Fixed-dose-rate gemcitabine: a viable first-line treatment option for advanced pancreatic and biliary tract cancer

Extracellular Matrix Composition Modulates the Responsiveness of Differentiated and Stem Pancreatic Cancer Cells to Lipophilic Derivate of Gemcitabine

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal disease. Gemcitabine (GEM) is used as the gold standard drug in PDAC treatment. However, due to its poor efficacy, it remains urgent to identify novel strategies to overcome resistance issues. In this context, an intense stroma reaction and the presence of cancer stem cells (CSCs) have been shown to influence PDAC aggressiveness, metastatic potential, and chemoresistance.

METHODS

We used three-dimensional (3D) organotypic cultures grown on an extracellular matrix composed of Matrigel or collagen I to test the effect of the new potential therapeutic prodrug 4-(N)-stearoyl-GEM, called C18GEM. We analyzed C18GEM cytotoxic activity, intracellular uptake, apoptosis, necrosis, and autophagy induction in both Panc1 cell line (P) and their derived CSCs.

RESULTS

PDAC CSCs show higher sensitivity to C18GEM treatment when cultured in both two-dimensional (2D) and 3D conditions, especially on collagen I, in comparison to GEM. The intracellular uptake mechanisms of C18GEM are mainly due to membrane nucleoside transporters' expression and fatty acid translocase CD36 in Panc1 P cells and to clathrin-mediated endocytosis and CD36 in Panc1 CSCs. Furthermore, C18GEM induces an increase in cell death compared to GEM in both cell lines grown on 2D and 3D cultures. Finally, C18GEM stimulated protective autophagy in Panc1 P and CSCs cultured on 3D conditions.

CONCLUSION

We propose C18GEM together with autophagy inhibitors as a valid alternative therapeutic approach in PDAC treatment.

Metastatic pancreatic cancer: Is there a light at the end of the tunnel?

Due to extremely poor prognosis, pancreatic cancer (PDAC) represents the fourth leading cause of cancer-related death in Western countries. For more than a decade, gemcitabine (Gem) has been the mainstay of first-line PDAC treatment. Many efforts aimed at improving single-agent Gem efficacy by either combining it with a second cytotoxic/molecularly targeted agent or pharmacokinetic modulation provided disappointing results. Recently, the field of systemic therapy of advanced PDAC is finally moving forward. Polychemotherapy has shown promise over single-agent Gem: regimens like PEFG-PEXG-PDXG and GTX provide significant potential advantages in terms of survival and/or disease control, although sometimes at the cost of poor tolerability. The PRODIGE 4/ACCORD 11 was the first phase III trial to provide unequivocal benefit using the polychemotherapy regimen FOLFIRINOX; however the less favorable safety profile and the characteristics of the enrolled population, restrict the use of FOLFIRINOX to young and fit PDAC patients. The nanoparticle albumin-bound paclitaxel (nab-Paclitaxel) formulation was developed to overcome resistance due to the desmoplastic stroma surrounding pancreatic cancer cells. Regardless of whether or not this is its main mechanisms of action, the combination of nab-Paclitaxel plus Gem showed a statistically and clinically significant survival advantage over single agent Gem and significantly improved all the secondary endpoints. Furthermore, recent findings on maintenance therapy are opening up potential new avenues in the treatment of advanced PDAC, particularly in a new era in which highly effective first-line regimens allow patients to experience prolonged disease control. Here, we provide an overview of recent advances in the systemic treatment of advanced PDAC, mostly focusing on recent findings that have set new standards in metastatic disease. Potential avenues for further development in the metastatic setting and current efforts to integrate new effective chemotherapy regimens in earlier stages of disease (neoadjuvant, adjuvant, and multimodal approaches in both resectable and unresectable patients) are also briefly discussed.

First-line erlotinib and fixed dose-rate gemcitabine for advanced pancreatic cancer

AIM: To investigate activity, toxicity, and prognostic factors for survival of erlotinib and fixed dose-rate gemcitabine (FDR-Gem) in advanced pancreatic cancer.

METHODS: We designed a single-arm prospective, multicentre, open-label phase II study to evaluate the combination of erlotinib (100 mg/d, orally) and weekly FDR-Gem (1000 mg/m², infused at 10 mg/m² per minute) in a population of previously untreated patients with locally advanced, inoperable, or metastatic pancreatic cancer. Primary endpoint was the rate of progression-free survival at 6 mo (PFS-6); secondary endpoints were overall response rate (ORR), response duration, tolerability, overall survival (OS), and clinical benefit. Treatment was not considered to be of further interest if the PFS-6 was < 20% (p0 = 20%), while a PFS-6 > 40% would be of considerable interest (p1 = 40%); with a 5% rejection error (α = 5%) and a power of 80%, 35 fully evaluable patients with metastatic disease were required to be enrolled in order to complete the study. Analysis of prognostic factors for survival was also carried out.

RESULTS: From May 2007 to September 2009, 46 patients were enrolled (male/female: 25/21; median age: 64 years; median baseline carbohydrate antigen 19-9 (CA 19-9): 897 U/mL; locally advanced/metastatic disease: 5/41). PFS-6 and median PFS were 30.4% and 14 wk (95%CI: 10-19), respectively; 1-year and median OS were 20.2% and 26 wk (95%CI: 8-43). Five patients achieved an objective response (ORR: 10.9%, 95%CI: 1.9-19.9); disease control rate was 56.5% (95%CI: 42.2-70.8); clinical benefit rate was 43.5% (95%CI: 29.1-57.8). CA 19-9 serum levels were decreased by > 25% as compared to baseline in 14/23 evaluable patients (63.6%). Treatment was well-tolerated, with skin rash being the most powerful predictor of both longer PFS (P < 0.0001) and OS (P = 0.01) at multivariate analysis (median OS for patients with or without rash: 42 wk vs 15 wk, respectively, Log-rank P = 0.03). Additional predictors of better outcome were: CA 19-9 reduction, female sex (for PFS), and good performance status (for OS).

CONCLUSION: Primary study endpoint was not met. However, skin rash strongly predicted erlotinib efficacy, suggesting that a pharmacodynamic-based strategy for patient selection deserves further investigation.

Phase I dose-escalation study and population pharmacokinetic analysis of fixed dose rate gemcitabine plus carboplatin as second-line therapy in patients with ovarian cancer

OBJECTIVE

This phase I study of fixed dose rate (FDR) gemcitabine and carboplatin assessed the maximum tolerated dose (MTD), dose-limiting toxicities (DLTs), safety, pharmacokinetic (PK)/pharmacodynamic (PD) profile and preliminary anti-tumor activity in patients with recurrent ovarian cancer (OC).

METHODS

Patients with recurrent OC after first line treatment were treated with carboplatin and FDR gemcitabine (infusion speed 10mg/m(2)/min) on days 1, 8 and 15, every 28 days. Pharmacokinetics included measurement of platinum concentrations in plasma ultrafiltrate (pUF) and plasma concentrations of gemcitabine (dFdC) and metabolite dFdU. Intracellular levels of dFdC triphosphate (dFdC-TP), the most active metabolite of gemcitabine, were determined in peripheral blood mononuclear cells (PBMCs). Population pharmacokinetic modeling and simulation were performed to further investigate the optimal schedule.

RESULTS

Twenty three patients were enrolled. Initial dose escalation was performed using FDR gemcitabine 300 mg/m(2) (administered at infusion speed of 10 mg/m(2)/min) combined with carboplatin AUC 2.5 and 3. Excessive bone marrow toxicity led to a modified dose escalation schedule: carboplatin AUC 2 and dose escalation of FDR gemcitabine (300 mg/m(2), 450 mg/m(2), 600 mg/m(2) and 800 mg/m(2)). DLT criteria as defined per protocol prior to the study were not met with carboplatin AUC 2 in combination with FDR gemcitabine 300-800 mg/m(2) because of myelosuppressive dose-holds (especially thrombocytopenia and neutropenia).

CONCLUSIONS

FDR gemcitabine in combination with carboplatin administered in this 28 days schedule resulted in increased grade 3/4 toxicity compared to conventional 30-minute infused gemcitabine. A two weekly schedule (chemotherapy on days 1 and 8) would be more appropriate.

Biliary tract carcinomas: from chemotherapy to targeted therapy

Biliary tract carcinomas (BTC) are a group of tumours arising from the epithelial cells of intra- and extra-hepatic biliaryducts and the gallbladder, characterised by a poor prognosis. Surgery is the only curative procedure, but the risk of recurrence is high and furthermore, the majority of patients present with unresectable disease at the time of diagnosis. Systemic therapy is the mainstay of treatment for patients who present recurrent or metastatic disease. Progress has been made in the last decade to identify the most effective chemotherapy regimens, with the recent recommendation of the combination of gemcitabine-cisplatin as the standard schedule. Comprehension of the molecular basis of cholangiocarcinogenesis and tumour progression has recently led to the experimentation of targeted therapies in patients with BTC, demonstrating promising results. In this review we will discuss the clinical experience with systemic treatment for BTC, focusing on future directions with targeted therapies.

Developments in metastatic pancreatic cancer: is gemcitabine still the standard?

In the past 15 years, we have seen few therapeutic advances for patients with pancreatic cancer, which is the fourth leading cause of cancer-related death in the United States. Currently, only about 6% of patients with advanced disease respond to standard gemcitabine therapy, and median survival is only about 6 mo. Moreover, phase III trials have shown that adding various cytotoxic and targeted chemotherapeutic agents to gemcitabine has failed to improve overall survival, except in cases in which gemcitabine combined with erlotinib show minimal survival benefit. Several meta-analyses have shown that the combination of gemcitabine with either a platinum analog or capecitabine may lead to clinically relevant survival prolongation, especially for patients with good performance status. Meanwhile, many studies have focused on the pharmacokinetic modulation of gemcitabine by fixed-dose administration, and metabolic or transport enzymes related to the response and toxicity of gemcitabine. Strikingly, a phase III trial in 2010 showed that, in comparison to gemcitabine alone, the FOLFIRINOX regimen in patients with advanced disease and good performance status, produced better median overall survival, median progression-free survival, and objective response rates. This regimen also resulted in greater, albeit manageable toxicity.