Phase I study of topotecan and cisplatin in patients with advanced solid tumors: a cancer and leukemia group B study

Silver Nanoparticles Potentiates Cytotoxicity and Apoptotic Potential of Camptothecin in Human Cervical Cancer Cells

Silver nanoparticles (AgNPs) are widely used metal nanoparticles in health care industries, particularly due to its unique physical, chemical, optical, and biological properties. It is used as an antibacterial, antiviral, antifungal, and anticancer agent. Camptothecin (CPT) and its derivatives function as inhibitors of topoisomerase and as potent anticancer agents against a variety of cancers. Nevertheless, the combined actions of CPT and AgNPs in apoptosis in human cervical cancer cells (HeLa) have not been elucidated. Hence, we investigated the synergistic combinatorial effect of CPT and AgNPs in human cervical cancer cells. We synthesized AgNPs using sinigrin as a reducing and stabilizing agent. The synthesized AgNPs were characterized using various analytical techniques. The anticancer effects of a combined treatment with CPT and AgNPs were evaluated using a series of cellular and biochemical assays. The expression of pro- and antiapoptotic genes was measured using real-time reverse transcription polymerase chain reaction. The findings from this study revealed that the combination of CPT and AgNPs treatment significantly inhibited cell viability and proliferation of HeLa cells. Moreover, the combination effect significantly increases the levels of oxidative stress markers and decreases antioxidative stress markers compared to single treatment. Further, the combined treatment upregulate various proapoptotic gene expression and downregulate antiapoptotic gene expression. Interestingly, the combined treatment modulates various cellular signaling molecules involved in cell survival, cytotoxicity, and apoptosis. Overall, these results suggest that CPT and AgNPs cause cell death by inducing the mitochondrial membrane permeability change and activation of caspase 9, 6, and 3. The synergistic cytotoxicity and apoptosis effect seems to be associated with increased ROS formation and depletion of antioxidant. Certainly, a combination of CPT and AgNPs could provide a beneficial effect in the treatment of cervical cancer compared with monotherapy.

Cellular and Clinical Pharmacokinetic/Pharmacodynamic Basis for Lack of Efficacy of 21-Day Continuous Topotecan in Patients with Untreated Advanced Adenocarcinoma of the Pancreas

Background

In a phase II study, topotecan was evaluated for response and toxicity in patients with advanced pancreatic carcinoma at the schedule of 0.7 mg/m2/day q 21 days q 28 days.

Methods

Responses were assessed after at least 2 courses using WHO criteria, and toxicity was evaluated after each course according to the CTC-NCI standards. Between December 1995 and September 1997, 15 assessable patients (median age, 55 years; range, 36-74; median ECOG performance, 1; range, 0-3) were included in the study. All had biopsy-proven and measurable disease, a life-expectancy of at least 3 months, and normal bone marrow, liver, and renal function. None of the patients had undergone prior cytotoxic or radiation therapy, and 10 were initially treated by surgery. Twenty-five cycles were assessable for toxicity. Plasma was collected from 7 patients who had received a total of 10 cycles and was, after extraction with methanol at −20°C, analyzed for total topotecan by an HPLC method. The thus determined steady-state concentrations were assessed for their capacity to affect growth and DNA integrity in the BxPC-3 human pancreatic carcinoma cell line after 21 days of continuous exposure. For these purposes, we used a sulforhodamine B staining assay, and agarose gel electrophoresis, respectively.

Results

Grades 3-4 leukopenia, thrombocytopenia, granulocytopenia, and anemia occurred in 8, 6, 8 and 8 cycles, respectively. Other mild to moderate side effects (grades 1-2) included malaise, nausea and vomiting, anorexia, and alopecia. No objective tumor response was documented. HPLC analysis of patients' plasma showed the attainment of constant steady-state levels of 1.0 ± 0.1 ng/mL during the entire infusion period. At such a concentration, topotecan did not significantly affect growth or DNA integrity in the BxPC-3 cells. Fifty percent cell growth inhibition and appreciable oligonucleosomal DNA fragmentation were only evident with 21 days topotecan ≥ 50 ng/mL.

Conclusions

Our data suggest that the lack of clinical activity of 0.7 mg/m2 daily topotecan for 21 days q 28 days in patients with advanced pancreatic carcinoma might be partially attributed to the achievement of non-tumoricidal plasma drug concentrations.

Review : Topoisomerase I inhibitors: 1. Topotecan

Purpose. The primary objective of this article is to discuss the pharmacology, pharmacokinetics, clin ical use, and adverse effects of the approved topoisomerase I inhibitors. This is the first in a series of two articles and will focus on topotecan.

Data Sources. We reviewed the literature through a MEDLINE search of English language articles from 1985 through 1997. Relevant articles cited in the titles obtained from the MEDLINE search were also used. The following terms were used for purpose of conducting the MEDLINE search: topoisomerase inhibitors, topotecan, topo isomerase I, Hycamtin, SKF 104864.

Data Extraction. We reviewed the current literature in order to discuss the pharmacology, pharmacokinetics, clinical use, toxicity, drug inter actions, indications, formulation, dosage and ad ministration, and pharmaceutical issues surround ing the use of topotecan.

Data Synthesis. The topoisomerase I inhibi tors are new antineoplastic agents with a unique mechanism of action. Promising areas of applica tion include ovarian cancer, lung cancer, radiation sensitization, and refractory leukemias. Clinical tri als detailing its activity in these areas are pre sented.

A novel trial of topotecan, ifosfamide, and carboplatin (TIC) in children with recurrent solid tumors

BACKGROUND

Ifosfamide, carboplatin, and etoposide (ICE) in children with refractory or recurrent solid tumors and lymphomas has resulted in good overall response rates (ORR). Etoposide, a topoisomerase-II inhibitor, however, has been associated with a significant increase in secondary leukemia. The rationale for substituting topotecan, a topoisomerase-I inhibitor, for etoposide in this regimen, a topoisomerase-II inhibitor, includes its limited toxicity profile and decreased leukemogenicity. Furthermore, topotecan in combination with both alkylators and platinating agents are additive and/or synergistic against a variety of solid tumors.

PROCEDURE

Patients with relapsed/refractory solid tumors received ifosfamide (9 g/m² ) and carboplatin (area under the curve: 3 mg/ml/min). Topotecan was also administered at 0.5 mg/m² /day × 3 days (N = 12) and in a small cohort (N = 3) at 0.75 mg/m² /day.

RESULTS

Fifteen patients were entered onto study. Two patients developed seizures/encephalitis secondary to ifosfamide. One patient had dose-limiting thrombocytopenia secondary to TIC that resolved with supportive care. Patients received a median of three cycles (1-3) of TIC. Of the 14 evaluable patients for response, 4/14 had a complete response (CR), 2/14 had a partial response (PR), and 1/14 patients had stable disease (SD). The ORR (CR + PR) was 43%.

CONCLUSION

TIC chemotherapy is feasible and tolerable in children and adolescents with refractory/recurrent solid tumors and lymphomas and results in a 43% excellent ORR in this poor-risk group of patients. A larger cohort of patients, especially in Wilms tumor and central nervous system (CNS) tumors, should be studied in the future to attempt to confirm these preliminary findings. Pediatr Blood Cancer 2015;62:274-278. © 2014 Wiley Periodicals, Inc.

A phase I study of paclitaxel, topotecan, cisplatin and Filgrastim in patients with newly diagnosed advanced ovarian epithelial malignancies: a Gynecologic Oncology Group study

OBJECTIVES

To determine a recommended dose level (RDL) of paclitaxel, cisplatin and topotecan in women with previously untreated epithelial ovarian or peritoneal cancer as a possible experimental arm in a future Gynecologic Oncology Group phase III study.

METHODS

Patients with newly diagnosed stage III or IV disease were treated with paclitaxel 175 mg/m2/3 h, followed 2 h later by cisplatin 50 mg/m2 on day 1. Topotecan was administered on consecutive days as a 30-minute infusion, beginning after cisplatin on day 1, receiving either 5 days beginning at 0.3 mg/m2 (cohort 1), or 3 days beginning at 0.5 mg/m2 (cohort 2). Treatment was given every 21 days for a maximum of 8 cycles.

RESULTS

Forty-five evaluable patients were enrolled in the two cohorts. Thrombocytopenia and prolonged neutropenia were the major dose-limiting toxicities. Dose-limiting neutropenia was seen at the first dose level, thus all subsequent dose escalations included Filgrastim. The RDL of cohort 1 was paclitaxel 175 mg/m2/3 h, cisplatin 50 mg/m2 and topotecan 0.5 mg/m2 daily x 5 with Filgrastim. The RDL of cohort 2 was paclitaxel 175 mg/m2/3 h, cisplatin 50 mg/m2 and topotecan 0.75 mg/m2 daily x 3 with Filgrastim.

CONCLUSION

In women with previously untreated epithelial ovarian or peritoneal cancer the combination of paclitaxel, cisplatin and topotecan is feasible. However, this treatment requires the use of Filgrastim and attenuated dosing of topotecan in both a 5-day and 3-day topotecan infusion schedule.

Phase I North Central Cancer Treatment Group Trial-N9923 of escalating doses of twice-daily thoracic radiation therapy with amifostine and with alternating chemotherapy in limited stage small-cell lung cancer

PURPOSE

The primary goal was to identify the maximum tolerable dose (MTD) of thoracic radiation therapy (TRT) that can be given with chemotherapy and amifostine for patients with limited-stage small-cell lung cancer (LSCLC).

METHODS AND MATERIALS

Treatment began with two cycles of topotecan (1 mg/m(2)) Days 1 to 5 and paclitaxel (175 mg/m(2)) Day 5 (every 3 weeks) given before and after TRT. The TRT began at 6 weeks. The TRT was given in 120 cGy fractions b.i.d. and the dose escalation (from 4,800 cGy, dose level 1, to 6,600 cGy, dose level 4) followed the standard "cohorts of 3" design. The etoposide (E) (50 mg/day) and cisplatin (C) (3 mg/m(2)) were given i.v. before the morning TRT and amifostine (500 mg/day) was given before the afternoon RT. This was followed by prophylactic cranial irradiation (PCI). The dose-limiting toxicities (DLTs) were defined as Grade > or =4 hematologic, febrile neutropenia, esophagitis, or other nonhematologic toxicity, Grade > or =3 dyspnea, or Grade > or =2 pneumonitis.

RESULTS

Fifteen patients were evaluable for the Phase I portion of the trial. No DLTs were seen at dose levels 1 and 2. Two patients on dose level 4 experienced DLTs: 1 patient had a Grade 4 pneumonitis, dyspnea, fatigue, hypokalemia, and anorexia, and 1 patient had a Grade 5 hypoxia attributable to TRT. One of 6 patients on dose level 3 had a DLT, Grade 3 esophagitis. The Grade > or =3 toxicities seen in at least 10% of patients during TRT were esophagitis (53%), leukopenia (33%), dehydration (20%), neutropenia (13%), and fatigue (13%). The median survival was 14.5 months.

CONCLUSION

The MTD of b.i.d. TRT was 6000 cGy (120 cGy b.i.d.) with EP and amifostine.

Topotecan in the management of cervical cancer

Topotecan, a semisynthetic camptothecin, exerts its cytotoxic effect through inhibition of DNA topoisomerase I. Single-agent topotecan has demonstrated activity against persistent, metastatic and recurrent cancer of the uterine cervix. When combined with cisplatin in Phase II trials, further improved response rates have been reported. The cisplatin/topotecan doublet subsequently proved to be the first regimen in a series of multiple Phase III studies to demonstrate improved disease-free and overall survival in this setting compared with cisplatin alone, thus leading to its third indication by both the US FDA and the European Medicines Agency in 2006. This survival advantage was achieved at the expense of an increase in grade 3-4 hematologic toxicity; however, there was no difference in patient-reported quality of life between the cisplatin/topotecan doublet and single-agent cisplatin. This article reviews the pharmacology of topotecan and its evolution as an active agent in advanced and metastatic cervical cancer that is not amenable to cure with surgery or radiotherapy.

Topotecan and cyclophosphamide in patients with refractory or relapsed Ewing tumors

BACKGROUND

The prognosis of Ewing tumor (ET) patients has significantly improved to cure rates approximating 70%. The prognosis in relapse, however, is poor. Promising response rates have recently been reported for the combination of topotecan (TOPO) and cyclophosphamide (CYC) encouraging wider application of this combination in patients with relapsed ETs. This report summarizes the experience of patients treated with TOPO/CYC for recurrent or refractory disease within the German ET trials.

PROCEDURE

Fifty-four patients aged 3.2-49.5 (median: 17.4) years received TOPO (0.75 mg/m2/day, days 1-5) and CYC (250 mg/m2/day, days 1-5) following first (40) or second (6) relapse or progression under first-line therapy (8).

RESULTS

A median of 3 (range: 1-11) TOPO/CYC courses were given. Sixteen patients (32.6%) showed partial response (PR), 13/49 (26.5%) had stable disease (SD), 14/49 (28.6%) progressed, 2/49 (4.1%) showed a mixed response (MR). In 4 patients response was not documented, 5/54 patients with complete initial resection at the diagnosis of relapse were excluded from the response analysis. At completion of relapse therapy, 24/54 patients had entered complete (19) or partial (5) remission, 2 had SD, 26 showed progression, information was unavailable in 2 patients. Of the 19 relapse patients achieving complete response (CR), 10 maintained remission (52.6%). At the time of evaluation, after a median follow-up for survivors of 23.1 (range: 7.8-59.8) months from the event prompting TOPO/CYC treatment, 14/54 patients (25.9%) were in continuous complete (13) or partial (1) remission. Overall survival (OAS) after 1 year was 0.61 (95%-CI 0.47-0.74).

CONCLUSION

TOPO/CYC is active in relapsed ETs and warrants further evaluation.

The cancer and leukemia group B pharmacology and experimental therapeutics committee: a historical perspective

The Chemotherapy Committee of Cancer and Leukemia Group B (CALGB) was established in the mid-1970s to assemble a group of experts in cancer chemotherapy and pharmacology who could advise the CALGB disease committees about the optimal use of drugs in the fight against cancer and to provide quality assurance for the chemotherapy section of CALGB protocols. Chaired initially by Edward Henderson and then David Van Echo, the committee was also the repository of studies in diseases for which CALGB did not have a formal committee, such as testis cancer and sarcoma. In 1990, following the appointment of Richard Schilsky as Chair, the name of the committee was changed to the Pharmacology and Experimental Therapeutics (PET) Committee to reflect a more specific focus and scientific agenda (i.e., studies of chemotherapy pharmacology and development of new agents). Three PET Committee reference pharmacology laboratories (led by Merrill Egorin, Tony Miller, and Mark Ratain) were established to measure drug concentrations in biological fluids and to perform pharmacokinetic analyses. In addition, the PET Committee embarked on a number of multi-institution phase I studies. These phase I studies included studies of special populations, including the first prospective study of an anticancer agent (paclitaxel) in patients with hepatic dysfunction. In addition, the Committee studied a number of phase I combinations destined for phase II evaluation in disease-specific committees. Following Dr. Schilsky's election as CALGB Group Chair in 1994, Mark Ratain took over as Chair of the PET Committee and continued to emphasize population pharmacology as the primary theme of the Committee's research agenda. In addition, the PET Committee began to develop novel clinical trial designs, including the first completed randomized discontinuation trial of an antineoplastic agent. Most recently, the PET Committee has launched an ambitious research program in pharmacogenetics, facilitated in large part through the recruitment of Howard McLeod as Vice Chair. This area of research is a collaborative effort with the NIH Pharmacogenetics Research Network and has the potential to definitively address the hypothesis that germ line polymorphisms are a significant determinant of the toxicity and efficacy of anticancer therapy. It is anticipated that the results of the current studies will contribute significantly to the goal of individualizing cancer treatment.

Topotecan, thiotepa, and carboplatin for neuroblastoma: failure to prevent relapse in the central nervous system

We report on a three-drug myeloablative regimen designed to consolidate remission and to prevent central nervous system (CNS) relapse of high-risk neuroblastoma (NB). Sixty-six NB patients received topotecan 2 mg/m2/day, x 4 days; thiotepa 300 mg/m2/day, x 3 days; and carboplatin approximately 500 mg/m2/day, x 3 days. Post-SCT treatments included radiotherapy, immunotherapy, 13-cis-retinoic acid, +/-oral etoposide. Significant nonhematologic toxicities were mucositis and skin-related in all patients, convulsions in three patients, and cardiac failure and venocclusive disease of liver in one patient each. Grade 2 hepatotoxicity led to truncating cytoreduction in two patients; both later relapsed in brain. Among 46 patients transplanted in first complete/very good partial remission (CR/VGPR), event-free survival is 54% (s.e.+/-8%) at 36 months post-SCT; notable events were three non-NB-related deaths (adenovirus on day +9, bowel necrosis at 5 months, multiorgan failure at seven months) and four relapses in brain. Of 12 patients transplanted with evidence of NB, two became long-term event-free survivors and two relapsed in the brain. Of eight patients transplanted in second or greater CR/VGPR, one became a long-term event-free survivor and seven relapsed though not in the CNS. This regimen has manageable toxicity but does not prevent CNS relapse.

Complete response following preoperative chemotherapy for resectable non-small cell lung cancer: accuracy of clinical assessment using the French trial database

BACKGROUND

Pathologic complete response (CR) to preoperative chemotherapy has been shown to be a strong prognostic factor in resected non-small cell lung cancer (NSCLC). This preoperative setting offers the opportunity to evaluate the clinical prediction of CR by investigators and an evaluation committee (EC) using the "gold standard" pathologic examination as the reference. The only published large randomized trial of preoperative chemotherapy (to our knowledge), the French neoadjuvant study, constitutes an interesting database to evaluate CT scan-based CR assessment. STUDY OBJECTIVES AND DESIGN: The French trial compared mitomycin-ifosfamide-cisplatin followed by surgery with surgery alone in stage I (except T1N0) to IIIa resectable NSCLC. Response was prospectively assessed in all patients receiving preoperative chemotherapy by the investigator in charge of the patient and by an EC, and was compared with pathologic postoperative data.

RESULTS

In the preoperative chemotherapy study, 167 patients were operated on. Nineteen patients were found to have a pathologic CR. Only seven patients were classified as having a CR by investigators and five patients by the EC. Evaluation of CR was correct in six of these seven cases and in three of these five cases, respectively. Sensitivity of the CR diagnosis was 31.6% for investigators and 15.8% for the EC. Specificities of the CR diagnosis were 99.4% and 98.8%, respectively. Positive predictive values were 85.7% and 60%, respectively. Negative predictive values were 91.9% and 90.1%, respectively. Accuracies were 91.6% and 89.2%, respectively.

CONCLUSION

Investigator assessment of CR was highly predictive of pathologic CR. However, this study showed that clinical CT scan-based assessment, whether performed by investigators or the EC, underestimated the frequency of CR after preoperative chemotherapy in resectable NSCLC.

A phase I study of 3-day topotecan and cisplatin in elderly patients with small-cell lung cancer

PURPOSE

The aim of this phase I study was to determine the maximum-tolerated dose (MTD) in elderly patients with small-cell lung cancer (SCLC).

PATIENTS AND METHODS

Patients aged over 75 years with previously untreated SCLC were enrolled in this study. Both topotecan and cisplatin were administered on days 1-3 and repeated every 3 weeks. The starting dose of topotecan was 0.5 mg/m2/day, while cisplatin was fixed at the dose of 20 mg/m2/day. Patients with limited disease (LD) SCLC received thoracic irradiation after the completion of chemotherapy.

RESULTS

Twenty-one elderly patients were enrolled in this study and received a total of 59 cycles. The major hematological toxicity was neutropenia and non-hematological toxicities including diarrhea were generally mild and reversible. The MTD of topotecan was determined as 1.2 mg/m2/day. The recommended phase II study dose of topotecan was determined as 1.0 mg/m2/day with cisplatin 20 mg/m2/day daily for 3 days. An objective response was observed in 6 of 10 patients (60%) with LD-SCLC and 6 of 11 (55%) with extensive disease (ED) SCLC. The median survival time in patients with LD-SCLC and those with ED-SCLC were 16.0 and 11.0 months, respectively.

CONCLUSION

The combination chemotherapy of 3-day topotecan and cisplatin appears to be tolerable and effective in elderly patients with SCLC.

Topotecan in the first-line treatment of small cell lung cancer

Small cell lung cancer (SCLC) is generally sensitive to first-line chemotherapy, but limited disease often recurs and extensive disease is rarely curable. The most common first-line therapy regimen is cisplatin (Platinol; Bristol-Myers Squibb; Princeton, NJ) plus etoposide (Etopophos; Bristol-Myers Squibb)--PE, which is associated with overall response rates >80% in patients with limited SCLC. Although it is associated with median survival times of approximately 18-20 months for limited disease, PE yields median survival times of only approximately 8-12 months in patients with extensive disease, and symptom palliation becomes the primary therapeutic goal. The toxicities of PE may undermine quality of life and leave patients more susceptible to adverse events during subsequent therapies. Topotecan (HYCAMTIN; GlaxoSmithKline; Philadelphia, PA), an established treatment for recurrent SCLC, is being investigated in the first-line setting because of its novel mechanism of action; predictable, noncumulative, and manageable toxicities; and potential synergy with other active agents. Several recent phase II trials have generated promising results for topotecan-based combination regimens, including topotecan/paclitaxel (TAXOL; Bristol-Myers Squibb) (overall response rates 45%-100%), topotecan/etoposide (overall response, 95%), and topotecan, paclitaxel, and platinum agent triplets (overall response rates 51%-93%). The most frequent serious toxicity associated with these regimens was reversible and noncumulative neutropenia, which was generally manageable with supportive care. Additional clinical trials to investigate topotecan-based combination regimens and confirm their role in the first-line treatment of SCLC are under way.

Cisplatin and irinotecan in squamous cell carcinoma of the cervix: a phase II study of the Gynecologic Oncology Group

OBJECTIVE

To evaluate the combination of cisplatin and irinotecan as first-line treatment of patients with advanced, persistent, or recurrent squamous cell carcinoma of the cervix.

METHODS

Patients with no prior treatment for metastatic disease, presence of measurable tumors, performance status of 0 or 1, and adequate bone marrow, renal, and hepatic functions were potentially eligible for this trial. Cisplatin and irinotecan were given weekly at starting doses of 25 and 65 mg/m(2), respectively, for three consecutive weeks. Cycles were to be repeated every 28 days with dose adjustments as required. Patient accrual was based on a two-stage design with at least seven responses out of 28 patients in the first stage required to proceed to a second stage of accrual seeking a response rate of 40% or better.

RESULTS

Of 34 patients entered onto the study, 31 were eligible and 27 were evaluable for response. Ten had received prior chemoradiation containing cisplatin. Among the five (two complete and three partial) observed responses, two were in the subset of patients who had received prior chemoradiation. This level of activity was deemed insufficient to warrant a second stage of accrual. Predominant toxicities were myelosuppression and gastrointestinal symptoms, although six patients experienced none of these adverse effects.

CONCLUSION

At these doses, weekly cisplatin and irinotecan failed to demonstrate sufficient activity to undertake a phase III study. Although not apparent in this study, prior chemoradiation may affect response to platinum-based combinations and its impact should be considered in the design of future trials.

A phase I study of OSI-211 and cisplatin as intravenous infusions given on days 1, 2 and 3 every 3 weeks in patients with solid cancers

BACKGROUND

OSI-211 (also known as NX211) is a liposomal preparation of the topoisomerase I inhibitor, lurtotecan, which has shown antitumor activity in phase I and II clinical trials. Cisplatin is a widely used antineoplastic agent with activity in a broad range of tumor types. This phase I trial was conducted to determine the recommended doses of these agents, and their pharmacokinetic properties and toxicities in patients with advanced solid malignancies.

PATIENTS AND METHODS

Fourteen patients with advanced and/or metastatic solid malignancies were enrolled in this trial. The first planned dose level was OSI-211 0.9 mg/m(2) with cisplatin 25 mg/m(2) administered intravenously daily for the first three consecutive days of a 21-day cycle. Patients were evaluated for hematological and non-hematological toxicities, and pharmacokinetic studies were performed on both agents.

RESULTS

The recommended phase II dose was determined to be 0.7 mg/m(2) OSI-211 given with 25 mg/m(2) cisplatin. Dose-limiting neutropenia was seen in two of three patients at the starting dose level. Three of 11 patients at the second (lower) dose level experienced dose-limiting thrombocytopenia; febrile neutropenia was also seen in one patient. Non-hematological toxicities were generally manageable and included fatigue, nausea and vomiting. Considerable variability was seen in both hematological toxicities and pharmacokinetics. One complete response and three partial responses were seen.

CONCLUSIONS

The recommended phase II dose for this combination is 0.7 mg/m(2) OSI-211 with 25 mg/m(2) cisplatin given as an intravenous infusion on days 1, 2 and 3 of a 21-day cycle. The main toxicity was myelosuppression. Preliminary evidence of antitumor activity was seen.

Topotecan as first-line therapy for small cell lung cancer

Although current treatments for small-cell lung cancer (SCLC) yield objective response rates exceeding 50%, most patients relapse. Hence, research into the identification of novel agents and combinations that may improve therapy is ongoing. Topotecan, an established treatment for patients with recurrent SCLC, is being investigated as first-line therapy for SCLC because of its novel mechanism of action, non-cumulative toxicity and in vitro synergy with other active agents. Several phase II studies of doublet and triplet combination therapy with other agents, including paclitaxel, cisplatin, carboplatin and etoposide, have reported promising results for first-line treatment of SCLC. For example, in combination with paclitaxel, complete and overall responses were 3-67% and 45-100%, respectively, in extensive-stage disease. Furthermore, two studies of the triplet combination of topotecan with paclitaxel plus carboplatin yielded impressive complete response rates of 37-51% in limited-stage SCLC. The most frequent adverse events associated with topotecan-based regimens have been reported as neutropenia and thrombocytopenia so growth factor support is often incorporated into treatments. Several ongoing phase III studies will help to clarify the role of topotecan in the first-line treatment of SCLC.

ZD0473 combined with other chemotherapeutic agents for the treatment of solid malignancies

Platinum-based combination chemotherapy regimens are the mainstay of current treatments for advanced solid malignancies. Preclinical in vitro studies have shown synergism with ZD0473 in combination with several agents, including vinorelbine and topotecan. This paper reviews the tolerability and activity observed with ZD0473 in combination with vinorelbine or topotecan, in two Phase I dose-escalating studies in patients with advanced, solid, refractory malignancies. Twenty-four patients were included in the ZD0473 plus vinorelbine trial and were treated with doses of ZD0473 60-150 mg/m2 and vinorelbine 15-25 mg/m2. In this trial, dose-limiting toxicity comprised non-haematological events and the most common grade 3/4 toxicities included neutropenia (54.2%), thrombocytopenia (29.2%) and anaemia (20.8%). Eleven patients were included in the ZD0473 plus topotecan trial and were treated with ZD0473 60-90 mg/m2 and topotecan 0.5 mg/m2/day for 3 or 5 days. In this trial, dose-limiting toxicity comprised haematological events and the most common grade 3/4 toxicities included thrombocytopenia (63.6%), neutropenia (36.4%) and anaemia (18.2%). No objective responses were observed in either trial, but disease stabilisation occurred in 29.2% and 27.3% of patients in the vinorelbine and topotecan trials, respectively.

Phase I study of sequential administration of topotecan and 5-fluorouracil in patients with advanced malignancies

Topotecan is a topoisomerase-I inhibitor, a drug that stabilizes a covalent complex of enzymes and causes strand cleavage of DNA. 5-Fluorouracil (5FU) is an antimetabolite that interferes with DNA synthesis. Preclinical studies using human cancer cell line models have shown potential therapeutic synergy between these two drugs by showing the maximum cytolytic effect using sequential 5FU followed by topotecan. In the current study, 5FU was used at a fixed dose of 375 mg/m2 given intravenously for five consecutive days on a 28 day cycle. Topotecan was dose-escalated in cohorts of patients from 0.5 to 1.0 mg/m2 given intravenously for 5 days after the 5FU dose. Eleven patients were entered at different dose levels. Both hematological and gastrointestinal toxicity were dose limiting. Diarrhea was the dose-limiting toxicity at the dose of 0.75 mg/m2 of topotecan. Two cases of grade 4 neutropenia were also observed at this dose level. One patient with small cell lung cancer had a complete response, while one patient with metastatic colorectal cancer had a partial remission. Three other patients had stable disease, lasting between 6 and 8 months. Overall, the regimen was well tolerated. A phase II study using a dose of 5FU at 375 mg/m2 followed by topotecan at 0.75 mg/m2 intravenously over 5 days every 28 days is recommended.

Topotecan preceded by oxaliplatin using a 3 week schedule: a phase I study in advanced cancer patients

Combinations of topoisomerase I (topo I) poisons and platinum derivatives have synergistic antitumoral effects. However, their clinical development is limited by supra-additive haematological toxicity. The aim of this study was to determine whether sustained doses of topotecan and oxaliplatin could be achieved using a synergistic sequence. 34 advanced cancer patients and 186 cycles were evaluable for toxicity over five dosing levels. Oxaliplatin at 85-110 mg/m(2) was given on day 1, followed by topotecan 0.5-1.25 mg/m(2)/day x 5 from day 1 to 5, every 3 weeks. Plasma pharmacokinetics (PK) of total and ultrafiltrable platinum, total and lactone forms of topotecan were determined in the first cycle. The dose-limiting toxicity (DT) was identified as grade 4 thrombocytopenia. The occurrence of grade 4 thrombocytopenia did not correlate with topotecan PK, but it did with the patient's characteristics. Severe thrombocytopenia was seen in 1/8 of patients without clinical or biological evidence of malnutrition, with a creatinine clearance higher than 1 ml/s, and no more than two previous chemotherapy regimens, while it was seen in 8/10 patients with one of these characteristics (P<0.004). In conclusion, the recommended doses of oxaliplatin 110 mg/m(2) and topotecan 1 mg/m(2)/day, every 3 weeks can be administered to patients with a favourable general status and pretreatment characteristics and a phase II study is worthwhile in ovarian cancer patients.

Phase II trial of topotecan and cisplatin in persistent or recurrent squamous and nonsquamous carcinomas of the cervix

OBJECTIVE

Cisplatin is a standard treatment in advanced, recurrent cervical cancer. Because topotecan is an established treatment in gynecologic malignancies such as ovarian cancer and exhibits nonoverlapping toxicity with cisplatin, a phase II trial was conducted to evaluate the tolerability and antitumor activity of a cisplatin/topotecan doublet in persistent or recurrent cervical cancer patients.

METHODS

Patients with bidimensionally measurable persistent or recurrent squamous cell and non squamous cell cervical cancer and adequate bone marrow were enrolled. Patients received 50 mg/m(2) of cisplatin intravenously over 1 h on Day 1 and 0.75 mg/m(2) of topotecan intravenously over 30 min on Days 1, 2, and 3 of 21-day cycles for six cycles or until disease progression. Tumor response and regimen toxicity were assessed using established Gynecologic Oncology Group criteria.

RESULTS

Thirty-two of 35 enrolled patients were evaluable for toxicity and tumor response. All but 2 evaluable patients had received previous radiotherapy. No patient received prior chemotherapy. The cisplatin/topotecan doublet was well tolerated, with 77 and 78% of courses given without interruption or delay and at full doses, respectively. As anticipated, the most common toxicity was hematologic, with grade 3/4 neutropenia and thrombocytopenia reported in 30 and 10% of cycles, respectively. The overall response rate was 28% (9/32), with 3 complete and 6 partial responses. The antitumor response in nonirradiated fields (30%) was similar to the response observed in previously irradiated fields (33%), suggesting good drug penetration. Median duration of response was 5 months (range, 2 to 15+ months). An additional 9 (28%) patients achieved stable disease. Median survival was 10 months, with 3 patients in lasting remission.

CONCLUSIONS

These results demonstrate that the cisplatin/topotecan combination is safe, well tolerated, and active in persistent or recurrent cervical cancer patients. A phase III, multicenter trial is under way (cisplatin/topotecan versus cisplatin) based on these favorable results to confirm the safety and efficacy profile in this patient population.

Combination of topotecan and oxaliplatin in inoperable hepatocellular cancer patients

Unresectable hepatocellular carcinoma (UHCC) is considered a chemoresistant disease. Moreover, because the liver underlies the disease, it decreases the tolerance to anticancer agents. Topotecan has shown some clinical activity in UHCC using the 5 days every 3 weeks schedule but is limited by severe hematotoxicity. Oxaliplatin is a diamino-cyclo-hexane-platin that exhibits in vitro synergy with topotecan. Thirteen UHCC patients received topotecan (0.5-1.5 mg/m(2) /d days 1-5) and oxaliplatin (85-110 mg/m(2) /d, day 1) every 21 days. All patients had liver biology within normal limits; 11 had World Health Organization performance status less than 2. Seven patients had received previous chemotherapy. Nine patients without cirrhosis received a median number of six cycles (range: 3-12). The main dose-limiting toxicity was severe thrombocytopenia observed in three patients and 4% of cycles. One objective response and eight stabilizations were observed. Conversely, among 4 patients with cirrhosis receiving a median number of 2.5 cycles (range: 1-6), severe thrombocytopenia occurred in 2 patients and 25% of cycles. Three patients with progressive disease and one with stabilization were observed. Overall, the median duration of stabilizations was 27 weeks (range: 16-97 weeks). Four of seven patients treated with 1 mg/m(2) /d or more topotecan experienced severe toxicity. These results warrant a phase II study of this combination in noncirrhotic patients with UHCC. The recommended doses for further studies should be 0.5 mg/m(2) /d to 0.75 mg/m(2) /d of topotecan with 85 mg/m(2) of oxaliplatin.

Topotecan in combination with carboplatin: phase I trial evaluation of two treatment schedules

BACKGROUND

Topotecan and cisplatin combinations have shown schedule-dependent toxicity, which may in part be due to cisplatin nephrotoxicity. As carboplatin is less nephrotoxic and increasingly replacing cisplatin in clinical practice, the aim of this study was to define the optimal sequence and dose for topotecan in combination with carboplatin.

PATIENTS AND METHODS

Two parallel phase I trials, with pharmacokinetic studies, were conducted administering carboplatin on day 1 with topotecan on days 1-5 (schedule A) or days 8-12 (schedule B). repeated every 3 weeks.

RESULTS

Twenty-one patients were treated over two dose levels, carboplatin AUC 4 [glomerular filtration rate (GFR) calculated from 51Cr-EDTA clearance] with topotecan 0.5 or 0.75 mg/m2. At the first dose level, six patients were evaluable for each schedule. With schedule A, from 34 cycles, there were two dose reductions and 10 treatment delays due to myelosuppression. With schedule B from 25 cycles, there was one reduction and 10 delays. At dose level 2, both patients in schedule A had dose-limiting neutropenia. In contrast, there was no dose-limiting toxicity with schedule B in six patients, although the majority of cycles were delayed.

CONCLUSION

The combination of topotecan and carboplatin using these 3-weekly schedules lead to significant myelotoxicity with attendant dose reductions and delays; the optimal scheduling of these agents remains to be defined.

Phase I trial of cisplatin and topotecan in children with recurrent solid tumors: Children's Cancer Group Study 0942

OBJECTIVES

To determine the maximum tolerated dose (MTD) and dose-limiting toxicities (DLTs) of cisplatin after a 72-hour continuous infusion of topotecan.

PATIENTS AND METHODS

Thirty-six children younger than age 22 years (range 3-21) with recurrent solid tumors were treated with cisplatin 45 to 75 mg/m2 infused over the course of 6 hours, followed by a 72-hour continuous infusion of topotecan 0.75 or 1 mg/m2 per day, followed by granulocyte colony stimulating factor (G-CSF), either immediately after treatment or when neutropenia developed. Patients were stratified by the presence of bone marrow tumor involvement and previous radiation to the bone marrow.

RESULTS

The DLT was neutropenia (absolute neutrophil count <500/microL for >7 days). The MTD was cisplatin 60 mg/m2 and topotecan 1 mg/m2 per day followed by G-CSF starting 24 hours after chemotherapy for patients without marrow involvement or previous radiation to the bone marrow. An acceptable MTD was not found for patients with previous radiation to the bone marrow or bone marrow involvement or without the use of G-CSF starting 24 hours after chemotherapy was completed. Topotecan clearance and steady-state levels were determined. Limited evidence for antitumor activity with this combination was found in rhabdomyosarcoma.

CONCLUSIONS

The recommended dose for phase II trials is cisplatin 60 mg/m2 followed by a 72-hour infusion of topotecan 1 mg/m2 per day with G-CSF starting 24 hours after the completion of topotecan.

Novel Doublets in Extensive-Stage Small-Cell Lung Cancer: A Randomized Phase II Study of Topotecan Plus Cisplatin or Paclitaxel (CALGB 9430)

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.

Camptothecins

Camptothecin analogues and derivatives appear to exert their antitumour activity by binding to topoisomerase I and have shown significant activity against a broad range of tumours. In general, camptothecins are not substrates for either the multidrug-resistance P-glycoprotein or the multidrug-resistance-associated protein (MRP). Because of manageable toxicity and encouraging activity against solid tumours, camptothecins offer promise in the clinical management of human tumours. This review illustrates the proposed mechanism(s) of action of camptothecins and presents a concise overview of current camptothecin therapy, including irinotecan and topotecan, and novel analogues undergoing clinical trails, such as exatecan (DX-8951f), IDEC-132 (9-aminocamptothecin), rubitecan (9-nitrocamptothecin), lurtotecan (GI-147211C), and the recently developed homocamptothecins diflomotecan (BN-80915) and BN-80927.

Phase I study of combination topotecan and carboplatin in pediatric solid tumors

PURPOSE

We conducted a phase I trial of escalating doses of topotecan (TOPO) in association with a fixed systemic exposure of carboplatin (CARBO) with or without granulocyte colony-stimulating factor (G-CSF) in children.

PATIENTS AND METHODS

Two separate cohorts of patients (pts) with solid tumors were studied: (A) pts with refractory or recurrent disease and (B) pts with no prior myelosuppressive therapy or newly diagnosed tumors for which there was no standard chemotherapy. CARBO was given on day 1 at an area under the curve of 6.5, followed by TOPO as a continuous infusion for 3 days; the starting dose of TOPO was 0.50 mg/m(2)/d. Cycles were repeated every 21 days. G-CSF was given at a dose of 5 microg/kg/d starting on day 4.

RESULTS

Forty-eight of 51 pts were assessable for toxicity. In group A, dose-limiting myelosuppression persisted despite de-escalation of TOPO to 0.3 mg/m(2)/d and use of G-CSF. In group B, the maximum-tolerated dose of TOPO was 0.5 mg/m(2)/d for 3 days, and 0.6 mg/m(2)/d for 3 days with G-CSF. No significant nonhematologic toxicities were observed. Among 46 pts assessable for response, one had complete response, five had partial response, and 18 had stable disease.

CONCLUSION

Although this combination possesses antineoplastic activity in pediatric solid tumors, hematologic toxicity precluded any meaningful TOPO dose escalation. The addition of G-CSF did not alter this. The potential for preservation of activity and diminution of toxicity with alternative sequences and schedules of administration (topoisomerase followed by alkylating or platinating agents) should be evaluated.

Dose and schedule-finding study of oral topotecan and weekly cisplatin in patients with recurrent ovarian cancer

Both weekly cisplatin chemotherapy and single agent topotecan have proven to be effective in recurrent ovarian cancer. Preclinical data show synergism between cisplatin and topotecan. Side effects for this combination are drug sequence dependent and predominantly haematologic. Since preclinical data suggest that Cremophor EL (CrEL), the formulation vehicle of paclitaxel, has a protective effect on haematological toxicity of cisplatin, CrEL was added to the combination cisplatin and topotecan. In this phase I study, escalating doses of oral topotecan administered on day 1, 2, 8, 9, 15, 16, 29, 30, 36, 37, 43, 44 were combined with weekly cisplatin 70 mg m(-2) d(-1) on day 1, 8, 15, 29, 36, 43 (scheme A) or with the presumably less myelotoxic sequence weekly cisplatin day 2, 9, 16, 30, 37, 44 (scheme B). In scheme C, CrEL 12 ml was administered prior to cisplatin in the sequence of Scheme A. 18 patients have received a total of 85 courses. In scheme A 4/10 patients, all treated with topotecan 0.45 mg m(-2) d(-1), experienced DLT: 1 patient had vomiting grade 4, 1 patient had grade 4 neutropenia >5 days, 1 patient had >2 weeks delay due to thrombocytopenia and 1 patient due to neutropenia. Both patients in scheme B (topotecan 0.45 mg m(-2) d(-1)) had DLT due to a delay > 2 weeks because of prolonged haematological toxicity. No DLT was observed in the first 3 patients in scheme C (topotecan 0.45 mg m(-2) d(-1)). However, 2 out of 3 patients treated at dose level topotecan 0.60 mg m(-2)d(-1) in scheme C experienced DLT due to >2 weeks delay because of persistent thrombocytopenia or neutropenia. We conclude that there is a modest clinical effect of CrEL on haematological toxicity for this cisplatin-based combination regimen, which seems to reduce these side effects but does not really enable an increase of the oral topotecan dose.

Topotecan combined with myeloablative doses of thiotepa and carboplatin for neuroblastoma, brain tumors, and other poor-risk solid tumors in children and young adults

Topotecan appears to be relatively unaffected by the most common multidrug resistance mechanisms, may potentiate cytotoxicity of alkylators, has good penetration into the central nervous system, is active against a variety of neoplasms, and has myelosuppression as its paramount toxicity. We present our experience with a myeloablative regimen that includes topotecan. Twenty-one patients with poor-prognosis tumors and intact function of key organs received topotecan 2 mg/m2 by 30-min intravenous (i.v.) infusion on days -8, -7, -6, -5, -4; thiotepa 300 mg/m2 by 3 h i.v. infusion on days -8, -7, -6; and carboplatin by 4 h i.v. infusion on days -5, -4, -3 with a daily dose derived from the pediatric Calvert formula, using a targeted area under the curve of seven mg/ml* min ( approximately 500 mg/m2/day). Stem cell rescue was on day 0. The patients were 1 to 29 (median 4) years old; 18 were in complete remission (CR) and three in partial remission (PR). Early toxicities were severe mucositis and erythema with superficial peeling in all patients and a seizure, hypertension, and renal insufficiency followed by veno-occlusive disease in one patient each. Post-transplant treatment included radiotherapy alone (four patients) or plus biological agents (11 patients with neuroblastoma). With a follow-up of 6+ to 32+ (median 11+) months, event-free survivors include 10/11 neuroblastoma patients (first CR), 4/5 brain tumor patients (second PR or CR), 1/3 patients with metastatic Ewing's sarcoma (first or second CR), and a patient transplanted for multiply recurrent immature ovarian teratoma; a patient with desmoplastic small round-cell tumor (second PR) had progressive disease at 8 months. Favorable results for disease control, manageable toxicity, and the antitumor profiles of topotecan, thiotepa, and carboplatin, support use of this three-drug regimen in the treatment of neuroblastoma and brain tumors; applicability to other tumors is still uncertain.

Repetitive high-dose topotecan, carboplatin, and paclitaxel with peripheral blood progenitor cell support in previously untreated ovarian cancer: results of a Phase I study

OBJECTIVE

In view of the significant activity of topotecan in ovarian cancer with dose-limiting toxicity (DLT) of myelosuppression, we evaluated the addition of topotecan to carboplatin and paclitaxel with peripheral blood progenitor cell (PBPC) support.

METHODS

Patients with previously untreated stage IIIC or IV ovarian cancer with macroscopic residual disease following primary debulking surgery were eligible. Patients received two cycles of carboplatin AUC = 5 and 175 mg/m(2) of paclitaxel with collection of PBPCs after the second cycle. Patients subsequently received three cycles of high-dose therapy (HDT) with topotecan on a daily x5 schedule, paclitaxel (250 mg/m(2) over 24 h), and carboplatin (AUC = 12-16).

RESULTS

Nineteen patients with a median age of 49 years (range 21-63) were enrolled and topotecan was escalated in 6 patient cohorts up to a dose of 4.5 mg/m(2)/day. Fifty-two of the planned 57 treatment cycles were delivered with no treatment-related deaths. Neutrophil and platelet recovery was rapid and the interval between HDT was 28 days. Febrile neutropenia occurred following 57% of all HDT cycles. DLTs of mucositis and diarrhea were observed at topotecan (4.5 mg/m(2)/day), paclitaxel (250 mg/m(2)) and carboplatin (AUC = 12). The protocol was subsequently modified to administer topotecan (2.5 mg/m(2)/day) with carboplatin (AUC = 16); however, 2 patients developed grade 4 diarrhea (1 with grade 3 mucositis and 1 with grade 4 mucositis). The clinical CR rate was 73% (14/19) with an overall clinical response rate of 95% (18/19). Of the 14 patients with a CCR, 13 of these underwent a second-look laparotomy with 8 (61%) achieving a pathological CR. With a median follow-up of 28 months (range 11-40 months), the median PFS is 36 months and OS has not been reached.

CONCLUSION

When combined with carboplatin (AUC = 12) and paclitaxel (250 mg/m(2)), the recommended topotecan dose is 3.5 mg/m(2)/day for 5 days. This outpatient HDT regimen combines three of the most active drugs in ovarian cancer with acceptable toxicity and promising activity.

Phase I dose escalation study of topotecan combined with alternating schedules of paclitaxel and carboplatin in advanced solid tumors

BACKGROUND

Combining topotecan with other cytotoxics has been problematic due to marrow suppression. A phase I trial was initiated to identify the optimal sequence and maximum-tolerated dose of topotecan in combination with paclitaxel and carboplatin.

PATIENTS AND METHODS

Patients with advanced cancer and performance status ECOG < or = 2. The starting dose was paclitaxel 175 mg/m2 day 1, carboplatin AUC 6.0 day 1, and topotecan 0.5 mg/m2 daily day 1-5 (early sequence). The next course of paclitaxel and carboplatin administration was delayed to day 5 (late sequence). Treatment was repeated every three weeks. After determining maximum-tolerated dose without cytokines, granulocyte colony-stimulating factor (G-CSF) was added and further dose escalation was pursued.

RESULTS

Fifty-one patients were entered; men: women ratio 30:21. Dose-limiting toxicity (DLT) for the early sequence was neutropenia at doses paclitaxel mg/m2/carboplatin AUC 5/topotecan mg/m2 (PCT) 175/5/0.75 for four to five days. DLT for the late sequence was neutropenia at PCT doses of 175/5/ 1.0 for four days. G-CSF 5 microg/kg subcutaneously starting day 6 permitted further topotecan dose escalation. After adding G-CSF, late sequence DLT was neutropenia at doses 175/5/1.25 for four days. Forty-six patients were evaluable for response and of those, there were thirteen partial responses.

CONCLUSIONS

The late sequence resulted in less toxicity and was better tolerated. The early sequence maximum-tolerated dose (MTD) was 175/6/0.5 for five days. The late sequence MTD was PCT 175/5/0.75 for five days. The late sequence MTD with G-CSF was 175/5/1.0 for four days. The recommended phase II PCT dose is the late sequence 175/5/1.0 for four days with G-CSF.

Phase I trial of multiple cycles of high-dose carboplatin, paclitaxel, and topotecan with peripheral-blood stem-cell support as front-line therapy

PURPOSE

To determine the safety and feasibility of delivering multiple cycles of front-line high-dose carboplatin, paclitaxel, and topotecan with peripheral-blood stem-cell (PBSC) support.

PATIENTS AND METHODS

Patients were required to have a malignant solid tumor for which they had received no prior chemotherapy. Mobilization of PBSC was achieved with either filgrastim alone or in combination with cyclophosphamide and paclitaxel. Patients then received three or four cycles of high-dose carboplatin (area under the concentration-time curve [AUC] 16), paclitaxel (250 mg/m(2)), and topotecan (10-15 mg/m(2)), with the latter two agents administered as 24-hour infusions and supported with PBSC and filgrastim. Cycles were repeated every 28 days.

RESULTS

Twenty patients were enrolled onto the trial and were assessable for toxicity and clinical outcome. Dose-limiting toxicities were stomatitis and prolonged hematopoietic recovery. The maximum-tolerated dose of topotecan was 12.5 mg/m(2) when given with high-dose carboplatin and paclitaxel for three cycles. Four cycles were able to be given with a dose of topotecan of 10 mg/m(2). The pharmacokinetics of each compound were not affected by the other agents. Eleven (85%) of 13 patients with assessable disease responded.

CONCLUSION

Multiple cycles of high-dose carboplatin, paclitaxel, and topotecan can be safely administered with filgrastim and PBSC support. The recommended doses for phase II study are carboplatin AUC 16, paclitaxel 250 mg/m(2), and topotecan 10 mg/m(2). Trials are currently being conducted with this regimen as front-line treatment in patients with advanced ovarian cancer and extensive small-cell carcinoma. This approach remains experimental and should be used only in the context of a clinical trial.

Clinical use of topoisomerase I inhibitors in anticancer treatment

The camptothecin analogs topotecan and irinotecan have shown to be among the most effective anticancer agents and, as S-phase specific agents, their antitumor effect is maximized when they are administered in protracted schedules. The documented activity as single agents in many adult and pediatric malignancies has been followed by their use in combination with other anticancer agents. These studies have shown promising results, and have placed topotecan and irinotecan in the first line treatment for some malignancies. However, studies to better determine the optimal schedules and sequence of combinations are needed.

A dose escalating study of topotecan preceding cisplatin in previously untreated patients with small-cell lung cancer

BACKGROUND

The aim was to define the MTD of topotecan (TPT) given before cisplatin in patients with previously untreated SCLC.

PATIENTS AND METHODS

Alternating cycles A and B to a total of 6 cycles were given. Cycle A: TPT days 1-5 and cisplatin (50 mg/m2) day 5. Cycle B consisted of teniposide, carboplatin, vincristine, and cisplatin. TPT was escalated at doses 0.75, 1.0, 1.25, and 1.5 mg/m2. DLT was defined for the first cycle as grade 4 neutropenia with fever or when lasting > 7 days, or grade 4 thrombocytopenia.

RESULTS

Fifteen patients with limited disease and six patients with extensive disease were included. No episodes of DLT were recorded in the first cycles A and consequently 1.5 mg/m2 was defined as MTD. At 1.5 mg/m2 (11 patients, 30 cycles), four and three episodes of grade 4 thrombocytopenia and neutropenia lasting more than seven days occurred in subsequent cycles A. Thrombocytopenia and anaemia were cumulative as more cycles were administrated. Non-hematological toxicity was mild. The response rate was 86% (95% confidence interval (95% CI): 64%-97%) with 33% (95% CI: 15%-57%) achieving CR.

CONCLUSIONS

1.5 mg/m2 TPT can be delivered safely with 50 mg/m2 cisplatin on day 5 in patients with previously untreated SCLC.

Oral topoisomerase 1 inhibitors in adult patients: present and future

The renewed interest in topoisomerase 1 inhibitors, based on new insights on the mechanism of action and the development of semi-synthetic derivates of camptothecin with a more favourable toxicity profile, has led to extensive preclinical and clinical research. Significant levels of anti-tumor activity in human tumor xenografts were seen especially with prolonged duration of exposure. Since oral drug delivery is a more convenient method for prolonged drug administration, and preferred by patients, further development of oral formulations seems attractive. Common concerns in the development of oral formulations are their sometimes low oral bioavailability and the frequently large intra- and interpatient variation in systemic exposure. Efforts to improve absorption and minimize intestinal metabolism/efflux of the oral chemotherapeutic agent using new formulas might lead to better bioavailability. Pharmacokinetic and pharmacodynamic evaluations have enabled guidance in recommendations of schedules. Given the interpatient variation in exposure it is interesting to note that flat dosing of topotecan resulted in the same systemic exposure compared with the more complex dosing per body surface area. In order to diminish the interpatient variation in exposure to 9-AC a limited sampling model for oral 9-AC was developed, enabling prediction of the systemic exposure for 9-AC and optimizing treatment for any given patient. Drug sequencing plays a key role in the combination topotecan/cisplatin and might be important for combination with other classes of drugs. Therefore, forthcoming phase 1 trials on combination therapy with oral topoisomerase 1 inhibitors should include studies on sequence dependence and pharmacokinetic analyses to evaluate any mutual interaction.

Phase I pharmacologic study of oral topotecan and intravenous cisplatin: sequence-dependent hematologic side effects

PURPOSE

In in vitro studies, synergism and sequence-dependent effects were reported for the combination of topotecan and cisplatin. Recently, an oral formulation of topotecan became available. This phase I study was performed to assess the feasibility of the combination of oral topotecan and cisplatin, the pharmacokinetic interaction, and sequence-dependent effects.

PATIENTS AND METHODS

Topotecan was administered orally (PO) daily for 5 days in escalating doses and cisplatin was given intravenously (IV) at a fixed dose of 75 mg/m(2) either before topotecan administration on day 1 (sequence CT) or after topotecan administration on day 5 (sequence TC) once every 3 weeks. Patients were treated in a randomized cross-over design.

RESULTS

Forty-nine patients were entered onto the study; one patient was not eligible. Sequence CT induced significantly more severe myelosuppression than did sequence TC, and the maximum-tolerated dosage of topotecan in sequence CT was 1.25 mg/m(2)/d x 5. In sequence TC, the maximum-tolerated dosage of topotecan was 2.0 mg/m(2)/d x 5. Dose-limiting toxicity consisted of myelosuppression and diarrhea. Pharmacokinetics of topotecan and cisplatin were linear over the dose range studied; no sequence-dependent effects were observed. In addition, topotecan did not influence the protein binding of cisplatin or the platinum-DNA adduct formation in peripheral leukocytes in either sequence.

CONCLUSION

The recommended dosages for phase II studies involving patients like the patients in our study are topotecan 1.25 mg/m(2)/d PO x 5 preceded by cisplatin 75 mg/m(2) IV day 1 once every 3 weeks, and topotecan 2.0 mg/m(2)/d PO followed by cisplatin 75 mg/m(2) IV day 5. No pharmacokinetic interaction could be discerned in our study. The antitumor efficacy of both schedules should be evaluated in a randomized phase II study.

Phase II evaluation of 24-h continuous infusion topotecan in recurrent, potentially platinum-sensitive ovarian cancer: A Gynecologic Oncology Group study

OBJECTIVES

The aim of this study was to develop an alternative effective and more convenient administration schedule for intravenous topotecan when used as palliative treatment in ovarian cancer.

METHODS

The Gynecologic Oncology Group conducted a Phase II trial of 24-h infusional topotecan (8.5 mg/m(2)) with treatment repeated every 3 weeks in 29 patients with platinum-sensitive recurrent ovarian cancer (prior response to platinum-based chemotherapy with a minimum treatment-free interval >/=6 months).

RESULTS

The major toxicities of therapy were grade 4 neutropenia and thrombocytopenia which developed in 86 and 14% of patients, respectively. Other severe side effects were uncommon. Only 2 partial responses (7%) were observed in the 28 patients evaluable for response.

CONCLUSIONS

Despite the relatively favorable ovarian cancer patient population treated in this trial (platinum-sensitive recurrent disease), the response rate was disappointingly low. Considering the three- to fivefold higher objective response rates observed in other trials employing topotecan in individuals with platinum-sensitive ovarian cancer utilizing a 5-day treatment program (delivered every 3 weeks), the results of the current study provide strong support for the conclusion that clinically relevant antineoplastic activity of this agent is highly schedule dependent.

New cytotoxics and non-cytotoxics in epithelial ovarian cancer

Several new cytotoxic agents with activity in relapsed ovarian cancer are being combined with paclitaxel plus platinum as the first step to assess their impact in randomized trials against the standard treatment. These include topotecan, gemcitabine, epirubicin, and liposomal doxorubicin. Because of overlapping toxicities, there have been challenges in combining some of these agents in full dose with combination paclitaxel plus platinum. These have been overcome by use of sequenced administration. In addition to these new agents, novel non-cytotoxic drugs targeting specific signaling molecules or the tumor microenvironment provide additional avenues for clinical investigation. Many of these agents are rational to assess in ovarian cancer where laboratory research has pinpointed a number of alterations in molecules involved in cell signaling and cell cycle control. Examples include the antibody to HER 2/neu, agents targeting protein kinase C alpha, the p53 gene, and matrix metalloproteinase inhibitors. The challenges facing their assessment include how to determine adequate dosing when toxic effects are minimal and how to assess evidence of antitumor activity, short of conducting randomized studies. Finally, how best to use such agents together with conventional chemotherapy, in combination or in sequence, is unknown. Large clinical studies with some of these agents will provide some answers to their impact and how best to use them in the first-line management of advanced epithelial ovarian cancer.

Lack of efficacy of 24-h infusional topotecan in platinum-refractory ovarian cancer: A Gynecologic Oncology Group trial

BACKGROUND

The aim of this study was to evaluate the efficacy of a more convenient topotecan administration schedule in the second-line treatment of advanced platinum-refractory ovarian cancer.

METHODS AND MATERIALS

The Gynecologic Oncology Group conducted a Phase II trial of 24-h infusional topotecan (8.5 mg/m(2)), repeated every 3 weeks in 26 patients with platinum-refractory ovarian cancer (failure to respond to initial platinum-based treatment or development of recurrent disease within 6 months of completion of chemotherapy).

RESULTS

Grade 4 neutropenia (85% of patients) and thrombocytopenia (12%) were the major toxicities encountered. Of the 25 patients evaluable for response, only a single patient experienced an objective response (4%).

CONCLUSIONS

When employed at this dose and schedule (24-h infusion every 3 weeks), topotecan has minimal second-line activity in platinum-refractory ovarian cancer.

Role of salvage chemotherapy with topotecan and cisplatin in patients with paclitaxel- and platinum-resistant recurrent ovarian or primary peritoneal cancer: a phase II pilot study

BACKGROUND AND OBJECTIVES

We assessed the role of salvage chemotherapy with topotecan and cisplatin in patients with platinum- and paclitaxel-resistant advanced and recurrent ovarian or primary peritoneal cancer, based on the reported in vivo and in vitro synergism between these two drugs.

METHODS

Twenty patients were entered in this phase II trial from November 1997 to November 1998. They received cisplatin at 50 mg/m(2) on day 1 with topotecan at 0.6 mg/m(2) from day 1 to 5 every 28 days. In 70% of patients (14/20), this combination represented at least a third line of therapy.

RESULTS

A clinical response rate of 13.3% (two partial responses) was obtained in the 15 patients with evaluable disease. Sixty percent of patients (9/15) had stable disease and 26.7% (4/15) had progression. The median progression-free interval and survival were 4 months and 7 months, respectively. The 20 patients evaluable for toxicity received a mean of four chemotherapy cycles. Dose reductions were required in 45% of patients despite the administration of growth factors. The major dose-limiting toxicity was a 50% occurrence (10/20) of grade 4 thrombocytopenia and 30% (6/20) grade 4 neutropenia. There was one septic death.

CONCLUSIONS

These data suggest that combination therapy with topotecan and cisplatin has minimal activity in platinum- and paclitaxel-resistant advanced and recurrent ovarian or primary peritoneal cancer at the doses utilized in this trial.

Phase I and pharmacologic study of the combination of paclitaxel, cisplatin, and topotecan administered intravenously every 21 days as first-line therapy in patients with advanced ovarian cancer

PURPOSE

To evaluate the feasibility of administering topotecan in combination with paclitaxel and cisplatin without and with granulocyte colony-stimulating factor (G-CSF) support as first-line chemotherapy in women with incompletely resected stage III and stage IV ovarian carcinoma.

PATIENTS AND METHODS

Starting doses were paclitaxel 110 mg/m2 administered over 24 hours (day 1), followed by cisplatin 50 mg/m2 over 3 hours (day 2) and topotecan 0.3 mg/m2/d over 30 minutes for 5 consecutive days (days 2 to 6). Treatment was repeated every 3 weeks. After encountering dose-limiting toxicities (DLTs) without G-CSF support, the maximum-tolerated dose was defined as 5 microg/kg of G-CSF subcutaneously starting on day 6.

RESULTS

Twenty-one patients received a total of 116 courses at four different dose levels. The DLT was neutropenia. At the first dose level, all six patients experienced grade 4 myelosuppression. G-CSF support permitted further dose escalation of cisplatin and topotecan. Nonhematologic toxicities, primarily fatigue, nausea/vomiting, and neurosensory neuropathy, were observed but were generally mild. Of 15 patients assessable for response, nine had a complete response, four achieved a partial response, and two had stable disease.

CONCLUSION

Neutropenia was the DLT of this combination of paclitaxel, cisplatin, and topotecan. The recommended phase II dose is paclitaxel 110 mg/m2 (day 1), followed by cisplatin 75 mg/m2 (day 2) and topotecan 0.3 mg/m2/d (days 2 to 6) with G-CSF support repeated every 3 weeks.

Cisplatin-topotecan-paclitaxel weekly administration with G-CSF support for ovarian and small-cell lung cancer patients: a dose-finding study

PURPOSE

Paclitaxel (PTX) and topotecan (TPT) have shown promising antitumor activity in both ovarian cancer (OC) and small-cell lung cancer (SCLC) patients. This phase I study was aimed at determining the maximum tolerable dose (MTD) of TPT given weekly over 30 min in combination with fixed doses of cisplatin (CDDP) and (PTX), and with G-CSF support.

PATIENTS AND METHODS

Forty-four patients with OC (19) or SCLC (25), either chemo-naïve (20) or pretreated (24) received CDDP 40 mg/m2, PTX 85 mg/m2 (one-hour infusion) and escalating TPT doses (starting from 0.75 mg/m2) in a 30-min infusion in weekly administration. Filgrastim 5 mg/kg was administered on days 3 to 5 of each week.

RESULTS

Eight different dose levels were tested for a total of 295 delivered cycles. The dose escalation was interrupted at the TPT dose of 2.50 mg/m2. No toxic deaths occurred in this study. Grade 3 to 4 neutropenia, thrombocytopenia, and anemia occurred in 15 patients (36 cycles), seven patients (15 cycles), and four patients (five cycles), respectively. Severe vomiting and diarrhoea occurred in seven and four patients. Peripheral neuropathy was recorded in 11 patients (42 cycles), but it was never severe. An overall 11 of 19 (58%) OC and 11 of 25 (44%) SCLC patients obtained objective responses. Eight patients showed complete responses (three OC and three SCLC). Among the 20 chemo-naïve patients, 9 of 11 (82%) OC and seven of nine (78%) SCLC responded.

CONCLUSIONS

The CDDP/TPT/PTX weekly administration with filgrastim support represents a well-tolerated and active therapeutic approach in both chemo-naïve and pretreated OC and SCLC patients. A weekly dose of TPT of 2.25 mg/m2 is recommended for the phase II study.