Gemcitabine/paclitaxel-based three-drug regimens in advanced urothelial cancer

Role of Toll-like receptor 4 in drug-drug interaction between paclitaxel and irinotecan in vitro

The bacterial receptor, Toll-like receptor (TLR) 4 mediates inflammatory responses and has been linked to a broad array of diseases. TLR4 agonists are being explored as potential treatments for cancer and other diseases. We have previously shown that activation of TLR4 by lipopolysaccharide (LPS) leads to down-regulation of drug metabolizing enzymes/transporters (DMETs), and altered pharmacokinetics/pharmacodynamics (PK/PD) of drugs. These changes can increase the risk of drug-drug interactions (DDIs) in patients on multiple medications. Clinically, DDI was observed for combination chemotherapy of paclitaxel (TLR4 ligand) and irinotecan. To determine the role of TLR4 in DDI between paclitaxel and irinotecan in vitro, primary hepatocytes from TLR4-wild-type (WT) and mutant mice were pre-treated with paclitaxel, followed by irinotecan. Gene expression of DMETs was determined. Paclitaxel treatment increased the levels of irinotecan metabolites, SN-38 and SN-38 glucuronide (SN-38G) in TLR4-dependent manner. Paclitaxel-mediated induction of genes involved in irinotecan metabolism such as Cyp3a11 and Ugt1a1 was TLR4-dependent, while induction of the transporter Mrp2 was TLR4-independent. These novel findings demonstrate that paclitaxel can affect irinotecan metabolism by a TLR4-dependent mechanism. This provides a new perspective towards evaluation of marketed drugs according to their potential to exert DDIs in TLR4-dependent manner.

Comparison of global versus epidermal growth factor receptor pathway profiling for prediction of lapatinib sensitivity in bladder cancer

Chemotherapy for metastatic bladder cancer is rarely curative. The recently developed small molecule, lapatinib, a dual epidermal growth factor receptor (EGFR)/human epidermal growth factor receptor-2 receptor tyrosine kinase inhibitor, might improve this situation. Recent findings suggest that identifying which patients are likely to benefit from targeted therapies is beneficial, although controversy remains regarding what types of evaluation might yield optimal candidate biomarkers of sensitivity. Here, we address this issue by developing and comparing lapatinib sensitivity prediction models for human bladder cancer cells. After empirically determining in vitro sensitivities (drug concentration necessary to cause a 50% growth inhibition) of a panel of 39 such lines to lapatinib treatment, we developed prediction models based on profiling the baseline transcriptome, the phosphorylation status of EGFR pathway signaling targets, or a combination of both data sets. We observed that models derived from microarray gene expression data showed better prediction performance (93%-98% accuracy) compared with models derived from EGFR pathway profiling of 23 selected phosphoproteins known to be involved in EGFR-driven signaling (54%-61% accuracy) or from a subset of the microarray data for transcripts in the EGFR pathway (86% accuracy). Combining microarray data and phosphoprotein profiling provided a combination model with 98% accuracy. Our findings suggest that transcriptome-wide profiling for biomarkers of lapatinib sensitivity in cancer cells provides models with excellent predictive performance and may be effectively combined with EGFR pathway phosphoprotein profiling data. These results have significant implications for the use of such tools in personalizing the approach to cancers treated with EGFR-directed targeted therapies.

Phase II trial of paclitaxel, carboplatin and gemcitabine in patients with locally advanced carcinoma of the bladder

PURPOSE

This 2-arm phase II multicenter trial was designed to assess the efficacy and toxicity of neoadjuvant paclitaxel, gemcitabine and carboplatin in patients with invasive bladder cancer.

MATERIALS AND METHODS

Patients in arm I had clinical stage T2 with hydronephrosis or T3 bladder cancer. They received 3 cycles of chemotherapy (200 mg/m(2) paclitaxel on day 1, AUC 5 carboplatin on day 1, and 800 mg/m(2) gemcitabine on days 1 and 8 of each 21-day cycle). Response was defined as achievement of a pathological complete response (pT0). Patients in arm II with T4 or lymph node positive disease received up to 6 cycles of paclitaxel, carboplatin and gemcitabine. Response was defined as conversion to surgical resectability.

RESULTS

In arm I, 31 patients were enrolled and 22 were evaluable for response. Seven patients had pT0 disease (32% of evaluable patients, 22% by intent to treat). In arm II, 37 patients were enrolled and 29 were evaluable for response with 24 suitable for surgical resection (83% of evaluable and 65% by intent to treat). The most common toxicity was neutropenia with 39 events in arm I and 68 in arm II. There were 7 deaths on study (5 during chemotherapy and 2 after cystectomy).

CONCLUSIONS

Neoadjuvant paclitaxel, carboplatin and gemcitabine resulted in a significant number of responses in both arms but greater than anticipated toxicity. The pT0 rate was modest and overall efficacy was difficult to assess due to the toxicity. More studies of novel agents and combinations are needed to improve the efficacy and reduce the toxicity of neoadjuvant therapy for bladder cancer.

Hypermethylation of tumor-suppressor gene CpG islands in small-cell carcinoma of the urinary bladder

Small-cell carcinoma of the urinary bladder (SCBC) is a rare tumor, which shows a common clonal origin with urothelial carcinoma. It bears a high metastatic potential, even when discovered in a localized state. Identifying the molecular underpinnings of this disease may elucidate useful clinical information regarding prevention, diagnosis, prognosis, treatment, and surveillance. As DNA methylation is widely recognized as having a pivotal role in the process of carcinogenesis, we analyzed the DNA methylation status of four frequently hypermethylated tumor suppressors in small-cell and transitional-cell carcinoma (TCC) arising concomitantly in 13 patients. Fourteen cases of pure TCC were also included in the analysis. We identified frequent methylation of RASSF1 and MGMT and infrequent methylation of MLH1 and DAPK1 in cases of concomitant TCC and SCBC. Similar rates of methylation were found in pure and concomitant histopathologies, with the exception of MGMT, which was much less frequently methylated in pure TCC. These findings suggest that SCBC and TCC have common origins, establish DNA methylation of some tumor suppressors as frequent occurrences in both histopathologies, and suggest that MGMT methylation may be an SCBC-specific epimutation.

Gemcitabine and oxaliplatin combination: a multicenter phase II trial in unfit patients with locally advanced or metastatic urothelial cancer

BACKGROUND

Up to 50% of patients with bladder cancer cannot be treated with cisplatin because they are considered unfit due to poor renal function. Gemcitabine and oxaliplatin are active, nonnephrotoxic therapies with nonoverlapping toxicity profiles that provide an alternative therapy for this group of patients.

PATIENTS AND METHODS

In a multicenter study, patients received gemcitabine 1200 mg/m(2) on days 1 and 8 and oxaliplatin 100 mg/m(2) on day 8 every 21 days. Eligible criteria were creatinine clearance >30 ml/min and/or Eastern Cooperative Oncology Group (ECOG) performance status of two or less.

RESULTS

Forty-six patients were assessable for response and toxicity. Median age was 69 years (range 52-85), median ECOG two (range 0-2). Median number of metastatic sites was 2 (range 1-6). Median creatinine clearance was 50.73 ml/min (range 30-87). A total of 187 cycles were given with a median of 5 (range 1-6). Hematological toxicity was mild with grade 3-4 peripherical neuropathy occurring in 4% of patients. Overall response rate was 48% (three complete response, 19 partial response, seven stable disease and 17 progressive disease). Median time to disease progression was 5 months.

CONCLUSION

Gemcitabine-oxaliplatin is an active and tolerable combination with response rate that merits further study in patients with impaired renal function but good performance status.

Docetaxel and gemcitabine combination therapy in advanced transitional cell carcinoma of the urothelium: results of a phase II and pharmacologic study

Our objective was to determine the response to gemcitabine plus docetaxel in advanced urothelial transitional cell carcinoma in a phase II trial, and gemcitabine distribution between plasma and erythrocytes, following docetaxel administration. Patients with locally advanced or metastatic transitional cell carcinoma, following a maximum of one prior chemotherapy regimen, were given gemcitabine 800 mg/m on days 1 and 8 plus docetaxel 85 mg/m on day 8, every 21 days. Gemcitabine was measured in the plasma and erythrocytes of nine patients before and after docetaxel administration. Thirty-four patients (median 63 years; range 49-79 years), of whom seven had prior chemotherapy and 27 were chemotherapy-naive, received a median of six cycles (range 1-6). Complete and partial remissions were observed in two and 16 (including three pretreated) patients, respectively, for an overall response rate of 53%. Median response duration was 5 months (range 1-39+). Haematoxicity was manageable, despite grade 3 infections in 24% of patients, but other toxicities were mostly mild. An apparent shift of gemcitabine from plasma to erythrocytes occurred after docetaxel in five of six patients evaluable for this analysis. We conclude gemcitabine plus docetaxel is tolerable and highly active in treated and untreated patients with advanced transitional cell carcinoma.

A phase II study of gemcitabine and docetaxel therapy in patients with advanced urothelial carcinoma

BACKGROUND

The objectives of the current study were to evaluate the safety and efficacy of gemcitabine plus docetaxel in patients with unresectable (Stage T4 or >/= N1) metastatic or locally advanced transitional cell carcinoma (TCC) of the urothelial tract.

METHODS

A total of 27 patients were enrolled in the current multisite study, which was performed within the University of California-Los Angeles Community Oncology Research Network. The first 10 patients in the study received 800 mg/m(2) of gemcitabine intravenously on Days 1, 8, and 15 of a 28-day treatment cycle. In addition, on Day 1, the first 10 patients received 80 mg/m(2) of docetaxel intravenously after completion of the gemcitabine infusion. Because of dose-limiting toxicity (neutropenia), the initial dose of docetaxel was reduced to 60 mg/m(2) for the remaining patients who entered the study (n = 17 patients).

RESULTS

Neutropenia was the most common adverse event that occurred in patients at the Grade 3 level (in 10 of 27 patients; 37.0%) and the Grade 4 level (in 6 of 27 patients; 22.2%). There were no other adverse events at the Grade 4 toxicity level. Twenty-five of 27 patients (92.6%) completed more than 1 cycle of combination therapy and were evaluated for antitumor responses. The frequency of objective clinical responses was 33.3% (9 of 27 patients). Complete responses to therapy were observed in 2 of 27 patients (7.4%), and partial responses were observed in 7 of 27 patients (25.9%). The median duration of response was 20 weeks (range, 12+ weeks to 152 weeks). The median survival duration was 52 weeks (range, 12 weeks to 160+ weeks). Four of 27 patients (14.8%) remained alive at the time of the current data analysis.

CONCLUSIONS

The results of the current study suggested that combination therapy with gemcitabine and docetaxel was an effective treatment for patients with unresectable (Stage T4 or >/= N1) metastatic or locally advanced TCC of the urothelial tract. Gemcitabine plus docetaxel appeared to be tolerated well, and treatment-related toxicities were limited to hematologic toxicities. Because cisplatin-containing regimens are contraindicated for patients with impaired renal function, the gemcitabine plus docetaxel combination may prove to be an effective and well tolerated treatment option for these patients.