A phase II clinical trial of topotecan in Japanese patients with relapsed ovarian carcinoma

A ciprofloxacin derivative with four mechanisms of action overcomes paclitaxel resistance in p53-mutant and MDR1 gene-expressing type II human endometrial cancer

Dysfunction of the p53 gene and the presence of the MDR1 gene are associated with many malignant tumors including endometrial cancer and are responsible for cancer therapeutic resistance and poor survival. Thus, there is a critical need to devise novel combinatorial therapies with multiple mechanisms of action to overcome drug resistance. Here, we report a new ciprofloxacin derivative (CIP2b) tested either alone or in combination with taxanes against four human endometrial cancer cell lines. In vitro studies revealed that a combination of paclitaxel + CIP2b had synergistic cytotoxic effects against MDR1-expressing type-II human endometrial cancer cells with loss-of-function p53 (Hec50co LOFp53). Enhanced antitumor effects were confirmed by substantial increases in caspase-3 expression, cell population shifts toward the G2/M phase, and reduction of cdc2 phosphorylation. It was found that CIP2b targets multiple pathways including the inhibition of MDR1, topoisomerase I, and topoisomerase II, as well as enhancing the effects of paclitaxel (PTX) on microtubule assembly. In vivo treatment with the combination of PTX + CIP2b also led to significantly increased accumulation of PTX in tumors (compared to CIP2b alone) and reduction in tumor growth. Enhanced in vivo cytotoxic effects were confirmed by histological and immunohistochemical examination of the tumor tissues. Complete blood count and blood biochemistry data confirmed the absence of any apparent off-target toxicity. Thus, combination therapy involving PTX and CIP2b targeted multiple pathways and represents an approach that could result in improved tolerance and efficacy in patients with type-II endometrial cancer harboring the MDR1 gene and p53 mutations.

A phase II study of irinotecan and pegylated liposomal doxorubicin in platinum-resistant recurrent ovarian cancer (Tohoku Gynecologic Cancer Unit 104 study)

PURPOSE

We report a phase II clinical study of the combination of irinotecan (CPT-11) and pegylated liposomal doxorubicin (PLD) in platinum- and taxane-resistant recurrent ovarian cancer, based on the recommended doses determined in a phase I trial.

METHODS

PLD was administered intravenously at a dose of 30 mg/m² on day 3. CPT-11 was administered intravenously at a dose of 80 mg/m² on days 1 and 15, according to the recommendations of the phase I study. A single course of chemotherapy lasted 28 days, and patients underwent at least 2 courses until disease progression. The primary endpoint was antitumor efficacy, and the secondary endpoints were adverse events, progression-free survival (PFS), and overall survival (OS).

RESULTS

The response rate was 32.3% and the disease control rate was 64.5%. Grade 3 and 4 neutropenia, anemia, and a decrease in platelet count were observed in 17 (54.9%), 3 (9.7%), and 1 patient (3.2%), respectively. In terms of grade 3 or higher non-hematologic toxicities, grade 3 nausea occurred in 1 patient (3.2%), vomiting in 3 patients (9.7%), and grade 3 diarrhea and fatigue in 1 patient (3.2%). The median PFS and OS rates were 2 months and not reached, respectively. Of the 11 patients with a treatment-free interval (TFI) of ≥3 months, the response rate was 63.3%, and the median PFS was 7 months.

CONCLUSIONS

The treatment outcomes for the 31 patients enrolled in this study were unsatisfactory. However, sub-analysis suggested that patients with a TFI of ≥3 months had a good response rate and PFS. This suggests that CPT-11/PLD combination therapy may be a chemotherapy option for platinum-resistant recurrent ovarian cancer.

A phase I study of irinotecan and pegylated liposomal doxorubicin in recurrent ovarian cancer (Tohoku Gynecologic Cancer Unit 104 study)

Purpose

A phase I clinical study was conducted to determine the maximum tolerated dose (MTD) and the recommended dose (RD) of irinotecan hydrochloride (CPT-11) in CPT-11/pegylated liposomal doxorubicin (PLD) combination therapy, a novel treatment regimen for platinum- and taxane-resistant recurrent ovarian cancer.

Methods

Pegylated liposomal doxorubicin was administered intravenously on day 3 at a fixed dose of 30 mg/m². CPT-11 was administered intravenously on days 1 and 15, at a dose of 50 mg/m² on both days. One course of chemotherapy was 28 days, and patients were given a maximum of six courses, with the CPT-11 dose being increased in increments of 10 mg/m² (level 1, 50 mg/m²; level 2, 60 mg/m²; level 3, 70 mg/m²; level 4, 80 mg/m²) to determine MTD and RD.

Results

During the period from April 2010 to March 2013, three patients were enrolled for each level. In the first course, no dose-limiting toxicity occurred in any of the patients. Grade 4 neutropenia was observed in two of three patients at level 4. At level 4, the antitumor effect was a partial response (PR) in two of the three patients and stable disease (SD) in one. At level 3, one of the three patients showed PR and two had SD. At level 4, the start of the next course was postponed in two of three patients. In addition, one patient at level 4 experienced hemotoxicity that met the criteria for dose reduction in the next course. The above results suggested that administration of CPT-11 at dose level 5 (90 mg/m²) would result in more patients with severe neutropenia and in more patients requiring postponement of the next course or a dose reduction. Based on the above, the RD of CPT-11 was determined to be 80 mg/m².

Conclusions

The results suggest that CPT-11/PLD combination therapy for recurrent ovarian cancer is a useful treatment method with a high response rate and manageable adverse reactions. In the future phase II study, the safety and efficacy of this therapy will be assessed at 80 mg/m² of CPT-11 and 30 mg/m² of PLD.

The chemotherapeutic agent topotecan differentially modulates the phenotype and function of dendritic cells

The camptothecin analogue topotecan (TPT) induces tumor cell apoptosis due to interference with topoisomerase I and is clinically used as a second-line chemotherapeutic in the treatment for metastasizing ovarian and small cell lung carcinoma. Based on the more recent finding of TPT-mediated inhibition of the transcription factor hypoxia-induced factor-1α, a hallmark of solid tumors, TPT, is currently tested in clinical trials for its suitability as a first-line chemotherapeutic for the treatment for various types of tumors. Due to the gained clinical interest in TPT and in light of its modulatory effect on signaling pathways, which are also of importance for immune cell functions, we asked for potential effects of TPT on dendritic cells (DCs), the main antigen-presenting cell population of the immune system. Here, we show that TPT at a therapeutically relevant dose partially activated monocyte-derived DCs as reflected by enhanced migratory activity, elevated expression of HLA-DR and costimulatory/maturation markers, and accordingly an increased allogenic CD4(+) T cell stimulation. In marked contrast, TPT prevented full maturation of DCs stimulated with a cocktail of proinflammatory mediators, accompanied by somewhat lower upregulation of NF-κB factors p65 and RelB.