Sorafenib does not improve efficacy of chemotherapy in advanced pancreatic cancer: A GISCAD randomized phase II study

Targeting KRAS for the potential treatment of pancreatic ductal adenocarcinoma: Recent advancements provide hope (Review)

Kirsten rat sarcoma viral oncogene homolog (KRAS) is one of the most frequently mutated oncogenes in solid tumors. More than 90% of pancreatic ductal adenocarcinoma (PDAC) are driven by mutations in the KRAS gene, suggesting the importance of targeting this oncogene in PDAC. Initial efforts to target KRAS have been unsuccessful due to its small size, high affinity for guanosine triphosphate/guanosine diphosphate, and lack of distinct drug‑binding pockets. Therefore, much of the focus has been directed at inhibiting the activation of major signaling pathways downstream of KRAS, most notably the PI3K/AKT and RAF/MAPK pathways, using tyrosine kinase inhibitors and monoclonal antibodies. While preclinical studies showed promising results, clinical data using the inhibitors alone and in combination with other standard therapies have shown limited practicality, largely due to the lack of efficacy and dose‑limiting toxicities. Recent therapeutic approaches for KRAS‑driven tumors focus on mutation‑specific drugs such as selective KRASG12C inhibitors and son of sevenless 1 pan‑KRAS inhibitors. While KRASG12C inhibitors showed great promise against patients with non‑small cell lung cancer (NSCLC) harboring KRASG12C mutations, they were not efficacious in PDAC largely because the major KRAS mutant isoforms in PDAC are G12D, G12V, and G12R. As a result, KRASG12D and pan‑KRAS inhibitors are currently under investigation as potential therapeutic options for PDAC. The present review summarized the importance of KRAS oncogenic signaling, challenges in its targeting, and preclinical and clinical targeted agents including recent direct KRAS inhibitors for blocking KRAS signaling in PDAC.

Phase Ib Study of Ulixertinib Plus Gemcitabine and Nab-Paclitaxel in Patients with Metastatic Pancreatic Adenocarcinoma

BACKGROUND

Ulixertinib is a novel oral ERK inhibitor that has shown promising single-agent activity in a phase I clinical trial that included patients with RAS-mutant cancers.

METHODS

We conducted a phase Ib trial combining ulixertinib with gemcitabine and nab-paclitaxel (GnP) for untreated metastatic pancreatic adenocarcinoma. The trial comprised a dose de-escalation part and a cohort expansion part at the recommended phase II dose (RP2D). Primary endpoint was to determine the RP2D of ulixertinib plus GnP and secondary endpoints were to assess toxicity and safety profile, biochemical and radiographic response, progression-free survival (PFS) and overall survival (OS).

RESULTS

Eighteen patients were enrolled. Ulixertinib 600 mg PO twice daily (BID) with GnP was initially administered but was de-escalated to 450 mg BID as RP2D early during dose expansion due to poor tolerability, which ultimately led to premature termination of the study. Common treatment-related adverse events (TRAEs) were anemia, thrombocytopenia, rash and diarrhea. For 5 response evaluable patients, one patient achieved a partial response and 2 patients achieved stable disease. For 15 patients who received the triplet, median PFS and OS were 5.46 and 12.23 months, respectively.

CONCLUSION

Ulixertinib plus GnP had similar frequency of grade ≥3 TRAEs and potentially efficacy as GnP, however was complicated by a high rate of all-grade TRAEs (ClinicalTrials.gov Identifier: NCT02608229).

Targeting RAS–RAF–MEK–ERK signaling pathway in human cancer: Current status in clinical trials

Molecular target inhibitors have been regularly approved by Food and Drug Administration (FDA) for tumor treatment, and most of them intervene in tumor cell proliferation and metabolism. The RAS-RAF-MEK-ERK pathway is a conserved signaling pathway that plays vital roles in cell proliferation, survival, and differentiation. The aberrant activation of the RAS-RAF-MEK-ERK signaling pathway induces tumors. About 33% of tumors harbor RAS mutations, while 8% of tumors are driven by RAF mutations. Great efforts have been dedicated to targeting the signaling pathway for cancer treatment in the past decades. In this review, we summarized the development of inhibitors targeting the RAS-RAF-MEK-ERK pathway with an emphasis on those used in clinical treatment. Moreover, we discussed the potential combinations of inhibitors that target the RAS-RAF-MEK-ERK signaling pathway and other signaling pathways. The inhibitors targeting the RAS-RAF-MEK-ERK pathway have essentially modified the therapeutic strategy against various cancers and deserve more attention in the current cancer research and treatment.

Moving Towards Dawn: KRas Signaling and Treatment in Pancreatic Ductal Adenocarcinoma

"Pancreatic ductal adenocarcinoma (PDAC)" is robust, nearly clueless, and all-around deadly among all tumors. Below 10 %, the general 5-year endurance period has remained adamantly unaltered in the last 30 years, regardless of enormous clinical and therapeutic endeavors. The yearly number of deaths is more than the number of recently analyzed cases. Not a classic one, but "Carbohydrate Antigen CA19- 9" remains the prevailing tool for diagnosis. MicroRNAs and non-invasive techniques are now incorporated for the effective prognosis of PDAC than just CA19-9. Mutated "Rat sarcoma virus Ras" conformation "V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog KRas" is 95 % accountable for PDAC, and its active (GTP-bound) formation activates signaling cascade comprising "Rapidly accelerated fibrosarcoma Raf"/"Mitogen-activated protein kinase MEK"/ "Extracellular signal-regulated kinase ERK" with "Phosphoinositide 3-kinase PI3K"/ "protein kinase B Akt"/ "mammalian target of rapamycin mTOR" pathways. KRas has acquired the label of 'undruggable' since the crosstalk in the nexus of pathways compensates for Raf and PI3K signaling cascade blocking. It is arduous to totally regulate KRascoordinated PDAC with traditional medicaments like "gemcitabine GEM" plus nabpaclitaxel/ FOLFIRINOX. For long-haul accomplishments aiming at KRas, future endeavors should be directed to combinatorial methodologies to adequately block KRas pathways at different standpoints. Currently they are contributing to healing PDAC. In this review article, we outline the function of KRas in carcinogenesis in PDAC, its signaling cascade, former techniques utilized in hindering Kras, current and future possibilities for targeting Kras.

Oncogenic KRAS-Induced Feedback Inflammatory Signaling in Pancreatic Cancer: An Overview and New Therapeutic Opportunities

Pancreatic ductal adenocarcinoma (PDAC) remains highly refractory to treatment. While the KRAS oncogene is present in almost all PDAC cases and accounts for many of the malignant feats of PDAC, targeting KRAS or its canonical, direct effector cascades remains unsuccessful in patients. The recalcitrant nature of PDAC is also heavily influenced by its highly fibro-inflammatory tumor microenvironment (TME), which comprises an acellular extracellular matrix and various types of non-neoplastic cells including fibroblasts, immune cells, and adipocytes, underscoring the critical need to delineate the bidirectional signaling interplay between PDAC cells and the TME in order to develop novel therapeutic strategies. The impact of tumor-cell KRAS signaling on various cell types in the TME has been well covered by several reviews. In this article, we critically reviewed evidence, including work from our group, on how the feedback inflammatory signals from the TME impact and synergize with oncogenic KRAS signaling in PDAC cells, ultimately augmenting their malignant behavior. We discussed past and ongoing clinical trials that target key inflammatory pathways in PDAC and highlight lessons to be learned from outcomes. Lastly, we provided our perspective on the future of developing therapeutic strategies for PDAC through understanding the breadth and complexity of KRAS and the inflammatory signaling network.

A Clinically Applicable 24-Protein Model for Classifying Risk Subgroups in Pancreatic Ductal Adenocarcinomas using Multiple Reaction Monitoring-Mass Spectrometry

PURPOSE

Pancreatic ductal adenocarcinoma (PDAC) subtypes have been identified using various methodologies. However, it is a challenge to develop classification system applicable to routine clinical evaluation. We aimed to identify risk subgroups based on molecular features and develop a classification model that was more suited for clinical applications.

EXPERIMENTAL DESIGN

We collected whole dissected specimens from 225 patients who underwent surgery at Seoul National University Hospital [Seoul, Republic of Korea (South)], between October 2009 and February 2018. Target proteins with potential relevance to tumor progression or prognosis were quantified with robust quality controls. We used hierarchical clustering analysis to identify risk subgroups. A random forest classification model was developed to predict the identified risk subgroups, and the model was validated using transcriptomic datasets from external cohorts (N = 700), with survival analysis.

RESULTS

We identified 24 protein features that could classify the four risk subgroups associated with patient outcomes: stable, exocrine-like; activated, and extracellular matrix (ECM) remodeling. The "stable" risk subgroup was characterized by proteins that were associated with differentiation and tumor suppressors. "Exocrine-like" tumors highly expressed pancreatic enzymes. Two high-risk subgroups, "activated" and "ECM remodeling," were enriched in terms such as cell cycle, angiogenesis, immunocompetence, tumor invasion metastasis, and metabolic reprogramming. The classification model that included these features made prognoses with relative accuracy and precision in multiple cohorts.

CONCLUSIONS

We proposed PDAC risk subgroups and developed a classification model that may potentially be useful for routine clinical implementations, at the individual level. This clinical system may improve the accuracy of risk prediction and treatment guidelines.See related commentary by Thakur and Singh, p. 3272.

CONKO-006: A randomised double-blinded phase IIb-study of additive therapy with gemcitabine + sorafenib/placebo in patients with R1 resection of pancreatic cancer - Final results

BACKGROUND

CONKO-006 was designed for patients with pancreatic adenocarcinoma with postsurgical R1 residual status to evaluate the efficacy and safety of the combination of gemcitabine and sorafenib (GemSorafenib) compared with those of gemcitabine + placebo (GemP) for 12 cycles.

PATIENTS AND METHODS

This randomised, double-blind, placebo-controlled, multicenter study was planned to detect an improvement in recurrence-free survival (RFS) from 42% to 60% after 18 months. Secondary objectives were overall survival (OS), safety and duration of treatment.

RESULTS

122 patients were included between 02/2008 and 09/2013; 57 were randomised to GemSorafenib and 65 to GemP. Patient characteristics were wellbalanced (GemSorafenib/GemP) in terms of median age (63/63 years), tumour size (T3/T4: 97/97%), and nodal positivity (86/85%). Grade 3/4 toxicities comprised diarrhoea (GemSorafenib: 12%; GemP: 2%), elevated gamma-glutamyl transferase (GGT) (19%; 9%), fatigue (5%; 2%) and hypertension (5%; 2%), as well as neutropenia (18%; 25%) and thrombocytopenia (9%; 2%). By August 2017, 118 (97%) RFS event had occurred. There were no difference in RFS (median GemSorafenib: 8.5 versus GemP: 9.4 months; p = 0.730) nor OS (median GemSorafenib: 17.6 versus GemP: 17.5 months; p = 0.481). Landmark analyses suggest that patients who received more than six cycles of postoperative chemotherapy had significantly longer OS (p = 0.021).

CONCLUSION

CONKO-006 is the first randomised clinical trial to include exclusively patients with PDAC with postsurgical R1 status thus far. Sorafenib added to gemcitabine did neither improve RFS nor OS. However, postoperative treatment exceeding six months seemed to prolong survival and should be further investigated in these high-risk patients.

CLINICAL TRIAL INFORMATION

German Tumor Study Registry (Deutsches Krebsstudienregister), DRKS00000242.

Regorafenib in patients with refractory metastatic pancreatic cancer: a Phase II study (RESOUND)

Aim: Regorafenib may be active in different cancer types. This Phase II trial included patients with various refractory cancer types treated with regorafenib. Here, we report the results of the pancreatic adenocarcinoma cohort. Methods: The primary end point was progression-free survival (PFS) rate at 8 weeks; further investigation of regorafenib would be warranted with a PFS rate ≥50%. Results: A total of 20 patients were enrolled. The best response was stable disease in four patients (20%). The 8-week PFS rate was 25% with a median PFS of 1.7 months (95% CI: 1.5–2.0). A total of 13 patients (65%) experienced grade 3–4 treatment-related adverse events. Conclusion: The study did not meet its primary end point. Further investigation of regorafenib monotherapy in this setting is not recommended.

Clinical Trial Registration: NCT02307500

Combination Therapies and Drug Delivery Platforms in Combating Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC), the fourth leading cause of cancer-related death in the United States, is highly aggressive and resistant to both chemo- and radiotherapy. It remains one of the most difficult-to-treat cancers, not only due to its unique pathobiological features such as stroma-rich desmoplastic tumors surrounded by hypovascular and hypoperfused vessels limiting the transport of therapeutic agents, but also due to problematic early detection, which renders most treatment options largely ineffective, resulting in extensive metastasis. To elevate therapeutic effectiveness of treatments and overt their toxicity, significant enthusiasm was generated to exploit new strategies for combating PDAC. Combination therapy targeting different barriers to mitigate delivery issues and reduce tumor recurrence and metastasis has demonstrated optimal outcomes in patients' survival and quality of life, providing possible approaches to overcome therapeutic challenges. This paper aims to provide an overview of currently explored multimodal therapies using either conventional therapy or nanomedicines along with rationale, up-to-date progress, as well as the key challenges that must be overcome. Understanding the future directions of the field may assist in the successful development of novel treatment strategies for enhancing therapeutic efficacy in PDAC.

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.

Risk of hand-foot skin reaction associated with vascular endothelial growth factor-tyrosine kinase inhibitors: A meta-analysis of 57 randomized controlled trials involving 24,956 patients

BACKGROUND

Multiple randomized controlled trials have assessed hand-foot skin reaction (HFSR) caused by vascular endothelial growth factor receptor-tyrosine kinase inhibitors (VEGFR-TKIs).

OBJECTIVE

We performed a meta-analysis to determine the incidence and the relative risk (RR) of HFSR associated with these agents.

METHODS

Databases were searched for relevant studies. Statistical analyses were conducted to calculate the summary incidences, RR, and 95% confidence intervals (CIs) by using random-effects or fixed-effects models according to the heterogeneity of the included studies.

RESULTS

A total of 24,956 patients from 57 studies were included. The overall incidence of all-grade and high-grade HFSR associated with VEGFR-TKIs was 35.0% (95% CI, 28.6%-41.6%) and 9.7% (95% CI, 7.3%-12.3%), respectively. The use of VEGFR-TKIs significantly increased the risk of developing all-grade (RR, 5.09; 95% CI, 3.52-7.35; P < .001) and high-grade (RR, 9.42; 95% CI, 5.59-15.90; P < .001) HFSR. Subgroup analyses revealed that the risk of HFSR was significantly increased according to tumor type, VEGFR-TKI, trial phase, treatment regimen, and control therapy. No evidence of publication bias was observed.

LIMITATION

High heterogeneity in most studies.

CONCLUSION

High risk of HFSR is prone to develop in cancer patients receiving VEGFR-TKIs.

Efficacy and safety of gemcitabine plus anti-angiogenesis therapy for advanced pancreatic cancer: a systematic review and meta-analysis of clinical randomized phase III trials

Purpose: Pancreatic cancer is a common digestive neoplasm with a high fatality rate. We performed this systematic review and meta-analysis of clinical randomized phase III trials to explore the efficacy and safety of gemcitabine plus anti-angiogenesis therapy versus gemcitabine monotherapy for locally advanced or metastatic pancreatic cancer. Methods: We searched PubMed, Embase and the Cochrane Library to identify eligible studies. Data were collected for the period from January 1, 2000 to August 20, 2018. Hazard ratios (HRs) and odds ratios (ORs) were used as main evaluation parameters. Results: A total of eight eligible studies with 3,586 individuals were included in the present meta-analysis. The results showed that the combination of gemcitabine plus anti-angiogenesis therapy had a significant effect on progression-free survival (HR = 0.92, 95% CI: 0.86 - 1.00, P = 0.04), but led to no significant difference in the overall survival (HR = 0.96, 95% CI: 0.88 - 1.05, P = 0.38). In terms of safety, gemcitabine plus anti-angiogenesis therapy did not increase the rate of grade 3-4 common adverse effects except for hypertension. Conclusions: Although gemcitabine plus anti-angiogenesis therapy might prolong the progression-free survival in locally advanced or metastatic pancreatic cancer, these successful results did not translate into a significant improvement in the overall survival or change in the clinical guidelines.

First-line chemotherapy regimens for locally advanced and metastatic pancreatic adenocarcinoma: a Bayesian analysis

Background

Systemic chemotherapy is the standard treatment for locally advanced and metastatic pancreatic cancer, but there is no consensus on the optimum regimen. We aimed to compare and rank the locally advanced and metastatic pancreatic adenocarcinoma chemotherapy regimens evaluated in randomized controlled trials (RCTs) in the past 15 years.

Materials and methods

PubMed, Embase, Cochrane Collaboration database, and ClinicalTrials.gov were searched for RCTs comparing chemotherapy regimens as first-line treatment for locally advanced and metastatic pancreatic adenocarcinomas. By using Bayesian network meta-analysis, we compared and ranked all included chemotherapy regimens in terms of overall survival, progression-free survival, response rate, and hematological toxicity.

Results

The analysis included 68 RCTs, with 14,908 patients and 63 treatment strategies. For overall survival, NSC-631570 (hazard ratio [HR] vs gemcitabine monotherapy 0.44, 95% credible interval: 0.24–0.76) and gemcitabine+NSC-631570 (HR 0.45, 0.24–0.86) were the two top-ranked chemotherapy regimens. For progression-free survival, PEFG (cisplatin + epirubicin + fluorouracil + gemcitabine) ranked first (HR 0.51, 0.34–0.77). PG (gemcitabine + pemetrexed) (odds ratio [OR] 4.68, 2.24–9.64) and FLEC (fluorouracil + leucovorin + epirubicin + carboplatin) (OR 4.52, 1.14–24.00) were ranked the most hematologically toxic, with gastrazole having the least toxicity (OR 0.03, 0.00–0.46).

Conclusion

The chemotherapy regimens NSC-631570 and gemcitabine+NSC-631570 were ranked the most efficacious for locally advanced and metastatic pancreatic adenocarcinomas in terms of overall survival, which warrants further confirmation in large-scale RCTs.

Characterization of zolbetuximab in pancreatic cancer models

In healthy tissue, the tight junction protein Claudin 18.2 (CLDN18.2) is present only in the gastric mucosa. Upon malignant transformation of gastric epithelial tissue, perturbations in cell polarity lead to cell surface exposure of CLDN18.2 epitopes. Moreover, CLDN18.2 is aberrantly expressed in malignancies of several other organs, such as pancreatic cancer (PC). A monoclonal antibody, zolbetuximab (formerly known as IMAB362), has been generated against CLDN18.2. In a phase 2 clinical trial (FAST: NCT01630083), zolbetuximab in conjunction with chemotherapy prolonged overall and progression-free survival over chemotherapy alone and improved quality of life. In this study, the mechanism of action and antitumor activity of zolbetuximab were investigated using nonclinical PC models. Zolbetuximab bound specifically and with strong affinity to human PC cells that expressed CLDN18.2 on the cell surface. In ex vivo systems using immune effector cells and serum from healthy donors, zolbetuximab induced antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC), resulting in the lysis of cultured human PC cells. The amplitude of ADCC and CDC directly correlated with cell surface CLDN18.2 levels. The chemotherapeutic agent gemcitabine upregulated CLDN18.2 expression in cultured human PC cells and enhanced zolbetuximab-induced ADCC. In mouse xenograft tumors derived from human PC cell lines, including gemcitabine-refractory ones, zolbetuximab slowed tumor growth, benefited survival, and attenuated metastases development. The results presented here validate CLDN18.2 as a targetable biomarker in PC and support extension of the clinical development of zolbetuximab to patients with CLDN18.2-expressing PC.

Concurrent HER or PI3K Inhibition Potentiates the Antitumor Effect of the ERK Inhibitor Ulixertinib in Preclinical Pancreatic Cancer Models

Effective treatment for pancreatic ductal adenocarcinoma (PDAC) is an urgent, unmet medical need. Targeting KRAS, the oncogene that is present in >95% of PDAC, is a heavily pursued strategy, but remains unsuccessful in the clinic. Therefore, targeting key effector cascades of KRAS oncoprotein, particularly the mitogenic RAF-MEK-ERK pathway, represents the next best strategy. However, RAF or MEK inhibitors have failed to show clinical efficacy in PDAC. Several studies have shown that cancer cells treated with RAF or MEK inhibitors adopt multiple mechanisms to reactivate ERK signaling. Therefore, development of ERK-specific inhibitors carries the promise to effectively abrogate this pathway. Ulixertinib (or BVD-523) is a first-in-class ERK-specific inhibitor that has demonstrated promising antitumor activity in a phase I clinical trial for advanced solid tumors with NRAS and BRAF mutations, providing a strong rationale to test this inhibitor in PDAC. In this study, we show that ulixertinib effectively inhibits in vitro growth of multiple PDAC lines and potentiates the cytotoxic effect of gemcitabine. Moreover, we found that PDAC cells treated with ulixertinib upregulates the parallel PI3K-AKT pathway through activating the HER/ErbB family proteins. Concurrent inhibition of PI3K or HER proteins synergizes with ulixertinib in suppressing PDAC cell growth in vitro and in vivo Overall, our study provides the preclinical rationale for testing combinations of ulixertinib with chemotherapy or PI3K and HER inhibitors in PDAC patients. Mol Cancer Ther; 17(10); 2144-55. ©2018 AACR.

Biomarker-driven and molecularly targeted therapies for pancreatic adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) remains a deadly disease with few effective treatment options. Our knowledge of molecular alterations in PDAC has significantly grown and helped identify new therapeutic targets. The success of immune checkpoint inhibition in mismatch repair deficient tumors, PARP inhibitors for tumors with DNA repair defects, and targeting hyaluronan with PEGPH20 in patients with high expressing (hyaluronan-high) tumors are examples of promising biomarker-driven therapies. We review the major biological mechanisms in PDAC and discuss current and future directions for molecularly targeted therapies in this disease.

Chemotherapy and radiotherapy for advanced pancreatic cancer

BACKGROUND

Pancreatic cancer (PC) is a highly lethal disease with few effective treatment options. Over the past few decades, many anti-cancer therapies have been tested in the locally advanced and metastatic setting, with mixed results. This review attempts to synthesise all the randomised data available to help better inform patient and clinician decision-making when dealing with this difficult disease.

OBJECTIVES

To assess the effect of chemotherapy, radiotherapy or both for first-line treatment of advanced pancreatic cancer. Our primary outcome was overall survival, while secondary outcomes include progression-free survival, grade 3/4 adverse events, therapy response and quality of life.

SEARCH METHODS

We searched for published and unpublished studies in CENTRAL (searched 14 June 2017), Embase (1980 to 14 June 2017), MEDLINE (1946 to 14 June 2017) and CANCERLIT (1999 to 2002) databases. We also handsearched all relevant conference abstracts published up until 14 June 2017.

SELECTION CRITERIA

All randomised studies assessing overall survival outcomes in patients with advanced pancreatic ductal adenocarcinoma. Chemotherapy and radiotherapy, alone or in combination, were the eligible treatments.

DATA COLLECTION AND ANALYSIS

Two review authors independently analysed studies, and a third settled any disputes. We extracted data on overall survival (OS), progression-free survival (PFS), response rates, adverse events (AEs) and quality of life (QoL), and we assessed risk of bias for each study.

MAIN RESULTS

We included 42 studies addressing chemotherapy in 9463 patients with advanced pancreatic cancer. We did not identify any eligible studies on radiotherapy.We did not find any benefit for chemotherapy over best supportive care. However, two identified studies did not have sufficient data to be included in the analysis, and many of the chemotherapy regimens studied were outdated.Compared to gemcitabine alone, participants receiving 5FU had worse OS (HR 1.69, 95% CI 1.26 to 2.27, moderate-quality evidence), PFS (HR 1.47, 95% CI 1.12 to 1.92) and QoL. On the other hand, two studies showed FOLFIRINOX was better than gemcitabine for OS (HR 0.51 95% CI 0.43 to 0.60, moderate-quality evidence), PFS (HR 0.46, 95% CI 0.38 to 0.57) and response rates (RR 3.38, 95% CI 2.01 to 5.65), but it increased the rate of side effects. The studies evaluating CO-101, ZD9331 and exatecan did not show benefit or harm when compared with gemcitabine alone.Giving gemcitabine at a fixed dose rate improved OS (HR 0.79, 95% CI 0.66 to 0.94, high-quality evidence) but increased the rate of side effects when compared with bolus dosing.When comparing gemcitabine combinations to gemcitabine alone, gemcitabine plus platinum improved PFS (HR 0.80, 95% CI 0.68 to 0.95) and response rates (RR 1.48, 95% CI 1.11 to 1.98) but not OS (HR 0.94, 95% CI 0.81 to 1.08, low-quality evidence). The rate of side effects increased. Gemcitabine plus fluoropyrimidine improved OS (HR 0.88, 95% CI 0.81 to 0.95), PFS (HR 0.79, 95% CI 0.72 to 0.87) and response rates (RR 1.78, 95% CI 1.29 to 2.47, high-quality evidence), but it also increased side effects. Gemcitabine plus topoisomerase inhibitor did not improve survival outcomes but did increase toxicity. One study demonstrated that gemcitabine plus nab-paclitaxel improved OS (HR 0.72, 95% CI 0.62 to 0.84, high-quality evidence), PFS (HR 0.69, 95% CI 0.58 to 0.82) and response rates (RR 3.29, 95% CI 2.24 to 4.84) but increased side effects. Gemcitabine-containing multi-drug combinations (GEMOXEL or cisplatin/epirubicin/5FU/gemcitabine) improved OS (HR 0.55, 95% CI 0.39 to 0.79, low-quality evidence), PFS (HR 0.43, 95% CI 0.30 to 0.62) and QOL.We did not find any survival advantages when comparing 5FU combinations to 5FU alone.

AUTHORS' CONCLUSIONS

Combination chemotherapy has recently overtaken the long-standing gemcitabine as the standard of care. FOLFIRINOX and gemcitabine plus nab-paclitaxel are highly efficacious, but our analysis shows that other combination regimens also offer a benefit. Selection of the most appropriate chemotherapy for individual patients still remains difficult, with clinicopathological stratification remaining elusive. Biomarker development is essential to help rationalise treatment selection for patients.

Nimbolide reduces CD44 positive cell population and induces mitochondrial apoptosis in pancreatic cancer cells

Pancreatic ductal adenocarcinoma (PDAC) is highly aggressive disease and current treatment regimens fail to effectively cure PDAC. Development of resistance to current therapy is one of the key reasons for this outcome. Nimbolide (NL), a triterpenoid obtained from Azadirachta indica, exhibits anticancer properties in various cancer including PDAC cells. However, the underlying mechanism of this anticancer agent in PDAC cells remains undefined. We show that NL exerts a higher level of apoptotic cell death compared to the first-line agent gemcitabine for PDAC, as well as other anticancer agents including sorafenib and curcumin. The anticancer efficacy of NL was further evidenced by a reduction in the CD44⁺ as well as cancer stem-like cell (CSC) population, as it causes decreased sphere formation. Mechanistically, the anticancer efficacy of NL associates with reduced mutant p53 as well as increased mitochondrial activity in the form of increased mitochondrial reactive oxygen species and mitochondrial mass. Together, this study highlights the therapeutic potential of NL in mutant p53 expressing pancreatic cancer.

Inefficiencies and Patient Burdens in the Development of the Targeted Cancer Drug Sorafenib: A Systematic Review

Failure in cancer drug development exacts heavy burdens on patients and research systems. To investigate inefficiencies and burdens in targeted drug development in cancer, we conducted a systematic review of all prelicensure trials for the anticancer drug, sorafenib (Bayer/Onyx Pharmaceuticals). We searched Embase and MEDLINE databases on October 14, 2014, for prelicensure clinical trials testing sorafenib against cancers. We measured risk by serious adverse event rates, benefit by objective response rates and survival, and trial success by prespecified primary endpoint attainment with acceptable toxicity. The first two clinically useful applications of sorafenib were discovered in the first 2 efficacy trials, after five drug-related deaths (4.6% of 108 total) and 93 total patient-years of involvement (2.4% of 3,928 total). Thereafter, sorafenib was tested in 26 indications and 67 drug combinations, leading to one additional licensure. Drug developers tested 5 indications in over 5 trials each, comprising 56 drug-related deaths (51.8% of 108 total) and 1,155 patient-years (29.4% of 3,928 total) of burden in unsuccessful attempts to discover utility against these malignancies. Overall, 32 Phase II trials (26% of Phase II activity) were duplicative, lacked appropriate follow-up, or were uninformative because of accrual failure, constituting 1,773 patients (15.6% of 11,355 total) participating in prelicensure sorafenib trials. The clinical utility of sorafenib was established early in development, with low burden on patients and resources. However, these early successes were followed by rapid and exhaustive testing against various malignancies and combination regimens, leading to excess patient burden. Our evaluation of sorafenib development suggests many opportunities for reducing costs and unnecessary patient burden in cancer drug development.

The value of lactate dehydrogenase serum levels as a prognostic and predictive factor for advanced pancreatic cancer patients receiving sorafenib

Although lactate dehydrogenase (LDH) serum levels, indirect markers of angiogenesis, are associated with a worse outcome in several tumours, their prognostic value is not defined in pancreatic cancer. Moreover, high levels are associated even with a lack of efficacy of tyrosine kinase inhibitors, contributing to explain negative results in clinical trials. We assessed the role of LDH in advanced pancreatic cancer receiving sorafenib.

Seventy-one of 114 patients included in the randomised phase II trial MAPS (chemotherapy plus or not sorafenib) and with available serum LDH levels, were included in this analysis. Patients were categorized according to serum LDH levels (LDH ≤vs.> upper normal rate).

A significant difference was found in progression free survival (PFS) and in overall survival (OS) between patients with LDH values under or above the cut-off (PFS: 5.2 vs. 2.7 months, p = 0.0287; OS: 10.7 vs. 5.9 months, p = 0.0021).

After stratification according to LDH serum levels and sorafenib treatment, patients with low LDH serum levels treated with sorafenib showed an advantage in PFS (p = 0.05) and OS (p = 0.0012).

LDH appears to be a reliable parameter to assess the prognosis of advanced pancreatic cancer patients, and it may be a predictive parameter to select patients candidate to receive sorafenib.

Molecular targeted therapy for pancreatic adenocarcinoma: A review of completed and ongoing late phase clinical trials

Molecular targeted therapy is widely utilized and effective in a number of solid tumors. In pancreatic adenocarcinoma, targeted therapy has been extensively evaluated; however, survival improvement of this aggressive disease using a targeted strategy has been minimal. The purpose of this study is to review therapeutic molecular targets in completed and ongoing later phase (II and III) clinical trials to have a better understanding of the rationale and progress towards targeted molecular therapies for pancreatic cancer. The PubMed database and the NCDI clinical trial website (www.clinicaltrials.gov) were queried to identify phase II and III completed and published (PubMed) and ongoing (clinicaltrials.gov) trials using the keywords: pancreatic cancer and molecular targeted therapy. The search engines were further limited by adding Phase II or III, active enrollment and North American. A total of 14 completed and published phase II/III clinical trials and 17 ongoing trials were identified. Evaluated strategies included inhibition of growth factor receptors (EGFR, PDGFR, VGFR, IGF-1R), tyrosine kinase inhibitors, MEK1/2, mTOR blockade and PI3K and HER2-neu pathway inhibitors. Only one trial conducted by the National Cancer Institute of Canada and the PANTAR trial have demonstrated a survival improvement from EGFR inhibition using erlotinib. These trials ultimately led to FDA approval of erlotinib/Tarceva in advanced stage disease. It remains unclear whether new combinations of cytotoxic chemotherapy or immunotherapy plus molecular targeted therapy will be beneficial in management of pancreatic adenocarcinoma. Despite a number of phase II and III trials, to date, only erlotinib has emerged as an approved targeted therapy in pancreatic adenocarcinoma. There are several ongoing late phase trials evaluating a number of targets, the results of which will become available over the next 1 to 2 years.

Identification of Potential Off-Targets of Chemotherapeutic Agent Sorafenib: A Molecular Docking Approach

B-Raf is a multi- drug target serine/threonine protein kinase, involved in the transduction of mitogenic signals from the cell membrane to the nucleus. Mutated B-Raf causes overactive downstream signaling via MEK and ERK, leading to excessive cell proliferation and survival, independent of growth factors causing cancers such as Pancreatic carcinoma. A novel bi-aryl urea- Sorafenib, is a potent inhibitor of Raf-1 that has been approved for the treatment of a number of cancers including pancreatic cancer. The present investigation was designed to identify the potential off-targets of Sorafenib which could be responsible for its reported undesirable side effects. Molecular docking was used to test the efficacy of structural analogs of Sorafenib against B-Raf using FlexX and it was found that the analog with CID:10151557 had a high potency with minimum number of clashes, low lipophilic score and high match score, similar to Sorafenib. To identify the potential off-target/s of Sorafenib, macromolecular surface similarity detection software MEDIT SA MED-SuMo was used and the results obtained were validated through literature. The possible off-targets obtained belonged to the family of protein tyrosine kinases i.e. VEGFR-2, VEGFR-3, platelet-derived growth factor receptor beta, Flt-3, and c-KIT, each of which were docked with Sorafenib. Based on high docking scores and similarity with B-Raf for its binding site interacting residues, it was concluded that Vascular endothelial growth factor tyrosine kinase receptor (VEGFR) is a potential off-target of anti-cancer chemotherapeutic agent Sorafenib.

Identification of Potential Off-Targets of Chemotherapeutic Agent Sorafenib: A Molecular Docking Approach

B-Raf is a multi- drug target serine/threonine protein kinase, involved in the transduction of mitogenic signals from the cell membrane to the nucleus. Mutated B-Raf causes overactive downstream signaling via MEK and ERK, leading to excessive cell proliferation and survival, independent of growth factors causing cancers such as Pancreatic carcinoma. A novel bi-aryl urea- Sorafenib, is a potent inhibitor of Raf-1 that has been approved for the treatment of a number of cancers including pancreatic cancer. The present investigation was designed to identify the potential off-targets of Sorafenib which could be responsible for its reported undesirable side effects. Molecular docking was used to test the efficacy of structural analogs of Sorafenib against B-Raf using FlexX and it was found that the analog with CID:10151557 had a high potency with minimum number of clashes, low lipophilic score and high match score, similar to Sorafenib. To identify the potential off-target/s of Sorafenib, macromolecular surface similarity detection software MEDIT SA MED-SuMo was used and the results obtained were validated through literature. The possible off-targets obtained belonged to the family of protein tyrosine kinases i.e. VEGFR-2, VEGFR-3, platelet-derived growth factor receptor beta, Flt-3, and c-KIT, each of which were docked with Sorafenib. Based on high docking scores and similarity with B-Raf for its binding site interacting residues, it was concluded that Vascular endothelial growth factor tyrosine kinase receptor (VEGFR) is a potential off-target of anti-cancer chemotherapeutic agent Sorafenib.

Overview of pre-clinical and clinical studies targeting angiogenesis in pancreatic ductal adenocarcinoma

The importance of angiogenesis in pancreatic ductal adenocarcinoma (PDAC) and its therapeutic potential have been explored in both pre-clinical and clinical studies. Human PDACs overexpress a number of angiogenic factors and their cognate high-affinity receptors, and anti-angiogenic agents reduce tumor volume, metastasis, and microvessel density (MVD), and improve survival in subcutaneous and orthotopic pre-clinical models. Nonetheless, clinical trials using anti-angiogenic therapy have been overwhelmingly unsuccessful. This review will focus on these pre-clinical and clinical studies, the potential reasons for failure in the clinical setting, and ways these shortcomings could be addressed in future investigations of angiogenic mechanisms in PDAC.

Risk of cardiovascular toxicities in patients with solid tumors treated with sorafenib: an updated systematic review and meta-analysis

BACKGROUND

We performed a systematic review and meta-analysis of cardiovascular toxicities associated with sorafenib.

PATIENTS & METHODS

Eligible studies included randomized Phase II and III trials of patients with solid tumors receiving daily sorafenib treatment that described the following events: hypertension, bleeding, venous thromboembolism, left ventricular dysfunction myocardial ischemia and cerebrovascular events.

RESULTS

A total of 18 randomized clinical trials were considered eligible for the meta-analysis. Patients treated with sorafenib had a significantly increased risk of hypertension (relative risk [RR]: 2.93; 95% CI: 1.52-5.66), bleeding (RR: 2.42; 95% CI: 1.63-3.62) and left ventricular dysfunction (RR: 9.38; 95% CI: 1.24-71.22). The risk for venous thromboembolism, myocardial ischemia and cerebrovascular events was nonsignificant. Subgroup analyses showed that tumor type and treatment regimen had no effect on the RR of cardiovascular toxicities.

CONCLUSION

Our meta-analysis demonstrated that sorafenib is associated with a higher risk of developing all grade hypertension and bleeding compared with controls.

Pancreatic cancer: optimizing treatment options, new, and emerging targeted therapies

Pancreatic cancer is the fourth leading cause of cancer death in the US and is expected to become the second leading cause of cancer-related deaths in the next decade. Despite 5-fluorouracil/leucovorin with irinotecan and oxaliplatin (FOLFIRINOX) and gemcitabine/nab-paclitaxel significantly improving outcomes for metastatic cancer, refractory disease still poses significant challenges. Difficulties with early detection and the inherent chemo- and radio-resistant nature of this malignancy led to attempts to define the sequential biology of pancreatic cancer in order to improve survival outcomes. Pancreatic adenocarcinoma is characterized by several germline or acquired genetic mutations, the most common being KRAS (90%), CDK2NA (90%), TP53 (75%-90%), DPC4/SMAD4 (50%). In addition, the tumor microenvironment, chemoresistant cancer stem cells, and the desmoplastic stroma have been the target of some promising clinical investigations. Among the core pathways reproducibly shown to lead the development and progression of this disease, DNA repair, apoptosis, G1/S cell cycle transition, KRAS, Wnt, Notch, Hedgehog, TGF-beta, and other cell invasion pathways, have been the target of "precision therapeutics". No single molecularly targeted therapeutic though has been uniformly successful, probably due to the tumor heterogeneity, but biomarker research is evolving and it hopes to select more patients likely to benefit. Recent reports note activity with immunotherapies such as CD40 agonists, CCR2 inhibitors, cancer vaccines, and novel combinations against the immunosuppressive tumor milieu are ongoing. While many obstacles still exist, clearly we are making progress in deciphering the heterogeneity within pancreatic cancers. Integrating conventional and immunological targeting will be the key to effective treatment of this deadly disease.

A phase II study of sorafenib, oxaliplatin, and 2 days of high-dose capecitabine in advanced pancreas cancer

PURPOSE

Fluoropyrimidines and oxaliplatin have demonstrated some efficacy against pancreatic adenocarcinoma, but survival remains brief. Sorafenib is an oral multikinase inhibitor which we sought to combine with a unique capecitabine and oxaliplatin regimen for pancreatic adenocarcinoma.

METHODS

We performed a multicenter phase II study of sorafenib 200 mg orally twice daily along with oxaliplatin 85 mg/m(2) IV on days 1 and 15, followed by capecitabine 2250 mg/m(2) orally every 8 h for six doses starting on days 1 and 15 of a 28-day cycle in patients who had no more than one previous chemotherapy regimen for their pancreatic adenocarcinoma. The primary objective was response rate; secondary objectives were progression-free survival (PFS), overall survival (OS), and safety.

RESULTS

Twenty-four patients were enrolled; median age was 63 years (range 48-83). The most common related toxicities were fatigue, neuropathy, anemia, thrombocytopenia, diarrhea, nausea, leukopenia, and hand-foot syndrome. Grade 3 hand-foot syndrome was rare (4 %). Other grade 4 toxicities included abdominal pain (8 %), pulmonary embolism (4 %), and anemia (4 %). Three partial responses were seen (13 %), and 11 patients had stable disease (46 %) as their best response. Median PFS was 6.0 months (range 1.5-13 months). Median OS was 8.1 months (range 1.5-13.6 months).

CONCLUSIONS

Sorafenib, oxaliplatin, and capecitabine produced partial responses in patients with advanced pancreatic cancer including previously treated patients and demonstrated a PFS of 6 months with few grade 3/4 toxicities.

New targeted therapies in pancreatic cancer

Patients with pancreatic cancer have a poor prognosis with a median survival of 4-6 mo and a 5-year survival of less than 5%. Despite therapy with gemcitabine, patient survival does not exceed 6 mo, likely due to natural resistance to gemcitabine. Therefore, it is hoped that more favorable results can be obtained by using guided immunotherapy against molecular targets. This review summarizes the new leading targeted therapies in pancreatic cancers, focusing on passive and specific immunotherapies. Passive immunotherapy may have a role for treatment in combination with radiochemotherapy, which otherwise destroys the immune system along with tumor cells. It includes mainly therapies targeting against kinases, including epidermal growth factor receptor, Ras/Raf/mitogen-activated protein kinase cascade, human epidermal growth factor receptor 2, insulin growth factor-1 receptor, phosphoinositide 3-kinase/Akt/mTOR and hepatocyte growth factor receptor. Therapies against DNA repair genes, histone deacetylases, microRNA, and pancreatic tumor tissue stromal elements (stromal extracellular matric and stromal pathways) are also discussed. Specific immunotherapies, such as vaccines (whole cell recombinant, peptide, and dendritic cell vaccines), adoptive cell therapy and immunotherapy targeting tumor stem cells, have the role of activating antitumor immune responses. In the future, treatments will likely include personalized medicine, tailored for numerous molecular therapeutic targets of multiple pathogenetic pathways.

Risk of mucocutaneous toxicities in patients with solid tumors treated with sorafenib: an updated systematic review and meta-analysis

We performed a systematic review and meta-analysis of mucocutaneous toxicities associated with sorafenib, an oral multi tyrosine kinase inhibitor. Eligible studies included randomized Phase II and III trials of patients with solid tumors on sorafenib daily describing events of hand foot skin reaction, skin rash, alopecia, stomatitis or pruritis. Patients treated with sorafenib had a significantly increased risk of all-grade mucocutaneous toxicities. The RR of all-grade hand foot skin reaction, skin rash, alopecia, stomatitis and pruritis were 4.33 (95% CI: 3.06-6.14), 2.67 (95% CI: 1.86-3.83), 3.93 (95% CI: 2.07-7.45), 2.9 (95% CI: 2.26-3.73), 2.29 (95% CI: 1.87-3.03); respectively. Exploratory subgroup analysis showed no effect of tumor types or treatment regimen (monotherapy versus combination) on the RR of mucocutaneous toxicities. Our meta-analysis has demonstrated that sorafenib is associated with a higher risk of developing all grade mucocutaneous toxicities compared with control.