                Topotecan and paclitaxel have similar activity as second-line therapies with regard to response rates and progression-free and overall survival. We demonstrated that the two drugs have a degree of non-cross-resistance. Thus, there is a good rationale for incorporating these drugs into future first-line regimens. Chemotherapy for extensive-stage small-cell lung cancer (E-SCLC) produces high response rates and improved survival but few cures. We tested three new regimens for E-SCLC that might merit further investigation in a subsequent phase III trial. Cancer and Leukemia Group B 9430 was a randomized phase II study evaluating 4 treatment arms in 57 evaluable, previously untreated E-SCLC patients. Each arm consisted of the following: Arm 1: cisplatin plus topotecan; Arm 2: cisplatin plus paclitaxel; Arm 3: paclitaxel 230 mg/m2 plus topotecan; and Arm 4: paclitaxel 175 mg/m2 plus topotecan. Because of an accrual time difference, Arm 2 will not be discussed in this manuscript. Arm 1 (12 patients) produced 1 complete response (CR, 8%) and an overall response rate (ORR) of 42%. Toxicity was excessive, with 3 deaths (25%). Arm 3 (13 patients) produced no CRs, 7 partial responses (PRs, 54%), median survival of 13.8 months, and failure-free survival (FFS) of 7.41 months, with 3 toxic deaths (25%). Among 32 evaluable patients on Arm 4, there were 2 CRs (6%) and 20 PRs (63%) for an ORR of 69%, median survival of 9.9 months, FFS of 5.21 months, and 1-year survival of 40%. There was 1 possible treatment-related death (3%). Topotecan plus cisplatin, in the doses and schedule employed, produced excessive toxicity and modest efficacy in E-SCLC patients. Paclitaxel (230 mg/m2 on day 1) plus topotecan (1 mg/m2 on days 1-5) produced excessive toxicity that was ameliorated with an attenuated paclitaxel dose (175 mg/m2). With the latter regimen (Arm 4) in patients with a performance status of 0/1, CR rates, FFS, overall survival, and 1-year survival were similar to standard etoposide plus cisplatin chemotherapy. Further exploration of topoisomerase inhibitors and taxanes in SCLC patients is warranted. Topotecan and paclitaxel were evaluated in a randomized, multicenter study of patients with advanced epithelial ovarian carcinoma who had progressed during or after one platinum-based regimen.
                Patients received either topotecan (1.5 mg/m2) as a 30-minute infusion daily for 5 days every 21 days (n = 112) or paclitaxel (175 mg/m2) infused over 3 hours every 21 days (n = 114). Patients had bidimensionally measurable disease and were assessed for efficacy and toxicity.
                Response rate was 23 of 112 (20.5%) in topotecan-treated patients and 15 of 114 (13.2%) in paclitaxel-treated patients (P = .138). Disease stabilization for at least 8 weeks was noted in 30% of patients with topotecan and 33% of patients with paclitaxel. Median durations of response to topotecan and paclitaxel were 32 and 20 weeks, respectively (P = .222) and median times to progression were 23 and 14 weeks, respectively (P = .002). Median survival was 61 weeks for topotecan and 43 weeks for paclitaxel (P = .515). Response rates for topotecan and paclitaxel were 13.3% versus 6.7% (P = .303) in resistant patients (not responded to prior platinum-based therapy or progressed within 6 months of an initial response) and 28.8% versus 20.0% (P = .213) in sensitive patients (progressed > 6 months after response). Neutropenia was significantly more frequent on the topotecan arm 79% versus paclitaxel arm 23% (P < .01). It was short-lasting and noncumulative in both arms. Nonhematologic toxicities were generally mild (grades 1 to 2) for both agents.
                Topotecan has efficacy at least equivalent to paclitaxel manifested by the higher response rate and significantly longer time to progression. Topotecan is an active second-line treatment for advanced ovarian cancer. Its efficacy as consolidation treatment after first-line standard chemotherapy is unknown.
                To investigate whether topotecan (1.5 mg/m(2) on days 1 through 5, four cycles, every 3 weeks) prolonged progression-free survival (PFS) for patients responding to standard carboplatin (area under the curve 5) and paclitaxel (175 mg/m(2) administered as a 3-hour infusion in six cycles; CP), a multicenter phase III study was performed with an 80% power to detect a 50% prolongation of median PFS. Patients were registered at diagnosis and randomized after the end of CP.
                Two hundred seventy-three patients were randomly assigned (topotecan, n = 137; observation, n = 136), with a median age of 56 years. Stage at diagnosis was advanced in three fourths of patients (stage III in 65% of patients; stage IV in 10%); after primary surgery, 46% had no residual disease and 20% were optimally debulked. After CP, 87% reached a clinical complete response, and 13% achieved a partial response. Neutropenia (grade 3/4 in 58% of the patients) and thrombocytopenia (grade 3 in 21%; grade 4 in 3%) were the most frequent toxicities attributed to topotecan. There was no statistically significant difference in PFS between the arms (P =.83; log-rank test): median PFS was 18.2 months in the topotecan arm and 28.4 in the control arm. Hazard ratio of progression for patients receiving topotecan was 1.18 (95% CI, 0.86 to 1.63) after adjustment for residual disease, interval debulking surgery, and response to CP.
                The present analysis indicates that consolidation with topotecan does not improve PFS for patients with advanced ovarian cancer who respond to initial chemotherapy with carboplatin and paclitaxel. To compare the combination of paclitaxel (Taxol; Bristol-Myers Squibb, Princeton, NJ, http://www.bms.com) and topotecan (Hycamtin; Glaxo SmithKline, Philadelphia, http://www.gsk.com) with paclitaxel, carboplatin (Paraplatin; Bristol-Myers Squibb), and etoposide (Etopophos, VePesid; Bristol-Myers Squibb) in patients with previously untreated extensive-stage small cell lung cancer.
                In this phase II trial, 120 patients were randomly allocated to receive either topotecan (1.5 mg/m(2) i.v. days 1, 2, and 3) and paclitaxel (175 mg/m(2) i.v. day 1) every 21 days orpaclitaxe l (200 mg/m(2) i.v. day 1), carboplatin (area under the concentration-time curve 6 i.v. day 1), and etoposide (50 mg/100 mg alternating daily by mouth days 1-10) every 21 days, each regimen for a maximum of eight cycles. The primary end points were objective response rate and time to progression.
                The paclitaxel-carboplatin-etoposide combination produced a significantly higher overall response rate (78% versus 48%), longer median time to progression (7.6 months versus 5.5 months), and greater number of patients free from progression at 1 year (14% versus 8%) compared with paclitaxel plus topotecan. There was no difference in overall survival. Toxicities were similar in the two treatment arms.
                The paclitaxel-carboplatin-etoposide combination produced a superior overall response rate and time to progression in patients with extensive-stage small cell lung cancer compared with paclitaxel plus topotecan. The platinum compounds continue to be a necessary component of the initial therapy for these patients. To compare the efficacy and safety of pegylated liposomal doxorubicin (PLD) and topotecan in patients with epithelial ovarian carcinoma that recurred after or didn't respond to first-line, platinum-based chemotherapy.
                Patients with measurable and assessable disease were randomized to receive either PLD 50 mg/m(2) as a 1-hour infusion every 4 weeks or topotecan 1.5 mg/m(2)/d for 5 consecutive days every 3 weeks. Patients were stratified prospectively for platinum sensitivity and for the presence or absence of bulky disease.
                A total of 474 patients were treated (239 PLD and 235 topotecan). They comprised the intent-to-treat population. The overall progression-free survival rates were similar between the two arms (P =.095). The overall response rates for PLD and topotecan were 19.7% and 17.0%, respectively (P =.390). Median overall survival times were 60 weeks for PLD and 56.7 weeks for topotecan. Data analyzed in platinum-sensitive patients demonstrated a statistically significant benefit from PLD for progression-free survival (P =.037), with medians of 28.9 for PLD versus 23.3 weeks for topotecan. For overall survival, PLD was significantly superior to topotecan (P =.008), with a median of 108 weeks versus 71.1 weeks. The platinum-refractory subgroup demonstrated a nonstatistically significant survival trend in favor of topotecan (P =.455). Severe hematologic toxicity was more common with topotecan and was more likely to be associated with dosage modification, or growth factor or blood product utilization.
                The comparable efficacy, favorable safety profile, and convenient dosing support the role of PLD as a valuable treatment option in this patient population.
Topotecan appears to have a similar level of effectiveness as paclitaxel and PLD, though with different patterns of side effects. Larger, well-designed RCTs are required in order to define an optimal regime.