PD-L1 Immune Checkpoint Targeted Photoactivable Liposomes (iTPALs) Prime the Stroma of Pancreatic Tumors and Promote Self-Delivery

Desmoplasia in pancreatic ductal adenocarcinoma (PDAC) limits the penetration and efficacy of therapies. It has been previously shown that photodynamic priming (PDP) using EGFR targeted photoactivable multi-inhibitor liposomes remediates desmoplasia in PDAC and doubles overall survival. Here, bifunctional PD-L1 immune checkpoint targeted photoactivable liposomes (iTPALs) that mediate both PDP and PD-L1 blockade are presented. iTPALs also improve phototoxicity in PDAC cells and induce immunogenic cell death. PDP using iTPALs reduces collagen density, thereby promoting self-delivery by 5.4-fold in collagen hydrogels, and by 2.4-fold in syngeneic CT1BA5 murine PDAC tumors. PDP also reduces tumor fibroblast content by 39.4%. Importantly, iTPALs also block the PD-1/PD-L1 immune checkpoint more efficiently than free α-PD-L1 antibodies. Only a single sub-curative priming dose using iTPALs provides 54.1% tumor growth inhibition and prolongs overall survival in mice by 42.9%. Overall survival directly correlates with the extent of tumor iTPAL self-delivery following PDP (Pearson's r = 0.670, p = 0.034), while no relationship is found for sham non-specific IgG constructs activated with light. When applied over multiple cycles, as is typical for immune checkpoint therapy, PDP using iTPALs promises to offer durable tumor growth delay and significant survival benefit in PDAC patients, especially when used to promote self-delivery of integrated chemo-immunotherapy regimens.

Surface Presentation of Hyaluronic Acid Modulates Nanoparticle-Cell Association

Nanoparticle (NP) drug carriers have revolutionized medicine and increased patient quality of life. Clinically approved formulations typically succeed because of reduced off-target toxicity of the cargo. However, increasing carrier accumulation at disease sites through precise targeting remains one of the biggest challenges in the field. Novel multivalent ligand presentations and self-assembled constructs can enhance cell association, but an inability to draw direct comparisons across formulations has hindered progress. Furthermore, how nanoparticle structure influences function often is unclear. In this report, we leverage the well-characterized hyaluronic acid (HA)-CD44 binding pair to investigate how the surface architecture of modified NPs impacts their association with ovarian cancer cells that overexpress CD44. We functionalized anionic liposomes with 5 kDa HA by either covalent conjugation via surface coupling or electrostatic self-assembly using the layer-by-layer (LbL) adsorption method. Comparing these two methods, we observed a consistent enhancement of NP-cell association with the self-assembly LbL technique, particularly with higher molecular weight (≥10 kDa) HA. To further optimize association, we increased the surface-available HA. We synthesized a bottlebrush glycopolymer composed of a polynorbornene backbone and pendant 5 kDa HA and layered this macromolecule onto NPs. Flow cytometry revealed that the LbL HA bottlebrush NP outperformed the LbL linear display of HA. Cellular visualization by deconvolution optical microscopy corroborated results from all three constructs. Using exogenous HA to block NP-CD44 interactions, we found the LbL HA bottlebrush NP had a 4-fold higher binding avidity than the best-performing LbL linear HA NP. We further observed that decreasing the density of HA bottlebrush side chains to 75% had minimal impact on LbL NP stability or cell association, though we did see a reduction in binding avidity with this side-chain-modified NP. Our studies indicate that LbL surfaces are highly effective for multivalent displays, and the mode in which they present a targeting ligand can be optimized for NP cell targeting.

Current progress of nanomedicine for prostate cancer diagnosis and treatment

Prostate cancer (PCa) is the most common new cancer case and the second most fatal malignancy in men. Surgery, endocrine therapy, radiotherapy and chemotherapy are the main clinical treatment options for PCa. However, most prostate cancers can develop into castration-resistant prostate cancer (CRPC), and due to the invasiveness of prostate cancer cells, they become resistant to different treatments and activate tumor-promoting signaling pathways, thereby inducing chemoresistance, radioresistance, ADT resistance, and immune resistance. Nanotechnology, which can combine treatment with diagnostic imaging tools, is emerging as a promising treatment modality in prostate cancer therapy. Nanoparticles can not only promote their accumulation at the pathological site through passive targeting techniques for enhanced permeability and retention (EPR), but also provide additional advantages for active targeting using different ligands. This property results in a reduced drug dose to achieve the desired effect, a longer duration of action within the tumor and fewer side effects on healthy tissues. In addition, nanotechnology can create good synergy with radiotherapy, chemotherapy, thermotherapy, photodynamic therapy and gene therapy to enhance their therapeutic effects with greater scope, and reduce the resistance of prostate cancer. In this article, we intend to review and discuss the latest technologies regarding the use of nanomaterials as therapeutic and diagnostic tools for prostate cancer.

A Prospective Feasibility Trial to Challenge Patient-Derived Pancreatic Cancer Organoids in Predicting Treatment Response

Real-time isolation, propagation, and pharmacotyping of patient-derived pancreatic cancer organoids (PDOs) may enable treatment response prediction and personalization of pancreatic cancer (PC) therapy. In our methodology, PDOs are isolated from 54 patients with suspected or confirmed PC in the framework of a prospective feasibility trial. The drug response of single agents is determined by a viability assay. Areas under the curves (AUC) are clustered for each drug, and a prediction score is developed for combined regimens. Pharmacotyping profiles are obtained from 28 PDOs (efficacy 63.6%) after a median of 53 days (range 21-126 days). PDOs exhibit heterogeneous responses to the standard-of-care drugs, and are classified into high, intermediate, or low responder categories. Our developed prediction model allows a successful response prediction in treatment-naïve patients with an accuracy of 91.1% for first-line and 80.0% for second-line regimens, respectively. The power of prediction declines in pretreated patients (accuracy 40.0%), particularly with more than one prior line of chemotherapy. Progression-free survival (PFS) is significantly longer in previously treatment-naïve patients receiving a predicted tumor sensitive compared to a predicted tumor resistant regimen (mPFS 141 vs. 46 days; p = 0.0048). In conclusion, generation and pharmacotyping of PDOs is feasible in clinical routine and may provide substantial benefit.

Opportunities and delusions regarding drug delivery targeting pancreatic cancer-associated fibroblasts

A dense desmoplastic stroma formed by abundant extracellular matrix and stromal cells, including cancer-associated fibroblasts (CAFs) and immune cells, is a feature of pancreatic ductal adenocarcinoma (PDAC), one of the most lethal cancer types. As the dominant cellular component of the PDAC stroma, CAFs orchestrate intensive and biologically diverse crosstalk with pancreatic cancer cells and immune cells and contribute to a unique PDAC tumor microenvironment promoting cancer proliferation, metastasis, and resistance against both chemo- and immunotherapies. Therefore, CAFs and CAF-related mechanisms have emerged as promising targets for PDAC therapy. However, several clinical setbacks and accumulating knowledge of the PDAC stroma have revealed the heterogeneity and multifaceted biological roles of CAFs, and concerns regarding "what to deliver" and "how to deliver" have arisen when designing CAF-targeted drug delivery systems to specifically inhibit tumor-supporting CAFs without impairing tumor-restricting CAFs. In this review, we will discuss the complexity of CAFs in the PDAC stroma as well as the potential opportunities and common misconceptions regarding drug delivery efforts targeting PDAC CAFs.

Safety Considerations of Cancer Nanomedicine-A Key Step toward Translation

The rate of translational effort of nanomedicine requires strategic planning of nanosafety research in order to enable clinical trials and safe use of nanomedicine in patients. Herein, the experiences that have emerged based on the safety data of classic liposomal formulations in the space of oncology are discussed, along with a description of the new challenges that need to be addressed according to the rapid expansion of nanomedicine platform beyond liposomes. It is valuable to consider the combined use of predictive toxicological assessment supported by deliberate investigation on aspects such as absorption, distribution, metabolism, and excretion (ADME) and toxicokinetic profiles, the risk that may be introduced during nanomanufacture, unique nanomaterials properties, and nonobvious nanosafety endpoints, for example. These efforts will allow the generation of investigational new drug-enabling safety data that can be incorporated into a rational infrastructure for regulatory decision-making. Since the safety assessment relates to nanomaterials, the investigation should cover the important physicochemical properties of the material that may lead to hazards when the nanomedicine product is utilized in humans.

Pancreatic Ductal Adenocarcinoma: Current and Evolving Therapies

Pancreatic ductal adenocarcinoma (PDAC), which constitutes 90% of pancreatic cancers, is the fourth leading cause of cancer-related deaths in the world. Due to the broad heterogeneity of genetic mutations and dense stromal environment, PDAC belongs to one of the most chemoresistant cancers. Most of the available treatments are palliative, with the objective of relieving disease-related symptoms and prolonging survival. Currently, available therapeutic options are surgery, radiation, chemotherapy, immunotherapy, and use of targeted drugs. However, thus far, therapies targeting cancer-associated molecular pathways have not given satisfactory results; this is due in part to the rapid upregulation of compensatory alternative pathways as well as dense desmoplastic reaction. In this review, we summarize currently available therapies and clinical trials, directed towards a plethora of pathways and components dysregulated during PDAC carcinogenesis. Emerging trends towards targeted therapies as the most promising approach will also be discussed.

Nanomedicine strategies to overcome the pathophysiological barriers of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is one of the leading causes of cancer- related deaths. PDAC remains one of the most difficult-to-treat cancers, owing to its unique pathobiological features: a nearly impenetrable desmoplastic stroma, and hypovascular and hypoperfused tumour vessels render most treatment options largely ineffective. Progress in understanding the pathobiology and signalling pathways involved in disease progression is helping researchers to develop novel ways to fight PDAC, including improved nanotechnology-based drug-delivery platforms that have the potential to overcome the biological barriers of the disease that underlie persistent drug resistance. So-called 'nanomedicine' strategies have the potential to enable targeting of the Hedgehog-signalling pathway, the autophagy pathway, and specific RAS-mutant phenotypes, among other pathological processes of the disease. These novel therapies, alone or in combination with agents designed to disrupt the pathobiological barriers of the disease, could result in superior treatments, with increased efficacy and reduced off-target toxicities compared with the current standard-of-care regimens. By overcoming drug-delivery challenges, advances can be made in the treatment of PDAC, a disease for which limited improvement in overall survival has been achieved over the past several decades. We discuss the approaches to nanomedicine that have been pursued to date and those that are the focus of ongoing research, and outline their potential, as well as the key challenges that must be overcome.

Activity of MM-398, nanoliposomal irinotecan (nal-IRI), in Ewing's family tumor xenografts is associated with high exposure of tumor to drug and high SLFN11 expression

PURPOSE

To determine the pharmacokinetics and the antitumor activity in pediatric cancer models of MM-398, a nanoliposomal irinotecan (nal-IRI).

EXPERIMENTAL DESIGN

Mouse plasma and tissue pharmacokinetics of nal-IRI and the current clinical formulation of irinotecan were characterized. In vivo activity of irinotecan and nal-IRI was compared in xenograft models (3 each in nu/nu mice) of Ewing's sarcoma family of tumors (EFT), neuroblastoma (NB), and rhabdomyosarcoma (RMS). SLFN11 expression was assessed by Affymetrix HuEx arrays, Taqman RT-PCR, and immunoblotting.

RESULTS

Plasma and tumor concentrations of irinotecan and SN-38 (active metabolite) were approximately 10-fold higher for nal-IRI than for irinotecan. Two doses of NAL-IRI (10 mg/kg/dose) achieved complete responses maintained for >100 days in 24 of 27 EFT-xenografted mice. Event-free survival for mice with RMS and NB was significantly shorter than for EFT. High SLFN11 expression has been reported to correlate with sensitivity to DNA damaging agents; median SLFN11 mRNA expression was >100-fold greater in both EFT cell lines and primary tumors compared with NB or RMS cell lines or primary tumors. Cytotoxicity of SN-38 inversely correlated with SLFN11 mRNA expression in 20 EFT cell lines.

CONCLUSIONS

In pediatric solid tumor xenografts, nal-IRI demonstrated higher systemic and tumor exposures to SN-38 and improved antitumor activity compared with the current clinical formulation of irinotecan. Clinical studies of nal-IRI in pediatric solid tumors (especially EFT) and correlative studies to determine if SLFN11 expression can serve as a biomarker to predict nal-IRI clinical activity are warranted.

Second-line therapy for advanced pancreatic cancer: evaluation of prognostic factors and review of current literature

BACKGROUND

FOLFIRINOX is a standard first-line treatment for advanced pancreatic cancer (aPC) and no accepted second-line regimen exists.

MATERIAL & METHODS

We enrolled 71 aPC patients progressed to modified FOLFIRINOX (mFOLFIRINOX) treated with second-line chemotherapy.

RESULTS

Five partial responses (7.1%) and 19 (27.1%) disease stabilizations were reported. After a median follow-up of 20.1 months, median progression-free survival was 2.5 months (95% CI: 2.1-2.9 months) and median overall survival was 6.2 months (95% CI: 5.3-7.1 months). At multivariate analysis, CA19.9 level ≥ 59 upper normal limit resulted associated with worse survival (hazard ratio: 2.32; 95% CI: 1.12-4.78; p = 0.023).

CONCLUSION

Salvage chemotherapy could be useful for a subgroup of aPC patients. Prognostic factors might be helpful to identify patients with greater benefit.

PEPCOL: a GERCOR randomized phase II study of nanoliposomal irinotecan PEP02 (MM-398) or irinotecan with leucovorin/5-fluorouracil as second-line therapy in metastatic colorectal cancer

A multicenter, open‐label, noncomparative, randomized phase II study (PEPCOL) was conducted to evaluate the efficacy and safety of the irinotecan or PEP02 (MM‐398, nanoliposomal irinotecan) with leucovorin (LV)/5‐fluorouracil (5‐FU) combination as second‐line treatment in patients with metastatic colorectal cancer (mCRC). Patients with unresectable mCRC who had failed one prior oxaliplatin‐based first‐line therapy were randomized toirinotecan with LV/5‐FU (FOLFIRI) or PEP02 with LV/5‐FU (FUPEP; PEP02 80 mg/m² with LV 400 mg/m² on day 1 and 5‐FU 2400 mg/m² on days 1–2). Bevacizumab (5 mg/kg, biweekly) was allowed in both arms. The primary endpoint was 2‐month response rate (RR). Fifty‐five patients were randomized (FOLFIRI, n = 27; FUPEP, n = 28). In the intent‐to‐treat population (n = 55), 2‐month RR response rate was observed in two (7.4%) and three (10.7%) patients in the FOLFIRI and FUPEP arms, respectively. The most common grade 3–4 adverse events reported in the respective FOLFIRI and FUPEP arms were diarrhea (33% vs. 21%), neutropenia (30% vs. 11%), mucositis (11% vs. 11%), and grade 2 alopecia (26% vs. 25%). FUPEP has activity and acceptable safety profile in oxaliplatin‐pretreated mCRC patients.

Advances in Molecular Pathology and Treatment of Periampullary Cancers

OBJECTIVES

Periampullary cancers (PACs) include the following 4 traditional anatomic subtypes: pancreatic, ampullary, biliary, or duodenal cancers. This review was performed to highlight recent advances in the genomic and molecular understanding of each PAC subtype and the advances in chemotherapeutic and molecular trials in these cancer subtypes.

RESULTS

Recent advances have highlighted differences in the genomic and molecular features within each PAC subtype. Ampullary cancers can now be further defined accurately into their intestinal and pancreatobiliary subtypes using histomolecular profiling. K-ras mutation, which occurs in most pancreatic cancers, is found to occur less frequently in ampullary (42%-52%), biliary (22%-23%), and duodenal cancers (32%-35%), suggesting crucial differences in targetable mutations in these cancer subtypes.Ampullary cancers of intestinal subtype and duodenal cancers seem to share similarities with colorectal cancer, given that they respond to similar chemotherapeutic regimens. This has potential implications for clinical trials and treatment selection, where PACs are often considered together.

CONCLUSIONS

Future trials should be designed in view of our increased understanding of the different anatomic and histomolecularly profiled subtypes of PAC cancers, which respects their individual molecular characteristics, phenotype, and response to treatment.

International Association of Pancreatology (IAP)/European Pancreatic Club (EPC) consensus review of guidelines for the treatment of pancreatic cancer

BACKGROUND

Pancreatic cancer is one of the most devastating diseases with an extremely high mortality. Medical organizations and scientific societies have published a number of guidelines to address active treatment of pancreatic cancer. The aim of this consensus review was to identify where there is agreement or disagreement among the existing guidelines and to help define the gaps for future studies.

METHODS

A panel of expert pancreatologists gathered at the 46th European Pancreatic Club Meeting combined with the 18th International Association of Pancreatology Meeting and collaborated on critical reviews of eight English language guidelines for the clinical management of pancreatic cancer. Clinical questions (CQs) of interest were proposed by specialists in each of nine areas. The recommendations for the CQs in existing guidelines, as well as the evidence on which these were based, were reviewed and compared. The evidence was graded as sufficient, mediocre or poor/absent.

RESULTS

Only 4 of the 36 CQs, had sufficient evidence for agreement. There was also agreement in five additional CQs despite the lack of sufficient evidence. In 22 CQs, there was disagreement regardless of the presence or absence of evidence. There were five CQs that were not addressed adequately by existing guidelines.

CONCLUSION

The existing guidelines provide both evidence- and consensus-based recommendations. There is also considerable disagreement about the recommendations in part due to the lack of high level evidence. Improving the clinical management of patients with pancreatic cancer, will require continuing efforts to undertake research that will provide sufficient evidence to allow agreement.

A Multicenter, Open-Label Phase II Clinical Trial of Combined MEK plus EGFR Inhibition for Chemotherapy-Refractory Advanced Pancreatic Adenocarcinoma

PURPOSE

On the basis of preclinical evidence of synergistic activity between MEK and EGFR inhibitors in pancreatic ductal adenocarcinoma (PDAC), we evaluated the safety and efficacy of selumetinib, a MEK1/2 inhibitor, plus erlotinib in patients with previously treated advanced PDAC.

EXPERIMENTAL DESIGN

In this single-arm phase II trial, eligible patients received the combination of erlotinib 100 mg plus selumetinib 100 mg daily in 3-week cycles. Study assessments included measurement of clinical outcomes, with a primary endpoint of overall survival, and exploration of potential molecular predictors of treatment benefit.

RESULTS

Forty-six patients were enrolled and received a median of two cycles (range, 1-7). Although no objective responses were observed, 19 patients (41%) showed evidence of stable disease for ≥6 weeks, and 13 of 34 patients (38%) had a CA19-9 decline ≥50%. Median progression-free survival was 1.9 months [95% confidence interval (CI), 1.4-3.3 months], with a median overall survival of 7.3 months (95% CI, 5.2-8.0 months). Common adverse events included rash, diarrhea, and nausea/vomiting. Patients with tumors exhibiting an epithelial phenotype (demonstrated by a high level of E-cadherin expression) were more likely to be sensitive to study treatment. Tumor-derived DNA was detectable in plasma from the majority of patients using next-generation digital DNA sequencing, and its relative abundance correlated with tumor burden.

CONCLUSIONS

A therapeutic strategy of dual targeted inhibition of the MEK and EGFR pathways shows modest antitumor activity in pancreatic cancer. Specific molecular subtypes may derive greatest benefit from this combination. Further exploration, both with more potent MEK inhibitors and in molecularly enriched patient subsets, is warranted.

Longitudinal tumor hypoxia imaging with [(18)F]FAZA-PET provides early prediction of nanoliposomal irinotecan (nal-IRI) treatment activity

Background

Non-invasive measurement of tumor hypoxia has demonstrated potential for the evaluation of disease progression, as well as prediction and assessment of treatment outcome. [¹⁸F]fluoroazomycin arabinoside (FAZA) positron emission tomography (PET) has been identified as a robust method for quantification of hypoxia both preclinically and clinically. The goal of this investigation was to evaluate the feasibility and value of repeated FAZA-PET imaging to quantify hypoxia in tumors that received multi-dose chemotherapy.

Methods

FAZA-PET imaging was conducted over a 21-day period in a mouse xenograft model of HT-29 human colorectal carcinoma, following multi-dose chemotherapy treatment with irinotecan (CPT-11) or nanoliposomal irinotecan (nal-IRI, MM-398).

Results

Tumors treated with 10 mg/kg nal-IRI maintained significantly lower levels of hypoxia and smaller hypoxic fractions compared to tumors that received 50 mg/kg CPT-11. Specifically, differences in FAZA uptake were detectable 9 days before any significant differences in tumor volume were observed between the treatment groups.

Conclusions

These findings highlight the potential use of FAZA-PET as an early marker of treatment response following multi-dose chemotherapy.

Electronic supplementary material

The online version of this article (doi:10.1186/s13550-015-0135-x) contains supplementary material, which is available to authorized users.

A randomized phase II study of weekly nab-paclitaxel plus gemcitabine or simplified LV5FU2 as first-line therapy in patients with metastatic pancreatic cancer: the AFUGEM GERCOR trial

BACKGROUND

Metastatic pancreatic adenocarcinoma (PAC) prognosis remains dismal and gemcitabine monotherapy has been the standard treatment over the last decade. Currently, two first-line regimens are used in this setting: FOLFIRINOX and nab-paclitaxel plus gemcitabine. Increasing translational data on the predictive value of hENT1 for determining gemcitabine efficacy suggest that a non-gemcitabine-based regimen is favored in about 60 % of patients with PAC due to high resistance of PAC to this cytotoxic drug. This study aims to evaluate the efficacy of weekly nab-paclitaxel combined with gemcitabine or a simplified (s) LV5FU2 regimen in patients with previously untreated metastatic PAC.

METHODS/DESIGN

AFUGEM is a two-stage, open-label, randomized, multicenter, phase II trial. Patients with PAC who meet the inclusion criteria and provide written informed consent will be randomized in a 1:2 ratio to either nab-paclitaxel (125 mg/m(2)) plus gemcitabine (1000 mg/m(2)) given on days 1, 8, and 15 every 28 days or nab-paclitaxel (125 mg/m(2)) plus sLV5FU2 (leucovorin 400 mg/m(2) followed by bolus 400 mg/m(2) 5-fluorouracil and by 5-fluorouracil 2400 mg/m(2) as an 46-h intravenous infusion) given on days 1 and 15 every 28 days. A total of 114 patients will be randomized to one of the treatment arms. The primary endpoint is progression-free survival at 4 months. Secondary outcomes are rate and duration of response, disease control, overall survival, safety, and quality of life. Potential biomarkers of gemcitabine (hENT1, dCK) and 5-fluorouracil (TS) efficacy will be assessed.

DISCUSSION

The AFUGEM trial is designed to provide valuable information regarding efficacy and tolerability of nab-paclitaxel plus gemcitabine and nab-paclitaxel plus sLV5FU2 regimens. Identification of potential predictive biomarkers of gemcitabine and 5-fluorouracil is likely to drive therapeutic decisions in patients with metastatic PAC.

TRIAL REGISTRATION

AFUGEM is registered at Clinicaltrials.gov: NCT01964534 , October 15, 2013.

Nab-paclitaxel plus gemcitabine for metastatic pancreatic adenocarcinoma after Folfirinox failure: an AGEO prospective multicentre cohort

BACKGROUND

There is currently no standard second-line treatment for metastatic pancreatic adenocarcinoma (MPA), and progression-free survival is consistently <4 months in this setting. The aim of this study was to evaluate the efficacy and tolerability of Nab-paclitaxel plus gemcitabine (A+G) after Folfirinox failure in MPA.

METHODS

From February 2013 to July 2014, all consecutive patients treated with A+G for histologically proven MPA after Folfirinox failure were prospectively enrolled in 12 French centres. A+G was delivered as described in the MPACT trial, until disease progression, patient refusal or unacceptable toxicity.

RESULTS

Fifty-seven patients were treated with Nab-paclitaxel plus gemcitabine, for a median of 4 cycles (range 1-12). The disease control rate was 58%, with a 17.5% objective response rate. Median overall survival (OS) was 8.8 months (95% CI: 6.2-9.7) and median progression-free survival was 5.1 months (95% CI: 3.2-6.2). Since the start of first-line chemotherapy, median OS was 18 months (95% CI: 16-21). No toxic deaths occurred. Grade 3-4 toxicities were reported in 40% of patients, consisting of neutropenia (12.5%), neurotoxicity (12.5%), asthenia (9%) and thrombocytopenia (6.5%).

CONCLUSIONS

A+G seems to be effective, with a manageable toxicity profile, after Folfirinox failure in patients with MPA.

New avenues for improving pancreatic ductal adenocarcinoma (PDAC) treatment: Selective stroma depletion combined with nano drug delivery

The effectiveness of chemotherapy in PDAC is hampered by the dynamic interaction between stroma and cancer cell. The two opposing schools of thought - non-depletion of the stroma vs its depletion - to better drug efficacy are here discussed. Disrupting stroma-cancer cell interaction to reduce tumor progression and promote apoptosis is identified as the new direction of treatment for PDAC. Clinical data have shown that elimination of fibrosis and blockade of the Hedgehog pathway in stroma effectively promote drug delivery to tumor site and apoptosis. Reduced stiffness of ECM, lower fibrosis, higher permeability and higher blood flow after stroma depletion increase drug delivery. Combination strategies involving selective stroma depletion coupled with chemotherapy is currently proving to be the most efficient at clinical level. Striking the right balance between fibrosis depletion and angiogenesis promotion resulting in enhanced drug delivery and apoptosis is a major challenge. The use of nano drug delivery devices coupled with stroma depletion is emerging as the next phase treatment for PDAC. The breakthrough to combat PDAC will likely be a combination of early diagnosis and the emerging chemotherapy strategies.

Therapeutic Approaches for Metastatic Pancreatic Adenocarcinoma

Since the US Food and Drug Administration's approval of gemcitabine in 1996, numerous randomized trials have investigated treatment programs to further improve the quality of life and survival of patients with advanced pancreatic cancer. After little progress over the ensuing 15 years, 2 combination treatment programs recently conferred improved survival compared with gemcitabine monotherapy in patients with metastatic pancreatic cancer: FOLFIRINOX (folinic acid, 5-fluorouracil, irinotecan, oxaliplatin) and gemcitabine plus nab-paclitaxel. Importantly, our understanding of the biology of pancreatic cancer continues to grow. This improved biologic understanding holds great promise for integrating new targeted and immune-modifying therapies into current treatment programs.

(90)Y-clivatuzumab tetraxetan with or without low-dose gemcitabine: A phase Ib study in patients with metastatic pancreatic cancer after two or more prior therapies

BACKGROUND

For patients with metastatic pancreatic adenocarcinoma, there are no approved or established treatments beyond the 2nd line. A Phase Ib study of fractionated radioimmunotherapy was undertaken in this setting, administering (90)Y-clivatuzumab tetraxetan (yttrium-90-radiolabelled humanised antibody targeting pancreatic adenocarcinoma mucin) with or without low radiosensitising doses of gemcitabine.

METHODS

Fifty-eight patients with three (2-7) median prior treatments were treated on Arm A (N=29, (90)Y-clivatuzumab tetraxetan, weekly 6.5 mCi/m(2)doses×3, plus gemcitabine, weekly 200 mg/m(2) doses×4 starting 1 week earlier) or Arm B (N=29, (90)Y-clivatuzumab tetraxetan alone, weekly 6.5 mCi/m(2)doses×3), repeating cycles after 4-week delays. Safety was the primary endpoint; efficacy was also evaluated.

RESULTS

Cytopaenias (predominantly transient thrombocytopenia) were the only significant toxicities. Fifty-three patients (27 Arm A, 26 Arm B, 91% overall) completed ⩾1 full treatment cycles, with 23 (12 Arm A, 11 Arm B; 40%) receiving multiple cycles, including seven (6 Arm A, 1 Arm B; 12%) given 3-9 cycles. Two patients in Arm A had partial responses by RECIST criteria. Kaplan-Meier overall survival (OS) appeared improved in Arm A versus B (hazard ratio [HR] 0.55, 95% CI: 0.29-0.86; P=0.017, log-rank) and the median OS for Arm A versus Arm B increased to 7.9 versus 3.4 months with multiple cycles (HR 0.32, P=0.004), including three patients in Arm A surviving >1 year.

CONCLUSIONS

Clinical studies of (90)Y-clivatuzumab tetraxetan combined with low-dose gemcitabine appear feasible in metastatic pancreatic cancer patients beyond 2nd line and a Phase III trial of this combination is now underway in this setting.

Progress in the treatment of metastatic pancreatic cancer and the search for next opportunities

A growing number of therapeutic options are now available for patients with metastatic pancreatic cancer, informed by positive results from recently completed phase III clinical trials. These have led to modest, if not necessarily transformative, improvements in clinical outcomes. Although the standard of care for metastatic disease remains cytotoxic therapy, a variety of novel therapeutic approaches are currently under active investigation, several of which have already demonstrated encouraging results in phase I/II studies. The following three broad categories (with significant overlap among them) are highlighted here: stromal-depleting agents, immunotherapies, and signal transduction inhibitors. The mechanistic rationale, limitations, and promise of each of these strategies specific to pancreatic cancer are discussed, as are the aspects of this disease and this patient population that pose ongoing challenges in terms of both therapeutic management and biomarker-driven trial design.

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

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

TOP1 gene copy numbers are increased in cancers of the bile duct and pancreas

BACKGROUND

Bile duct and pancreatic cancer (PC) have poor prognoses and treatment options for inoperable patients are scarce. In order to improve outcome for these patients, there is an urgent need for biomarkers predictive of treatment effect. Irinotecan is a topoisomerase 1 (Top1) poison. Top1 protein, TOP1 gene copy number and mRNA expression, respectively, have been proposed as predictive biomarkers of response to irinotecan in other cancers. Here we investigate the occurrence of TOP1 gene aberrations in cancers of the bile ducts and pancreas.

MATERIAL AND METHODS

TOP1 and centromere 20 (CEN-20) numbers were investigated by fluorescence in situ hybridization analyses in tumor tissue from 226 patients. The frequencies of aberration in the TOP1 gene copy number, the CEN-20 copy number and the TOP1/CEN-20 ratio were analyzed. As TOP1 is located on chromosome 20, the CEN-20 probe was included to distinguish between chromosomal and gene amplifications.

RESULTS

In PC, 29.8% had an increased TOP1 copy number (≥ 3.5n gene copies per cell) and 10.8% had a TOP1/CEN-20 ratio >1.5. In bile duct cancer, 12.8 % had an increased TOP1 copy number and 6.4% had a TOP1/CEN-20 ratio >1.5. Neither the TOP1 copy number nor the TOP1/CEN-20 ratios could predict overall survival.

CONCLUSION

We here report that a substantial number of patients with bile duct or PC have increased TOP1 copy number and increased TOP1/CEN-20 ratio making further analyses on the association between TOP1 gene copy number and irinotecan efficacy clinically relevant.

Pancreatic cancer: from state-of-the-art treatments to promising novel therapies

Pancreatic cancer is expected to be the second deadliest malignancy in the USA by 2020. The survival rates for patients with other gastrointestinal malignancies have increased consistently during the past 30 years; unfortunately, however, the outcomes of patients with pancreatic cancer have not changed significantly. Although surgery remains the only curative treatment for pancreatic cancer, therapeutic strategies based on initial resection have not substantially improved the survival of patients with resectable disease over the past 25 years; presently, more than 80% of patients suffer disease relapse after resection. Preclinical evidence that pancreatic cancer is a systemic disease suggests a possible benefit for early administration of systemic therapy in these patients. In locally advanced disease, the role of chemoradiotherapy is increasingly being questioned, particularly considering the results of the LAP-07 trial. Novel biomarkers are clearly needed to identify subsets of patients likely to benefit from chemoradiotherapy. In the metastatic setting, FOLFIRINOX (folinic acid, 5-fluorouracil, irinotecan, and oxaliplatin), and nab-paclitaxel plus gemcitabine have yielded only modest improvements in survival. Thus, new treatments are urgently needed for patients with pancreatic cancer. Herein, we review the state-of-the-art of pancreatic cancer treatment, and the upcoming novel therapeutics that hold promise in this disease are also discussed.

N of 1 case reports of exceptional responders accrued from pancreatic cancer patients enrolled in first-in-man studies from 2002 through 2012

PURPOSE

To identify exceptional responders among patients with advanced pancreatic cancer enrolled in first-in-man (FIM) studies.

METHODS

A Scopus search identified 66 FIM studies that enrolled at least one patient with advanced pancreatic cancer between 2002-2012. Descriptive statistics were used to summarize categorical variables. We also screened CRKL amplifications in the FoundationOne™ pancreatic cancer database.

RESULTS

Most FIM studies included targeted therapies (76 vs. 24%). The most common targeted therapy involved cell cycle inhibitors (24%). Pharmacodynamic analyses were more frequently done in trials with targeted therapies (70 vs. 31%, p=0.006). Response rates were similar. Treatment-related death was 0.5%. Skin, cardiovascular and metabolic grade 3-4 toxicities were more frequent with targeted therapies. Four exceptional responses were identified including a complete response to bosutinib (Src Inhibitor) and partial responses to trametinib (MEK inhibitor) (2 patients) and CHR-3996 (histone deacetylase inhibitor). We found that CRKL amplifications, a potential biomarker for Src inhibitors, are present in 1% of PDA.

CONCLUSIONS

We retrospectively identified extraordinary responses among patients with advanced PDA enrolled in FIM studies with Src, HDAC and MEK inhibitors. We identified CRKL amplifications are present in 1% of PDA and need to be evaluated as predictive biomarker for Src inhibitors.

Advanced pancreatic adenocarcinoma: a review of current treatment strategies and developing therapies

Pancreatic adenocarcinoma is one of the deadliest solid malignancies. A large proportion of patients are diagnosed with locally advanced or metastatic disease at the time of presentation and, unfortunately, this severely limits the number of patients who can undergo surgical resection, which offers the only chance for cure. Recent therapeutic advances for patients with advanced pancreatic cancer have extended overall survival, but prognosis still remains grim. Given that traditional chemotherapy is ineffective in curing advanced pancreatic adenocarcinoma, current research is taking a multidirectional approach in the hopes of developing more effective treatments. This article reviews the major clinical trial data that is the basis for the current chemotherapy regimens used as first- and second-line treatments for advanced pancreatic adenocarcinoma. We also review the current ongoing clinical trials, which include the use of agents targeting the oncogenic network signaling of K-Ras, agents targeting the extracellular matrix, and immune therapies.

Making sense of current and emerging therapies in pancreatic cancer: balancing benefit and value

Pancreatic cancer remains the fourth leading cause of cancer deaths in the United States with a dismal prognosis and a 5-year survival of less than 5% across all stages.(1) In 2014, there were approximately 46,420 new cases of pancreatic cancer with only 9% of patients having localized disease.(2) Given that the vast majority of patients present with advanced disease, much of the focus for drug development has been in the metastatic setting, which is evident with the advent of two combination chemotherapy regimens for this indication. Although conventional cytotoxic chemotherapy remains the standard of care, an ongoing search for novel therapeutic approaches continues. We will highlight several new approaches here, with a particular emphasis on immunotherapeutic strategies. We will also introduce concepts regarding the potential economic effects associated with the development and implementation of new treatments in pancreatic cancer.

Pancreatic Cancer: Progress in Systemic Therapy

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is a leading cause of cancer-related deaths in the Western world. Due to lack of specific symptoms and no accessible precursor lesions, primary diagnosis is commonly delayed, resulting in the identification of only 15-20% of patients with potentially curable disease. The major limiting factor is an already locally advanced or metastatic disease at the time of diagnosis. Consequently, systemic therapy forms the backbone of treatment strategy for the majority of patients.

SUMMARY

A deeper understanding of the molecular characteristics of pancreatic cancer has led to the identification of several potential therapeutic targets. A variety of targeted therapies are currently under clinical evaluation as single agents or in combination with chemotherapy for PDAC. This review highlights the current state of chemotherapy in pancreatic cancer and provides an outlook on its future perspectives.

KEY MESSAGE

This review focuses on the current chemotherapy regimens for the systemic treatment of PDAC.

PRACTICAL IMPLICATIONS

Various neoadjuvant approaches have been explored, including chemoradiation, chemotherapy followed by chemoradiation or intensified chemotherapy without defining a standard of care so far. The standard of care is gemcitabine or 5-fluorouracil. The oral fluoropyrimidine S-1 may be a promising new agent in this setting. For first-line treatment of metastatic pancreatic cancer, no targeted therapy has yet demonstrated clinical benefit apart from the combination of the tyrosine kinase inhibitor erlotinib plus gemcitabine. Recently, novel chemotherapeutic regimens such as FOLFIRINOX and gemcitabine plus nanoparticle albumin-bound paclitaxel have been introduced. Both combinations have proved to be superior to the standard gemcitabine regimen. For second-line treatment the combination of 5-fluorouracil/leucovorin and oxaliplatin yields improved results compared to best supportive care.