Dose finding and early efficacy study of gemcitabine plus capecitabine in combination with bevacizumab plus erlotinib in advanced pancreatic cancer

Opportunities and challenges in targeted therapy and immunotherapy for pancreatic cancer

Pancreatic cancer is one of the most malignant tumours with a poor prognosis. In recent years, the incidence of pancreatic cancer is on the rise. Traditional chemotherapy and radiotherapy for pancreatic cancer have been improved, first-line and second-line palliative treatments have been developed, and adjuvant treatments have also been used in clinical. However, the 5-year survival rate is still less than 10% and new treatment methods such as targeted therapy and immunotherapy need to be investigated. In the past decades, many clinical trials of targeted therapies and immunotherapies for pancreatic cancer were launched and some of them showed an ideal prospect in a subgroup of pancreatic cancer patients. The experience of both success and failure of these clinical trials will be helpful to improve these therapies in the future. Therefore, the current research progress and challenges of selected targeted therapies and immunotherapies for pancreatic cancer are reviewed.

Therapeutic Application of Monoclonal Antibodies in Pancreatic Cancer: Advances, Challenges and Future Opportunities

Pancreatic cancer remains as one of the most aggressive cancer types. In the absence of reliable biomarkers for its early detection and more effective therapeutic interventions, pancreatic cancer is projected to become the second leading cause of cancer death in the Western world in the next decade. Therefore, it is essential to discover novel therapeutic targets and to develop more effective and pancreatic cancer-specific therapeutic agents. To date, 45 monoclonal antibodies (mAbs) have been approved for the treatment of patients with a wide range of cancers; however, none has yet been approved for pancreatic cancer. In this comprehensive review, we discuss the FDA approved anticancer mAb-based drugs, the results of preclinical studies and clinical trials with mAbs in pancreatic cancer and the factors contributing to the poor response to antibody therapy (e.g. tumour heterogeneity, desmoplastic stroma). MAb technology is an excellent tool for studying the complex biology of pancreatic cancer, to discover novel therapeutic targets and to develop various forms of antibody-based therapeutic agents and companion diagnostic tests for the selection of patients who are more likely to benefit from such therapy. These should result in the approval and routine use of antibody-based agents for the treatment of pancreatic cancer patients in the future.

Clinical Trials Targeting the Stroma in Pancreatic Cancer: A Systematic Review and Meta-Analysis

The tumor microenvironment plays an important role in the initiation and progression of pancreatic adenocarcinoma (PDAC). In this systematic review, we provide an overview of clinical trials with stroma-targeting agents. We systematically searched MEDLINE/PubMed and the EMBASE database, using the PRISMA guidelines, for eligible clinical trials. In total, 2330 records were screened, from which we have included 106 articles. A meta-analysis could be performed on 51 articles which describe the targeting of the vascular endothelial growth factor (VEGF) pathway, and three articles which describe the targeting of hyaluronic acid. Anti-VEGF therapies did not show an increase in median overall survival (OS) with combined hazard ratios (HRs) of 1.01 (95% confidence interval (CI) 0.90-1.13). Treatment with hyaluronidase PEGPH20 showed promising results, but, thus far, only in combination with gemcitabine and nab-paclitaxel in selected patients with hyaluronic acid (HA)high tumors: An increase in median progression free survival (PFS) of 2.9 months, as well as a HR of 0.51 (95% CI 0.26-1.00). In conclusion, we found that anti-angiogenic therapies did not show an increased benefit in median OS or PFS in contrast to promising results with anti-hyaluronic acid treatment in combination with gemcitabine and nab-paclitaxel. The PEGPH20 clinical trials used patient selection to determine eligibility based on tumor biology, which underlines the importance to personalize treatment for pancreatic cancer patients.

Low-Dose Continuous 5-Fluorouracil Combined with Leucovorin, nab-Paclitaxel, Oxaliplatin, and Bevacizumab for Patients with Advanced Pancreatic Cancer: A Retrospective Analysis

BACKGROUND

Continuous-infusion 5-fluorouracil (5FU) and calcium leucovorin plus nab-paclitaxel and oxaliplatin have been shown to be active in patients with pancreatic cancer. As a protracted low-dose infusion, 5FU is antiangiogenic, and has synergy with bevacizumab. As shown in the treatment of breast cancer, bevacizumab and nab-paclitaxel are also synergetic.

OBJECTIVE

In this paper we retrospectively analyze the survival of 65 patients with advanced pancreatic cancer who were treated with low-dose continuous (metronomic) chemotherapy given in conjunction with conventional anti-VEGF therapy.

PATIENTS AND METHODS

Since July of 2008, we have treated 65 patients with 5FU (180 mg/m2/day × 14 days) via an ambulatory pump. Calcium leucovorin (20 mg/m2 IV), nab-paclitaxel (60 mg/m2) IV as a 30-min infusion, and oxaliplatin (50 mg/m2) IV as a 60-min infusion were given on days 1, 8, and 15. Bevacizumab (5 mg/kg) IV over 30 min was administered on days 1 and 15. Cycles were repeated every 28-35 days. There were 42 women and 23 men, and the median age was 59 years. Forty-six patients had stage IV disease.

RESULTS

The median survival was 19 months, with 82% of patients surviving 12 months or longer. The overall response rate was 49%. There were 28 patients who had received prior treatment, 15 of whom responded to therapy. Fifty-two patients had elevated CA 19-9 prior to treatment. Of these, 21 patients had 90% or greater reduction in CA 19-9 levels. This cohort had an objective response rate of 71% and a median survival of 27 months. Thirty patients stopped treatment due to disease progression, and an additional 22 stopped because of toxicity. One patient died while on therapy.

CONCLUSIONS

This non-gemcitabine-based regimen resulted in higher response rates and better survival than what is commonly observed with therapy given at conventional dosing schedules. Low-dose continuous (metronomic therapy) cytotoxic chemotherapy combined with antiangiogenic therapy is safe and effective.

Phase Ib trial combining capecitabine, erlotinib and bevacizumab in pancreatic adenocarcinoma - REBECA trial

Background Purpose of this phase Ib trial was to establish the maximum tolerable dose (MTD) of capecitabine and to escalate the dosages of erlotinib and bevacizumab to determine the recommended phase II dose (RP2D) in patients with advanced/metastatic pancreatic adenocarcinoma not pretreated for metastatic disease. Methods Starting doses were capecitabine 500 mg/m² bid orally continuously, erlotinib 100 mg orally daily, and bevacizumab 5 mg/kg intravenously q 2 weeks. Dose escalation was performed according to a 3 + 3 design for capecitabine until MTD, for erlotinib and bevacizumab until the maximum doses registered by applying a substance-related, toxicity-based scheme accompanied by pharmacokinetic analysis. Circulating tumor cells (CTCs) were determined pretherapeutically by immunohistochemical identification after enrichment with immunomagnetic separation. Results Thirty patients were evaluable at six dose levels. 900 mg/m² bid were determined as MTD for capecitabine based on dose-limiting toxicities: cutaneous in two patients and vascular in another. The most severe (Grade (G)3/4) drug-related treatment-emergent adverse events (toxicities) belonged to the categories gastrointestinal, vascular, cutaneous, cardiovascular, metabolic/nutritional or hematological. G3 toxicities occurred in 14 (47%), G3 + G4 in a single (3%) patient. 2 out of 28 patients (7%) exerted partial response, 17 (61%) stable disease. Pharmacokinetic evaluation revealed lack of drug-drug interaction between capecitabine and erlotinib and their metabolites. Presence of CTCs was associated with shorter progression-free survival (p = 0.009). Conclusions The study met the primary objective. RP2D was capecitabine 800 mg/m² bid continuously, erlotinib 150 mg daily, and bevacizumab 10 mg/kg q 2 weeks. The regimen could be applied safely, but demonstrated limited efficacy.

Management of metastatic pancreatic cancer: Current treatment options and potential new therapeutic targets

Pancreatic ductal adenocarcinoma is a malignancy with a poor prognosis, with the majority of patients diagnosed with advanced disease on presentation. Treatment options remain limited with little progress over the last 40 years. This review will focus on the current management of metastatic pancreatic ductal adenocarcinoma, with a discussion of new and future treatment strategies based on an improved understanding of tumour biology and mechanisms of pathogenesis.

Advanced pancreatic cancer: flourishing novel approaches in the era of biological therapy

The progress in the development of systemic treatment for advanced pancreatic cancer (APC) has been slow. The mainstream treatment remains using chemotherapy including gemcitabine, FOLFIRINOX, and nab-paclitaxel. Erlotinib is the only approved biological therapy with marginal benefit. Studies of agents targeting epidermal growth factor receptor, angiogenesis, and RAS signaling have not been satisfying, and the usefulness of targeted therapy in APC is uncertain. Understanding in molecular processes and tumor biology has opened the door for new treatment strategies such as targeting insulin-like growth factor 1 receptor, transforming growth factor β, phosphoinositide 3-kinase/AKT/mammalian target of rapamycin pathway, and Notch pathway. New directions also include the upcoming immunotherapy and many novel agents that act on the microenvironment. The practice of personalized medicine using predictive biomarkers and pharmacogenomics signatures may also enhance the effectiveness of existing treatment. Future treatment approaches may involve comprehensive genomic assessment of tumor and integrated combinations of multiple agents to overcome treatment resistance.

The combination of a chemotherapy doublet (gemcitabine and capecitabine) with a biological doublet (bevacizumab and erlotinib) in patients with advanced pancreatic adenocarcinoma. The results of a phase I/II study

BACKGROUND

Preclinical data support the combined inhibition of vascular endothelial growth factor (VEGF) and epidermal growth factor receptor (EGFR) pathways in the treatment of pancreatic cancer. Following a dose finding phase I study the efficacy and toxicity of a four-drug regimen utilising the cytotoxic doublet of gemcitabine and capecitabine (GemCap), with the biological doublet of erlotinib and bevacizumab were further assessed in patients with advanced pancreatic cancer.

PATIENTS AND METHODS

In a phase II expansion cohort, patients with chemonaive locally advanced or metastatic pancreatic cancer received gemcitabine (1000mg/m(2) D1, 8, 15), capecitabine (1400mg/m(2) D1-21), erlotinib (100mg daily) and bevacizumab (5mg/kg D1, 15) every 28days. The primary endpoint was radiological response rate by response evaluation criteria in solid tumours (RECIST). Computed tomography (CT) assessment was performed every 8weeks. Consolidation radiotherapy was considered in locally advanced patients following six cycles of treatment.

RESULTS

In total 44 patients (phases I & II) were recruited. The median cycles delivered were 6 (range 1-16). Confirmed radiological responses were seen in 23% (95% confidence interval (CI): 11-38%) of patients. The median progression-free and overall survival for the entire cohort was 8.4 and 12.6months, respectively. In patients with metastatic disease the median overall survival was 10.1months. Common grade 3/4 toxicities were; neutropenia 52%, lethargy 32%, diarrhoea 18% and hand-foot syndrome 18%.

CONCLUSION

The combination of gemcitabine, capecitabine, erlotinib and bevacizumab was feasible with a manageable toxicity profile and demonstrated encouraging efficacy data in a good performance status population.

Role of bevacizumab in colorectal cancer growth and its adverse effects: A review

Angiogenesis affects both wound healing and malignant cell growth through nutrients and oxygen. Vascular endothelial growth factor (VEGF) is the most important element involved in this complex process. Inhibition of VEGF influences angiogenesis and may restrict tumor growth and metastatic ability. Modern anti-angiogenic therapy is based on this theory. Bevacizumab is a recombinant humanized monoclonal antibody (immunoglobulin G1) which binds with VEGF-A forming a large molecule. It can not be bound with VEGF tyrosine kinase receptors preventing VEGF-A incorporation; thus its activity is inhibited inducing blockage of VEGF-mediated angiogenesis. Bevacizumab, in combination with chemotherapy or other novel targeted therapeutic agents, is currently used more frequently in clinical practice, mainly for managing advanced colorectal cancer. It is also used for managing other malignancies, such as breast cancer, pancreatic cancer, prostate cancer, non small-cell lung cancer, metastatic renal carcinoma and ovarian tumors. Although it is generally considered a safe treatment, there are reports of some rare side effects which should be taken into account. Recent experiments in rats and mice show promising results with a wider therapeutic range.

Molecularly targeted therapies in metastatic pancreatic cancer: a systematic review

Pancreatic cancer is the fourth leading cause of cancer-related death. Most patients present with an advanced stage of disease that has a dismal outcome, with a median survival of approximately 6 months. Evidently, there is a clear need for the development of new agents with novel mechanisms of action in this disease. A number of biological agents modulating different signal transduction pathways are currently in clinical development, inhibiting angiogenesis and targeting epidermal growth factor receptor, cell cycle, matrix metalloproteinases, cyclooxygenase-2, mammalian target of rapamycin, or proteasome. This is the first systematic review of the literature to synthesize all available data coming from trials and evaluate the efficacy and safety of molecular targeted drugs in unresectable and metastatic pancreatic cancer. However, it should be stressed that although multiple agents have been tested, only 9 phase 3 trials have been conducted and one agent (erlotinib) has been approved by the Food and Drug Administration for use in clinical practice. As knowledge accumulates on the molecular mechanisms underlying carcinogenesis in the pancreas, the anticipated development and assessment of molecularly targeted agents may offer a promising perspective for a disease which, to date, remains incurable.

CHC promotes tumor growth and angiogenesis through regulation of HIF-1α and VEGF signaling

Pancreatic adenocarcinoma is an aggressive disease with a high mortality rate. In this study, we have newly generated a monoclonal antibody (mAb), Pa65-2, which specifically binds to pancreatic cancer cells and tumor blood vessels. The target protein of Pa65-2 is identified as human clathrin heavy chain (CHC). In vitro and In vivo study showed that suppression of CHC either by shRNA or by Pa65-2 inhibited tumor growth and angiogenesis. One of the key functions of CHC was to bind with the hypoxia-inducing factor (HIF)-1α protein, increasing the stability of this protein and facilitating its nuclear translocation, thereby regulating the expression of VEGF. Taken together, our findings indicate that CHC plays a role in the processes of tumorigenesis and angiogenesis. Pa65-2 antibody or CHC shRNA can potentially be used for pancreatic cancer therapy.

Correlation between radiographic classification and pathological grade of portal vein wall invasion in pancreatic head cancer

OBJECTIVES

A retrospective study was performed to clarify the correlation between radiographic type of portal vein (PV) invasion and pathological grade of PV wall invasion, and their correlation with postoperative prognosis.

BACKGROUND

In many patients with pancreatic cancer, PV resection is necessary to increase resectability and obtain cancer-free margins.

METHODS

We analyzed 671 patients who had undergone surgery for invasive adenocarcinoma of the pancreas between July 1981 and June 2010. Radiographic types of PV invasion of pancreatic head cancer were classified into A (normal), B (unilateral narrowing), C (bilateral narrowing), or D (complete obstruction with collateral veins), by portography or computed tomography. Pathological grades of PV wall invasion were classified as 0 (no invasion), 1 (tunica adventitia), 2 (tunica media), or 3 (tunica intima).

RESULTS

Four hundred and sixty-three patients underwent resection, and PV resection was performed in 297. Combined arterial vessel resection was performed in 16 cases. No significant difference in operative mortality was observed between PV preservation (0.6%) and PV-only resection (2.1%), and no operative deaths occurred after 1999. Radiographic classification of PV invasion correlated with incidence of pathological PV wall invasion. In pancreatic head carcinoma, no pathological PV wall invasion was observed in type A (n = 111). Pathological PV invasion was observed in 51% of type B (42/82), 74% of type C (72/97), and 93% of type D (63/68). Long-term survival (>5 years) was observed in types A and B, and grades 0 and 1 subgroups.

CONCLUSIONS

Pancreatectomy with PV resection can be performed safely. Even in radiographic classification type B, pathological PV wall invasion was observed in 51% of patients. Long-term survival was observed in types A and B, and grades 0 and 1.

Intraperitoneal administration of bevacizumab intraoperatively does not affect abdominal wound healing in rats

BACKGROUND

Bevacizumab is a monoclonal antibody targeted at vascular endothelial growth factor (VEGF) to treat advanced colorectal cancer as well as other malignancies, but the ideal time point for its administration in patients scheduled for surgery is not well defined due to serious concerns regarding possible side effects on wound healing. Therefore, we conducted an experimental study in rats to clarify this issue.

METHODS

Four groups of 10 Wistar rats each underwent a 4-cm midline laparotomy and closure of the wound in 2 layers. In the treatment groups (A and B), bevacizumab (Avastin(®)) received a single dose of 5 mg/kg i.p., and an equal amount of saline was given to the control groups (C and D). Groups A and C were sacrificed on the 7th postoperative day, and groups B and D on the 14th postoperative day. Wounds were inspected by two independent observers upon sacrifice and results were recorded; wound tissues were sent for histology to assess the degree of fibrosis and measurement of tissue hydroxyproline levels. Serum levels of endothelin-1, C-reactive protein, pro-oxidant/antioxidant balance and carbonylated proteins were also determined. For statistical analysis, the Mann-Whitney U test was used.

RESULTS

Wound healing did not differ among groups both on the 7th and the 14th postoperative days, and there was also no significant difference regarding the degree of inflammation, fibroblast proliferation and collagen synthesis, as well as hydroxyproline and biochemical marker levels among the groups.

CONCLUSIONS

Intraperitoneal bevacizumab administered intraoperatively does not significantly affect abdominal wound healing in rats.

The molecular targets for the diagnosis and treatment of pancreatic cancer

Pancreatic cancer is considered an aggressive malignancy that responds poorly to current treatments and therefore has a dismal survival rate. This disease is usually not diagnosed until a late stage, at which point palliative chemotherapy with the purine analogue gemcitabine and/or a fluoropyrimidine or a platinum agent is the standard approach. There are some new data on the molecular and genetic changes that take place in pancreatic cancer, which may facilitate the accuracy of diagnosis and efficacy of treatments. However, translational efforts in clinical practice have increased clinicians' options with a targeted agent, erlotinib, in combination with the standard gemcitabine chemotherapy. Many other novel drugs currently being tested in the field of pharmaco-oncology target various altered biological pathways and molecules. Nevertheless, the lack of clinically significant improvements in treatments is rendering efforts to develop methods of early diagnosis both more urgent and promising. The aim of this review was to summarize the molecular basis of pancreatic carcinogenesis and the latest developments in diagnosis by molecular means, focusing on the results of clinical research into targeted and personalized treatments.