Improved therapeutic index of lower dose topotecan chemotherapy in recurrent ovarian cancer

Antitumor Therapy Targeting the Tumor Microenvironment

The development and progression of tumors in human tissues extensively rely on its surrounding environment, that is, tumor microenvironment which includes a variety of cells, molecules, and blood vessels. These components are modified, organized, and integrated to support and facilitate the growth, invasion, and metabolism of tumor cells, suggesting them as potential therapeutic targets in anticancer treatment. An increasing number of pharmacological agents have been developed and clinically applied to target the oncogenic components in the tumor microenvironment, and in this review, we will summarize these pharmacological agents that directly or indirectly target the cellular or molecular components in the tumor microenvironment. However, difficulties and challenges still exist in this field, which will also be reported in this literature.

Synergistic combination of DT-13 and Topotecan inhibits aerobic glycolysis in human gastric carcinoma BGC-823 cells via NM IIA/EGFR/HK II axis

DT-13 combined with topotecan (TPT) showed stronger antitumour effects in mice subcutaneous xenograft model compared with their individual effects in our previous research. Here, we further observed the synergistically effect in mice orthotopic xenograft model. Metabolomics analysis showed DT-13 combined with TPT alleviated metabolic disorders induced by tumour and synergistically inhibited the activity of the aerobic glycolysis-related enzymes in vivo and in vitro. Mechanistic studies revealed that the combination treatment promoted epidermal growth factor receptor (EGFR) degradation through non-muscle myosin IIA (NM IIA)-induced endocytosis of EGFR, further inhibited the activity of hexokinase II (HK II), and eventually promoted the aerobic glycolysis inhibition activity more efficiently compared with TPT or DT-13 monotherapy. The combination therapy also inhibited the specific binding of HK II to mitochondria. When using the NM II inhibitor (-)002Dblebbistatin or MYH-9 shRNA, the synergistic inhibition effect of DT-13 and TPT on aerobic glycolysis was eliminated in BGC-823 cells. Immunohistochemical analysis revealed selective up-regulation of NM IIA while specific down-regulation of p-CREB, EGFR, and HK II by the combination therapy. Collectively, these findings suggested that this regimen has significant clinical implications, warranted further investigation.

Synchronized Ratiometric Codelivery of Metformin and Topotecan through Engineered Nanocarrier Facilitates In Vivo Synergistic Precision Levels at Tumor Site

The combination of metabolic modulators with chemotherapy holds vast promise for effective inhibition of tumor progression and invasion. Herein, a ratiometric codelivery platform is developed for metformin (MET), a known metabolic modulator and topotecan (TPT), a chemotherapeutic drug, by engineering lipid bilayer-camouflaged mesoporous silica nanoparticles (LB-MSNs). In an attempt to deliver and maintain high tumor site concentrations of MET and TPT, a novel ion pairing-assisted loading procedure is developed using pamoic acid (PA) as an in situ trapping agent. PA, a hydrophobic counterion, increases the hydrophobicity of MET and TPT and facilitates MSNs with exceptionally high payload capacity (>40 and 32 wt%, respectively) and controlled release profile. Further, the synergy between MET and TPT determined by a modeling approach helps to afford synchronized delivery of both the drugs. Coloaded MET and TPT LB-MSNs present synergistic cytotoxicity against MDA-MB-231/4T1 cells and effectively promote apoptosis via mitochondrial membrane depolarization and cell cycle arrest. Extended pharmacokinetic profiles in preclinical models with fourfold to sevenfold longer circulation half-life and 7.5-100 times higher tumor site concentrations correspond to a significant increase in pharmacodynamic efficacy. Taken together, the developed codelivery approach effectively addresses the challenges in the chemotherapeutic efficacy of MET and TPT collectively.

Synergistic combination of DT-13 and topotecan inhibits human gastric cancer via myosin IIA-induced endocytosis of EGF receptor in vitro and in vivo

Combination therapy has a higher success rate for many cancers compared to mono-therapy. The treatment of Topotecan (TPT) on gastric cancer (GC) is limited by its toxicity and the potential drug resistance. We found that the combination of the saponin monomer 13 from the dwarf lilyturf tuber (DT-13), performing anti-metastasis and anti-angiogenesis effects, with TPT synergistically induced apoptotic cytotoxicity in GCs with high EGF receptor (EGFR) expression, which was dependent on DT-13-induced endocytosis of EGFR. With TPT, DT-13 promoted EGFR ubiquitin--mediated degradation through myosin IIA-induced and Src/ caveolin-1 (Cav-1)-induced endocytosis of EGFR; inhibited EGFR downstream signalling and then increased the pro-apoptotic effects. Moreover, the synergistic pro-apoptotic efficacy of DT-13 and TPT in GCs with high EGFR expression was eliminated by both the NM II inhibitor (-)-blebbistatin and MYH-9 shRNA. The combination therapy of DT-13 with TPT showed stronger anti-tumour effects in vivo compared with their individual effects. Moreover, the results of combination therapy revealed selective upregulation of pro-apoptotic activity in TUNEL assays and cleaved caspase-3 and NM IIA in immunohischemical analysis; while specific downregulation of p-extracellular regulated kinase 1/2 (p-ERK1/2), EGFR and Cav-1 in immunohischemical analysis. Collectively, these findings have significant clinical implications for patients with tumours harbouring high EGFR expression due to the possible high sensitivity of this regimen.

Low-dose irinotecan as a second-line chemotherapy for recurrent small cell lung cancer

OBJECTIVE

Irinotecan is a potent inhibitor of deoxyribonucleic acid topoisomerase 1 and the weekly schedule of 100-125 or 350 mg/m(2) administration on Day 1 every 3 weeks is recommended for recurrent small cell lung cancer. However, severe gastrointestinal toxic effects and myelosuppression are often observed in this dose setting. We conducted a retrospective study to evaluate the efficacy and safety of low-dose irinotecan monotherapy (60 mg/m(2) on Days 1, 8 and 15 every 4 weeks) as second-line chemotherapy for small cell lung cancer.

METHODS

The medical charts of small cell lung cancer patients who had received second-line chemotherapy at the National Cancer Center Hospital East between April 2003 and June 2012 were reviewed. Consecutive 57 patients who were treated with low dose of irinotecan (60 mg/m(2) on Days 1, 8 and 15 every 4 weeks) were analyzed in this study.

RESULTS

Median age was 70 years (range, 51-83). Fifty-two (91%) were male, 36 (63%) had an Eastern Cooperative Oncology Group performance status 0-1 and 26 (46%) were sensitive relapse. The median number of chemotherapy cycles was 2. The objective response rate was 32% (95% confidence interval: 20-45%).The median progression-free survival and the median overall survival were 2.9 months (95% confidence interval: 1.9-3.4 months) and 5.3 months (95% confidence interval: 3.6-7.6 months), respectively. The incidence of Grade 3/4 neutropenia, diarrhea and nausea/vomiting was 21, 4 and 5%, respectively.

CONCLUSIONS

Low-dose irinotecan monotherapy for recurrent small cell lung cancer might be effective with favorable toxicity. Randomized trial of 60 mg/m(2) versus standard dose of irinotecan is warranted.

A phase II study of two topotecan regimens evaluated in recurrent platinum-sensitive ovarian, fallopian tube or primary peritoneal cancer: a Gynecologic Oncology Group Study (GOG 146Q)

OBJECTIVE

To evaluate the efficacy and safety of topotecan in patients with recurrent ovarian, primary peritoneal, and fallopian tube carcinomas.

METHODS

A randomized phase II analysis of platinum-sensitive patients with measurable disease was performed independently assessing intravenous topotecan 1.25 mg/m2 daily×5 every 21 days (regimen I) and topotecan 4.0 mg/m2/day on days 1, 8, and 15 of a 28-day cycle (regimen II). All patients were treated until disease progression, unmanageable toxicity, or patient refusal. Insufficient accrual related to regimen I resulted in a redesign of the study as a single arm phase II trial assessing only regimen II. More complete efficacy data is presented for regimen II as enrollment on regimen I was insufficient for some analyses.

RESULTS

A total of 81 patients were enrolled. One patient was ineligible. Fifteen patients received regimen I, while 65 patients were treated with regimen II. The response rate on regimen I (daily×5) was 27% (90% CI: 10-51%) and 12% (90% CI: 6-21%) on regimen II (weekly). The median PFS and OS were 4.8 and 27.8 months, respectively, for regimen II. Grade 3/4 neutropenia rate was 93% with daily×5 dosing and 28% for weekly treatment. Febrile neutropenia was very low in both groups.

CONCLUSION

The weekly regimen of topotecan appeared less active but resulted in less toxicity than the daily regimen in platinum-sensitive recurrent ovarian cancer patients.

Treatment for recurrent ovarian cancer-at first relapse

Recurrent ovarian cancer is a lethal disease, and few patients can be cured. Although most patients receive standardized surgery and chemotherapy, the status of recurrent disease is heterogeneous. The site of recurrence and the survival intervals after recurrence are also widely distributed. Among a number of factors, many clinical trials identified time to recurrence was the factor most related to chemosensitivity at first relapse. The current recommendation for platinum sensitive ovarian cancer is a carboplatin containing combination chemotherapy. Generally, a single agent is chosen for platinum resistant ovarian cancer. Patients with single site recurrence and a long disease free interval are candidates for secondary cytoreduction, which may provide longer survival. There are several treatment choices at first relapse, and disease status, chemotherapy-free interval, and the patient's condition play a major role in the decision making process.

Review role of topotecan in gynaecological cancers: current indications and perspectives

BACKGROUND

Ovarian cancer is the fourth cause of death from gynaecological cancer and cervical cancer is the first in women <45 years old in developing countries. The aim of this article is to review the role of topotecan (Hycamtin), a semi-synthetic alkaloid derivative of camptothecin, in ovarian and cervical cancer in monotherapy and in combination.

METHODS

This article reviews the mechanism of action, pharmacokinetics, toxicity and efficacy of topotecan. The paper also reports the principal phases II and III studies of topotecan in advanced or recurrent ovarian and cervical cancer.

RESULTS

Topotecan (Hycamtin), currently indicated for the treatment of relapsed ovarian cancer, has demonstrated activity both in platinum-sensitive and in platinum-resistant disease. The combination cisplatin-topotecan for the treatment of advanced and recurrent cervical cancer has demonstrated a clinical benefit in terms of response rate, overall survival and progression free survival. Haematological toxicity of topotecan also is easy to manage and not cumulative, especially with the weekly scheduled recently introduced in clinical practice.

CONCLUSION

Topotecan (Hycamtin) will continue to play a role in the treatment of advanced ovarian and cervical cancer, in monotherapy or in combination with other cytotoxic agents.

Topotecan inhibits cancer cell migration by down-regulation of chemokine CC motif receptor 7 and matrix metalloproteinases

AIM

The aim of this study was to investigate the effect of topotecan (TPT) on cancer cell migration.

METHODS

Growth inhibition of TPT was analyzed by MTT assay, and cancer cell migration was measured by transwell double chamber assay. To verify the effect of TPT on the chemokine receptors CXCR4 and CCR7, quantitative PCR, semi-quantitative PCR and Western blot analysis were performed. The secretion of MMP-2 and MMP-9 was detected by enzyme-linked immunosorbent assay (ELISA) and gelatin zymography. To evaluate possible contributions of CCR7 to MMP secretion, the overexpression vectors pcDNA3.1(+)-CCR7 and CCR7 siRNA were transiently transfected into MDA-MB-435 cells.

RESULTS

TPT inhibited cancer cell migration in a dose-dependent manner. Additionally, TPT significantly decreased the expression of CCR7 in both MDA-MB-435 and MDA-MB-231 cells and moderately reduced the expression of CXCR4 in MDA-MB-435 cells. The secretion of MMPs (MMP-2, MMP-9) was also inhibited by TPT. Overexpression of CCR7 increased the secretion of MMP-2/9 and cancer cell migration, whereas knockdown of CCR7 reduced active MMP-2/9 production and migration of MDA-MB-435 cells.

CONCLUSION

TPT inhibited cancer cell migration by down-regulation of CCR7 and MMPs (MMP-2 and MMP-9).

Key role of topoisomerase I inhibitors in the treatment of recurrent and refractory epithelial ovarian carcinoma

Ovarian cancer remains one of the most difficult gynecologic cancers to treat, owing to its aggressive biology and high relapse rate, as well as the toxic side effects of available chemotherapeutic agents used to treat recurrent disease. Topoisomerase I inhibitors, including topotecan and irinotecan, are some of the most effective and tolerable treatment options for recurrent ovarian cancer. The ideal dosing, timing of administration, role in combination with other chemotherapies or biologics and potential role in up-front therapy remains an area of active research. This article reviews the mechanism of action of topoisomerase I inhibitors and the efficacy, dosing, schedule and toxicity for topotecan, irinotecan, 9-nitrocamptothecin, DX-8951 and 9-aminocamptothecin. Conclusions include a discussion of future avenues of research and ongoing projects.

Topotecan weekly bolus chemotherapy for relapsed platinum-sensitive ovarian and peritoneal cancers

OBJECTIVE

Topotecan at a dose of 1.5 mg/m(2) on days 1 to 5 of a 21-day cycle is an approved therapy for recurrent ovarian cancer. However, heavily pretreated patients may be predisposed to hematologic adverse events. This prospective study, therefore, investigates the safety and efficacy of an alternate weekly schedule of topotecan in patients with recurrent ovarian or peritoneal cancer.

METHODS

Patients with potentially platinum-sensitive recurrent ovarian or peritoneal cancer were treated with 4.0 mg/m(2) weekly topotecan as tolerated until disease progression. Antitumor response and safety were assessed. Dose reductions, delays, or omissions were implemented for grades 3-4 adverse events.

RESULTS

Of the 41 enrolled patients (median age, 62 years; range, 42 to 82 years), 39 patients had ovarian cancer, and 2 patients had peritoneal cancer. The median platinum-free interval was 11.7 months. A median of 9 topotecan cycles (range, 1 to 45 doses) was administered. Weekly topotecan was well tolerated: 7 (17%) patients had grades 3-4 neutropenia, and 9 (22%) had grades 3-4 fatigue. No grade 4 thrombocytopenia or anemia was reported. Of 38 response-evaluable patients, 1 (3%) had a complete response, 8 (21%) had a partial response, 16 (42%) had stable disease, and 13 (34%) had progressive disease.

CONCLUSIONS

Weekly topotecan was well tolerated in patients with platinum-sensitive ovarian or peritoneal cancer at first relapse, with a hematologic profile that compared favorably with that of the 5-day topotecan regimen. Moreover, antitumor activity was similar to that reported for the 5-day regimen.

"Conflict-of-interest" and participation in IRB deliberations: an alternative perspective

A natural tension exists as an IRB attempts of fulfill its mission of providing an independent and unbiased evaluation of a study while also insuring appropriate consideration of all relevant risks, benefits, and alternative strategies. IRB members with often critically relevant knowledge of unique issues involved in a protocol under review may be the individuals with the greatest potential for a perceived "conflict," due to current or past involvement in sponsor-associated research in the particular area. Management of real or perceived conflict must include full disclosure, but exclusion of such individuals from the deliberative process may result in undesirable consequences.

A phase II clinical trial of topotecan and carboplatin in patients with newly diagnosed advanced epithelial ovarian cancer

A phase II clinical trial conducted to evaluate the efficacy and tolerability of topotecan and carboplatin as first-line therapy for women with advanced epithelial ovarian cancer was the objective of this study. Patients had histologically confirmed ovarian epithelial cancer with at least one measurable lesion. Patients received topotecan 1.5 mg/m(2) on days 1-3 and carboplatin at an area under the curve (AUC) of 5 on day 3 every 21 days for six cycles. All 42 patients enrolled were evaluable for response and toxicity. Median number of cycles delivered was six. Overall response rate was 71%, with 19 clinical complete responses (45%) and 11 clinical partial responses (26%). Median survival time was 47 months and 5-year survival was 42%. Myelosuppression was the predominant toxicity, with grade 3 or 4 neutropenia occurring in 100% of patients. However, this toxicity was transient and easily manageable; no patients experienced febrile neutropenia. The combination of topotecan and carboplatin is active in advanced epithelial ovarian cancer. Delay of therapy by 1 week or topotecan dose reduction to 1.25 mg/m(2) is the first-choice option to reduce topotecan toxicity without affecting the efficacy. Moreover, a chemotherapy regimen using weekly topotecan, which is currently being tested, should be considered.

Safety of topotecan in the treatment of recurrent small-cell lung cancer and ovarian cancer

The topoisomerase I inhibitor, topotecan, is approved for the treatment of recurrent small-cell lung cancer (SCLC) and ovarian cancer (OC). Patients with recurrent SCLC and OC typically experience multiple relapses and receive multiple rounds of chemotherapy. In these settings, disease stabilisation is considered a treatment benefit, and quality-of-life effects and cumulative toxicities of treatments should be considered. Many patients with recurrent cancer may be predisposed to treatment-related adverse events because of advanced age, renal impairment or extensive prior therapy. The standard regimen of topotecan, 1.5 mg/m(2) on days 1-5 of a 21-day cycle, has generally mild nonhaematological toxicity and a well-defined haematological toxicity profile characterised by reversible and noncumulative neutropenia. Alternative regimens may lower the incidence of haematological toxicities and maintain antitumour efficacy. Topotecan may provide physicians with a versatile therapeutic option for the treatment of patients with relapsed SCLC or OC.

The current treatment of recurrent ovarian cancer

Contemporary management of recurrent ovarian, primary peritoneal, and fallopian tube cancers has continued to evolve and now offers women the hope of extended survival with an improved quality of life. Platinum continues to be the single most active agent in the treatment of ovarian cancer, but acquired resistance to platinum often emerges. Fortunately, a number of novel agents and treatment strategies have been developed to meet the goals of ameliorating symptoms while extending survival. Classically, patients have been treated based upon the interval from last platinum administration during front-line therapy until time of recurrence. This review focuses upon the current treatment strategies used for platinum-refractory, platinum-resistant, and platinum-sensitive patients. The incorporation of targeted biologic agents is also discussed, along with the role of secondary cytoreduction. It is hoped that the results of future and ongoing clinical trials will offer further advances in the treatment of this devastating disease.

New, Expanded, and Modified Use of Approved Antineoplastic Agents in Ovarian Cancer

Over the past several years, clinical research efforts in ovarian cancer employing a number of U.S. Food and Drug Administration (FDA)-approved antineoplastic agents have permitted the development of approaches that both improve the effectiveness and decrease the toxicities of systemic therapy of ovarian cancer. These initiatives, including prospective trials and retrospective examinations of large clinical experience, have involved agents previously approved by the FDA for use in ovarian cancer (e.g., cisplatin, paclitaxel, topotecan, and liposomal doxorubicin) and the development of new strategies for drugs approved for other malignant conditions (e.g., gemcitabine, docetaxel, etoposide, irinotecan, vinorelbine, and bevacizumab). It can be anticipated that future studies involving novel approved agents will further expand the oncologist's weapons against ovarian cancer.

Effectiveness of weekly topotecan in patients with recurrent epithelial ovarian cancer

The objective of this study was to investigate the effectiveness and toxicity of weekly topotecan in patients with recurrent epithelial ovarian cancer. Twenty patients were treated with topotecan at a dose of 4 mg/m2weekly. Efficacy was determined according to the Response Criteria in Solid Tumors (RECIST) Gynecologic Cancer Inter Group criteria. Median age was 62 years (45–78). Patients had received 1–7 (median 3) prior chemotherapy lines. A total of 203 weekly treatments were administered. In 13 patients (65%) treatment delay was necessary due to bone marrow toxicity. Grade 3/4 neutropenia occurred in 11 patients (55%) and grade 3/4 thrombocytopenia in four patients (20%). Six patients (30%) needed a dose reduction, and 42 cycles (21%) were given with dose reduction. No neutropenia, fever, or sepsis was observed. There was one complete response and one partial response (response rate 10%). All patients with response had platin-sensitive disease (three out of eight). Six patients needed blood transfusion. None of the patients required granulocyte/granulocyte-macrophage colony-stimulating factor. The median duration of response was 13 months. In addition, there were four patients (20%) with a stable disease lasting at least for 4 months. Based on the results of this Phase II study, the toxicity of weekly topotecan seems to be lower than with the 3-weekly topotecan. The response rate of 10% is low but was not expected to be higher as these patients were heavily pretreated.

Phase II evaluation of a 3-day infusion of topotecan in patients with recurrent ovarian or primary peritoneal cancer

OBJECTIVE

To assess the efficacy and toxicity profile in patients treated with topotecan at 2.0 mg/m2/day x 3 days every 3 weeks.

MATERIALS AND METHODS

Eligibility criteria included patients with recurrent primary peritoneal or epithelial ovarian cancer with > or =6 months elapsed from time of prior platinum treatment. Patients were required to have a performance status of < or =2 and normal hepatic and renal function. Response to therapy and toxicity was assessed using standard criteria. Chi-square and Student's t tests were used as appropriate. Survival was assessed with Kaplan-Meier method.

RESULTS

All 40 patients enrolled were assessable for response. The mean age of the patients was 63.2 years (range 43-85). Median time to progression from initial treatment was 11.8 months. A total of 286 cycles of chemotherapy were administered with an average of 7.1 cycles per patient. Overall median time to progression (TTP) with 3-day topotecan treatment was 21 weeks (range 6-43 weeks). Of the 33 patients with measurable disease, 24% (11-42%, 95% CI) demonstrated a response. Seven patients had CA-125 evaluable disease with a response of 43% (10-89%, 95% CI). Median progression-free survival (PFS) was 16 weeks (range 12-21 weeks, 95% CI). Median overall survival was 106 weeks (range 76-117 weeks, 95% CI). Assessment of toxicity by patient showed 90% demonstrating grade 3/4 neutropenia with the vast majority being uncomplicated. No severe non-hematological toxicity was observed.

CONCLUSION

Administration of topotecan as a 3-day regimen is feasible with demonstrable activity and tolerable toxicity. Critical comparison to the 5-day regimen in a randomized fashion is warranted.

Ethnicity is a factor to be considered before dose planning in ovarian cancer patients to be treated with topotecan

The objective of this study was to determine the efficacy and toxicity of topotecan in Chinese patients with ovarian cancer. A retrospective analysis on recurrent ovarian cancer patients receiving topotecan 1.25 mg/m(2) daily for 5 consecutive days on a 21-day cycle from 1997 to 2002 was conducted. The patients included were all treated with at least two cycles of topotecan. The patient characteristics were compared in relation to their toxicity profile and their response to treatment. Response was evaluated by physical findings, imaging techniques, and serum CA125 level. A total of 60 patients were included in the study. All patients were evaluable for response and toxicities. A total of 361 cycles were given (median, 5 per patient; range 2-15). The major toxicity was neutropenia, which was grade 4 in 45.0% of the patients and 10.2% of the cycles. Age was the only covariate predicting the occurrence of grade 4 neutropenia (logistic regression P= 0.046, CI 1.01-1.12). Neutropenic fever occurred in 8.3% of the patients. Eighteen (30%) patients were required to delay their chemotherapy and 11 (18.3%) required dose reduction. Nonhematologic toxicities were mild. The overall response rate was 21.6%, with eight (13.3%) complete responses and five (8.3%) partial responses. The median duration of response and median time to progression were 11 and 5 months, respectively. The median survival was 14 months. Topotecan 1.25 mg/m(2) in a five-times-daily schedule was well tolerated in a cohort of Chinese patients. Myelotoxicity was the most important side effect in our study, but the incidence is much lower than that reported in other studies. Age was an independent factor predicting the occurrence of grade 4 neutropenia.

Topotecan as second-line therapy for ovarian cancer: dosage versus toxicity

In this issue of The Oncologist, Armstrong et al. present an analysis of the use of topotecan (Hycamtin; GlaxoSmithKline, Philadelphia, http://www.gsk.com) in the second-line treatment of both ovarian cancer and small cell carcinoma of the lung. This cytotoxic agent has clearly been demonstrated to be a useful drug in a population of patients with both of these conditions. However, the description of the nature of the toxicity, as stated in the manuscript, must be questioned along with comments made regarding the relative toxicity of alternative cytotoxic agents frequently used in similar settings. The purpose of this discussion absolutely is not to negate the unquestioned, demonstrated usefulness of topotecan as second-line therapy in ovarian cancer but rather to point out that the U.S. Food and Drug Administration-approved dose level of 1.5 mg/m(2) per day x 5 days can cause substantial and highly clinically relevant bone marrow toxicity. Whether this toxicity, which can result in a level of fatigue that may cause responding patients to discontinue treatment, should simply be labeled "excessive" rather than "cumulative" appears to be a matter of semantics rather than an important distinction. Whether delivery of a lower dose of topotecan (1 mg/m(2)-1.25 mg/m(2) per day x 5 days) will essentially eliminate concern for the development of severe clinically relevant marrow toxicity is uncertain, but the risk will certainly be substantially reduced.

Topotecan in heavily pretreated patients with recurrent ovarian, peritoneal, and fallopian tube carcinoma

Topotecan has demonstrated antitumor activity in heavily pretreated patients with ovarian carcinoma. This report examines the activity and toxicity of topotecan in 29 heavily pretreated patients with recurrent ovarian, peritoneal, and fallopian tube carcinoma. Topotecan 1.5 mg/m2 was administered intravenously on days 1-5, every 21 days. It was second-line chemotherapy in 6 (20.7%) patients, third-line in 15 (51.7%), fourth-line in 4 (13.8%), fifth-line in 3 (10.3%), and seventh-line in 1 (3.4%). Median dose intensity was 1.667 mg/m(2)/week, and median relative dose intensity was 0.67. Disease complete response was observed in 5 (17.2%) patients, partial response in 1 (3.4%), stable disease in 12 (41.4%), and progressive disease in 11 (37.9%). CA-125 complete response was observed in 3 (10.3%) patients, partial response in 11 (37.9%), stable level in 5 (17.2%), and progressive level in 9 (31%), and no data were available in 1 (3.4%) patient. Toxicity was mainly hematologic: grade 3-4 neutropenia was observed in 20 (69%) patients, grade 3-4 leukopenia in 12 (41.4%), grade 3-4 thrombocytopenia in 9 (31%), and grade 3-4 anemia in 2 (6.9%). It is concluded that topotecan has considerable activity and noncumulative hematologic toxicity in heavily pretreated patients with recurrent ovarian, peritoneal, and fallopian tube carcinoma.

Efficacy and tolerability of lower-dose topotecan in recurrent ovarian cancer: a retrospective case review

Topotecan (1.5 mg/m(2)/day for 5 consecutive days of a 21-day cycle) is an established recurrent ovarian cancer treatment, but myelosuppression can be dose limiting. This study evaluates the activity and tolerability of low-dose topotecan in our clinical experience. Case records were reviewed for patients with recurrent ovarian cancer in first through third relapse. Eligible patients had received > or =2 cycles of < or =1.25 mg/m(2) topotecan. Adverse events were evaluated using laboratory and clinical evaluation data. Twenty-seven eligible patients, most with advanced disease, received a total of 209 cycles (median, six cycles). Grade 3 or 4 hematologic toxicities during 184 cycles in 24 assessed patients were neutropenia, leukopenia, thrombocytopenia, and anemia in 35%, 28%, 36%, and 11% of cycles, and 21, 19, 16, and 10 patients, respectively. Only four grade 4 toxicities occurred: anemia (one) and thrombocytopenia (three). Myelosuppression was reversible, noncumulative, and manageable. Moreover, nonhematologic toxicity was generally mild to moderate, and the only two grade 3 events were constipation and deep vein thrombosis. Low-dose topotecan was active in this setting. Lower-dose topotecan is generally well tolerated and active in patients with pretreated ovarian cancer. Prospective clinical trials of low-dose topotecan in recurrent ovarian cancer are warranted.

The use of topotecan for relapsed ovarian cancer in accordance with the National Institute for Clinical Excellence Guidance 2001: the Nottingham experience

AIMS

The topoisomerase-1 inhibitor, topotecan, is an established chemotherapy agent for the treatment of relapsed ovarian cancer after the failure of platinum-based chemotherapy, and is an established treatment choice at first relapse. In line with National Institute for Clinical Excellence (NICE) guidance, topotecan has been used at Nottingham City Hospital for the last 2 years.

MATERIALS AND METHODS

A retrospective audit, over the period September 2001 to September 2002, was carried out to assess response rates and side-effects for patients with relapsed ovarian cancer who were treated with topotecan. Twenty-five patients received topotecan as a 30-min intravenous infusion for 5 consecutive days, every 21 days. The starting dose was either 1.5 mg/m2/day (n = 22) or 1.25 mg/m2/day (n = 3). Patient response was monitored by physical examination and serological CA125 tumour marker level. Radiological assessment was by computed tomography.

RESULTS

Eighteen (72%) patients had their previous platinum-based treatment less than 6 months before topotecan therapy. Thirteen patients received topotecan therapy as second-line, seven as third-line and five as > or = fourth-line treatment. Twenty-two (88%) patients who received more than one cycle of chemotherapy were evaluable for response. A clinical benefit was observed in 11 (44%) patients (two [8%] partial response and nine [36%] stable disease). Seven patients achieving clinical benefit received topotecan as second-line treatment. Dose was reduced from 1.5 to 1.25 mg/m2/day in six patients after the first cycle of topotecan. Twelve (48%) patients had dose delay of at least 1 week. Grade 3/4 neutropenia, observed in nine (36%) patients, was the main dose-limiting toxicity. One patient died as a result of treatment.

CONCLUSION

The Nottingham experience with topotecan in platinum-resistant ovarian cancer has been encouraging, even in such a heavily pre-treated patient population. There is a better chance of response if the patients receive topotecan at first relapse. The haematological toxicity is significant but manageable with dose reduction and dose delay.

Sequential topotecan and oral etoposide in recurrent ovarian carcinoma pretreated with platinum-taxane

BACKGROUND

The objectives of this study were to determine the maximum tolerable dose (MTD), toxicity, efficacy, and feasibility of a sequential regimen of fixed-dose topotecan (1.00 mg/m2 on Days 1-5) and increasing doses of oral etoposide (50 mg, 75 mg, and 100 mg on Days 6-12 or Days 6-19) in patients with recurrent ovarian carcinoma.

METHODS

This multicenter, open-label study was planned as a Phase I-II study that included patients with epithelial ovarian carcinoma who failed or who developed recurrent disease < 12 months after the end of platinum and taxane-containing chemotherapy. Dose-limiting toxicity (DLT) was defined as follows: Grade 4 neutropenia for > 1 week, or neutropenic fever 38.5 degrees C for > 24 hours/sepsis, or Grade 4 thrombocytopenia for > 1 week, or thrombocytopenia with bleeding, or Grade 3-4 nonhematologic toxicity.

RESULTS

The MTD, as defined in the protocol, could not be settled because of unpredictable toxicity, because DLT was found at all dose levels except the starting dose level. In 28 patients (Phase I), 155 cycles were evaluable for toxicity. The main DLT was neutropenia Grade 4 for > 1 week or neutropenic fever/sepsis. Overall, neutropenia Grade 4 that lasted > 1 week and sepsis were noticed in 3% and 2% of cycles, respectively. Because no MTD was reached, the planned Phase II trial was not initiated. However, the patients from Phase I were followed until they developed progressive disease and, among them, 9 patients (32%) obtained an objective response (according to Response Evaluation Criteria in Solid Tumors (RECIST) or CA125 response criteria).

CONCLUSIONS

Combined topotecan and oral etoposide was inappropriate in patients with recurrent ovarian carcinoma because of unpredictable hematologic toxicity. However, the high objective response rate highlighted the potential additive effect of topoisomerase I and II inhibitors.

Review of the use of topotecan in ovarian carcinoma

Ovarian cancer is the fifth leading cause of cancer deaths in women. The majority of patients present with advanced disease and relapse after first-line platinum-based chemotherapy; therefore, many proceed to treatment with salvage chemotherapy. Currently available treatment options are generally no longer curative in the relapse setting; hence, the emphasis of treatment is towards disease control and palliation of symptoms. There are several agents available for the treatment of relapsed ovarian carcinoma, of which topotecan is one of the most widely studied and characterised. This review aims to evaluate the role of topotecan in the management of this disease by considering the properties of the compound, the clinical efficacy in Phase II and III studies, its role in first- and second-line treatment and alternative dosing strategies to overcome toxicity.

Sequential Intraperitoneal Topotecan and Oral Etoposide Chemotherapy in Recurrent Platinum-Resistant Ovarian Carcinoma

PURPOSE

The purpose is to investigate the safety and efficacy of i.p. topotecan and oral etoposide as salvage treatment for patients with platinum-resistant ovarian or primary peritoneal cancer.

EXPERIMENTAL DESIGN

Patients were treated with i.p. topotecan initial dose, 1 mg/m2 on days 1 to 5, followed by oral etoposide 100 mg on days 6 to 9 of a 28-day cycle for six cycles. Dose reduction of topotecan was used for severe bone marrow suppression. Peritoneal (topotecan) and plasma (topotecan and etoposide) levels were assessed at multiple time points using high-pressure liquid chromatography.

RESULTS

Twenty-two patients (mean age, 61 years) with a median of 1.5 prior treatments were enrolled. Etoposide peak plasma concentrations ranged from 1.9 to 6.9 microg/mL (mean, 3.6 microg/mL). Topotecan plasma levels rose with increasing peritoneal concentration and were detectable within 1 hour but tended to decrease rapidly to below detectable levels within 24 hours. The peak plasma concentration of topotecan was 12.82 +/- 8.55 microg/mL with a plasma half-life of 6.17 +/- 2.75 hours. A total of 104 cycles was administered; 14 patients (64%) completed all six planned cycles. All patients were evaluable for toxicity, and 21 patients were evaluable for response. The most common grade 4 toxicities were neutropenia and thrombocytopenia in eight and four patients (36 and 18%), respectively. There were no treatment-related deaths. The overall response rate was 38% [complete response, three (14%); partial response, five (24%)]. Seven patients had stable disease and six progressed while on treatment.

CONCLUSIONS

The combination of i.p. topotecan and oral etoposide is an active and well-tolerated regimen in platinum-resistant ovarian carcinoma. Additional studies investigating topotecan in combination with etoposide are warranted.

The role of topotecan in the treatment of brain metastases

Despite advances in the treatment of systemic malignancies, the prognosis for patients with brain metastases continues to be dismal. Because the majority of cytotoxic agents seem to be unable to penetrate the blood-brain barrier, the role of chemotherapy in the treatment of brain metastases remains controversial. However, growing amounts of both laboratory and clinical data suggest that a few of the newly developed cytotoxic agents can cross the blood-brain barrier and may have a role in the treatment of patients with brain metastases. Topotecan, a novel topoisomerase I inhibitor, freely crosses the blood-brain barrier and may be clinically effective in both the therapeutic and prophylactic settings in patients with brain metastases. Recent studies have demonstrated the antitumor activity of topotecan against brain metastases, with objective response rates ranging from 33%-63% in patients with various solid tumors. The antitumor response in the central nervous system was often greater and occurred more quickly than the systemic antitumor response to topotecan treatment. This result may be explained by the lack of exposure of brain metastases to previous cytotoxic agents, suggesting a role for topotecan in patients with brain metastases. Early studies have also suggested that topotecan, an apparent radiosensitizer, may be particularly effective in combination with radiotherapy, the current standard of care for patients with brain metastases. In addition, preliminary data suggest that topotecan in combination with temozolomide (another cytotoxic agent that can cross the blood-brain barrier) may have synergistic antitumor activity against brain metastases. This review summarizes the available preclinical and clinical evidence for the role of topotecan in the treatment of brain metastases and concludes with three case studies.

Topotecan Dosing Guidelines in Ovarian Cancer: Reduction and Management of Hematologic Toxicity

Topotecan dosing considerations and alternative dosing schedules to reduce and manage myelosuppression during the treatment of relapsed ovarian cancer were reviewed. The myelosuppression patterns from phase I, II, and III clinical trials were analyzed to evaluate the degree of hematologic toxicity and to determine risk factors predictive of myelosuppression. Additionally, recent publications of alternative topotecan doses and schedules were examined. Extent of prior therapy, prior platinum therapy (particularly carboplatin), advanced age, impaired renal function, and prior radiation therapy were identified as potential risk factors for greater hematologic toxicity after topotecan therapy. Reducing the starting topotecan dose to 1.0 or 1.25 mg/m2/day is recommended to reduce the incidence of severe myelosuppression in high-risk individuals receiving topotecan for 5 consecutive days. Hematopoietic growth factors, transfusion therapy, and schedule adjustments may also help manage myelosuppression. Alternative schedules of 3-day or weekly dosing appear to have less myelotoxicity and are currently under evaluation. The clinical aspects of topotecan-related myelosuppression and results from clinical trials indicate that the dose, and possibly the dosing schedule, of topotecan can be modified to reduce hematologic toxicity and improve tolerance without compromising efficacy. Prospective individualization of topotecan dosing may prevent or minimize dose-limiting myelosuppression and allow patients to achieve the maximum topotecan benefit by improving their ability to complete therapy with fewer treatment delays. Ongoing clinical trials evaluating alternative dosing schedules with superior hematologic tolerability may facilitate the inclusion of topotecan in combination regimens for patients with ovarian cancer. Proposed topotecan dosing guidelines to reduce and manage myelosuppression are outlined.

Phase II evaluation of three-day topotecan in recurrent platinum-sensitive ovarian carcinoma: a gynecologic oncology group study

BACKGROUND

Topotecan, administered intravenously at a dose of 1.5 mg/m(2) per day for 5 days every 21 days, is an established regimen in the treatment of recurrent ovarian carcinoma. Alternate dosing strategies have sought to improve toxicity. The authors evaluated the tolerability and antitumor activity of a 3-day topotecan regimen.

METHODS

A multicenter Phase II study, which included patients with platinum-sensitive ovarian carcinoma, was conducted. Patients were to receive an intravenous dose of topotecan of 2.0 mg/m(2) per day for 3 days every 21 days until disease progression or unacceptable toxicity occurred. Doses were modified in 0.25-mg/m(2) increments based on tolerability. Granulocyte-colony-stimulating factor support was used as necessary.

RESULTS

From February to June 2000, 30 patients were enrolled. Their median age was 56 years (range, 41-81 years). Twenty-nine patients were evaluable for toxicity and efficacy. A median of 5 courses (range, 1-11 courses) of topotecan was administered. Eighteen of 30 (60%) patients experienced Grade 4 neutropenia. There was one report each of Grade 4 thrombocytopenia, anemia, and gastrointestinal toxicity (grading performed according to National Cancer Institute Common Toxicity Criteria). Ten patients developed Grade 3 leukopenia and 9 had Grade 3 neutropenia. Serious nonhematologic events were rare. There were 2 (7%) complete and 2 (7%) partial responses, for an overall response rate of 14%. Sixteen (55%) patients had stable disease and 9 (31%) experienced disease progression.

CONCLUSIONS

A 3-day regimen of topotecan at a dose of 2.0 mg/m(2) per day was generally well tolerated, although the response rate was lower than that for the standard 5-day schedule.

Workshop: options for therapy in ovarian cancer

Current and future options for sequential therapy for first and subsequent relapses in ovarian cancer were discussed in three workshops centered around a number of case studies. The participants included investigator oncologists from the USA, Europe, and Asia. For a platinum-resistant patient, topotecan or pegylated liposomal doxorubicin was considered the treatment of choice at first relapse. Since optimal tolerability with topotecan is achieved in less heavily pretreated patients, it may be best to use it earlier rather than later in the treatment schedule. For subsequent relapse within 6 months, most clinicians would use liposomal-encapsulated doxorubicin if the prior treatment had been topotecan and vice versa. Alternative agents may be considered with the aim of achieving symptom palliation rather than prolongation of survival. For late relapse after optimal debulking and treatment with carboplatin/paclitaxel, retreatment with carboplatin/paclitaxel (possibly after further surgery) was considered the best approach in platinum-sensitive patients. For first relapse after 10 months in a suboptimally debulked patient, retreatment with carboplatin/paclitaxel was also considered a viable option. Alternatively, single-agent therapy with paclitaxel, pegylated liposomal doxorubicin, or topotecan may be appropriate to prolong the platinum-free interval. For second relapse, oral etoposide was felt to be useful. Treatment for subsequent relapses included gemcitabine, docetaxel, and agents above not previously utilized. Topotecan tolerability and convenience may be improved by employing a lower dose, shorter schedule, 21-day continuous infusion or weekly dosing in relapsed/refractory disease. The progression-free interval may be extended by continuing topotecan until disease progression in patients with stable disease or by topotecan consolidation therapy in treatment responders.

Clinical experience with topotecan in relapsed ovarian cancer

Topotecan is an established therapy for the treatment of recurrent ovarian cancer and has demonstrated significant antitumor activity in both platinum-sensitive and platinum-resistant patient populations. The main toxicity associated with topotecan when used in the standard 5-day dosing schedule is myelosuppression, which is generally predictable, reversible, noncumulative, and manageable. Comparative trials have shown that topotecan is as effective as paclitaxel and pegylated liposomal doxorubicin in achieving tumor response, disease stabilization, and improved overall survival. Follow-up data extending to 4 years indicate that the survival benefit persists in long-term therapy without cumulative toxic effects. There appears to be little cross-resistance between topotecan and paclitaxel, indicating that the use of concurrent or sequential combination therapy could be a valuable option. Encouraging preliminary data suggest that alternative dosing schedules may improve the therapeutic index of topotecan and that topotecan may also be active as first-line therapy in combination with taxanes and/or platinum agents. Optimization of the use of topotecan may offer potential opportunities for further improving the management of ovarian cancer.

Amifostine pretreatment for protection against topotecan-induced hematologic toxicity: results of a multicenter phase III trial in patients with advanced gynecologic malignancies

OBJECTIVE

To determine if amifostine could reduce the hematologic toxicity associated with topotecan.

METHODS

Thirty patients with recurrent/refractory gynecologic malignancies were randomized to receive topotecan (TOPO) (1.5 mg/m(2)/day days 1-5) with or without amifostine (AMI/TOPO) (500 mg/m(2)/day days 1-5) every 3 weeks for six cycles. The primary study endpoints were the incidence of grade 3 and 4 neutropenia.

RESULTS

Fifteen patients were randomized to each arm for a total of 49 TOPO and 53 AMI/TOPO cycles. Patient characteristics and pretreatment ANC were similar between groups. Topotecan 1.5 mg/m(2)/day days 1-5 was initially administered to seven patients. Five developed neutropenic fevers, one an uncomplicated grade 4 neutropenia, and the other an uncomplicated grade 3 neutropenia. There were two treatment-related deaths due to sepsis (one in each treatment arm). The starting dose was thereafter reduced to 1.25 mg/m(2)/day days 1-5 every 21 days. No treatment related deaths occurred after this dose reduction. The incidence of combined grade 3/4 neutropenia was reduced from 67% (33/49 cycles) to 38% (20/53 cycles) with the addition of amifostine (P = 0.003; OR 0.29; 95% CI 0.12-0.71).

CONCLUSIONS

Topotecan at 1.5 mg/m(2)/day days 1-5 in heavily pretreated patients resulted in excessive toxicity not manageable with amifostine. At the reduced topotecan dose (1.25 mg/m(2) x 5 days), pretreatment with amifostine reduced the hematologic toxicity associated with topotecan chemotherapy in women with recurrent/refractory gynecologic malignancies.

Three-consecutive-day topotecan is an active regimen for recurrent epithelial ovarian cancer

OBJECTIVE

The aim was to determine the response rate and toxicity of topotecan administered Days 1-3 every 21 days for recurrent epithelial cancers of the ovary, peritoneum, or fallopian tube. A 3-day regimen may be more convenient and less expensive than a 5-day schedule.

METHODS

Patients with recurrent epithelial cancer of the ovary, peritoneum, or fallopian tube who had adequate hepatic, renal, and hematologic function were eligible for participation. Topotecan (2 mg/m(2)) was administered for 3 consecutive days every 21 days. Response was measured clinically and serologically. Granulocyte colony stimulating factors (GCSF) were not utilized prophylactically, but could be added under specific conditions.

RESULTS

Thirty-one patients with recurrent ovarian cancer whose median age was 63 (range 32-84) received 165 cycles of topotecan (median = 6; range 2-8) and are evaluable for toxicity. The median number of prior regimens was 1. Topotecan was administered on schedule in 96.6% of cycles. Grade 3/4 neutropenia was seen in 29.1 and 23.6% of courses, respectively; but only 3.4% of cycles required GCSF support (6 cycles for 2 patients). Grade 4 thrombocytopenia was rare (1% of cycles). Nonhematologic toxicity was mild. The response rate for 28 evaluable patients was 32.1% (10.7% complete response (CR) and 21.4% partial response (PR)); stable disease was seen in 17.9% of patients. The median progression-free interval (PFI) for all patients was 15.5 weeks (range 5-40). Eighteen platinum-sensitive patients demonstrated a 43.4% response rate (12.5% CR and 31.3% PR); stable disease was documented in 18.8%. The median PFI for platinum-sensitive patients was 18.5 weeks (range 5-40).

CONCLUSION

Topotecan is an effective regimen with acceptable toxicity for recurrent ovarian cancer when administered for 3 consecutive days (2 mg/m(2)) every 21 days. It can be delivered on schedule without GCSF support in the vast majority of patients.

Update on the role of topotecan in the treatment of recurrent ovarian cancer

Ovarian cancer is the fifth leading cause of cancer death in women. Most patients with ovarian cancer respond to first-line chemotherapy, but many relapse within 18 to 22 months. The development of efficacious salvage therapies that increase overall survival while maintaining quality of life is a great challenge in the treatment of this disease. Topotecan, a novel topoisomerase I inhibitor, is currently indicated for the treatment of recurrent metastatic carcinoma of the ovary. In patients with relapsed ovarian cancer, the overall response rates on treatment with topotecan range from 19%-33% in platinum-sensitive patients, 14%-18% in platinum-resistant patients, and 5%-11% in platinum-refractory patients. The proportion of patients achieving stable disease ranges between 17% in refractory and 48% in sensitive patients. In phase III studies, topotecan was shown to be equivalent in efficacy to both paclitaxel and liposomal doxorubicin as second-line therapy in patients with relapsed ovarian cancer. Further, non-cross-resistance between topotecan and paclitaxel was demonstrated in a third-line, phase III crossover study, suggesting that topotecan may be effective in the first-line setting with paclitaxel and/or platinum. Hematologic toxicities include neutropenia, thrombocytopenia, and anemia; however, these toxicities are usually short lived, noncumulative, and manageable with dose modifications, including low-dose topotecan regimens. Nonhematologic toxicities are usually mild to moderate in severity. These data support the use of topotecan for second-line therapy and suggest that topotecan may also be effective in first-line therapy. Further studies with topotecan alone and in combination with other agents are needed to fully characterize the role and sequencing of topotecan in the salvage and first-line settings.

Management of treatment-related toxicity in advanced ovarian cancer

Recognition of recurrent ovarian cancer as a disease with significant secondary responses and remissions has led to an increase in the need for oncologists to plan for the long-term therapy of patients. However, many of the currently available front-line and salvage agents used in advanced ovarian cancer are associated with cumulative and/or irreversible toxicities that pose challenges in long-term planning. The irreversible effects associated with some of these therapies may render patients less tolerant to subsequent treatments and lead to a cycle of diminishing treatment options with each remission and disease relapse. Additionally, the potential for patients to experience cumulative toxicity must be carefully weighed against the goals of prolonging the disease-free interval and improving patient quality of life. A number of agents are available in the treatment armamentarium (platinum, paclitaxel, gemcitabine, etoposide, liposomal doxorubicin, and topotecan), many, but not all of which are associated with cumulative toxicity. For instance, cumulative neurotoxicity associated with cisplatin as first-line therapy may diminish the option for retreatment with platinum at first relapse. In contrast, the main toxicity associated with topotecan is noncumulative, manageable myelosuppression. In this review, the major toxicities associated with the predominant chemotherapy agents used in advanced ovarian cancer are discussed along with selected management approaches in the context of long-term treatment planning and sequencing.

Management of recurrent ovarian cancer: evidence-based decisions

In this era of advanced medical technology, recurrent ovarian cancer continues to be a therapeutic dilemma. Most of these patients will succumb to their disease process. For this reason, it is of paramount importance for all clinicians to recognize that the primary goal of salvage therapy is to maximize disease-free survival and quality of life. With this goal in mind, they can offer patients a variety of different modalities to control disease, including second-look surgery, secondary or interval cytoreduction, second-line chemotherapy, hormonal therapy, and immunotherapy. The role of second-look surgery has yet to be delineated, but the modality can be helpful in evaluating disease status and guiding further therapy in patients receiving first-line platinum-based chemotherapy or in research protocols. Interval cytoreductive surgery has been shown to confer a survival advantage in a small subset of patients with localized resectable disease proven to be platinum sensitive. The choice of chemotherapeutic agents and the prognosis depend directly on whether the patient is a platinum-sensitive responder. Many agents are approved for the treatment of recurrent ovarian cancer, and the treatment of each patient should be individualized depending on the cumulative toxicities and performance status. Extensive ongoing research trials are underway to elucidate the best salvage therapy.

Chemotherapy for advanced epithelial ovarian carcinoma

Advanced epithelial ovarian cancer (AOC) is the most common clinical presentation of ovarian cancer. Virtually all patients will require some form of chemotherapy with curative or palliative intent. Prognostic factors, first- and second-line therapy, as well as experimental approaches for AOC are reviewed.