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Immune-checkpoint inhibitors (ICI) have revolutionized the therapeutic landscape of cancer. However, optimal patient selection is still an unmet need. One-hundred-forty-six patients with metastatic cancer candidates to ICI at the Hospital Clinic of Barcelona Clinical Trials Unit were prospectively recruited in this observational study. Blood samples were collected at different timepoints, baseline LIPI score calculated and pre-ICI archived tissues retrieved to evaluate PD-L1, tumor-infiltrating lymphocytes (TILs) and PD1 mRNA levels. Tumor assessments were centrally reviewed by RECIST 1.1 criteria. Associations with overall response rates (ORR), durable clinical benefit (DCB), progression-free survival (PFS) and overall survival (OS) were performed with univariable/multivariable logistic and Cox regressions, where appropriate. At a median follow-up of 26.9 months, median PFS and OS were 2.7 and 12.9 months. Response rates were 17.8% with duration of response (DOR) of 4.4 months. LIPI score was independently associated with PFS (p = 0.025) and OS (p p = 0.005). Time-to-best response (TTBR) and ORR (p p p = 0.028) and DCB (univariate p = 0.043). PD1 mRNA levels were strikingly associated to complete responses (p = 0.021). To resume, in our prospective observational pan-cancer study, baseline LIPI score, immunotherapy-naïve status, cancer type and RT before starting ICI were the most relevant clinical factors independently correlated with immunotherapy outcomes. Longer TTBR seemed to associate with better survival, while PD1 mRNA and PD-L1 protein levels might be tumor-agnostic predictive factors of response to ICI and should be furtherly explored.

Cholangiocarcinoma (CCA) is a neoplasm with high mortality that represents 15% of all primary liver tumors. Its worldwide incidence is on the rise, and despite important advances in the knowledge of molecular mechanisms, diagnosis, and treatment, overall survival has not substantially improved in the last decade. Surgical resection remains the cornerstone therapy for CCA. Unfortunately, complete resection is only possible in less than 15–35% of cases, with a risk of recurrence greater than 60%. Liver transplantation (LT) has been postulated as an effective therapeutic strategy in those intrahepatic CCA (iCCA) smaller than 3 cm. However, the low rate of early diagnosis in non-resectable patients justifies the low applicability in clinical practice. The evidence regarding LT in locally advanced iCCA is scarce and based on small, retrospective, and, in most cases, single-center case series. In this setting, the response to neoadjuvant chemotherapy could be useful in identifying a subgroup of patients with biologically less aggressive tumors in whom LT may be successful. The results of LT in pCCA are promising, however, we need a very careful selection of patients and adequate experience in the transplant center. Locoregional therapies may be relevant in unresectable, liver-only CCA. In iCCA smaller than 2 cm, particularly those arising in patients with advanced chronic liver disease in whom resection or LT may not be feasible, thermal ablation may become a reliable alternative. The greatest advances in the management of CCA occur in systemic treatment. Immunotherapy associated with chemotherapy has emerged as the gold standard in the first-line treatment. Likewise, the most encouraging results have been obtained with targeted therapies, where the use of personalized treatments has shown high rates of objective and durable tumor response, with clear signs of survival benefit. In conclusion, the future of CCA treatment seems to be marked by the development of new treatment strategies but high-quality, prospective studies that shed light on their use and applicability are mandatory.

Background: MSI-H/dMMR is considered the first predictive marker of efficacy for immune checkpoint inhibitors (ICIs). However, around 39% of cases are refractory and additional biomarkers are needed. We explored the prognostic value of pretreatment LIPI in MSI-H/dMMR patients treated with ICIs, including identification of fast-progressors. Methods: A multicenter retrospective study of patients with metastatic MSI-H/dMMR tumors treated with ICIs between April 2014 and May 2019 was performed. LIPI was calculated based on dNLR &gt, 3 and LDH &gt, upper limit of normal. LIPI groups were good (zero factors), intermediate (one factor) and poor (two factors). The primary endpoint was overall survival (OS), including the fast-progressor rate (OS &lt, 3 months). Results: A total of 151 patients were analyzed, mainly female (59%), with median age 64 years, performance status (PS) 0 (42%), and sporadic dMMR status (68%). ICIs were administered as first or second-line for 59%. The most frequent tumor types were gastrointestinal (66%) and gynecologic (22%). LIPI groups were good (47%), intermediate (43%), and poor (10%). The median follow-up was 32 months. One-year OS rates were 81.0%, 67.1%, and 21.4% for good, intermediate, and poor-risk groups (p &lt, 0.0001). After adjustment for tumor site, metastatic sites and PS, LIPI remained independently associated with OS (HR, poor-LIPI: 3.50, 95%CI: 1.46–8.40, p = 0.02. Overall, the fast-progressor rate was 16.0%, and 35.7% with poor-LIPI vs. 7.5% in the good-LIPI group (p = 0.02). Conclusions: LIPI identifies dMMR patients who do not benefit from ICI treatment, particularly fast-progressors. LIPI should be included as a stratification factor for future trials.

Background The purpose of our study was to develop an online calculator to estimate the effect of docetaxel triplets (DPF) in first line of advanced gastric cancer (AGC), and to assess the external validity of docetaxel trials in individual patients. Methods The study includes patients with HER2(-) AGC treated with platin and fluoropyrimidine (PF) or with DPF in first line. Treatment effect and interactions were assessed using Bayesian accelerated failure time models. Result The series comprises 1376 patients; 238 treated with DPF and 1138 with PF between 2008 and 2019. DPF was associated with increased progression-free survival (PFS) and overall survival (OS) with time ratio (TR) 1.27 (95% credible interval [CrI], 1.15–1.40), and TR 1.19 (95% CrI, 1.09–1.27), respectively. Serious adverse events were more common with DPF, particularly hematological effects (32% vs 22%). Younger participants received greater DPF dose density without achieving greater disease control, while severe toxicity was likewise higher. DPF yielded superior OS in Lauren intestinal (TR 1.27, 95% CrI, 1.08–1.11) vs diffuse subtype (TR 1.17, 95% CrI, 1.09–1.24) and the probability of increasing OS > 15% was 90% vs 67% in each subtype, respectively. The effect dwindles over time, which can be attributed to pathological changes and clinical practice changes. Conclusion Our study confirms the effect of DPF is highly dependent on several clinical–pathological variables, with discreet and gradually declining benefit over platinum doublets in later years, at the expense of increased toxicity. These results may help to underpin the idea that external validity of AGC trials should be revised regularly.

Background Advanced esophageal adenocarcinoma (EAC) is generally treated similarly to advanced gastroesophageal junction (GEJ-AC) and gastric (GAC) adenocarcinomas, although GAC clinical trials rarely include EAC. This work sought to compare clinical characteristics and treatment outcomes of advanced EAC with those of GEJ-AC and GAC and examine prognostic factors. Patients and methods Participants comprised patients with advanced EAC, intestinal GEJ-AC, and GAC treated with platin and fluoropyrimidine (plus trastuzumab when HER2 status was positive). Overall and progression-free survival were estimated using the Kaplan-Meier method. Cox proportional hazards regression gauged the prognostic value of the AGAMENON model. Results Between 2008 and 2019, 971 participants from the AGAMENON-SEOM registry were recruited at 35 centers. The sample included 67.3% GAC, 13.3% GEJ-AC, and 19.4% EAC. Pulmonary metastases were most common in EAC and peritoneal metastases in GAC. Median PFS and OS were 7.7 (95% CI 7.3-8.0) and 13.9 months (12.9-14.7). There was no difference in PFS or OS between HER2- and HER2+ tumors from the three locations (p > 0.05). Five covariates were found to be prognostic for the entire sample: ECOG-PS, histological grade, number of metastatic sites, NLR, and HER2+ tumors treated with trastuzumab. In EAC, the same variables were prognostic except for grade. The favorable prognosis for HER2+ cancers treated with trastuzumab was homogenous for all three subgroups (p = 0.351) and, after adjusting for the remaining covariates, no evidence supported primary tumor localization as a prognostic factor (p = 0.331). Conclusion Our study supports the hypothesis that EAC exhibits clinicopathological characteristics, prognostic factors, and treatment outcomes comparable to intestinal GEJ-AC and GAC.

4152 Background: Despite huge efforts patients (pts) with advanced PDAC, still have a dismal long-term prognosis. The lack of available good-quality tissue samples for next generation sequencing (NGS) prevents from finding actionable alterations that could guide personalized treatments. Circulating tumor DNA (ctDNA) provides a non-invasive method for obtaining molecular information with therapeutic potential. Here, we present prospective data of ctDNA sequencing in pts with PDAC. Methods: We collected a single blood sample from advanced PDAC pts at any line of treatment (Tx) and at least 10 days apart from their last therapy. The samples were analyzed by Guardant360 plasma-based NGS, a standardized assay which covers microsatellite instability [MSI] evaluation and analysis of all four types of somatic alterations in 74 genes. Alterations were reported either as pathogenic or non-pathogenic. We classified each gene alteration according to the different OncoKB therapeutic levels of evidence [LE]. Additionally, we gathered the dates of both blood collection and molecular report. In case the molecular report showed no tumor-related alterations, it was interpreted as either absence of detectable mutations or low ctDNA levels, which would translate low disease burden or pts responding to therapy. Demographic and clinical data have been accessed from the medical records. Results: From 08/2019 to 09/2021 we collected blood samples from 94 PDAC pts. 56% of them were male and 53% were >65 years old. At the time of sample collection, nearly all pts were metastatic (98%). Regarding previous lines of Tx, 57% pts were Tx naïve; 10% were receiving active systemic Tx and 33% had experienced disease progression. Molecular reports were available in an average of 9.1 days. A total of 243 gene alterations were detected, having 94% of pts at least 1 genomic alteration, which was pathogenic in 69% of the cases (see Table). There were no pathogenic alterations ranked as OncoKB LE 1-2 ( MSI or NTRK). Seventy alterations (30%) were ranked as OncoKB LE 3A and 4 ( ARID1A, BRAC2, CDKN2A, KRAS). Three of these pts were treated with PARP inhibitors due to the presence of BRCA2 mutations. No ctDNA was detected in 15 pts (16%), despite being the sample collected >10 days from receiving their last Tx. Of these, 11 had low tumor burden (only peritoneal or lung metastases) and 4 had documented response to the Tx by the time the samples were collected. Conclusions: Real-time and prospective genomic profiling of pts with advanced PDAC using ctDNA is feasible and conveniently fast, which would allow its role in identifying and developing therapeutic targets for approved Tx or clinical trial treatments. [Table: see text]

518 Background: Eryaspase, asparaginase encapsulated in red blood cells is an investigational product under development. The encapsulated asparaginase induces the degradation of asparagine and glutamine, crucial for cancer cell growth and survival. An earlier Phase 2b study in patients with advanced pancreatic cancer showed an improvement in overall survival (OS) and progression free survival (PFS) with eryaspase plus chemotherapy. Methods: TRYbeCA-1 was a randomized, open-label Phase 3 trial of eryaspase combined with chemotherapy in patients with advanced adenocarcinoma of the pancreas who have progressed on only one prior line of systemic anti-cancer therapy. Patients were randomized in a 1:1 ratio to gemcitabine/nab-paclitaxel or irinotecan/fluorouracil (5FU) therapy (depending on first-line received) with or without eryaspase, administered as IV infusion on Day 1 and Day 15 of each 4-week cycle. Key eligibility criteria included progression on or following first-line systemic treatment, ECOG performance status 0 or 1, stage III-IV disease, documented evidence of disease progression, available tumor tissue and adequate organ function. The primary endpoint was OS. A total of 412 events were required for 90% power to detect a treatment effect hazard ratio (HR) of 0.725 at a two-sided significance level of 5%. Results: A total of 512 patients were included. Baseline characteristics were well balanced between the treatment arms. The study did not meet the OS primary endpoint [HR: 0.92 (95% confidence interval (CI), 0.76-1.11), p-value 0.375]. The median OS for patients treated with eryaspase plus chemotherapy was 7.5 mo (95% CI, 6.5-8.3), compared to 6.7 mo (95% CI, 5.4-7.5) for chemotherapy alone. There was a trend of nominal OS benefit in 107 patients treated with eryaspase and irinotecan-5FU compared to 109 patients in control subgroup, with a median OS of 8.0 mo versus 5.7 mo, respectively [HR: 0.81 (95% CI: 0.60- 1.09)]. Treatment effect was consistent across various prognosis factors. Median PFS was 3.7 mo vs. 3.5 mo in the eryaspase and control arms, respectively [HR: 0.89 (95% CI: 0.73-1.07), p-value 0.215]. Disease control rate was 57.6% and 49.0% (p-value 0.047) in the eryaspase and control arms, respectively. The most common adverse events were in the eryaspase arm were asthenia, diarrhea, and anemia (Grade 3-4: 16.9%, 7.66% and 17.3%, respectively). Eryaspase did not appear to enhance toxicity of chemotherapy. Conclusion: This large prospective study did not meet it primary endpoint of improving OS in patients treated with eryaspase. The addition of eryaspase demonstrated nevertheless a well-tolerated profile and an encouraging survival benefit in the irinotecan/5FU subgroup, warranting further investigation. Clinical trial information: NCT03665441.

Over the last 10 years, crucial improvements have been made in the pursuit of more effective therapies for colorectal cancer (CRC). In understanding the basis of CRC biology we have evolved from the classical ‘adenoma to carcinoma transition’ hypothesis, to the identification of two CRC clusters (microsatellite instability and chromosomal instability) and further classifications based on epigenetic events. Thanks to these advances in molecular analyses, key pathways, notably that of the EGFR, are now integrated into standard practice for therapeutic management and other pathways are being explored for blocking driving mutations and overcoming drug resistance. Genetic profiling is being developed to better predict prognosis and treatment response. The CRC subtyping consortium has combined and reanalyzed genetic signature data sets from several international groups. A definitive genetic CRC classification is currently being established and will be critical for clinical development of therapeutic strategies.

Neuroendocrine neoplasms (NENs) are a heterogeneous group of neoplasms that originate from neuroendocrine stem cells and express both neural and endocrine markers. They are found in almost every organ, and while NENs are mostly associated with slow growth, complications due to the uncontrolled secretion of active peptides, and metastatic disease, may significantly impair the quality of life and can ultimately lead to the death of affected individuals. Expanding knowledge of the genetic, epigenetic, and proteomic landscapes of NENs has led to a better understanding of their molecular pathology and consequently increased treatment options for patients. Here, we review the principal breakthroughs in NEN treatment management, owing largely to omics technologies over the last few years, current recommendations of systemic treatment, and ongoing research into the identification of predictive and response biomarkers based on molecular targeted therapies.

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.

Colorectal cancer; Driver gene; Mutant allele fraction Càncer colorectal; Gen conductor; Fracció d'al·lel mutant Cáncer colorrectal; Gen conductor; Fracción de alelo mutante 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.

Despite improvements in clinical outcomes of patients with colorectal cancer (CRC) over the past decades, prognosis remains poor, with a 5-year survival rate of less than 10 %. Fluoropyrimidine-based regimens have defined the standard of care for metastatic disease. However, with the identification of different genetic alterations involved in tumor cell signaling pathways, understanding the molecular pathogenesis of CRC has become of increasing importance in order to select personalized targeted therapies from which patients may potentially benefit. RAS mutations have proven to predict response to anti-epidermal growth factor receptor treatments. Additional hypothetical biomarkers of response, such as BRAF, PI3KCA, and PTEN, are under evaluation in ongoing clinical trials. In this article, we seek to review the recent development of novel drugs aimed to target these molecular aberrations and their impact on metastatic CRC patients.

Energy- and nutrient-sensing proteins such as AMPK, mTOR and S6K1 are now recognized as novel regulators of mitotic completion in proliferating cells. We investigated the cellular distribution of the Ser2481 autophosphorylation of mTOR, which directly monitors mTORC-specific catalytic activity, during mammalian cell mitosis and cytokinesis. Automated immunofluorescence experiments in human carcinoma cell lines revealed that phospho-mTOR (Ser2481) exhibited profound spatial and temporal dynamics during cell division. Phospho-mTOR (Ser2481) was strikingly enriched in mitotic cells, and in prophase, bright phospho-mTOR (Ser2481) staining could be clearly observed among condensed chromosomes. Phospho-mTOR (Ser2481) then redistributes from diffuse cytosolic staining that partially colocalizes with the mitotic spindle during the early phases of mitosis to the furrow at the onset of cytokinesis. Like the bona fide chromosomal passenger proteins (CPPs) INCENP and Aurora B, phospho-mTOR (Ser2481) displayed noteworthy accumulation in the central spindle midzone and the midbody regions, which persisted during the furrowing process. Accordingly, double-staining experiments confirmed that phospho-mTOR (Ser2481) largely colocalized with CCPs in the midbodies. The CPP-like mitotic localization of phospho-mTOR (Ser2481) was fully prevented by the microtubule-depolymerizing drug nocodazole; mitotic traveling of phospho-mTOR (Ser2481) to the midbody during telophase and cytokinesis, where it appears to be integrated into the CPP-driven cytokinetic machinery, may therefore require dynamic microtubules. Although the Ser2448-phosphorylated form of mTOR was also found at high levels during M-phase in human cancer cells, we failed to observe a significant association of phospho-mTOR (Ser2448) with CCP-positive mitotic and cytokinetic structures. Our findings add phospho-mTOR (Ser2481) to the growing list of phospho-active forms of proteins belonging to the AMPK/mTOR/S6K1 signaling axis that reside at the mitotic and cytokinetic apparatus. Future studies should elucidate how the specific ability of phospho-mTOR (Ser2481) to spatially and temporally couple to the cleavage furrow and midbody region as a CPP-like protein can signal to or from adjacent signaling complexes and/or with the basic machinery of cell abscission.

Autophagy, an evolutionary conserved catabolic process whereby cells generate energy and building blocks by promoting large-scale recycling of cytoplasmic macromolecules and organelles, represents a novel drug-targetable molecular mechanism underlying de novo (primary) refractoriness of HER2 gene-amplified breast cancer (BC) to HER2 inhibition. JIMT-1 cells, which were obtained from a HER2-positive BC patient that rapidly progressed on trastuzumab (Herceptin™) ab initio and that show cross-resistance to multiple HER1/2 inhibiting drugs including lapatinib (Tykerb™), were found to constitutively exhibit an enhanced autophagic vesicle content as assessed by immunoblotting of endogenous ATG8/LC3 lipidation and confocal imaging of the recruitment of ATG8/LC3 to autophagic vesicles. A significant decrease in the expression status of the specific autophagy receptor p62/SQSTM1 -a protein selectively degraded by autophagy- confirmed further a constitutive activation of the autophagic flux in trastuzumab-refractory JIMT-1 cells. When the Human Autophagy RT2 Profiler™ PCR Array was employed to profile the expression of 84 genes involved in autophagy, ATG12 was the most differentially up-regulated gene in JIMT-1 cells (>10-fold) as compared with trastuzumab-responsive SKBR3 cells. Upon collection of the transcriptional profile of the ATG12 gene across two sets of > 50 widely used BC cell lines, HER2+ BC cells with well-established de novo resistance to trastuzumab were characterized by expressing significantly higher levels of ATG12. When lentiviral-delivered small hairpin RNA was employed to stably & specifically knock-down ATG12 gene, JIMT-1 ATG12-shRNA cells were more significantly growth-inhibited by trastuzumab (up to 5-fold) than parental JIMT-1 cells. Moreover, the half-maximal inhibitory concentration (IC50) values for the small-molecule HER1/2 Tyrosine Kinase Inhibitors gefitinib, erlotinib and lapatinib were drastically reduced by up to 10 times in response to ATG12 gene silencing. Knockdown of autophagy-regulatory genes other than ATG12 (e.g. ATG5, ATG8/LC3B) similarly suppressed refractoriness to trastuzumab as well as co-existing resistance to other HER1/2-targeted agents. Knockdown of autophagy-specific genes, however, did not alter basal sensitivity of JIMT-1 cells to multiple cytotoxics including doxorubicin, cisplatin, paclitaxel and vinorelbine. When lysosomal degradation was pharmacologically inhibited by using the antimalarial lysosomotropic drug chloroquine we found a massive accumulation of abnormal autophagolysosomes that promoted synergistic re-sensitization of JIMT-1 cells to the growth inhibitory and apoptotic activity of trastuzumab. In summary, autophagy-specific genes appear to play a potent protective role against HER2 inhibiting drugs currently in use. Given that genetic and pharmacological targeting of autophagy was found to be detrimental to intrinsic BC refractoriness to HER2−targeted therapies, our current findings may provide rationale for novel, chloroquine-based therapeutic approaches aimed to circumvent primary-resistance and potentiate the efficacy of both trastuzumab and lapatinib in patients treated for HER2−positive BC disease. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-12-14.

Primary resistance of HER2 gene-amplified breast carcinomas (BC) to HER-targeted therapies can be explained in terms of overactive HER2-independent downstream pro-survival pathways. We here confirm that constitutive overexpression of Inhibitor of Apoptosis (IAP) survivin is indispensable for survival of HER2-positive BC cells with intrinsic cross-resistance to multiple HER1/2 inhibitors. The IC₅₀ values for the HER1/2 Tyrosine Kinase Inhibitors (TKIs) gefitinib, erlotinib and lapatinib were up to 40-fold higher in trastuzumab-unresponsive JIMT-1 cells than in trastuzumab-naïve SKBR3 cells. ELISA-based and immunoblotting assays demonstrated that trastuzumab-refractory JIMT-1 cells constitutively expressed ~ 4 times more survivin protein than trastuzumab-responsive SKBR3 cells. In response to trastuzumab, JIMT-1 cells accumulated ~10 times more survivin than SKBR3 cells. HER1/2 TKIs failed to down-regulate survivin expression in JIMT-1 cells whereas equimolar doses of HER1/HER2 TKIs drastically depleted survivin protein in SKBR3 cells. ELISA-based detection of histone-associated DNA fragments confirmed that trastuzumab-refractory JIMT-1 cells were intrinsically protected against the apoptotic effects of HER1/2 TKIs. Of note, when we knocked-down survivin expression using siRNA and then added trastuzumab, cell proliferation and colony formation were completely suppressed in JIMT-1 cells. Our current findings may be extremely helpful to design successful combinatorial strategies aimed to circumvent the occurrence of de novo resistance to HER2-directed drugs using survivin antagonists.

1072Background: PM1183 (lurbinectedin, Zepsyre) is a new anticancer drug that blocks transcription, induces DNA double-strand breaks, and modulates the tumor microenvironment. Single-agent PM1183 h...

Colorectal cancer (CRC) is currently one of the most lethal and prevalent tumors worldwide. Prognosis in the metastatic setting remains poor despite therapeutic advances. In addition to chemotherapy, new drugs have recently been developed targeting signaling pathways involved in tumor growth, differentiation and angiogenesis. Aflibercept , a recombinant protein derived from VEGF receptors 1 and 2, also targets this angiogenesis pathway but via a different mechanism, acting as VEGF decoy, thus blocking other VEGFs.A comprehensive review of preclinical studies with aflibercept in cell lines and xenografts of different tumor types is presented. Aflibercept safety, pharmacokinetics and pharmacodynamics data from Phase I studies in solid tumor patients are discussed. Implications of Phase II studies and the pivotal Phase III VELOUR trial of second-line treatment in metastatic CRC (mCRC) patients evaluating aflibercept alone or combined with chemotherapy are also described.In this challenging field, aflibercept offers a good option for oxaliplatin-refractory mCRC patients when combined with irinotecan and 5-fluorouracil irrespective of prior anti-angiogenic treatment. Therapeutic management may be further advanced by characterization of patients with predictive biomarkers and molecular profiles to improve benefit with this treatment.

3539 Background: VEGF-A and ANG-2 have complementary roles in regulation of tumor angiogenesis. Targeting VEGF-A with BEV in combination chemotherapy (CT) in mCRC has proven to increase PFS and OS. ANG-2 is overexpressed and associated with poor outcome of mCRC pts receiving BEVcontaining treatment. Hence, dual blockade of VEGF-A and ANG-2 by the bispecific mAb VAN with standard CT may improve clinical activity in mCRC. Methods: All pts received mFOLFOX-6 and were randomized 1:1 to also receive intravenous VAN 2000 mg every other week (Q2W) (Arm A) or BEV 5 mg/kg Q2W (Arm B). The primary end point was investigator assessed progression-free survival (PFS). Key eligibility criteria included pts with non-resectable mCRC, no prior therapy for advanced disease, PS 0-1, adequate organ functions, and no history of GI fistula/perforation or intraabdominal abscess within the last 6 months. Results: 192 pts were randomized (Arms A/B, n = 95/97) by 39 sites in 7 countries, between Oct 2014 and May 2016. Median follow-up was 17.6 months (range 2.8 – 20.7). In the ITT population (n = 189; Arms A/B, n = 94/95), median PFS in Arms A and B was 11.3 and 11.0 months (stratified hazard ratio (HR) 1.00 (95%CI 0.64-1.58; p = 0.985)), respectively. Objective response rate was 52.1% vs 57.9%. Relevant prognostic factors incl. RAS/BRAF status and tumor sidedness were balanced between arms and did not significantly influence outcome. Baseline plasma ANG-2 levels were prognostic in both arms but not predictive for response to VAN. The overall incidence of adverse events (AEs) grade ≥ 3 was similar (Arms A/B, 83.9%/82.1%); AEs grade ≥ 3 attributed to the mode of action of VAN/BEV included hypertension (37.6%/18.9%), hemorrhage (2.2%/1.1%), thromboembolic events (venous 6.5%/2.1%; arterial 1.1%/3.2%) and GI perforations incl. GI fistula & abdominal abscess (10.6%/8.4%). Conclusions: The combination of VAN and FOLFOX did not improve PFS and was associated with a marked increase in hypertension compared with BEV plus FOLFOX. Our results strongly suggest that ANG-2 is not a relevant therapeutic target in the setting of first line mCRC. Clinical trial information: NCT02141295.

409 Background: PC is the 4th leading cause of cancer-related death, with limited efficacy of systemic treatment (tx) beyond first-line chemotherapy (chemo). We aimed to assess the potential benefit of phase 1 trials in this setting. Methods: From 2011 to 2016, 49 pts were enrolled in 54 phase 1 trials at our institution. Clinical and molecular data were retrospectively extracted from medical records. Time to progression (TTP) was calculated from time of tx start to discontinuation due to progressive disease, and clinical benefit rate (CBr) was defined as partial response or stable disease > 4 months. Results: Median age was 58 (41-75), 69% were male, 60% had metastases in liver. Most pts received gemcitabine-based regimens (47%) or Folforinox (32%) as first-line tx (median TTP of 5.63 months [CI 95% 4.0-8.1]). Median tx line of Phase 1 trial was 3 (range 2-5). Regimens included chemo or immunotherapies (chemo-imm group) in 16 cases (12 and 4, respectively), small molecule inhibitor (SMI) as single-agent in 19 cases (SMI.1 group), and SMI in combinations in 19 cases (SMI.2 group). In 17 cases, tx was matched to genomic profile; most frequent matches were PI3K + MEK SMI or RAF SMI ( KRAS mut in 7 pts), PI3K SMI ( PTEN loss/ PIK3CA mut in 3 pts) and PD1 blockade (PDL1 high in 4 pts). There were 3 (6%) partial responses (PI3K SMI unmatched, RAF SMI matched and anti-PD1 agent matched) and 12 (24%) disease stabilizations. Median TTP in phase 1 trial was 1.9 months [CI 95% 1.6-2.5], without significant differences if matched/unmatched agent (p = 0.5) or tx given as second-line/later regimen (p = 0.5). Median TTP was 2.7 months [CI95% 1.6-10.7] with chemo-imm (control arm), 2.0 months [CI95% 1.8-5.6] with SMI.2 (HR = 1.8, p = 0.13) and 1.4 months [CI95% 1.3-2.8] with SMI.1 (HR = 3.0, p = 0.004). This difference was maintained in a multivariable model (HR = 2.9, p = 0.005). CBr with chemo-imm (38%) or SMI.2 (21%) was higher as compared with SMI.1 (5%; p = 0.06). Conclusions: Selected PC pts are eligible to phase 1 trials and up to one-third derive substantial benefit from the intervention. In our experience, chemo-imm agents or targeted SMI given as combination regimens associate with longer TTP and CBr when compared with single-agent SMI.

Colorectal cancer (CRC) is currently the third most common cancer worldwide, with up to 1 million new cases diagnosed each year. Despite improvements in clinical outcomes of patients with this tumor over the past decades, prognosis remains poor with a 5-year survival rate of10%. The currently available systemic chemotherapeutic options for patients with colon cancer consist essentially of fluoropyrimidine-based regimens, alone or in combination with oxaliplatin or irinotecan. The addition of the anti-vascular endothelial growth factor (VEGF) monoclonal antibody (mAb) bevacizumab to the above mentioned first- or second-line chemotherapies has demonstrated an improvement in overall survival and a delay in disease progression. Aflibercept is a recombinant protein from the domain 2 of the VEGF receptor-2 attached to the Fc portion of IgG1. In preclinical studies, aflibercept has demonstrated a more favorable pharmacokinetic profile. Aflibercept has been evaluated in a Phase III study in combination with irinotecan-based chemotherapy in patients with metastatic CRC refractory to oxaliplatin-based chemotherapy. The results of the VELOUR study showed that the addition of aflibercept produced an advantage in both progression-free and overall survival.In this review article, we will look over the preclinical and clinical development of aflibercept.In our opinion research is moving forward on a good path; we have seen the recent approval of aflibercept, and in the following years we might have newer standard treatment options among the latest compounds under development.

3509Background: The mutant allele fractions (MAFs) of a driver gene may influence response to matched targeted therapies, such as KRAS and anti-EGFR antibodies in CRC. We performed a comprehensive ...

4085Background: BTC is an heterogeneous disease that includes intrahepatic cholangiocarcinoma (IHC), extrahepatic cholangiocarcinoma (EHC), gallbladder carcinomas (GBC) and ampulloma (AM), typicall...

272 Molecular prescreening (MP) to treat advanced pancreatic cancer (PC) patients (pts) in early clinical trials Background: Advanced PC has a dismal prognosis, with conventional therapies having poor impact on disease course. The aim of this study was to investigate the impact of a MP program to identify potentially targetable alterations (PTa) in PC pts eligible for clinical trials with matched targeted therapies. Methods: From Jan 2011 to June 2015, a total of 86 chemorefractory PC pts were referred to MP at the VHIO Phase I Unit. Archived tumor samples were analyzed for selected gene mutations (mut) in using mass spectrometry (MassARRAY, Sequenom) until June 2014 or next-generation sequencing (Amplicon, MiSeq) thereafter. PTEN and PDL1 expression levels were measured with immunohistochemistry. All demographic, treatment and survival data were extracted retrospectively from electronic medical records. Results: Median age was 61 years (range 29-78) and 64% were male. Median treatment lines before MP was 2 (range 1-5). Tissue used for MP was primary tumor in 74% and metastatic lesion in 26%. In total, 29% of the samples did not have enough material for mut analysis. The most common PTa were KRAS mut (20/35 with Sequenom, 57%; 22/26 with Amplicon, 85%; p = 0.02), PTEN low (9/22, 41%), PTEN null (4/22, 18%) and CDKN2A mut (2/26, 8%). RNF43 mut, STK11 mut, BRAF V600E and BRAF G469A were found in one sample each. A total of 30 pts were enrolled in Phase I trials following MP, 10 of them with a direct matched therapy (5 with PI3K pathway inh - PTEN low/null, 3 with PI3K + MEK inhibitor - KRAS mut, 1 anti-PDL1 therapy - PDL1 high, 1 HDM2 inh - TP53 wild-type). Partial response was observed in 1 case (PI3K inh + chemotherapy, PTEN null) and stable disease in additional 4 pts (3 with PI3K inh +/- chemotherapy, PTEN low/null; 1 PI3K + MEK inh, KRASmut). Median time on treatment with matched therapy was 2.5 months (CI95% 1.8 – not reached). Conclusions: Genomic/proteomic characterization of PC is able to identify a subpopulation eligible for matched therapy in early clinical trials, with rare cases presenting a clear treatment benefit. Low recruitment can be linked to lack of enough material for MP, low prevalence of PTa and patient characteristics

578 Background: CRC site is associated with differences in key molecular features that may impact survival in the metastatic (met) setting. We assessed the magnitude of outcome differences in a non-clinical trial scenario and explored how rectum cancer (RC) compares with right- and left-sided (RS and LS) colon tumors. Methods: Retrospective analysis of clinicopathological and molecular data from all mCRC patients (pts) treated at VHIO from January 2010 to June 2015. Targeted mutation (mut) profiling of driver oncogenes was performed by mass spectrometry (MassARRAY, Sequenom) or with next generation sequencing (Amplicon MiSeq, Illumina). Survival after relapse (SAR) was defined as time from diagnosis of met disease to death. Tumor site was categorized as RS (cecum, ascending, hepatic flexure, and transverse), LS (splenic flexure, descending, and sigmoid) or RC. We performed Cox proportional hazards models and adjusted for covariates including number and location of met sites, surgical resection of met lesions, and KRAS, BRAF and PIK3CA mut. Results: From 686 pts analyzed, primary site was RS/LS/RC in 29.4%/43.4%/27.2%, respectively. Pts with LS tumors were less likely to have ≥ 2 met sites (32%/20%/29%; p = 0.01). Lung metastases were more common in RC pts (20%/15%/36%; p < 0.001), peritoneal metastasis in pts with RS tumors (28%/14%/5%, p < 0.001). Surgical resection of any met disease was performed less frequently in pts with RS tumors (28%/46%/41%; p < 0.001). KRAS mut (59%/45%/44%), BRAF V600E mut (9%/5%/3%) and PIK3CAmut (25%/14%/11%) were more prevalent in RS tumors. In the overall population with survival data (n = 606, 424 events), SAR was significantly lower in pts with RS tumors (31/46/46 months; RS vs. LS HR = 1.54 [1.2-2.0], p < 0.001; rectum vs. left HR = 1.0 [0.7-1.3], p = 0.83). For comparison, worse SAR was also seen in the subset of pts (n = 337; 276 events) not eligible for surgical resection of met disease (26/31/35 months; right vs. left HR = 1.60 [1.2-2.2], p = 0.004; rectum vs. left HR = 0.9 [0.6-1.2], p = 0.42). Conclusions: The worse SAR of pts diagnosed with right-sided CRC tumors cannot be explained only by their distinctive met pattern or mutation profile of common oncogenes. Left-sided and rectum tumors have similar outcomes.

In the previous issue of Breast Cancer Research, Jin and colleagues [1] demonstrated that the lipogenic enzyme fatty acid synthase (FASN) is phosphorylated when it is in complex with the tyrosine kinase receptor HER2. HER2-dependent activating phosphorylation of FASN was related to tumor progression and was sensitive to the dual HER1/HER2 tyrosine kinase inhibitor lapatinib [1]. Adding to knowledge of the therapeutic value of the phosphorylation status of FASN in HER2-driven breast cancer (BC), we now provide experimental evidence that the expression status of FASN in the extracellular milieu (that is, extracellular FASN) may function as a novel biomarker that distinctively predicts molecular functioning of lapatinib. AMP-activated protein kinase (AMPK)-activating drugs, by mimicking an elevated AMP/ATP ratio in BC cells, drastically augment the release of extracellular FASN in HER2-positive BC cells [2]. Lapatinib-induced deprivation of tumor cell energy activates AMPK to trigger an entire cascade of metabolic events, including suppression of FASN expression and activity [1,3]. We hypothesized that a differential ability to initiate AMPK-sensed metabolic stress responses may provide information about the efficacy of HER-targeting drugs via changes in the extracellular FASN status. Enzyme-linked immunosorbent assay (ELISA)-based quantitative analyses revealed that lapatinib treatment drastically enhanced extracellular FASN concentration (by at least 8.0-fold) (Figure ​(Figure1a).1a). Immunoblotting assessment of AMPK phosphorylation at Thr172 confirmed that lapatinib treatment induced a strong activation of AMPK (Figure ​(Figure1b).1b). A weak but detectable upregulation of PP-AMPKThr172 was observed upon treatment with gefitinib. Trastuzumab, cetuximab, and erlotinib - all of which are unable to promote FASN release - failed to activate AMPK. AMPK knockdown using short interfering RNA (siRNA) transfection [2] fully prevented lapatinib-induced FASN release (Figure S1). Immunoblotting and cell imaging analyses confirmed that FASN was depleted from the cytosol of lapatinib-treated HER2 overexpressors and accumulated in their extracellular milieu (Figure S1). Figure 1 Lapatinib's molecular functioning involves AMPK-dependent release of extracellular fatty acid synthase (FASN). (a) HER1 or HER2 inhibitors (or both) differentially regulate extracellular expression of FASN. FASN concentration in cell culture supernatants ... Treatment with lapatinib dramatically increased FASN release (by approximately 17 times) in lapatinib-responsive SKBR3 TzbR cells (Figure ​(Figure1c),1c), which were selected for long-term outgrowth in trastuzumab-containing culture medium. Extracellular FASN remained unaltered in response to trastuzumab or lapatinib in JIMT-1 BC cells, which exhibit de novo cross-refractoriness to multiple HER1/2-targeted therapies (Figure ​(Figure1c).1c). Lapatinib treatment significantly activated AMPK and promoted an enormous accumulation of extracellular FASN in lapatinib-hypersensitive MCF-7/HER2 cells (Figure ​(Figure1d).1d). Equimolar concentrations of lapatinib failed to activate AMPK or to alter FASN release into the extracellular milieu of MCF-7/HER2 LapR cells, which were obtained by continuously subculturing parental MCF-7/HER2 cells with high-dose lapatinib. High levels of circulating FASN can be found in peripheral blood of HER2-overexpressing BC patients [4]. The exclusive ability of lapatinib to actively promote the extracellular release of FASN via AMPK-sensed energy depletion in metabolically demanding HER2-driven BC cell growth might provide a molecular rationale to evaluate the predictive value of circulating FASN in HER2-positive BC patients receiving lapatinib.

Background: Integrins promote cell survival, metastasis, and angiogenesis, with integrins ανβ3 and ανβ5 promoting neovascularization. Abituzumab (EMD 525797) is a humanized monoclonal IgG2 antibody that specifically binds to the αν integrin subunit to inhibit αν integrin-mediated functions. It has shown antitumor activity in preclinical models and clinical trials. We investigated the tolerability and potential anti-angiogenic activity of abituzumab using DCE-MRI. Methods: This phase I study recruited patients (pts) ≥18 years with liver metastases (3-10 cm in diameter) of either colorectal (CRC) or ovarian cancer (OC) who had failed standard therapy. Pts received abituzumab 250, 500, 1,000, or 1,500 mg IV q2w, with ≥6 pts per dose. The decision to escalate the dose was based on the occurrence of dose-limiting toxicity (DLT). DCE-MRI scans were performed 24 and 96 hours after the first abituzumab dose, 1 week after first dose, and immediately prior to the second dose to identify changes in parameters including Ktrans, extracellular/extravascular volume, and blood plasma volume during one cycle of therapy. DCE-MRI scan data were analyzed centrally. Tumor response was evaluated every 6 weeks. Primary objectives were to assess the tolerability of abituzumab and to investigate vascular and volumetric responses to abituzumab using DCE-MRI. Secondary objectives included characterization of the pharmacokinetics of abituzumab and its effect on exploratory pharmacodynamic markers, including tumor markers. Results: 41 pts were enrolled (CRC, n = 30; OC, n = 11). All pts had received ≥1 prior anticancer treatment. Four of 31 pts included in the dose-escalation analysis set had DLTs: myocardial ischemia (250 mg, n = 1/6), intracranial hemorrhage (500 mg, n = 1/12), and drug hypersensitivity (1,500 mg, n = 2/7). With the exception of drug hypersensitivity, the nature and incidence of adverse events (AEs) were similar between the dose levels. The most frequently reported treatment-related AEs were fatigue (12.2%) and headache (12.2%). Of 32 patients with available response information, 3 with OC had a best overall response of stable disease (SD) lasting ≥6 weeks (2 treated with abituzumab 500 mg, 1 with abituzumab 1,000 mg); one 73-year-old pt with high-grade serous OC who received abituzumab as 5th-line therapy had SD for 33 weeks and a CA-125 response. No complete or partial responses were observed. No trends in differences in mean DCE-MRI parameters between abituzumab doses and no vascular or volumetric responses to abituzumab were observed, although alterations in DCE-MRI parameters were noted in individual patients. Small changes in IAUC60, Ktrans, and blood plasma volume were observed between Week 1 Day 5 and Week 2 Day 1 that may have been due to abituzumab-induced effects, but did not correlate with clinical activity (SD). Conclusions: This phase I trial has confirmed the tolerability of abituzumab, although hypersensitivity reactions represent a new event that warrants further investigation. The occurrence of SD in pts with OC with large liver metastases suggests that abituzumab has activity. However, there was little evidence of a clear effect of abituzumab on tumor vasculature, suggesting limited dependence on neovascularization in advanced tumors. Citation Format: Josep Tabernero, Geoffrey Parker, Andrew Clamp, Elena Elez, Nerissa Mescallado, Rodrigo Dienstmann, Tamara Sauri, Jurjees Hasan, Jose J. Mateos, Rolf Bruns, Claude Gimmi, Gordon C. Jayson. Investigation of the anti-angiogenic effects of abituzumab in patients with colorectal or ovarian cancer and liver metastases using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr C119.

3598 Background: Molecular screening and biomarker enrichment strategies in mCRC trials may impact patient (pt)´s outcome. The introduction of NGS technologies in clinical investigation may enhance...

4063 Background: AGC represents the third leading cause of cancer related deaths. Chemotherapy for AGC is active but still of limited efficacy and targeted agents Trastuzumab and Ramucirumab have s...

587 Background: BRAF mutation (mt) occurs in 5-8% of mCRC and its role as a negative prognostic factor is well known. The up-front detection of BRAF mt is not standardized beyond the boundaries of research. However, since novel emerging specific therapies are increasingly available in clinical trials, the prior determination of this mutation is now warranted. Methods: From 07/2010 to 01/2014, 581 patients (pts) with advanced refractory mCRCunderwent genetic tumor profiling as part of the VHIO Phase I Trial Molecular Prescreening Program. BRAF mt was determined by Sanger sequencing or multiplex PCR and mass detection (MassARRAY, Sequenom) of 268 frequent hotspots in 25 oncogenes including, KRAS, NRAS, and PIK3CA. PTEN status was also assessed by immunohistochemistry. Results: 581 samples were analyzed detecting BRAF mt in 56 (9.6%). In the BRAF mt population, median age was 61 years (45-80) and 54% had right-sided CRC. Metastatic sites were found at: liver 61%; peritoneum 52%; lung 39%. Median number of standard treatment was 4 (0-8) including cetuximab and/or panitumumab in 73%. BRAF V600E mutation was detected in 53 samples whereas V600K, D594V and D594G were seen in one sample each. PTEN was analyzed in 44.6% of samples resulting in low expression (H-score

Aim: PM01183 is a promising new agent. It exerts antitumor activity through inhibition of trans-activated transcription and modulation of tumor microenvironment. PM01183 single-agent recommended dose (RD) is 5 mg D1 & 8 q3wk, with activity observed in PaC and MBC, but limited in pretreated CRC, and reversible myelosuppression as its main dose-limiting toxicity (DLT). Preclinical synergism/additivity in combination with 5FU/XEL was reported, thus prompting this phase I study. Methods: Adult MBC, CRC or PaC pts ≤ 75 years (y) old, with ECOG PS 0-1, adequate major organ function and 6 months after discontinuation. Results: As of 20 April 2014, 14 pts were treated at 2 DLs; 8 (57%) were males, median age: 55 y (r: 35-74), median BSA: 1.9 mg/m2 (r: 1.5-2.2). Median prior lines was 1.5 (r: 0-2) and 10 (71%) pts received prior XEL or infusional 5FU. DL#2 (PM01183 3 mg/D1& 8) was the maximal dose reached, as 2 of 5 evaluable pts had DLT as grade (G)4 neutropenia >3 D or delay of Cycle 2 for >15 D due to neutropenia. DL#1 was expanded to 9 evaluable pts and none had DLT, defining it as the RD. Common G1/2 toxicities across DLs in ≥15% of pts were: nausea, diarrhea, fatigue and HFS. G3 toxicities (other than reversible neutropenia) at any DLs were: anemia, pulmonary embolism, rash and DVT (1 each). One pt had G4 thrombocytopenia; no other G4 toxicities were reported. Antitumor activity: CRC (n = 6): 2 partial responses (PR) and 3 stable diseases for > 4 months (SD4); MBC (n = 3): one PR; PaC (n = 4): 2 SD4. Globally 23% response rate (RR) and 62% of 13 evaluable pts had clinically meaningful benefit from the combination. Median time to progression (TTP) was 32 wks (95%CI: 13-34). Conclusions: The combination of PM01183 and XEL is tolerable, with no DLT occurring at the RD of PM01183 2 mg on D1 & 8 + XEL 1650 mg/m2 b.i.d. q3wk. Promising activity was observed. A simplest schedule without the D8 infusion is being explored. Dose escalation is ongoing. Disclosure: S. Szyldergemajn, R. Moreno, A. Soto-Matos and S. Extremera: I am employee of PharmaMar and I am stock ownership. All other authors have declared no conflicts of interest.

3591 Background: Molecular screening and biomarker enrichment strategies in mCRC clinical trials have demonstrated to have an impact in treatment benefit and prognosis. The data obtained from these...