Clinical experience with topotecan in relapsed ovarian cancer

Overcoming cisplatin resistance in ovarian cancer: A novel approach via mitochondrial targeting peptide Pal-pHK-pKV

Cisplatin (DDP) resistance in advanced stages of ovarian cancer significantly reduces survival rates. Mitochondria may serve as a potential therapeutic target for ovarian cancer. Pal-pHK-pKV is a mitochondrial targeting peptide synthesized by supramolecular assembly. Our study aims to investigate whether Pal-pHK-pKV serves as a useful strategy to reverse DDP resistance in ovarian cancer. Subcutaneous tumor implantation of the DDP-resistant ovarian cancer cell line A2780CP was conducted in nude mice, and drugs were administered intraperitoneally to compare the inhibitory effects of Pal-pHK-pKV and DDP on A2780CP cells in vivo. Combination index values were calculated for various concentrations of DDP and Pal-pHK-pKV to determine the optimal combination concentration. Mitochondrial membrane potential, cytochrome C distribution and immunofluorescence were also measured. Our studies demonstrated that Pal-pHK-pKV treatment reduced the proliferation, invasion and metastasis of ovarian cancer cells and impaired mitochondrial function. Furthermore, the combination of Pal-pHK-pKV and DDP exhibited a synergistic effect. Mechanistically, Pal-pHK-pKV can impair mitochondrial function, reduce mitochondrial membrane potential and release ROS. On the other hand, Pal-pHK-pKV can affect ERK pathway activation and inhibit tumor development. In conclusion, the mitochondria-specific amphiphilic peptide Pal-pHK-pKV provides a novel approach for treating ovarian cancer and may potentially overcome DDP drug resistance.

Update on the Treatment of Recurrent Ovarian Cancer

Ovarian cancer is the leading cause of death for all gynecologic malignancies in developed countries, largely owing to the late stage of diagnosis. Despite response to initial surgery and chemotherapy, more than 65% of patients will have recurrent or persistent diseases. Approximately 50% of patients with recurrent ovarian cancer are asymptomatic. Recurrences are often diagnosed using a combination of tests, including cancer antigen 125, computed tomography, magnetic resonance imaging and positron emission tomography scan. The most significant prognostic factor among women with recurrent ovarian cancer is the length of time from initial diagnosis to recurrence. Treatment of recurrent ovarian cancer involves chemotherapy, with or without surgery. In selected patients, secondary cytoreductive surgery might significantly improve survival. Radiotherapy may have a role in the treatment of a small group of patients with localized symptomatic masses. New treatment modalities for women with recurrent ovarian cancer are needed, as none of the available treatments are curative.

A genomic instability score in discriminating nonequivalent outcomes of BRCA1/2 mutations and in predicting outcomes of ovarian cancer treated with platinum-based chemotherapy

Detecting mutation in BRCA1/2 is a generally accepted strategy for screening ovarian cancers that have impaired homologous recombination (HR) ability and improved sensitivity to PARP inhibitor. However, a substantial subset of BRCA-mutant ovarian cancer patients shows less impaired or unimpaired HR ability, resulting in nonequivalent outcome after ovarian cancer development. We hypothesize that genomic instability provides a lifetime record of DNA repair deficiency and predicts ovarian cancer outcome. Based on the multi-dimensional TCGA ovarian cancer data, we developed a biological rationale-driven genomic instability score integrating somatic mutation and copy number change in a tumor genome. The score successfully divided BRCA-mutant ovarian tumors into cases of significantly improved outcome and cases of unimproved outcome. The score was also capable of discriminating HR-deficiency indicated by BRCA1 epigenetically silencing, EMSY amplification and homozygous deletion of core HR genes. We further found that the score was positively correlated with the complete response rate of chemotherapy and the rate of platinum-sensitivity, and predicted improved outcome of ovarian cancer, regardless of BRCA-mutation status. The score may have important value in outcome prediction and clinical trial design.

Correlation between gene expression and mutator phenotype predicts homologous recombination deficiency and outcome in ovarian cancer

New strategies are needed to predict response to platinum-based chemotherapy and outcome of ovarian cancers. We hypothesized that the mutator phenotype in the cancer genome represents the overuse of alternative DNA repair mechanisms, which might be a sign of homologous recombination (HR) deficiency and can be captured by gene expression. Multidimensional data of ovarian cancer patients and breast cancer patients from The Cancer Genome Atlas (TCGA) database were used for the development and validation of a potential clinical information-independent score that correlates with HR deficiency and predicts outcome. Correlation of the score with platinum response, outcome, and BRCA mutations was assessed. The score correlated with increased genomic mutation rate in both ovarian cancer and breast cancer cases that harbored a substantial subset of HR-deficient samples. Significantly improved outcomes were observed in the high-scoring group versus the low-scoring group in the TCGA dataset and in three large gene expression microarray datasets. A strong correlation was found between the score and the likelihood of achieving complete response to chemotherapy. The score was also found to be highly robust to noises in genomic mutations. Sixty-four patients harboring BRCA mutations were successfully divided into two groups based on scores, with the high-scoring group showing significantly improved outcomes compared with wild-type cases and the low-scoring group showing no significance in all the same analyses. The score was significantly correlated with the response to platinum therapy and outcome. Evaluation of the score as a prognostic tool in ovarian cancer patients is warranted.

KEY MESSAGE

We develop a diagnostic signature for the HR-deficiency based on a novel hypothesis. HR-deficiency score is significantly correlated to platinum therapy and outcomes. HRDS was validated by its association with OS, PFS, DFS and CR in validation datasets. Evaluation of the score as a prognostic tool in ovarian cancer patients is warranted.

A phase 2 trial of flavopiridol (Alvocidib) and cisplatin in platin-resistant ovarian and primary peritoneal carcinoma: MC0261

PURPOSE

Based upon promising preclinical and phase 1 trial results, combined flavopiridol and cisplatin therapy was evaluated in patients with ovarian and primary peritoneal cancers.

METHODS

A two cohort phase 2 trial of cisplatin (60 mg/m2 IV) immediately followed by flavopiridol (100 mg/m2 IV, 24 h infusion; 21 day cycles) was undertaken in patients with recurrent platin-sensitive or platin-resistant disease (progression>vs. ≤6 months following prior platin-based therapy). Measurable disease (RECIST)--or evaluable disease plus CA125>2X post-treatment nadir--and ECOG performance≤2 were required.

RESULTS

Forty-five patients were enrolled between December 23, 2004 and February 25, 2010: 40 platin-resistant (Group 1), and 5 platin-sensitive (Group 2). In Group 1, the median number of treatment cycles was 3 (range 2-12). Only 10% of patients incurred grade 4 toxicities, but grade 3 toxicities were common (65%): neutropenia (17.5%); nausea (12.5%); vomiting, fatigue, thrombosis, anemia (10% each). Seven patients (17.5%) achieved a confirmed response (1 CR, 6 PR; median duration 118 days); ten additional patients (25%) attained maintained stable disease. Median time to progression was 4.3 months; overall survival was 16.1 months. Pilot translational studies assessed ascites flavopiridol level; surrogate marker studies were uninformative. In Group 2, although 4 of 5 patients responded (2 confirmed PRs with median time to progression, 10.8 months and median overall survival 20.6 months) the cohort was closed due to poor accrual.

CONCLUSIONS

The assessed flavopiridol and cisplatin regimen displayed clinical activity in platin resistant and sensitive ovarian/primary peritoneal cancers, meriting further study.

A DNA repair pathway-focused score for prediction of outcomes in ovarian cancer treated with platinum-based chemotherapy

Background

New tools are needed to predict outcomes of ovarian cancer patients treated with platinum-based chemotherapy. We hypothesized that a molecular score based on expression of genes that are involved in platinum-induced DNA damage repair could provide such prognostic information.

Methods

Gene expression data was extracted from The Cancer Genome Atlas (TCGA) database for 151 DNA repair genes from tumors of serous ovarian cystadenocarcinoma patients (n = 511). A molecular score was generated based on the expression of 23 genes involved in platinum-induced DNA damage repair pathways. Patients were divided into low (scores 0–10) and high (scores 11–20) score groups, and overall survival (OS) was analyzed by Kaplan–Meier method. Results were validated in two gene expression microarray datasets. Association of the score with OS was compared with known clinical factors (age, stage, grade, and extent of surgical debulking) using univariate and multivariable Cox proportional hazards models. Score performance was evaluated by receiver operating characteristic (ROC) curve analysis. Correlations between the score and likelihood of complete response, recurrence-free survival, and progression-free survival were assessed. Statistical tests were two-sided.

Results

Improved survival was associated with being in the high-scoring group (high vs low scores: 5-year OS, 40% vs 17%, P < .001), and results were reproduced in the validation datasets (P < .05). The score was the only pretreatment factor that showed a statistically significant association with OS (high vs low scores, hazard ratio of death = 0.40, 95% confidence interval = 0.32 to 0.66, P < .001). ROC curves indicated that the score outperformed the known clinical factors (score in a validation dataset vs clinical factors, area under the curve = 0.65 vs 0.52). The score positively correlated with complete response rate, recurrence-free survival, and progression-free survival (Pearson correlation coefficient [r²] = 0.60, 0.84, and 0.80, respectively; P < .001 for all).

Conclusion

The DNA repair pathway–focused score can be used to predict outcomes and response to platinum therapy in ovarian cancer patients.

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.

Molecular cytogenetic evaluation of the mechanism of micronuclei formation induced by camptothecin, topotecan, and irinotecan

We used the conventional bone marrow micronucleus test complemented with the fluorescent in situ hybridization with the minor satellite DNA probe to investigate the mechanisms of induction of micronuclei in mice treated with camptothecin and its clinical antineoplastic analogues topotecan and irinotecan. All experiments were performed with male Swiss albino mice. Single doses of 1 mg/kg camptothecin or 0.6 mg/kg topotecan were injected intraperitoneally and bone marrow was sampled at 30 hr (camptothecin) or 24 hr (topotecan) after treatment. A dose of 60 mg/kg irinotecan was injected intravenously, once every fourth day for 13 days and bone marrow was sampled 24 hr after the last treatment. In animals treated with camptothecin, a total of 1.07% micronuclei were found and 70% of them were centromere-negative, indicating their formation by DNA strand breaks and reflecting the predominant clastogenic activity of camptothecin. Exposure to topotecan and irinotecan yielded 1.71 and 0.83% micronuclei, respectively. About 52.7 and 48.8% of the induced micronuclei, respectively, were centromere-positive, indicating their formation by whole chromosomes and reflecting the aneugenic activity of both compounds. Correspondingly, about 47.3 and 51.2% of the induced micronuclei, respectively were centromere-negative, demonstrating that topotecan and irinotecan not only induce chromosome loss but also DNA strand breaks. Both the clastogenic and aneugenic potential of these drugs can lead to the development of secondary tumors and abnormal reproductive outcomes. Therefore, the clinical use of these agents must be weighed against the risks of secondary malignancies in cured patients and persistent genetic damage of their potential offspring.

Phase I dose escalation study of vinorelbine and topotecan combination chemotherapy in patients with recurrent lung cancer

Background

A platinum doublet is the current standard treatment for good performance status patients with advanced non-small cell lung cancer (NSCLC) and extensive stage small cell lung cancer (SCLC) with good performance status. However, platinum-based treatment may be associated with significant toxicities, therefore alternative platinum-free combinations should be investigated. Topotecan is a topoisomerase I inhibitor that exerts its cytotoxic effect through stabilization of the topoisomerase I-DNA complex. Preclinical data suggests synergy between topoisomerase I inhibitors and mitotic spindle poisons. Considerable hematologic toxicities have been reported with topotecan dosed for 5 consecutive days in combination with vinorelbine. Therefore, the aim of this study was to evaluate the optimal dosage and the maximal tolerated dose (MTD) of topotecan and vinorelbine in patients with relapsed or refractory non-small cell or small cell lung cancer administered on an alternate dosing schedule.

Methods

From February, 2004 to March, 2007 eighteen patients with advanced or recurrent NSCLC or SCLC previously treated with chemotherapy were enrolled. Patients were heavily pretreated with 22% having received at least 3 prior lines of chemotherapy. Vinorelbine was administered at a fixed dose (20 mg/m²) and topotecan at escalating doses (2, 2.5, 3, 3.5, and 4 mg/m²) on days 1 and 8 every 21 days.

Results

The MTD was not reached in any of the 5 cohorts, with only one dose limiting toxicity (DLT) occurring in cohort 4. Non-hematological toxicities were manageable. One patient had a partial response with four patients (27%) achieving stable disease. The median progression-free and overall survival for all patients, were 2.7 months (95% CI: 1.6, 9.1) and 10.5 months (95% CI: 4.2, 22.7), respectively.

Conclusion

Vinorelbine and topotecan administered on days 1 and 8 every 21 days is well tolerated without any DLT seen with previously investigated topotecan schedules. This doublet provides a potentially active non-platinum containing doublet for the treatment of patients with advanced SCLC and NSCLC. Vinorelbine and topotecan should therefore be investigated in subsequent phase II studies at a dose of 20 mg/m² and 4 mg/m², respectively.

Trial Registration Number

NCT00287963.

Optimizing gemcitabine regimens in ovarian cancer

Ovarian cancer represents the leading cause of death from gynecologic neoplasms. The chance of response to secondary treatment is currently disappointing; few agents have shown notable activity in recurrent/progressive patients. Among these agents, gemcitabine represents one of the most interesting newer antineoplastic agents, showing significant activity, synergism with cisplatin, and a mild toxicity profile in both platinum-sensitive and platinum-resistant (and also taxane-pretreated) recurrent/progressive patients. Moreover, first-line combination chemotherapy including gemcitabine has shown promising response rates in phase I and II studies. The ongoing phase III, five-arm, randomized Gynecologic Oncology Group Protocol 182/International Collaborative Ovarian Neoplasm 5 study should clarify the clinical impact of the addition of a third drug to the standard paclitaxel plus carboplatin treatment regimen.

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.

Cellular evaluation of oral chemotherapy carriers

Hydrogel nanospheres composed of methacrylic acid and poly(ethylene glycol) were loaded with bleomycin and tested as a potential oral delivery system for chemotherapeutic agents. The gastrointestinal epithelium was modeled through the use of Caco-2 monolayers for studies of permeation enhancement by the carriers as well as bleomycin transport. Bleomycin efficacy following release from the carrier was evaluated with a DLD-1 tumor cell model. The nanospheres release bleomycin in response to a pH increase similar to that seen when passing from the stomach into the upper small intestine. These carriers can also increase the permeability of a model of the epithelial barrier, which would hopefully improve drug transport into the bloodstream. Efficacy studies using a tumor cell model showed retention of activity for bleomycin following loading and release from the nanospheres. The carriers described performed well during in vitro evaluation and can hopefully expand the spectrum of chemotherapeutic agents capable of being administered orally.

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.

A review of selected anti-tumour therapeutic agents and reasons for multidrug resistance occurrence

It is assumed that proteins from the ABC family (i.e., glycoprotein P (Pgp)) and a multidrug resistance associated protein (MRP) play a main role in the occurrence of multidrug resistance (MDR) in tumour cells. Other factors that influence the rise of MDR are mechanisms connected with change in the effectiveness of the glutathione cycle and with decrease in expression of topoisomerases I and II. The aim of this review is to characterize drugs applied in anti-tumour therapy and to describe the present state of knowledge concerning the mechanisms of MDR occurrence, as well as the pharmacological agents applied in reducing this phenomenon.

Principles of transmucosal delivery of therapeutic agents

Recent advances in medicine have led to new treatment options for patients and physicians as a more developed understanding of the molecular basis of disease states is translated into new therapeutic agents. Many of these new agents are compounds that are not able to reach the bloodstream when administered by the oral route preventing the ability to enjoy the benefits this delivery route provides such as lower cost and increased quality of life. Our laboratory has focused on the use of hydrogel carriers to increase the bioavailability of orally administered therapeutic agents ranging from proteins such as insulin to chemotherapeutics like bleomycin. The foundations of this research as well as recent advances are reviewed along with a discussion of the challenges of oral administration and other emerging strategies for oral administration.

Optimal sequencing in the treatment of recurrent ovarian cancer

Improvements in ovarian cancer management mean that it may now be a long-term disease for which treatment must be carefully considered. Optimal sequencing of chemotherapy may help to enhance patients' benefit of therapy and minimize toxicity. The response to retreatment with platinum or a platinum/taxane combination is strongly influenced by the treatment-free interval after initial therapy with a platinum combination. Response rates to platinum retreatment in platinum-resistant patients (relapse within 6 months) are lower than those in platinum-sensitive patients (relapse after 6 months). Increasing the platinum-free interval by using non-platinum-based chemotherapy for treatment after relapse appears to increase the likelihood of response to later rechallenge with platinum. Many alternative agents have been investigated for the treatment of patients with relapsed ovarian cancer, including single-agent topotecan, which has been shown to achieve favorable responses. Topotecan may cause myelosuppression, which is noncumulative but tends to increase in direct correlation with the number of prior chemotherapy courses. Therefore, the best use of topotecan may be early in the course of salvage therapy. The hematologic toxicities associated with topotecan can also be reduced by adjusting the dose and schedule. Prolonged use of topotecan may be feasible and potentially beneficial in some patients.