Global, multicenter, randomized, phase II trial of gemcitabine and gemcitabine plus AGS-1C4D4 in patients with previously untreated, metastatic pancreatic cancer

The power and the promise of CAR-mediated cell immunotherapy for clinical application in pancreatic cancer

BACKGROUND

Pancreatic cancer, referred to as the "monarch of malignancies," is a neoplastic growth mostly arising from the epithelial cells of the pancreatic duct and acinar cells. This particular neoplasm has a highly unfavorable prognosis due to its marked malignancy, inconspicuous initial manifestation, challenging early detection, rapid advancement, and limited survival duration. Cellular immunotherapy is the ex vivo culture and expansion of immune effector cells, granting them the capacity to selectively target malignant cells using specialized techniques. Subsequently, these modified cells are reintroduced into the patient's organism with the purpose of eradicating tumor cells and providing therapeutic intervention for cancer.

PRESENT SITUATION

Presently, the primary cellular therapeutic modalities employed in the treatment of pancreatic cancer encompass CAR T-cell therapy, TCR T-cell therapy, NK-cell therapy, and CAR NK-cell therapy.

AIM OF REVIEW

This review provides a concise overview of the mechanisms and primary targets associated with various cell therapies. Additionally, we will explore the prospective outlook of cell therapy in the context of treating pancreatic cancer.

Exploring the heterogeneity of osteosarcoma cell characteristics and metabolic states and their association with clinical prognosis

Background

Osteosarcoma is a malignant tumor originating from mesenchymal bone tissue, characterized by high malignancy and poor prognosis. Despite progress in comprehensive treatment approaches, the five-year survival rate remains largely unchanged, highlighting the need to clarify its underlying mechanisms and discover new therapeutic targets.

Methods

This study utilized RNA sequencing data from multiple public databases, encompassing osteosarcoma samples and healthy controls, along with single-cell RNA sequencing data. Various methods were utilized, such as differential expression analysis of genes, analysis of metabolic pathways, and weighted gene co-expression network analysis (WGCNA), to pinpoint crucial genes. Using this list of genes, we developed and validated a prognostic model that incorporated risk signatures, and we evaluated the effectiveness of the model through survival analysis, immune cell infiltration examination, and drug sensitivity evaluation.

Results

We analyzed gene expression and metabolic pathways in nine samples using single-cell sequencing data. Initially, we performed quality control and clustering, identifying 21 statistically significant cell subpopulations. Metabolic analyses of these subpopulations revealed heterogeneous activation of metabolic pathways. Focusing on the osteoblastic cell subpopulation, we further subdivided it into six groups and examined their gene expression and differentiation capabilities. Differential expression and enrichment analyses indicated that tumor tissues were enriched in cytoskeletal and structural pathways. Through WGCNA, we identified core genes negatively correlated with four highly activated metabolic pathways. Using osteosarcoma patient data, we developed a risk signature model that demonstrated robust prognostic predictions across three independent cohorts. Ultimately, we performed a thorough examination of the model, which encompassed clinical and pathological characteristics, enrichment analysis, pathways associated with cancer markers, and scores of immune infiltration, highlighting notable and complex disparities between high-risk and low-risk populations.

Conclusion

This research clarifies the molecular mechanisms and metabolic features associated with osteosarcoma and how they relate to patient outcomes, offering novel perspectives and approaches for targeted therapy and prognostic assessment in osteosarcoma.

Chemotherapy and radiotherapy for advanced pancreatic cancer

BACKGROUND

Pancreatic cancer (PC) is a lethal disease with few effective treatment options. Many anti-cancer therapies have been tested in the locally advanced and metastatic setting, with mixed results. This review synthesises all the randomised data available to help better inform patient and clinician decision-making. It updates the previous version of the review, published in 2018.

OBJECTIVES

To assess the effects of chemotherapy, radiotherapy, or both on overall survival, severe or life-threatening adverse events, and quality of life in people undergoing first-line treatment of advanced pancreatic cancer.

SEARCH METHODS

We searched for published and unpublished studies in CENTRAL, MEDLINE, Embase, and CANCERLIT, and handsearched various sources for additional studies. The latest search dates were in March and July 2023.

SELECTION CRITERIA

We included randomised controlled trials comparing chemotherapy, radiotherapy, or both with another intervention or best supportive care. Participants were required to have locally advanced, unresectable pancreatic cancer or metastatic pancreatic cancer not amenable to curative intent treatment. Histological confirmation was required. Trials were required to report overall survival.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included 75 studies in the review and 51 in the meta-analysis (11,333 participants). We divided the studies into seven categories: any anti-cancer treatment versus best supportive care; various chemotherapy types versus gemcitabine; gemcitabine-based combinations versus gemcitabine alone; various chemotherapy combinations versus gemcitabine plus nab-paclitaxel; fluoropyrimidine-based studies; miscellaneous studies; and radiotherapy studies. In general, the included studies were at low risk for random sequence generation, detection bias, attrition bias, and reporting bias, at unclear risk for allocation concealment, and high risk for performance bias. Compared to best supportive care, chemotherapy likely results in little to no difference in overall survival (OS) (hazard ratio (HR) 1.08, 95% confidence interval (CI) 0.88 to 1.33; absolute risk of death at 12 months of 971 per 1000 versus 962 per 1000; 4 studies, 298 participants; moderate-certainty evidence). The adverse effects of chemotherapy and impacts on quality of life (QoL) were uncertain. Many of the chemotherapy regimens were outdated. Eight studies compared non-gemcitabine-based chemotherapy regimens to gemcitabine. These showed that 5-fluorouracil (5FU) likely reduces OS (HR 1.69, 95% CI 1.26 to 2.27; risk of death at 12 months of 914 per 1000 versus 767 per 1000; 1 study, 126 participants; moderate certainty), and grade 3/4 adverse events (QoL not reported). Fixed dose rate gemcitabine likely improves OS (HR 0.79, 95% CI 0.66 to 0.94; risk of death at 12 months of 683 per 1000 versus 767 per 1000; 2 studies, 644 participants; moderate certainty), and likely increase grade 3/4 adverse events (QoL not reported). FOLFIRINOX improves OS (HR 0.51, 95% CI 0.43 to 0.60; risk of death at 12 months of 524 per 1000 versus 767 per 1000; P < 0.001; 2 studies, 652 participants; high certainty), and delays deterioration in QoL, but increases grade 3/4 adverse events. Twenty-eight studies compared gemcitabine-based combinations to gemcitabine. Gemcitabine plus platinum may result in little to no difference in OS (HR 0.94, 95% CI 0.81 to 1.08; risk of death at 12 months of 745 per 1000 versus 767 per 1000; 6 studies, 1140 participants; low certainty), may increase grade 3/4 adverse events, and likely worsens QoL. Gemcitabine plus fluoropyrimidine improves OS (HR 0.88, 95% CI 0.81 to 0.95; risk of death at 12 months of 722 per 1000 versus 767 per 1000; 10 studies, 2718 participants; high certainty), likely increases grade 3/4 adverse events, and likely improves QoL. Gemcitabine plus topoisomerase inhibitors result in little to no difference in OS (HR 1.01, 95% CI 0.87 to 1.16; risk of death at 12 months of 770 per 1000 versus 767 per 1000; 3 studies, 839 participants; high certainty), likely increases grade 3/4 adverse events, and likely does not alter QoL. Gemcitabine plus taxane result in a large improvement in OS (HR 0.71, 95% CI 0.62 to 0.81; risk of death at 12 months of 644 per 1000 versus 767 per 1000; 2 studies, 986 participants; high certainty), and likely increases grade 3/4 adverse events and improves QoL. Nine studies compared chemotherapy combinations to gemcitabine plus nab-paclitaxel. Fluoropyrimidine-based combination regimens improve OS (HR 0.79, 95% CI 0.70 to 0.89; risk of death at 12 months of 542 per 1000 versus 628 per 1000; 6 studies, 1285 participants; high certainty). The treatment arms had distinct toxicity profiles, and there was little to no difference in QoL. Alternative schedules of gemcitabine plus nab-paclitaxel likely result in little to no difference in OS (HR 1.10, 95% CI 0.82 to 1.47; risk of death at 12 months of 663 per 1000 versus 628 per 1000; 2 studies, 367 participants; moderate certainty) or QoL, but may increase grade 3/4 adverse events. Four studies compared fluoropyrimidine-based combinations to fluoropyrimidines alone, with poor quality evidence. Fluoropyrimidine-based combinations are likely to result in little to no impact on OS (HR 0.84, 95% CI 0.61 to 1.15; risk of death at 12 months of 765 per 1000 versus 704 per 1000; P = 0.27; 4 studies, 491 participants; moderate certainty) versus fluoropyrimidines alone. The evidence suggests that there was little to no difference in grade 3/4 adverse events or QoL between the two groups. We included only one radiotherapy (iodine-125 brachytherapy) study with 165 participants. The evidence is very uncertain about the effect of radiotherapy on outcomes.

AUTHORS' CONCLUSIONS

Combination chemotherapy remains standard of care for metastatic pancreatic cancer. Both FOLFIRINOX and gemcitabine plus a taxane improve OS compared to gemcitabine alone. Furthermore, the evidence suggests that fluoropyrimidine-based combination chemotherapy regimens improve OS compared to gemcitabine plus nab-paclitaxel. The effects of radiotherapy were uncertain as only one low-quality trial was included. Selection of the most appropriate chemotherapy for individuals still remains unpersonalised, with clinicopathological stratification remaining elusive. Biomarker development is essential to assist in rationalising treatment selection for patients.

Developing and validating a survival prediction model based on blood exosomal ceRNA network in patients with PAAD

BACKGROUND

Among the most lethal cancers, pancreatic adenocarcinoma (PAAD) is an essential component of digestive system malignancies that still lacks effective diagnosis and treatment methods. As exosomes and competing endogenous RNA (ceRNA) regulatory networks in tumors go deeper, we expect to construct a ceRNA regulatory network derived from blood exosomes of PAAD patients by bioinformatics methods and develop a survival prediction model based on it.

METHODS

Blood exosome sequencing data of PAAD patients and normal controls were downloaded from the exoRbase database, and the expression profiles of exosomal mRNA, lncRNA, and circRNA were differentially analyzed by R. The related mRNA, circRNA, lncRNA, and their corresponding miRNA prediction data were imported into Cytoscape software to visualize the ceRNA network. Then, we conducted GO and KEGG enrichment analysis of mRNA in the ceRNA network. Genes that express differently in pancreatic cancer tissues compared with normal tissues and associate with survival (P < 0.05) were determined as Hub genes by GEPIA. We identified optimal prognosis-related differentially expressed mRNAs (DEmRNAs) and generated a risk score model by performing univariate and multivariate Cox regression analyses.

RESULTS

205 DEmRNAs, 118 differentially expressed lncRNAs (DElncRNAs), and 98 differentially expressed circRNAs (DEcircRNAs) were screened out. We constructed the ceRNA network, and a total of 26 mRNA nodes, 7 lncRNA nodes, 6 circRNA nodes, and 16 miRNA nodes were identified. KEGG enrichment analysis showed that the DEmRNAs in the regulatory network were mainly enriched in Human papillomavirus infection, PI3K-Akt signaling pathway, Osteoclast differentiation, and ECM-receptor interaction. Next, six hub genes (S100A14, KRT8, KRT19, MAL2, MYO5B, PSCA) were determined through GEPIA. They all showed significantly increased expression in cancer tissues compared with control groups, and their high expression pointed to adverse survival. Two optimal prognostic-related DEmRNAs, MYO5B (HR = 1.41, P < 0.05) and PSCA (HR = 1.10, P < 0.05) were included to construct the survival prediction model.

CONCLUSION

In this study, we successfully constructed a ceRNA regulatory network in blood exosomes from PAAD patients and developed a two-gene survival prediction model that provided new targets which shall aid in diagnosing and treating PAAD.

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.

Trial Watch: Tumor-targeting monoclonal antibodies in cancer therapy

In 1997, for the first time in history, a monoclonal antibody (mAb), i.e., the chimeric anti-CD20 molecule rituximab, was approved by the US Food and Drug Administration for use in cancer patients. Since then, the panel of mAbs that are approved by international regulatory agencies for the treatment of hematopoietic and solid malignancies has not stopped to expand, nowadays encompassing a stunning amount of 15 distinct molecules. This therapeutic armamentarium includes mAbs that target tumor-associated antigens, as well as molecules that interfere with tumor-stroma interactions or exert direct immunostimulatory effects. These three classes of mAbs exert antineoplastic activity via distinct mechanisms, which may or may not involve immune effectors other than the mAbs themselves. In previous issues of OncoImmunology, we provided a brief scientific background to the use of mAbs, all types confounded, in cancer therapy, and discussed the results of recent clinical trials investigating the safety and efficacy of this approach. Here, we focus on mAbs that primarily target malignant cells or their interactions with stromal components, as opposed to mAbs that mediate antineoplastic effects by activating the immune system. In particular, we discuss relevant clinical findings that have been published during the last 13 months as well as clinical trials that have been launched in the same period to investigate the therapeutic profile of hitherto investigational tumor-targeting mAbs.

Two decades of research toward the treatment of locally advanced and metastatic pancreatic cancer: Remarkable effort and limited gain

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy that is diagnosed at the locally advanced or metastatic stage in approximately 80% of cases. Relative to other tumor types, progress in the treatment of this disease has been painfully slow. While agents targeting DNA repair have proven successful in a subset of patients, the majority of PDACs do not exhibit validated molecular targets. Hence, conventional chemotherapy remains at the forefront of therapy for this disease. In this review, we study two decades of efforts to improve upon the gemcitabine backbone - 67 phase II and III trials enrolling 16,446 patients - that culminated in the approvals of gemcitabine/nab-paclitaxel (Gem/NabP) and FOLFIRINOX. Today, these remain gold standards for the first-line treatment of locally advanced unresectable and metastatic PDAC, while ongoing efforts focus on improving upon the Gem/NabP backbone. Because real world data often do not reflect the data of randomized controlled trials (RCTs), we also summarize the retrospective evidence comparing the efficacy of Gem/NabP and FOLFIRINOX in the first-line setting - 29 studies reporting a median overall survival of 10.7 and 9.1 months for FOLFIRINOX and Gem/NabP, respectively. These values are surprisingly comparable to those reported by the pivotal RCTs at 11.1 and 8.5 months. Finally, there is a paucity of RCT data regarding the efficacy of second-line therapy. Hence, we conclude this review by summarizing the data that ultimately demonstrate a small but significant survival benefit of second-line therapy with Gem/NabP or FOLFIRINOX. Collectively, these studies describe the long journey, the steady effort, and the myriad lessons to be learned from 20 years of PDAC trials to inform strategies for success in clinical trials moving forward.

Programming CAR T cells to enhance anti-tumor efficacy through remodeling of the immune system

Chimeric antigen receptor (CAR) T cells have been indicated effective in treating B cell acute lymphoblastic leukemia and non-Hodgkin lymphoma and have shown encouraging results in preclinical and clinical studies. However, CAR T cells have achieved minimal success against solid malignancies because of the additional obstacles of their insufficient migration into tumors and poor amplification and persistence, in addition to antigen-negative relapse and an immunosuppressive microenvironment. Various preclinical studies are exploring strategies to overcome the above challenges. Mobilization of endogenous immune cells is also necessary for CAR T cells to obtain their optimal therapeutic effect given the importance of the innate immune responses in the elimination of malignant tumors. In this review, we focus on the recent advances in the engineering of CAR T cell therapies to restore the immune response in solid malignancies, especially with CAR T cells acting as cellular carriers to deliver immunomodulators to tumors to mobilize the endogenous immune response. We also explored the sensitizing effects of conventional treatment approaches, such as chemotherapy and radiotherapy, on CAR T cell therapy. Finally, we discuss the combination of CAR T cells with biomaterials or oncolytic viruses to enhance the anti-tumor outcomes of CAR T cell therapies in solid tumors.

Evaluation of Phase II Trial Design in Advanced Pancreatic Cancer

OBJECTIVES

We evaluated how well phase II trials in locally advanced and metastatic pancreatic cancer (LAMPC) meet current recommendations for trial design.

METHODS

We conducted a systematic review of phase II first-line treatment trial for LAMPC. We assessed baseline characteristics, type of comparison, and primary end point to examine adherence to the National Cancer Institute recommendations for trial design.

RESULTS

We identified 148 studies (180 treatment arms, 7505 participants). Forty-seven (32%) studies adhered to none of the 5 evaluated National Cancer Institute recommendations, 62 (42%) followed 1, 31 (21%) followed 2, and 8 (5%) followed 3 recommendations. Studies varied with respect to the proportion of patients with good performance status (range, 0%-80%) and locally advanced disease (range, 14%-100%). Eighty-two (55%) studies concluded that investigational agents should progress to phase III testing; of these, 24 (16%) had documented phase III trials. Three (8%) phase III trials demonstrated clinically meaningful improvements for investigational agents. One of 38 phase II trials that investigated biological investigational agents was enriched for a biomarker.

CONCLUSIONS

Phase II trials do not conform well to current recommendations for trial design in LAMPC.

Estimating the subgroup and testing for treatment effect in a post-hoc analysis of a clinical trial with a biomarker

We consider the problem of estimating a biomarker-based subgroup and testing for treatment effect in the overall population and in the subgroup after the trial. We define the best subgroup as the subgroup that maximizes the power for comparing the experimental treatment with the control. In the case of continuous outcome and a single biomarker, both a non-parametric method of estimating the subgroup and a method based on fitting a linear model with treatment by biomarker interaction to the data perform well. Several procedures for testing for treatment effect in all and in the subgroup are discussed. Cross-validation with two cohorts is used to estimate the biomarker cut-off to determine the best subgroup and to test for treatment effect. An approach that combines the tests in all patients and in the subgroup using Hochberg's method is recommended. This test performs well in the case when there is a subgroup with sizable treatment effect and in the case when the treatment is beneficial to everyone.

Thapsigargin induces apoptosis of prostate cancer through cofilin-1 and paxillin

It is widely considered that endoplasmic reticulum stress may rapidly induce apoptosis. The aim of the present study was to investigate the effect of thapsigargin on the induction of apoptosis in prostate cancer cells, and to explore its possible mechanism. A Cell Counting Kit-8 was selected to determine the effect of thapsigargin (0, 1, 10 and 100 nM) on the proliferation of PC3 cells. Cell proliferation of the prostate cancer cells was effectively inhibited by treatment with thapsigargin, and thapsigargin significantly increased the rate of apoptosis and caspase-3/9 activities in prostate cancer cells. The protein expression of phosphorylated (p)-RAC-α serine threonine-protein kinase, p-mechanistic target of rapamycin, F-actin and paxillin were significantly decreased, and cofilin-1 protein expression was significantly increased by treatment with thapsigargin in prostate cancer cells. Overall, the data of the present study revealed that thapsigargin induced apoptosis in prostate cancer cells through cofilin-1 and paxillin.

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.

Characterization of a switchable chimeric antigen receptor platform in a pre-clinical solid tumor model

The universal modular chimeric antigen receptor (UniCAR) platform redirects CAR-T cells using a separated, soluble targeting module with a short half-life. This segregation allows precise controllability and flexibility. Herein we show that the UniCAR platform can be used to efficiently target solid cancers in vitro and in vivo using a pre-clinical prostate cancer model which overexpresses prostate stem cell antigen (PSCA). Short-term administration of the targeting module to tumor bearing immunocompromised mice engrafted with human UniCAR-T cells significantly delayed tumor growth and prolonged survival of recipient mice both in a low and high tumor burden model. In addition, we analyzed phenotypic and functional changes of cancer cells and UniCAR-T cells in association with the administration of the targeting module to reveal potential immunoevasive mechanisms. Most notably, UniCAR-T cell activation induced upregulation of immune-inhibitory molecules such as programmed death ligands. In conclusion, this work illustrates that the UniCAR platform mediates potent anti-tumor activity in a relevant in vitro and in vivo solid tumor model.

Exploratory investigation of PSCA-protein expression in primary breast cancer patients reveals a link to HER2/neu overexpression

BACKGROUND

Prostate stem cell antigen (PSCA) has been suggested as biomarker and therapeutic target for prostate cancer. Recent advances showed that PSCA is up-regulated in other cancer entities, such as bladder or pancreatic cancer. However, the clinical relevance of PSCA-expression in breast cancer patients has not yet been established and is therefore addressed by the current study.

METHODS

PSCA-protein expression was assessed in 405 breast cancer patients, using immunohistochemistry (PSCA antibody MB1) and tissue microarrays.

RESULTS

PSCA-expression was detected in 94/405 patients (23%) and correlated with unfavorable histopathological grade (p=0.011) and increased Ki67 proliferation index (p=0.006). We observed a strong positive correlation between PSCA-protein expression and HER2/neu receptor status (p<0.001). PSCA did not provide prognostic information in the analyzed cohort. Interestingly, the distribution of PSCA-expression among triple negative patients was comparable to the total population.

CONCLUSION

We identified a subgroup of PSCA-positive breast cancer patients, which could be amenable for a PSCA-targeted therapy. Moreover, given that we found a strong positive correlation between PSCA- and HER/neu expression, targeting PSCA may provide an alternative therapeutic option in case of trastuzumab resistance.

Improving Chimeric Antigen Receptor-Modified T Cell Function by Reversing the Immunosuppressive Tumor Microenvironment of Pancreatic Cancer

The adoptive transfer of T cells redirected to tumor-associated antigens via transgenic expression of chimeric antigen receptors (CARs) has produced tumor responses, even in patients with refractory diseases. To target pancreatic cancer, we generated CAR T cells directed against prostate stem cell antigen (PSCA) and demonstrated specific tumor lysis. However, pancreatic tumors employ immune evasion strategies such as the production of inhibitory cytokines, which limit CAR T cell persistence and function. Thus, to protect our cells from the immunosuppressive cytokine IL-4, we generated an inverted cytokine receptor in which the IL-4 receptor exodomain was fused to the IL-7 receptor endodomain (4/7 ICR). Transgenic expression of this molecule in CAR-PSCA T cells should invert the inhibitory effects of tumor-derived IL-4 and instead promote T cell proliferation. We now demonstrate the suppressed activity of CAR T cells in tumor-milieu conditions and the ability of CAR/ICR T cells to thrive in an IL-4-rich microenvironment, resulting in enhanced antitumor activity. Importantly, CAR/ICR T cells remained both antigen and cytokine dependent. These findings support the benefit of combining the 4/7 ICR with CAR-PSCA to treat pancreatic cancer, a PSCA-expressing tumor characterized by a dense immunosuppressive environment rich in IL-4.

Progression-free survival as a surrogate for overall survival in first-line chemotherapy for advanced pancreatic cancer

BACKGROUND

Overall survival (OS), as the primary end-point in first-line chemotherapy trials, requires a prolonged follow-up time and may be confounded by subsequent regimens. This study aimed to evaluate the correlation between OS and surrogate end-points (progression-free survival [PFS], response rate and disease control rate), and to identify a potential surrogate for OS in advanced pancreatic cancer.

METHODS

Based on an electronic search, we identified randomized controlled phase II and III trials of first-line chemotherapy for advanced pancreatic cancer. Correlation analyses were performed between surrogate end-points and OS, and between improvements in surrogates and those in OS.

RESULTS

Fifty trials (II/II-III/III, 17/2/31) with 111 treatment arms were identified, and 15,906 patients were analysed. PFS was most strongly correlated with OS (correlation coefficient, 0.76). Weighted linear regression models revealed the greatest determinant coefficient of 0.84 between the hazard ratio (HR) of the experimental arms compared with the control arms of PFS and that of OS. The approximate equation was log HROS = 0.01 + 0.77 × log HRPFS, indicating that risk reduction of OS via chemotherapy would translate into a 77% risk reduction of PFS. The surrogacy of PFS for OS was robust throughout our subgroup analyses: e.g., biologic versus non-biologic regimens, locally advanced versus metastatic disease.

CONCLUSIONS

The surrogacy of PFS for OS in pancreatic cancer was validated. Therefore, the use of PFS as the primary end-point in clinical trials could facilitate the early introduction of new effective chemotherapy regimens into clinical practice.

Therapeutic potential of targeting acinar cell reprogramming in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is a common pancreatic cancer and the fourth leading cause of cancer death in the United States. Treating this life-threatening disease remains challenging due to the lack of effective prognosis, diagnosis and therapy. Apart from pancreatic duct cells, acinar cells may also be the origin of PDAC. During pancreatitis or combined with activating KRas(G12D) mutation, acinar cells lose their cellular identity and undergo a transdifferentiation process called acinar-to-ductal-metaplasia (ADM), forming duct cells which may then transform into pancreatic intraepithelial neoplasia (PanIN) and eventually PDAC. During ADM, the activation of mitogen-activated protein kinases, Wnt, Notch and phosphatidylinositide 3-kinases/Akt signaling inhibits the transcription of acinar-specific genes, including Mist and amylase, but promotes the expression of ductal genes, such as cytokeratin-19. Inhibition of this transdifferentiation process hinders the development of PanIN and PDAC. In addition, the transdifferentiated cells regain acinar identity, indicating ADM may be a reversible process. This provides a new therapeutic direction in treating PDAC through cancer reprogramming. Many studies have already demonstrated the success of switching PanIN/PDAC back to normal cells through the use of PD325901, the expression of E47, and the knockdown of Dickkopf-3. In this review, we discuss the signaling pathways involved in ADM and the therapeutic potential of targeting reprogramming in order to treat PDAC.

Systematic review and meta-analysis on targeted therapy in advanced pancreatic cancer

AIM

A systematic review and meta-analysis from literature has been performed to assess the impact of targeted therapy in advanced pancreatic cancer.

METHODS

By searching different literature databases and major cancer meetings proceedings, data from all randomized clinical trials designed to investigate molecular targeted agents in the treatment of advanced pancreatic cancer were collected. The time-frame between January 2007 and March 2015 was selected. Data on predefined end-points, including overall survival, progression-free survival in terms of Hazard Ratio and response-rate were extracted and analyzed by a random effects model. Pooled data analysis was performed according to the DerSimonian and Laird test. The occurrence of publication bias was investigated through Begg's test by visual inspection of funnel plots.

RESULTS

Twenty-seven randomized clinical trials for a total of 8205 patients were selected and included in the final analysis. A significant benefit was demonstrated for anti-EGFR agents on overall survival (HR = 0.880; 95% confidence interval (CI) 0.797-0.972; p = 0.011). In the pooled analysis no benefit on overall survival (OS: pooled HR = 0.957; 95%CI 0.900-1.017; p = 0.153), or progression-free survival (PFS: pooled HR = 0.908; 95%CI 0.817-1.010; p = 0.075) for targeted-based therapies as compared to conventional treatments could be demonstrated. No advantage was reported in response-rate (OR for RR = 1.210; 95%CI 0.990-1.478; p = 0.063). Begg's funnel plot showed no evidence of publication bias.

CONCLUSION

The use of molecular targeted agents does not translate into clinical benefit. Therefore, our work highlights the need to identify predictive factors for patient selection and rationally designed clinical trials.

Novel agents for advanced pancreatic cancer

Pancreatic cancer is relatively insensitive to conventional chemotherapy. Therefore, novel agents targeting dysregulated pathways (MAPK/ERK, EGFR, TGF-β, HEDGEHOG, NOTCH, IGF, PARP, PI3K/AKT, RAS, and Src) are being explored in clinical trials as monotherapy or in combination with cytotoxic chemotherapy. This review summarizes the most recent advances with the targeted therapies in the treatment of patients with advanced pancreatic cancer.

A novel chimeric antigen receptor against prostate stem cell antigen mediates tumor destruction in a humanized mouse model of pancreatic cancer

Despite advances in the understanding of its molecular pathophysiology, pancreatic cancer remains largely incurable, highlighting the need for novel therapies. We developed a chimeric antigen receptor (CAR) specific for prostate stem cell antigen (PSCA), a glycoprotein that is overexpressed in pancreatic cancer starting at early stages of malignant transformation. To optimize the CAR design, we used antigen-recognition domains derived from mouse or human antibodies, and intracellular signaling domains containing one or two T cell costimulatory elements, in addition to CD3zeta. Comparing multiple constructs established that the CAR based on human monoclonal antibody Ha1-4.117 had the greatest reactivity in vitro. To further analyze this CAR, we developed a human pancreatic cancer xenograft model and adoptively transferred CAR-engineered T cells into animals with established tumors. CAR-engineered human lymphocytes induced significant antitumor activity, and unlike what has been described for other CARs, a second-generation CAR (containing CD28 cosignaling domain) induced a more potent antitumor effect than a third-generation CAR (containing CD28 and 41BB cosignaling domains). While our results provide evidence to support PSCA as a target antigen for CAR-based immunotherapy of pancreatic cancer, the expression of PSCA on selected normal tissues could be a source of limiting toxicity.

Phase II clinical trials on investigational drugs for the treatment of pancreatic cancers

INTRODUCTION

Despite some recent advances in treatment options, pancreatic cancer remains a devastating disease with poor outcomes. In a trend contrary to most malignancies, both incidence and mortality continue to rise due to pancreatic cancer. The majority of patients present with advanced disease and there are no treatment options for this stage that have demonstrated a median survival > 1 year. As the penultimate step prior to Phase III studies involving hundreds of patients, Phase II clinical trials provide an early opportunity to evaluate the efficacy of new treatments that are desperately needed for this disease.

AREAS COVERED

This review covers the results of published Phase II clinical trials in advanced pancreatic adenocarcinoma published within the past 5 years. The treatment results are framed in the context of the current standards of care and the historic challenge of predicting Phase III success from Phase II trial results.

EXPERT OPINION

Promising therapies remain elusive in pancreatic cancer based on recent Phase II clinical trial results. Optimization and standardization of clinical trial design in the Phase II setting, with consistent incorporation of biomarkers, is needed to more accurately identify promising therapies that warrant Phase III evaluation.

Novel approaches in the management of pancreatic ductal adenocarcinoma: potential promises for the future

Despite a few breakthroughs in therapy for advanced disease in the recent years, pancreatic ductal adenocarcinoma continues to remain one of the most challenging human malignancies to treat. The overall prognosis for the majority of patients with pancreatic cancer is rather dismal, and therefore, more effective treatment options are being desperately sought. The practical goals of management are to improve the cure rates for patients with resectable disease, achieve a higher conversion rate of locally advanced tumor into potentially resectable disease, and finally, prolong the overall survival for those who develop metastatic disease. Our understanding of the complex genetic alterations, the implicated molecular pathways, and the role of desmoplastic stroma in pancreatic cancer tumorigenesis has increased several folds in the recent years. This has facilitated the development of novel therapeutic strategies against pancreatic cancer, some of which are currently under evaluation in ongoing preclinical and clinical studies. This review will summarize the existing treatment approaches for this devastating disease and also discuss the promising therapeutic approaches that are currently in different stages of clinical development.

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.

Current and future systemic treatment options in metastatic pancreatic cancer

Although pancreatic adenocarcinoma is the fourth leading cause of cancer death, only modest improvement has been observed in the past two decades, single agent gemcitabine has been the only standard treatment in patients with advanced disease. Recently newer agents such as nab-paclitaxel, nimotuzumab and regimens such as FOLFIRINOX have been shown to have promising activity being superior to gemcitabine as a single agent. With better understanding of tumour biology coupled with the improvements in targeted and immunotherapies, there is increasing expectation for better response rates and extended survival in pancreatic cancer.

Specificity delivers: therapeutic role of tumor antigen-specific antibodies in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDA) is among the most deadly cancers with less than 5% of the patients living beyond 5 years post-diagnosis. Lack of early diagnostic biomarkers and resistance to current therapies help explain these disappointing numbers. Thus, more effective and better-targeted therapies are needed quickly. Monoclonal antibodies offer an attractive alternative targeted therapy option for PDA because they are highly specific and potent. However, currently available monoclonal antibody therapies for PDA are still in their infancy with a low success rate and low likelihood of being approved. The challenges faced by these therapies include the following: lack of predictive and response biomarkers, unfavorable safety profiles, expression of targets not restricted to the cancer cells, flawed preclinical model systems, drug resistance, and PDA's complex nature. Additionally, discovery of novel PDA-specific antigen targets, present on the cell surface or in the extracellular matrix, is needed. Predictive and response markers also need to be determined for PDA patient subgroups so that the most appropriate effective therapy can be delivered. Serologic approaches, recombinant antibody-producing technologies, and advances in antibody engineering techniques will help to identify these predictive biomarkers and aid in the development of new therapeutic antibodies. A combinatorial approach simultaneously targeting antigens on the PDA cell, stroma, and immunosuppressive cells should be employed.

Targeted therapies in urothelial carcinoma

PURPOSE OF REVIEW

Greater understanding of the biology and genetics of urothelial carcinoma is helping to identify and define the role of molecules and pathways appropriate for novel-targeted therapies. Here, we review the targeted therapies that have been reported or are in ongoing urothelial carcinoma clinical trials, and highlight molecular targets characterized in preclinical and clinical studies.

RECENT FINDINGS

Trials in nonmuscle-invasive bladder cancer are evaluating the role of immunotherapy and agents targeting vascular endothelial growth factor (VEGF) or fibroblast growth factor receptor-3. In muscle-invasive bladder cancer, neoadjuvant studies have focused on combining VEGF agents with chemotherapy; adjuvant studies are testing vaccines and agents targeting the human epidermal growth factor receptor 2, p53, and Hsp27. In the first-line treatment of metastatic urothelial carcinoma, tubulin, cytotoxic T-lymphocyte antigen 4, Hsp27, and p53 are novel targets in clinical trials. The majority of targeted agents studied in urothelial carcinoma are in the second-line setting; new targets include CD105, polo-like kinase-1, phosphatidylinositide 3-kinases (PI3K), transforming growth factor β receptor/activin receptor-like kinase β, estrogen receptor, and the hepatocyte growth factor receptor (HGFR or MET).

SUMMARY

Development of targeted therapies for urothelial carcinoma is still in early stages, consequently there have been no major therapeutic advances to date. However, greater understanding of urothelial carcinoma and solid tumor biology has resulted in a proliferation of clinical trials that could lead to significant advances in treatment strategies.

Optimum chemotherapy in the management of metastatic pancreatic cancer

Pancreatic cancer is one of the most devastating solid tumors, and it remains one of the most difficult to treat. The treatment of metastatic pancreatic cancer (MPC) is systemic, based on chemotherapy or best supportive care, depending on the performance status of the patient. Two chemotherapeutical regimens have produced substantial benefits in the treatment of MPC: gemcitabine in 1997; and FOLFIRIONOX in 2011. FOLFIRINOX improved the natural history of MPC, with overall survival (OS) of 11.1 mo. Nab-paclitaxel associated with gemcitabine is a newly approved regimen for MPC, with a median OS of 8.6 mo. Despite multiple trials, this targeted therapy was not efficient in the treatment of MPC. Many new molecules targeting the proliferation and survival pathways, immune response, oncofetal signaling and the epigenetic changes are currently undergoing phase I and II trials for the treatment of MPC, with many promising results.