The PARP1 selective inhibitor saruparib (AZD5305) elicits potent and durable antitumor activity in patient-derived BRCA1/2-associated cancer models.

BACKGROUND: Poly (ADP-ribose) polymerase 1 and 2 (PARP1/2) inhibitors (PARPi) are targeted therapies approved for homologous recombination repair (HRR)-deficient breast, ovarian, pancreatic, and prostate cancers. Since inhibition of PARP1 is sufficient to cause synthetic lethality in tumors with homologous recombination deficiency (HRD), PARP1 selective inhibitors such as saruparib (AZD5305) are being developed. It is expected that selective PARP1 inhibition leads to a safer profile that facilitates its combination with other DNA damage repair inhibitors. Here, we aimed to characterize the antitumor activity of AZD5305 in patient-derived preclinical models compared to the first-generation PARP1/2 inhibitor olaparib and to identify mechanisms of resistance. METHODS: Thirteen previously characterized patient-derived tumor xenograft (PDX) models from breast, ovarian, and pancreatic cancer patients harboring germline pathogenic alterations in BRCA1, BRCA2, or PALB2 were used to evaluate the efficacy of AZD5305 alone or in combination with carboplatin or an ataxia telangiectasia and Rad3 related (ATR) inhibitor (ceralasertib) and compared it to the first-generation PARPi olaparib. We performed DNA and RNA sequencing as well as protein-based assays to identify mechanisms of acquired resistance to either PARPi. RESULTS: AZD5305 showed superior antitumor activity than the first-generation PARPi in terms of preclinical complete response rate (75% vs. 37%). The median preclinical progression-free survival was significantly longer in the AZD5305-treated group compared to the olaparib-treated group (> 386 days vs. 90 days). Mechanistically, AZD5305 induced more replication stress and genomic instability than the PARP1/2 inhibitor olaparib in PARPi-sensitive tumors. All tumors at progression with either PARPi (39/39) showed increase of HRR functionality by RAD51 foci formation. The most prevalent resistance mechanisms identified were the acquisition of reversion mutations in BRCA1/BRCA2 and the accumulation of hypomorphic BRCA1. AZD5305 did not sensitize PDXs with acquired resistance to olaparib but elicited profound and durable responses when combined with carboplatin or ceralasertib in 3/6 and 5/5 models, respectively. CONCLUSIONS: Collectively, these results show that the novel PARP1 selective inhibitor AZD5305 yields a potent antitumor response in PDX models with HRD and delays PARPi resistance alone or in combination with carboplatin or ceralasertib, which supports its use in the clinic as a new therapeutic option.

ACT-Discover: identifying karyotype heterogeneity in pancreatic cancer evolution using ctDNA.

BACKGROUND: Liquid biopsies and the dynamic tracking of somatic mutations within circulating tumour DNA (ctDNA) can provide insight into the dynamics of cancer evolution and the intra-tumour heterogeneity that fuels treatment resistance. However, identifying and tracking dynamic changes in somatic copy number alterations (SCNAs), which have been associated with poor outcome and metastasis, using ctDNA is challenging. Pancreatic adenocarcinoma is a disease which has been considered to harbour early punctuated events in its evolution, leading to an early fitness peak, with minimal further subclonal evolution. METHODS: To interrogate the role of SCNAs in pancreatic adenocarcinoma cancer evolution, we applied whole-exome sequencing of 55 longitudinal cell-free DNA (cfDNA) samples taken from 24 patients (including 8 from whom a patient-derived xenograft (PDX) was derived) with metastatic disease prospectively recruited into a clinical trial. We developed a method, Aneuploidy in Circulating Tumour DNA (ACT-Discover), that leverages haplotype phasing of paired tumour biopsies or PDXs to identify SCNAs in cfDNA with greater sensitivity. RESULTS: SCNAs were observed within 28 of 47 evaluable cfDNA samples. Of these events, 30% could only be identified by harnessing the haplotype-aware approach leveraged in ACT-Discover. The exceptional purity of PDX tumours enabled near-complete phasing of genomic regions in allelic imbalance, highlighting an important auxiliary function of PDXs. Finally, although the classical model of pancreatic cancer evolution emphasises the importance of early, homogenous somatic events as a key requirement for cancer development, ACT-Discover identified substantial heterogeneity of SCNAs, including parallel focal and arm-level events, affecting different parental alleles within individual tumours. Indeed, ongoing acquisition of SCNAs was identified within tumours throughout the disease course, including within an untreated metastatic tumour. CONCLUSIONS: This work demonstrates the power of haplotype phasing to study genomic variation in cfDNA samples and reveals undiscovered intra-tumour heterogeneity with important scientific and clinical implications. Implementation of ACT-Discover could lead to important insights from existing cohorts or underpin future prospective studies seeking to characterise the landscape of tumour evolution through liquid biopsy.

Clinical Outcomes After Progression on First-Line Therapies in IDH1 Mutated Versus Wild-Type Intrahepatic Cholangiocarcinoma Patients.

BACKGROUND: Isocitrate dehydrogenase-1 (IDH1) mutations occur in a significant proportion of intrahepatic cholangiocarcinomas (iCCAs). No data are available regarding the prognostic impact of IDH1 mutations in advanced iCCA patients after progression on first-line therapies. OBJECTIVE: We investigated the role of IDH1 mutation in advanced iCCA after progression on first-line therapies. PATIENTS AND METHODS: After progression on first-line therapies for advanced iCCA, consecutive patients were retrospectively collected. The IDH1 status was tested at baseline. This analysis aimed to examine the association between the presence of IDH1 missense mutations and survival outcomes in patients with advanced iCCA treated with a second-line therapy. RESULTS: The analysis included 119 patients; 56/119 (47%) were IDH1 mutated (IDH1m) and 63/119 (53%) were IDH1 wild type (IDH1 WT). At univariate analysis for overall survival (OS), the presence of IDH1 mutation was associated with a worse median OS (mOS; 8.2 vs. 14.1 months; hazard ratio [HR] 1.9, 95% confidence interval [CI] 1.2-3.0, p = 0.0047). Patients harboring IDH1 mutations showed a worse objective response rate (ORR) compared with patients without IDH1 mutation, whereas no significant differences in disease control rate (DCR) were found. Multivariate analysis confirmed IDH1 mutations as an independent negative prognostic factor for OS (HR 1.7, 95% CI 1.1-2.7, p = 0.0256). By evaluating only patients receiving FOLFOX as second-line therapy, no statistically significant differences were found in terms of both OS and PFS between IDH1m and IDH1 WT patients. In this subset of patients, those harboring an IDH1 mutation showed a worse ORR and DCR compared with those without. Finally, at univariate analysis for OS from third-line treatment, the presence of an IDH1 mutation was associated with a trend toward a worse mOS (6.0 vs. 11.9 months; HR 1.6, 95% CI 0.8-3.2, p = 0.25). CONCLUSION: The present analysis constitutes the first evidence of a negative prognostic impact of IDH1 mutations in a cohort of patients treated after progression on first-line therapies in contrast to IDH1 inhibitors.

Human Metastatic Cholangiocarcinoma Patient-Derived Xenografts and Tumoroids for Preclinical Drug Evaluation.

PURPOSE: Cholangiocarcinoma (CCA) is usually diagnosed at advanced stages, with limited therapeutic options. Preclinical models focused on unresectable metastatic CCA are necessary to develop rational treatments. Pathogenic mutations in IDH1/2, ARID1A/B, BAP1, and BRCA1/2 have been identified in 30%-50% of patients with CCA. Several types of tumor cells harboring these mutations exhibit homologous recombination deficiency (HRD) phenotype with enhanced sensitivity to PARP inhibitors (PARPi). However, PARPi treatment has not yet been tested for effectiveness in patient-derived models of advanced CCA. EXPERIMENTAL DESIGN: We have established a collection of patient-derived xenografts from patients with unresectable metastatic CCA (CCA_PDX). The CCA_PDXs were characterized at both histopathologic and genomic levels. We optimized a protocol to generate CCA tumoroids from CCA_PDXs. We tested the effects of PARPis in both CCA tumoroids and CCA_PDXs. Finally, we used the RAD51 assay to evaluate the HRD status of CCA tissues. RESULTS: This collection of CCA_PDXs recapitulates the histopathologic and molecular features of their original tumors. PARPi treatments inhibited the growth of CCA tumoroids and CCA_PDXs with pathogenic mutations of BRCA2, but not those with mutations of IDH1, ARID1A, or BAP1. In line with these findings, only CCA_PDX and CCA patient biopsy samples with mutations of BRCA2 showed RAD51 scores compatible with HRD. CONCLUSIONS: Our results suggest that patients with advanced CCA with pathogenic mutations of BRCA2, but not those with mutations of IDH1, ARID1A, or BAP1, are likely to benefit from PARPi therapy. This collection of CCA_PDXs provides new opportunities for evaluating drug response and prioritizing clinical trials.

Molecular profile and its clinical impact of IDH1 mutated versus IDH1 wild type intrahepatic cholangiocarcinoma.

IDH1-mutated cholangiocarcinomas (CCAs) are an interesting group of neoplasia with particular behavior and therapeutic implications. The aim of the present work is to highlight the differences characterizing IDH1m and IDH1wt CCAs in terms of genomic landscape. 284 patients with iCCA treated for resectable, locally advanced or metastatic disease were selected and studied with the FOUNDATION Cdx technology. A comparative genomic analysis and survival analyses for the most relevant altered genes were performed between IDH1m and IDH1wt patients. Overall, 125 patients were IDH1m and 122 IDH1wt. IDH1m patients showed higher mutation rates compared to IDH1wt in CDKN2B and lower mutation rates in several genes including TP53, FGFR2, BRCA2, ATM, MAP3K1, NOTCH2, ZNF703, CCND1, NBN, NF1, MAP3KI3, and RAD21. At the survival analysis, IDH1m and IDH1wt patients showed no statistically differences in terms of survival outcomes, but a trend in favor of IDH1wt patients was observed. Differences in prognostic values of the most common altered genes were reported. In surgical setting, in IDH1m group the presence of CDKN2A and CDKN2B mutations negatively impact DFS, whereas the presence of CDKN2A, CDKN2B, and PBRM1 mutations negatively impact OS. In advanced setting, in the IDH1m group, the presence of KRAS/NRAS and TP53 mutations negatively impact PFS, whereas the presence of TP53 and PIK3CA mutations negatively impact OS; in the IDH1wt group, only the presence of MTAP mutation negatively impact PFS, whereas the presence of TP53 mutation negatively impact OS. We highlighted several molecular differences with distinct prognostic implications between IDH1m and IDH1wt patients.

Next-generation sequencing analysis of cholangiocarcinoma identifies distinct IDH1-mutated clusters.

BACKGROUND: IDH1-mutated intrahepatic cholangiocarcinomas (IDH1m iCCAs) could be treated with anti-IDH1 drugs, although the high heterogeneity in this class of tumours could limit treatment efficacy. METHODS: We selected 125 IDH1m iCCAs that were treated as resectable, locally advanced, or metastatic and were screened by the NGS-based FoundationOne gene panel. We conducted a mutation-based clustering of tumours and survival analysis. RESULTS: Three main clusters were identified. The most altered pathways in cluster 1 were cell cycle and apoptosis, RTK/RAS, PI3K, and chromatin modification. Of note, CDKN2A/2B were mutated in 41/44 patients of this cluster. In cluster 2, the most affected pathways were as follows: Chromatin modification, DNA damage control, PI3K, and RTK/RAS. In this cluster, the most frequently mutated genes were ARID1A and PBRM1. The most altered pathways in cluster 3 were as follows: Cell cycle and apoptosis, DNA damage control, TP53, and chromatin modification. Importantly, TP53 was mutated only in cluster 3 patients. In the cohort of patients treated with surgery, cluster 2 showed statistically significant better disease-free survival (DFS) and overall survival (OS) compared with patients in cluster 3 and cluster 1 (p = 0.0014 and p = 0.0003, respectively). In the advanced setting, cluster 2 experienced a statistically significant better PFS (p = 0.0012), a tendency toward a better OS from first-line treatment, and a better OS from first-line progression compared with patients in cluster 1 and cluster 3 (p = 0.0017). We proposed an easy-to-use algorithm able to stratify patients in the three clusters on the basis of the genomic profile. CONCLUSION: We highlighted three different mutation-based clusters with prognostic significance in a cohort of IDH1m iCCAs.

Gene mutational profile of BRCAness and clinical implication in predicting response to platinum-based chemotherapy in patients with intrahepatic cholangiocarcinoma.

BACKGROUND AND AIMS: Biliary tract cancers are rare malignancies with a poor prognosis and scarce therapeutic strategies. The significance of BRCAness in this setting is already unknown. METHOD: Tissue specimens of BTC patients treated with platinum-based chemotherapy have been analyzed through the FOUNDATIONPne assay. RESULTS: 72/150 (48%) BRCAness mutated and 78/150 (52.0%) wild type (WT) patients were included. The most commonly mutated genes in the BRCAness mutated group were: ARID1A (N = 32, 44%), CDKN2A (N = 23, 32%), KRAS/NRAS (N = 16, 22%), CDKN2B (N = 13, 18%), BRCA2 (N = 13, 18%), PBRM1 (N = 12, 17%), ATM (N = 11, 15%), FGFR2 (N = 10, 14%), TP53 (N = 8, 11%), IRS2 (N = 7, 10%), CREBBP (N = 7, 10%) (table 3, figure 1). At the univariate analysis BRCAness mutation was associated with longer median Progression Free Survival (mPFS) (HR 0.68; 95% CI 0.49-0.95; p = 0.0254); it was not associated with longer mOS but a trend toward a benefit in survival was found (HR 0.77; 95% CI 0.50-1.19; p = 0.2388). Patients with BRCAness mutation showed a higher percentage of disease control rate (77.8 vs 67.9; p = 0.04) compared to patients WT. Multivariate analysis confirmed BRCAness mutation (HR 0.66; 95% CI: 0.45-0.98; p = 0.0422) as independent favorable prognostic factors for PFS and a positive trend was found for OS (HR 0.84; 95% CI: 0.53-1.33; p = 0.3652). CONCLUSION: BRCAness BTC patients showed a better PFS compared BRCAnessWT patients after exposure to platinum-based chemotherapy. Moreover, the OS curves' trend showed in our analysis suggests that BRCAness mutated patients could benefit from a maintenance therapy with PARPi.

Phase I, multicenter, open-label study of intravenous VCN-01 oncolytic adenovirus with or without nab-paclitaxel plus gemcitabine in patients with advanced solid tumors.

BACKGROUND: VCN-01 is an oncolytic adenovirus (Ad5 based) designed to replicate in cancer cells with dysfunctional RB1 pathway, express hyaluronidase to enhance virus intratumoral spread and facilitate chemotherapy and immune cells extravasation into the tumor. This phase I clinical trial was aimed to find the maximum tolerated dose/recommended phase II dose (RP2D) and dose-limiting toxicity (DLT) of the intravenous delivery of the replication-competent VCN-01 adenovirus in patients with advanced cancer. METHODS: Part I: patients with advanced refractory solid tumors received one single dose of VCN-01. Parts II and III: patients with pancreatic adenocarcinoma received VCN-01 (only in cycle 1) and nab-paclitaxel plus gemcitabine (VCN-concurrent on day 1 in Part II, and 7 days before chemotherapy in Part III). Patients were required to have anti-Ad5 neutralizing antibody (NAbs) titers lower than 1/350 dilution. Pharmacokinetic and pharmacodynamic analyses were performed. RESULTS: 26% of the patients initially screened were excluded based on high NAbs levels. Sixteen and 12 patients were enrolled in Part I and II, respectively: RP2D were 1×1013 viral particles (vp)/patient (Part I), and 3.3×1012 vp/patient (Part II). Fourteen patients were included in Part III: there were no DLTs and the RP2D was 1×1013 vp/patient. Observed DLTs were grade 4 aspartate aminotransferase increase in one patient (Part I, 1×1013 vp), grade 4 febrile neutropenia in one patient and grade 5 thrombocytopenia plus enterocolitis in another patient (Part II, 1×1013 vp). In patients with pancreatic adenocarcinoma overall response rate were 50% (Part II) and 50% (Part III). VCN-01 viral genomes were detected in tumor tissue in five out of six biopsies (day 8). A second viral plasmatic peak and increased hyaluronidase serum levels suggested replication after intravenous injection in all patients. Increased levels of immune biomarkers (interferon-γ, soluble lymphocyte activation gene-3, interleukin (IL)-6, IL-10) were found after VCN-01 administration. CONCLUSIONS: Treatment with VCN-01 is feasible and has an acceptable safety. Encouraging biological and clinical activity was observed when administered in combination with nab-paclitaxel plus gemcitabine to patients with pancreatic adenocarcinoma. TRIAL REGISTRATION NUMBER: NCT02045602.

ESMO Scale for Clinical Actionability of Molecular Targets Driving Targeted Treatment in Patients with Cholangiocarcinoma.

PURPOSE: Treatment options for advanced cholangiocarcinoma are limited and prognosis is poor. Cholangiocarcinomas are highly heterogeneous at the molecular level, with divergent patterns between intrahepatic and extrahepatic forms, intrahepatic being particularly rich in actionable alterations. We compared survival in patients with advanced cholangiocarcinoma harboring alterations matched to targeted drugs, with patients harboring nonactionable alterations. EXPERIMENTAL DESIGN: Patients with cholangiocarcinoma treated between 2011 and 2020 at one institution, with available molecular analyses, were retrospectively reviewed. Genomic alteration actionability was classified according to the ESMO Scale for Clinical Actionability of Molecular Targets (ESCAT) and correlated with efficacy endpoints. RESULTS: Of 327 patients included, 78.9% had intrahepatic cholangiocarcinoma, 97.9% had received chemotherapy for metastatic disease. Actionable molecular alterations per ESCAT were identified in 184 patients (56.3%), including IDH1 mutations and FGFR2 fusions (23.1% and 8.0% of patients with intrahepatic cholangiocarcinoma, respectively). Median overall survival in 50 patients with ESCAT I-IV alterations who received matched therapy (48 with intrahepatic cholangiocarcinoma) was 22.6 months [95% confidence interval (CI), 20.1-32.8], compared with 14.3 months (95% CI 11.9-18.1) in 130 patients without actionable ESCAT alterations (HR, 0.58; 95% CI, 0.40-0.85; P = 0.005). Among patients receiving matched targeted therapy, median progression-free survival was longer for patients with alterations classified as ESCAT I-II compared with ESCAT III-IV (5.0 vs. 1.9 months; HR, 0.36; 95% CI, 0.15-0.87; P = 0.02). CONCLUSIONS: ESCAT represents a tool to guide clinicians in fine-tuning use of molecular profiling data to choose matched targeted therapies. Our data demonstrate that targeted treatment administered per alteration actionability according to ESCAT is associated with improved survival in cholangiocarcinoma, particularly in ESCAT I-II intrahepatic cholangiocarcinoma.

Emerging Treatment Strategies in Pancreatic Cancer.

ABSTRACT: Pancreatic ductal adenocarcinoma (PDAC) is one of the main causes of cancer death in well-developed countries. Therapeutic advances in PDAC to date have been modest. Recent progress to understand the molecular landscape of the disease has opened new treatment opportunities for a small subset of patients, frequently those with KRAS wild-type disease. Novel treatment strategies in PDAC include, among others, the use of nanotechnology and metabolic reprogramming. In addition, new strategies are being investigated, which are designed to overcome the resistance to checkpoint inhibitors, targeting DNA repair pathways including mismatch repair, increasing antigen presentation through the use of vaccines, targeting various signaling pathways, and reprogramming the tumor microenvironment. Here, we review the landscape of PDAC treatment strategies and some of these new agents.

A new targeted treatment for patients with a germline BRCA mutation: olaparib in pancreatic cancer.

Pancreatic cancer has a poor prognosis. Focused efforts in the development of novel treatments of this disease have led to the approval of new combinations. Improvements in knowledge of the biology of these tumors have been made, and it is now widely accepted that a proportion of patients have potentially targetable altered genes. One such gene is BRCA, which confers sensibility to PARP inhibitors. Olaparib, an oral PARP inhibitor, initially demonstrated activity in Phase II clinical trials including germline BRCA-mutated patients. This was confirmed in a Phase III clinical trial in pancreatic cancer patients with a germline BRCA mutation. After the results of this study, new scenarios have been evoked. We review the development of olaparib in pancreatic cancer.

Quality of life of patients with metastatic pancreatic adenocarcinoma initiating first-line chemotherapy in routine practice.

BACKGROUND: Despite advances in surgery, radiotherapy, and chemotherapy, pancreatic adenocarcinoma often progresses rapidly and causes death. The physical decline of these patients is expected to impact their quality of life (QoL). Therefore, in addition to objective measures of effectiveness, the evaluation of health-related QoL should be considered a matter of major concern when assessing therapy outcomes. METHODS: Observational, prospective, multicenter study including patients with metastatic pancreatic adenocarcinoma who started first-line chemotherapy in 12 Spanish centers. Treatment and clinical characteristics were recorded at baseline. Patients' health-related quality of life, ECOG, and Karnofsky index were measured at baseline, at Days 15 and 30, and every four weeks up to 6 months of chemotherapy. Health-related quality of life was measured using the EORTC-QLQ-C30 and EQ-5D questionnaires. Other endpoints included overall survival and progression-free survival. RESULTS: The study sample included 116 patients (median age of 65 years). Mean (SD) scores for the QLQ-C30 global health status scale showed a significant increasing trend throughout the treatment (p = 0.005). Patients with either a Karnofsky index of 70-80 or ECOG 2 showed greater improvement in the QLQ-C30 global health status score than the corresponding groups with better performance status (p ≤ 0.010). Pain, appetite, sleep disturbance, nausea, and constipation significantly improved throughout the treatment (p < 0.005). Patients with QLQ-C30 global health status scores ≥50 at baseline had significantly greater overall survival and progression-free survival (p = 0.005 and p = 0.021, respectively). No significant associations were observed regarding the EQ-5D score. CONCLUSIONS: Most metastatic pancreatic adenocarcinoma patients receiving first-line chemotherapy showed an increase in health-related quality of life scores throughout the treatment. Patients with lower performance status and health-related quality of life at baseline tended to greater improvement. The EORTC QLQ-C30 scale allowed us to measure the health-related quality of life of metastatic pancreatic adenocarcinoma patients receiving first-line chemotherapy.

NUC-1031/cisplatin versus gemcitabine/cisplatin in untreated locally advanced/metastatic biliary tract cancer (NuTide:121).

Gemcitabine/cisplatin is standard of care for first-line treatment of patients with advanced biliary tract cancer (aBTC); new treatments are needed. NUC-1031 is designed to overcome key cancer resistance mechanisms associated with gemcitabine. The tolerability/efficacy signal of NUC-1031/cisplatin in the Phase Ib ABC-08 study suggested that this combination may represent a more efficacious therapy than gemcitabine/cisplatin for patients with aBTC, leading to initiation of the global NuTide:121 study which will include 828 patients ≥18 years with untreated histologically/cytologically-confirmed aBTC (including cholangiocarcinoma, gallbladder or ampullary cancer); randomized (1:1) to NUC-1031 (725 mg/m2)/cisplatin (25 mg/m2) or gemcitabine (1000 mg/m2)/cisplatin (25 mg/m2), on days 1/8, Q21-days. Primary objectives are overall survival and objective response rate. Secondary objectives: progression-free survival, safety, pharmacokinetics, patient-reported quality of life and correlative studies. (Investigational new drug (IND) number: 139058, European Clinical Trials database: EudraCT Number 2019-001025-28, ClinicalTrials.gov identifier: NCT04163900).

The role of PIGF blockade in the treatment of colorectal cancer: overcoming the pitfalls.

Introduction: In colorectal cancer, anti-VEGF agents have demonstrated a survival benefit when combined with chemotherapy. However, development of resistance is very common. One of the mechanisms is due not to a failure in the VEGFR blockade, but rather to development of compensatory mechanisms of resistance, such as hypoxia-triggered upregulation of other proangiogenic factors, like placental growth factor (PlGF).Areas covered: This article summarizes the fundamental role of PlGF in the development of resistance to antiangiogenic treatment as well as the efficacy of aflibercept, ramucirumab, and regorafenib.Expert opinion: Aflibercept functions as a soluble decoy receptor precluding VEGFs and PlGF from binding to native VEGFR, and therefore preventing the emergence of resistance. Bevacizumab limits its function to preventing the interaction between VEGF-A and VEGFR. In combination with FOLFIRI (VELOUR trial), aflibercept improves survival in patients with metastatic CRC who are resistant or have progressed to oxaliplatin-based chemotherapy. Ramucirumab, a fully humanized immunoglobulin G1 (IgG-1) monoclonal antibody and regorafenib, a multikinase inhibitor, have significant improvement for overall survival as well as for progression-free survival in chemotherapy refractory settings.

New Horizons in the Treatment of Metastatic Pancreatic Cancer: A Review of the Key Biology Features and the Most Recent Advances to Treat Metastatic Pancreatic Cancer.

Only a limited number of therapeutic strategies are available for patients diagnosed with pancreatic adenocarcinoma, and disease recurrence and mortality are consequently high. For metastatic disease, two combinations are approved in the first line setting: a triplet with 5-fluoruracil, irinotecan, and oxaliplatin, and the combination of gemcitabine and nab-paclitaxel. In patients who have progressed on gemcitabine, a new nanoliposomal formulation of irinotecan has recently been approved. While these treatments have demonstrated some efficacy, there has been little increase in survival rates for metastatic pancreatic cancer patients. Consequently, there is an urgent need for research and development of new treatments. As there is now a deeper understanding of pancreatic cancer biology, new drugs targeting altered pathways are under research, including agents that target TGF-ß, IGF, or NOTCH. Furthermore, taking into account the role of the tumor stroma in this disease, some stroma-targeting drugs are being developed, including PEGPH20, a pegylated recombinant human hyaluronidase. In the immunotherapy field, although checkpoint inhibitors have failed to demonstrate benefit as monotherapies, combinations with other drugs are being investigated, with promising preliminary results. Other strategies under research are targeting tumor metabolism or DNA repair deficiency.

Initial Experience in the Treatment of "Borderline Resectable" Pancreatic Adenocarcinoma. / Experiencia inicial en el tratamiento del adenocarcinoma de páncreas borderline resectable.

INTRODUCTION: A borderline resectable group (APBR) has recently been defined in adenocarcinoma of the pancreas. The objective of the study is to evaluate the results in the surgical treatment after neoadjuvancy of the APBR. METHOD: Between 2010 and 2014, we included patients with APBR in a neoadjuvant and surgery protocol, staged by multidetector computed tomography (MDCT). Treatment with chemotherapy was based on gemcitabine and oxaliplatin. Subsequently, MDCT was performed to rule out progression, and 5-FU infusion and concomitant radiotherapy were given. MDCT and resection were performed in absence of progression. A descriptive statistical study was performed, dividing the series into: surgery group (GR group) and progression group (PROG group). RESULTS: We indicated neoadjuvant treatment to 22 patients, 11 of them were operated, 9 pancreatoduodenectomies, and 2 distal pancreatectomies. Of the 11 patients, 7 required some type of vascular resection; 5 venous resections, one arterial and one both. No postoperative mortality was recorded, 7 (63%) had any complications, and 4 were reoperated. The median postoperative stay was 17 (7-75) days. The pathological study showed complete response (ypT0) in 27%, and free microscopic margins (R0) in 63%. At study clossure, all patients had died, with a median actuarial survival of 13 months (9,6-16,3). The median actuarial survival of the GR group was higher than the PROG group (25 vs. 9 months; p < 0.0001). CONCLUSION: The neoadjuvant treatment of APBR allows us to select a group of patients in whom resection achieves a longer survival to the group in which progression is observed. Post-adjuvant pancreatic resection requires vascular resection in most cases.

Experiencia inicial en el tratamiento del adenocarcinoma de páncreas borderline resectable / Initial Experience in the Treatment of "Borderline Resectable" Pancreatic Adenocarcinoma

Introducción: Se ha definido un grupo de resecabilidad borderline resectable (APBR) en el adenocarcinoma de páncreas. El objetivo del estudio es evaluar los resultados en el tratamiento quirúrgico tras neoadyuvancia del APBR. Método: Entre 2010 y 2014 incluimos pacientes afectos de APBR en un protocolo de neoadyuvancia y cirugía, estadificados mediante tomografía computarizada multidetector (TCMD). El tratamiento con quimioterapia se basó en gemcitabina y oxaliplatino (GEMOX). Posteriormente, se realizó TCMD para descartar progresión, y se administró 5-FU en infusión y radioterapia concomitante. Se practicó TCMD y resección en ausencia de progresión. Se realizó un estudio estadístico descriptivo, dividiendo la serie en grupo resección (grupo GR) y grupo progresión (grupo PROG). El seguimiento finalizó en febrero de 2016. Resultados: Indicamos tratamiento neoadyuvante a 22 pacientes, 11 de ellos fueron finalmente intervenidos. Se realizaron 9 duodenopancreatectomías cefálicas, una duodenopancreatectomía total y una pancreatectomía corporocaudal. De los 11 pacientes, 7 requirieron algún tipo de resección vascular; 5 resecciones venosas, uno arterial y otro ambas. No hubo mortalidad postoperatoria, 7 (63%) tuvieron alguna complicación y 4 fueron reintervenidos. La estancia hospitalaria postoperatoria mediana fue 17 días (7-75). El estudio patológico evidenció márgenes microscópicos libres (R0) en el 63% de los pacientes y ausencia de afectación adenopática en 10 pacientes (ypN0). Al cierre del estudio, todos los pacientes habían fallecido, con una supervivencia actuarial mediana de 13 meses (9,6-16,3). La supervivencia actuarial mediana del grupo GR fue superior al grupo PROG (25 vs. 9 meses; p<0,0001). Conclusión: El tratamiento neoadyuvante del APBR permite seleccionar un grupo de pacientes en el que la resección consigue una supervivencia superior al grupo en el que se observa progresión. La resección pancreática posneoadyuvancia requiere resecciones vasculares en la mayoría de los casos (AU)

Introduction: A borderline resectable group (APBR) has recently been defined in adenocarcinoma of the pancreas. The objective of the study is to evaluate the results in the surgical treatment after neoadjuvancy of the APBR. Method: Between 2010 and 2014, we included patients with APBR in a neoadjuvant and surgery protocol, staged by multidetector computed tomography (MDCT). Treatment with chemotherapy was based on gemcitabine and oxaliplatin. Subsequently, MDCT was performed to rule out progression, and 5-FU infusion and concomitant radiotherapy were given. MDCT and resection were performed in absence of progression. A descriptive statistical study was performed, dividing the series into: surgery group (GR group) and progression group (PROG group). Results: We indicated neoadjuvant treatment to 22 patients, 11 of them were operated, 9 pancreatoduodenectomies, and 2 distal pancreatectomies. Of the 11 patients, 7 required some type of vascular resection; 5 venous resections, one arterial and one both. No postoperative mortality was recorded, 7 (63%) had any complications, and 4 were reoperated. The median postoperative stay was 17 (7-75) days. The pathological study showed complete response (ypT0) in 27%, and free microscopic margins (R0) in 63%. At study clossure, all patients had died, with a median actuarial survival of 13 months (9,6-16,3). The median actuarial survival of the GR group was higher than the PROG group (25 vs. 9 months; p < 0.0001). Conclusion: The neoadjuvant treatment of APBR allows us to select a group of patients in whom resection achieves a longer survival to the group in which progression is observed. Post-adjuvant pancreatic resection requires vascular resection in most cases (AU)

Predictive and prognostic biomarkers in personalized gastrointestinal cancer treatment.

Biomarkers play an important role in the detection and management of cancer patients. In gastrointestinal cancer, there is increasing interest in their development and validation according to specific tumor type. Prognostic biomarkers enable identification of patients with a more aggressive tumor evolution, while predictive biomarkers permit the identification of patients with a higher probability of responding or not to a specific treatment. Several biomarkers are currently widely employed in gastrointestinal cancers. These include rat sarcoma-2 virus (RAS) which is used to identify colorectal cancer (CRC) patients who will not respond to anti-epidermal growth factor receptor (EGFR) agents, while in gastric cancer, anti-human epidermal growth factor receptor 2 (HER2) therapy has been shown to only be active in HER2-positive patients. In pancreatic cancer, BRCA is a tool used to differentiate patients who are likely to respond to platinum-based combination therapies and to benefit from poly (ADP-ribose) polymerase (PARP) inhibitors. This review provides an update of the main biomarkers currently used in colorectal, gastric and pancreatic cancers, and reviews those that are being developed.

Analysis of mutant allele fractions in driver genes in colorectal cancer - biological and clinical insights.

Sequencing of tumors is now routine and guides personalized cancer therapy. Mutant allele fractions (MAFs, or the 'mutation dose') of a driver gene may reveal the genomic structure of tumors and influence response to targeted therapies. We performed a comprehensive analysis of MAFs of driver alterations in unpaired primary and metastatic colorectal cancer (CRC) at our institution from 2010 to 2015 and studied their potential clinical relevance. Of 763 CRC samples, 622 had detailed annotation on overall survival in the metastatic setting (OSmet) and 89 received targeted agents matched to KRAS (MEK inhibitors), BRAF (BRAF inhibitors), or PIK3CA mutations (PI3K pathway inhibitors). MAFs of each variant were normalized for tumor purity in the sample (adjMAFs). We found lower adjMAFs for BRAFV600E and PIK3CA than for KRAS, NRAS, and BRAF non-V600 variants. TP53 and BRAFV600E adjMAFs were higher in metastases as compared to primary tumors, and high KRAS adjMAFs were found in CRC metastases of patients with KRAS wild-type primary tumors previously exposed to EGFR antibodies. Patients with RAS- or BRAFV600E -mutated tumors, irrespective of adjMAFs, had worse OSmet. There was no significant association between adjMAFs and time to progression on targeted therapies matched to KRAS, BRAF, or PIK3CA mutations, potentially related to the limited antitumor activity of the employed drugs (overall response rate of 4.5%). In conclusion, the lower BRAFV600E and PIK3CA adjMAFs in subsets of primary CRC tumors indicate subclonality of these driver genes. Differences in adjMAFs between metastases and primary tumors suggest that approved therapies may result in selection of BRAFV600E - and KRAS-resistant clones and an increase in genomic heterogeneity with acquired TP53 alterations. Despite significant differences in prognosis according to mutations in driver oncogenes, adjMAFs levels did not impact on survival and did not help predict benefit with matched targeted agents in the metastatic setting.

Ramucirumab in metastatic colorectal cancer: evidence to date and place in therapy.

Colorectal cancer is the third most frequent cancer worldwide. Overall survival rates have improved greatly over the last few years due, at least in part, to the addition of targeted therapies to standard of care chemotherapy. Angiogenesis plays an important role in colorectal cancer, and therapies directed against the vascular endothelial growth factor (VEGF) axis have contributed significantly to improving the outcome of patients with metastatic colorectal cancer. Over the past few years, several new targeted antiangiogenic agents have been approved for this patient population, confirming the value of inhibiting tumour angiogenesis. The most recent among them is ramucirumab, a fully humanized monoclonal antibody that targets the extracellular domain of VEGF receptor 2. It has proven valuable in multiple tumour types including colorectal cancer. Several phase I and II clinical trials showed a favourable toxicity profile and promising clinical antitumour efficacy in colorectal cancer patients. In the phase III RAISE clinical trial, the addition of ramucirumab to FOLFIRI-based chemotherapy resulted in an improvement of overall survival in patients with metastatic colorectal cancer who had been previously treated with bevacizumab, oxaliplatin and a fluoropyrimidine. On the basis of these results, ramucirumab was approved by the US Food and Drug Administration for this setting. We present an overview of the key preclinical and clinical studies in the development of ramucirumab in the context of metastatic colorectal cancer.