von Felden Lab

AG von Felden

About us

We are a young and enthusiatsic junior research group located at the University Medical Center Hamburg-Eppendorf, Germany.

As an independent group, our work focusses on translational research projects in the field of hepatobiliary oncology, with the main objective to derive molecular biomarkers for implementing personalized cancer care for patients with liver cancer. We aim at deciphering mechanisms of hepatocarcinogenesis and identifying biomarkers for risk startification, early cancer detection, and to predict response to therapies. For this, we utilize state-of-the-art technologies and modern analytical pipelines, incl. liquid biopsy approaches and next-generation sequencing.

News

We will soon open a position for a bioinformatician / data scientist. Stay tuned. Job openings

Latest publications

Soluble and EV-bound CD27 act as antagonistic biomarkers in patients with solid tumors undergoing immunotherapy - Journal of Experimental & Clinical Cancer ResearchBackground The major breakthrough in cancer therapy with immune checkpoint inhibitors (ICIs) has highlighted the important role of immune checkpoints in antitumoral immunity. However, most patients do not achieve durable responses, making biomarker research in this setting essential. CD27 is a well known costimulatory molecule, however the impact of its soluble form in ICI is poorly investigated. Therefore, we aimed at testing circulating concentrations of soluble CD27 (sCD27) and CD27 bound to extracellular vesicles (EVs) as potential biomarkers to predict response and overall survival (OS) in patients undergoing ICI. Methods Serum and plasma levels of sCD27 were assessed by immunoassay in three patient cohorts (n = 187) with advanced solid malignancies including longitudinal samples (n = 126): a training (n = 84, 210 specimens, Aachen ICI) and validation cohort (n = 70, 70 specimens, Hamburg ICI), both treated with ICI therapy, and a second independent validation cohort (n = 33, 33 specimens, Hamburg non-ICI) undergoing systemic therapy without any ICI. In a subset (n = 36, 36 baseline and 108 longitudinal specimens), EV-bound CD27 from serum was measured, while EV characterization studies were conducted on a fourth cohort (n = 45). Results In the Aachen and Hamburg ICI cohorts, patients with lower circulating sCD27 levels before and during ICI therapy had a significantly longer progression-free survival (PFS) and OS compared to patients with higher levels, a finding that was confirmed by multivariate analysis (MVA) (Aachen ICI: pPFS = 0.012, pOS = 0.001; Hamburg ICI: pPFS = 0.040, pOS = 0.004) and after randomly splitting both cohorts into training and validation. This phenomenon was not observed in the Hamburg non-ICI cohort, providing a rationale for the predictive biomarker role of sCD27 in immune checkpoint blockade. Remarkably, EV-bound CD27 baseline levels and dynamics during ICI therapy also emerged as potent predictive biomarkers, acting however antagonistically to soluble sCD27, i.e. higher levels were associated with PFS and OS benefit. Combining both molecules (“multi-CD27” score) enhanced the predictive ability (HRPFS: 17.21 with p < 0.001, HROS: 6.47 with p = 0.011). Conclusion Soluble and EV-bound CD27 appear to have opposing immunomodulatory functions and may represent easily measurable, non-invasive prognostic markers to predict response and survival in patients undergoing ICI therapy.

Radiofrequency ablation via catheter and transpapillary access in patients with cholangiocarcinoma (ACTICCA-2 trial) – a multicenter, randomized, controlled, open-label investigator-initiated trial - BMC CancerBackground Despite the recent advances in cancer treatment, the therapeutic options for patients with biliary tract cancer are still very limited and the prognosis very poor. More than 50% of newly diagnosed patients with biliary tract cancer are not amenable to curative surgical treatment and thus treated with palliative systemic treatment. Malignant bile duct obstructions in patients with perihilar and/or ductal cholangiocarcinoma (CCA) represents one of the most important challenges in the management of these patients, owning to the risk represented by developing life-threatening cholangitis which, in turn, limits the use of systemic treatment. For this reason, endoscopic stenting and/or bile duct decompression is the mainstay of treatment of these patients. Data on efficacy and safety of adding radiofrequency ablation (RFA) to biliary stenting is not conclusive. The aim of this multicenter, randomized trial is to evaluate the effect of intraductal RFA prior to bile duct stenting in patients with unresectable perihilar or ductal CCA undergoing palliative systemic therapy. Methods/Design ACTICCA-2 is a multicenter, randomized, controlled, open-label, investigator-initiated trial. 120 patients with perihilar or ductal CCA with indication for biliary stenting and systemic therapy will be randomized 1:1 to receive either RFA plus bile duct stenting (interventional arm) or bile duct stenting alone (control arm). Patients will be stratified by trial site and tumor location (perihilar vs. ductal). Both arms receive palliative systemic treatment according to the local standard of care determined by a multidisciplinary tumorboard. The primary endpoint is time to first biliary event, which is determined by an increase of bilirubin to > 5 mg/dl and/or the occurrence of cholangitis leading to premature stent replacement and/or disruption of chemotherapy. Secondary endpoints include overall survival, safety according to NCI CTCAE v5, quality of life assessed by questionnaires (EORTC QLQ-C30 and QLQ-BIL21), clinical event rate at 6 months after RFA and total days of over-night stays in hospital. Follow-up for the primary endpoint will be 6 months, while survival assessment will be continued until end of study (maximum follow-up 30 month). All patients who are randomized and who underwent endoscopic stenting will be used for the primary endpoint analysis which will be conducted using a cause-specific Cox proportional hazards model with a frailty for trial site and fixed effects for the treatment group, tumor location, and stent material. Discussion ACTICCA-2 is a multicenter, randomized, controlled trial to assess efficacy and safety of adding biliary RFA to bile duct stenting in patients with CCA receiving palliative systemic treatment. Trial registration The study is registered with ClinicalTrials.gov (NCT06175845) and approved by the local ethics committee in Hamburg, Germany (2024-101232-BO-ff). This manuscript reflects protocol version 1 as of January 9th, 2024. Graphical Abstract

Highlighted publications

Unannotated small RNA clusters associated with circulating extracellular vesicles detect early stage liver cancerObjective Surveillance tools for early cancer detection are suboptimal, including hepatocellular carcinoma (HCC), and biomarkers are urgently needed. Extracellular vesicles (EVs) have gained increasing scientific interest due to their involvement in tumour initiation and metastasis; however, most extracellular RNA (exRNA) blood-based biomarker studies are limited to annotated genomic regions. Design EVs were isolated with differential ultracentrifugation and integrated nanoscale deterministic lateral displacement arrays (nanoDLD) and quality assessed by electron microscopy, immunoblotting, nanoparticle tracking and deconvolution analysis. Genome-wide sequencing of the largely unexplored small exRNA landscape, including unannotated transcripts, identified and reproducibly quantified small RNA clusters (smRCs). Their key genomic features were delineated across biospecimens and EV isolation techniques in prostate cancer and HCC. Three independent exRNA cancer datasets with a total of 479 samples from 375 patients, including longitudinal samples, were used for this study. Results ExRNA smRCs were dominated by uncharacterised, unannotated small RNA with a consensus sequence of 20 nt. An unannotated 3-smRC signature was significantly overexpressed in plasma exRNA of patients with HCC (p<0.01, n=157). An independent validation in a phase 2 biomarker case–control study revealed 86% sensitivity and 91% specificity for the detection of early HCC from controls at risk (n=209) (area under the receiver operating curve (AUC): 0.87). The 3-smRC signature was independent of alpha-fetoprotein (p<0.0001) and a composite model yielded an increased AUC of 0.93. Conclusion These findings directly lead to the prospect of a minimally invasive, blood-only, operator-independent clinical tool for HCC surveillance, thus highlighting the potential of unannotated smRCs for biomarker research in cancer. Data are available in a public, open access repository. RNA-sequencing data have been deposited in the ArrayExpress database at EMBL-EBI (www.ebi.ac.uk/arrayexpress) under accession numbers E-MTAB-8528 and E-MTAB-8529. Code availability statement: all code will be made publicly available at Dr Losic GitHub site.

Liquid biopsy in the clinical management of hepatocellular carcinomaWith increasing knowledge on molecular tumour information, precision oncology has revolutionised the medical field over the past years. Liquid biopsy entails the analysis of circulating tumour components, such as circulating tumour DNA, tumour cells or tumour-derived extracellular vesicles, and has thus come as a handy tool for personalised medicine in many cancer entities. Clinical applications under investigation include early cancer detection, prediction of treatment response and molecular monitoring of the disease, for example, to comprehend resistance patterns and clonal tumour evolution. In fact, several tests for blood-based mutation profiling are already commercially available and have entered the clinical field. In the context of hepatocellular carcinoma, where access to tissue specimens remains mostly limited to patients with early stage tumours, liquid biopsy approaches might be particularly helpful. A variety of translational liquid biopsy studies have been carried out to address clinical needs, such as early hepatocellular carcinoma detection and prediction of treatment response. To this regard, methylation profiling of circulating tumour DNA has evolved as a promising surveillance tool for early hepatocellular carcinoma detection in populations at risk, which might soon transform the way surveillance programmes are implemented. This review summarises recent developments in the liquid biopsy oncological space and, in more detail, the potential implications in the clinical management of hepatocellular carcinoma. It further outlines technical peculiarities across liquid biopsy technologies, which might be helpful for interpretation by non-experts.

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