Abstract only
e17043
Background: Checkpoint Inhibitors (CPI) have become a new standard of treatment in advanced urothelial carcinoma. However, little is known regarding the outcome of patients in ...daily practice.We aimed to assess tumor response and toxicity of CPIs in a cohort of patients treated in “real world” conditions. In parallel, a comprehensive molecular study in tumor samples from these patients, is ongoing. Methods: We designed an observational retrospective study within the “Grupo Centro” collaborative group. Adult patients diagnosed of metastasic urothelial carcinoma (mUC) and treated with CPIs between 2011-2019 in any of the 20 centers of the group, were eligible. Results: Up to date 100 patients have been included (82% males) with a median age of 74 years (48 -96). In 82% patients primary was bladder cancer. Most common metastasic sites were bone (26%) and liver (16%).With a median follow up of 10,6 months(mo) median progression free survival (mPFS) was 6,6mo (1,4-95,4 range) and median Overall Survival (mOS) was 21.3mo (3,8-121,8). 38% of patients received CPIs in first line(L): atezolizumab:27, pembrolizumab: 10, nivolumab:1. The median number of cycles was 8,2. Up to 51% received platinum-based combinations in first line. 69% (69/100) pts received 2L treatment: 68% with CPIs, 27,5% with chemotherapy and 4% with FGFR inhibitors (as part of a clinical trial). 2L mPFS was 3,5 mo (1,9-25.9). 23% (23/100) patients received 3L, of them 26% (6/23) were treated with CPIs. 3L mPFS:8,3mo(0,4-43,8). As a whole, patients treated with CPI accross different lines, achieved complete response in 8% of the cases, partial response in 18% and stable disease in 15%. Up to 44% of cases presented progressive disease as best response and evaluation was not available in 15%. Most common G1-2 AEs related to immunotherapy were: asthenia:31%,pruritus:16% and anorexia: 9%.10% pts experienced G3-4 toxicity: asthenia G3: 4, diarrhea G3: 1, erythrodysesthesia G3:1, arthromyalgia G3: 1, cardiac arrest G4:1,pneumonitis G4:1,anemia G3:1. Conclusions: This study confirms the efficacy and security of CPIs in real world. Response rates and toxicity profile were comparable to those reported in clinical trials.
Abstract
Background: Exosomes have been involved in tumor progression and the development of therapeutic resistances in several malignancies. These extracellular vesicles (EVs) promote angiogenesis, ...premetastatic niches formation and the communication between the tumor and its environment. Ovarian cancer (OC) is a highly lethal tumor that typically spreads within the abdominal cavity rather than through the blood vessels. Based on this behavior, we aimed to study the presence of exosomes in ascitic fluid of OC patients and explore their potential as predictors of tumor volume and chemoresistance.
Methods: We designed an observational prospective study in advanced OC patients who underwent a diagnostic laparoscopy or cytoreductive surgery at our institution. Abdominal washings of a cohort of non-cancer patients were collected as controls. All cases provided written consent. Clinical data and tumor genomic alterations (NGS, FoundationOne CDx) were recorded. EVs pellets were collected by ultracentrifugation and profiled by NTA and western blot (WB) (EVs markers: CD9, TSG101 and ALIX; non EVs related markers: ALB and APOB). PAX8, a protein characteristically expressed in OC cells, was used as a marker of tumor EVs. EVs proteins were quantified by BCA assay; mass spectrometry profiling is ongoing.
Results: 45 peritoneal fluids from 40 OC patients (median age range 62 44-79 years) and 29 peritoneal washings from controls have been collected. Our cohort comprise various histological subtypes (high-grade serous, n=32 80%; low-grade serous, n=2 5%; endometrioid, n=3 8%); clear cells, n=2 5% and mucinous, n=1 2%) and tumor stages (TI-II, n=5 12%; TIII; n=24 60%; TIV, n=11 28%). Samples were collected either from primary, n=18 (40%); interval, n=15 (33%); or relapse surgery, n=12 (27%). Pathogenic BRCA events were detected in 25% of patients. Mean concentration of exosomes (MCE) was 6.5x106 vs. 3.2x106 particles/ml (p/ml) in cases vs. controls (p<0.0005). No differences in MCE were observed regarding stages I-II vs. stages III-IV (7.1x106 vs. 6.5x106 p/ml; p=0.84), BRCA status (mutant=6.9x106 vs. wild type=6.8x106 p/ml, p=0.46) or platinum response (resistant=7.7x106 vs. sensitive=9.5x106 p/ml, p=0.14). WB analysis showed an enrichment in EVs markers from cancer patients vs. controls (>3-fold). Protein mean concentration in EVs of cancer patients vs. controls was 0.85µg/µl and 0.51µg/µl respectively (p=0.04). Proteomic characterization through mass spectrometry is ongoing and will be presented at the time of the meeting.
Conclusions: Our data, although preliminary, show a higher concentration of EVs and EVs proteins in OC cases vs controls with no difference between stages or genomic backgrounds. These results lead to the notion that exosomes could be involved in OC evolution and spread regardless of tumor volume or the molecular subtype.
Citation Format: Miguel Quiralte, Arantzazu Barquin, Elena Sevillano, Paloma Navarro, Monica Yagüe, Maria Barba, Juan F. Rodriguez-Moreno, Alejandra Balarezo, Héctor Peinado, Elena Izquierdo, Jesús García-Donas, Sergio Ruiz-Llorente. Prospective study for the assessment of exosomes in ascitic fluid as prognostic markers in patients with advanced ovarian cancer abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3223.
BackgroundTumour Infiltrating Lymphocytes (TILs) is a modality of ACT under development in solid tumours. Unfortunately, prior lymphodepletion is a key step that frequently requires the ...administration of antibiotics and antifungics for long periods of time. Although there is evidence that gut microbiome may influence tumour response in patients treated with checkpoint-inhibitors, it has not been extensively studied in ACT.1MethodsAnalysis of gut microbiome at three different times (T1: before lymphodepletion, T2: before TIL infusion and T3: day +15) has been performed in patients treated with ACT between 2018 and 2020. The composition and structure of the sampled microbial communities was assessed through the amplification and sequencing the V3-V4 variable regions of the 16S rRNA gene. The Illumina Miseq sequencing 300×2 approach was used. Taxonomic assignment of phylotypes was performed using a Bayesian Classifier trained with Silva database version 132 (99% OTUs full-length sequences). The following metrics were measured: observed OTUs (community richness), evenness (Pielou’s index) and Shannon’s diversity index. Differential abundance of taxa was tested using ANCOM test and Kruskal Wallis test.ResultsA total of 21 patients have been treated with TILs between 2018 and 2020 at our institution. 67% were female. Median age was 43 (range 26–70 years). All patients had stage IV pre-treated solid tumours: 55% cervical cancer, 33% melanoma, 10% lung adenocarcinoma and 5% head and neck cancer. Median previous treatment lines was 3 (range 2–4). Analysis of gut microbiome has been performed in 3 of these patients: one achieved PR, one progressed and the third one suffered an unexpected death. 971 phylotypes were detected. Analysis revealed differences in terms of observed OTUs, evenness and Shannon’s index when comparing T1 and T2 with T3. At T3 a tendency towards less diversity and evenness was observed when compared with T1 and T2 (H 3.0, p-value 0.083, not statistically significant). Comparing the distribution of considered taxa in ACT responders vs. non-responders, we observed significant differences for both class (Bacteroidia, Clostridia and Gammaproteobacteria) and order (Bacteroidales, Lactobacillales, Clostridiales and Enterobacteriales) levels.ConclusionsA deep change in gut microbiome composition along TILs therapy was observed. Though preliminary, differences between responders and non-responders were observed but should be confirmed in larger populations.ReferenceGopalakrishnan V, Spencer CN, Nezi L, et al. Gut microbiome modulates response to anti–PD-1 immunotherapy in melanoma patients. Science 2018;359:97–103.
Abstract
Introduction
The Fibroblast Growth Factor Receptor (FGFR) has become a key target in urothelial cancer. The FGFR inhibitor (FGFRi) erdafitinib has been approved for clinical use and many ...others are in development. Unfortunately, responses have shown to last short. Thus, it is urgently required to identify the underlying mechanisms of resistance and establish strategies to overcome it.
We designed a comprehensive in vitro study in FGFR3-altered urothelial cancer cell lines after acquiring resistance to FGFRis. In parallel, we monitored the clinical and molecular evolution (through tumor biopsies and ctDNA) of three patients treated with FGFRi at our institution.
Experimental Procedures
Drug sensitivity to FGFRi (Erdafitinib and AZD4547) was evaluated in bladder cancer cell lines harboring FGFR3 point mutations (pS249C) or rearrangements (FGFR3/BAIAP2L1 or TACC3). After performing 7-days proliferation assays, cell lines showing nM-range sensitivity were long-term treated with high concentrations of both compounds to induce therapeutic resistance.
Cell lysates were collected and protein arrays (Human Phospho-RTK and Kinases Array, R&D Systems) were used for the identification of proteins involved in the desensitization to FGFRi. Later, cell lines were treated with selective inhibitors of such kinases.
Regarding patients, after providing written consent, tumor tissue was collected retrospectively from the initial diagnosis and prospectively in any new tumor resection performed in daily practice. ctDNA from peripheral blood was also periodically extracted.
Results & Conclusions
Protein arrays showed an overactivation of phosphorylated forms of proteins involved in PI3K (EGFR and AKT, 4 and 9-fold increase) and MAPK pathways or proteins related to signal transduction (PLCγ, 80-fold increase, among others). When treated with trametinib, IGF1Ri, ipatasertib, everolimus or erlotinib, only trametinib and IGF1Ri demonstrated significant activity in cell cultures.
Three patients were included in the clinical cohort of our study (2 males, 1 female). All harbored the mutation p.S249C and initially achieved a partial response. Multiple biopsies (baseline and at tumor progression) were analyzed in case 1, showing a secondary mutation in FGFR3 and molecular alterations in EGFR and IGFR pathways as potential mechanisms of resistance, matching the results previously observed in in vitro models. Studies of the other 2 cases are ongoing and will be presented at the meeting.
Combination of FGFRi with additional TKIs could improve the efficacy of these drugs. Further studies and validation in clinical trials are required.
Citation Format: Sergio Ruiz-Llorente, Elena Fernández-Sevillano, Paloma Navarro, Juan Francisco Rodríguez-Moreno, Arantzazu Barquín-García, Sandra Amarilla-Quintana, Mónica Yagüe-Fernández, Juan María Roldan-Romero, Raquel Martín, Cristina Rodriguez-Antona, Jesús García-Donas. Mechanisms of resistance to FGFR inhibitors in urothelial cancer cell lines and patients harboring FGFR3 alterations and strategies to overcome it abstract. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5288.
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