Thomas Büttner

Mr. Thomas Büttner

orcid

Research Focus & Metrics

Academic Career Length

35Years (1992-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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19 December 2022 in Clinical Cancer Research
Verified
Journal Article
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NKNiklas Klümper
Niklas Klümper
DRDamian J. Ralser
Damian J. Ralser
Jörg EllingerJörg Ellinger
Jörg Ellinger
FRFlorian Roghmann
Florian Roghmann
JAJulia Albrecht
Julia Albrecht
Markus EcksteinMarkus Eckstein
Markus Eckstein
Purpose: The antibody–drug conjugate enfortumab vedotin (EV) releases a cytotoxic agent into tumor cells via binding to the membrane receptor NECTIN-4. EV was recently approved for patients with metastatic urothelial carcinoma (mUC) without prior assessment of the tumor receptor status as ubiquitous NECTIN-4 expression is assumed. Our objective was to determine the prevalence of membranous NECTIN-4 protein expression in primary tumors (PRIM) and patient-matched distant metastases (MET). Experimental Design: Membranous NECTIN-4 protein expression was measured (H-score) by IHC in PRIM and corresponding MET (N = 137) and in a multicenter EV-treated cohort (N = 47). Progression-free survival (PFS) after initiation of EV treatment was assessed for the NECTIN-4–negative/weak (H-score 0–99) versus moderate/strong (H-score 100–300) subgroup. The specificity of the NECTIN-4 IHC staining protocol was validated by establishing CRISPR-Cas9–induced polyclonal NECTIN-4 knockouts. Results: In our cohort, membranous NECTIN-4 expression significantly decreased during metastatic spread (Wilcoxon matched pairs P < 0.001; median H-score = 40; interquartile range, 0–140), with 39.4% of MET lacking membranous NECTIN-4 expression. In our multicenter EV cohort, absence or weak membranous NECTIN-4 expression (34.0% of the cohort) was associated with a significantly shortened PFS on EV (log-rank P < 0.001). Conclusions: Membranous NECTIN-4 expression is frequently decreased or absent in mUC tissue. Of note, the clinical benefit of EV strongly depends on membranous NECTIN-4 expression. Thus, our results are of highest clinical relevance and argue for a critical reconsideration of the current practice and suggest that the NECTIN-4 receptor status should be determined (ideally in a metastatic/progressive lesion) before initiation of EV. See related commentary by Aggen et al., p. 1377

10 July 2024 in Journal of Clinical Oncology
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Journal Article
Open access
NKNiklas Klümper
Niklas Klümper
NTNgoc Khanh Tran
Ngoc Khanh Tran
SZStefanie Zschäbitz
Stefanie Zschäbitz
Oliver HahnOliver Hahn
Oliver Hahn
TBThomas Büttner
Thomas Büttner
Markus EcksteinMarkus Eckstein
Markus Eckstein
PURPOSE: The anti-NECTIN4 antibody-drug conjugate enfortumab vedotin (EV) is approved for patients with metastatic urothelial cancer (mUC). However, durable benefit is only achieved in a small, yet uncharacterized patient subset. NECTIN4 is located on chromosome 1q23.3, and 1q23.3 gains represent frequent copy number variations (CNVs) in urothelial cancer. Here, we aimed to evaluate NECTIN4 amplifications as a genomic biomarker to predict EV response in patients with mUC. MATERIALS AND METHODS: We established a NECTIN4-specific fluorescence in situ hybridization (FISH) assay to assess the predictive value of NECTIN4 CNVs in a multicenter EV-treated mUC patient cohort (mUC-EV, n = 108). CNVs were correlated with membranous NECTIN4 protein expression, EV treatment responses, and outcomes. We also assessed the prognostic value of NECTIN4 CNVs measured in metastatic biopsies of non–EV-treated mUC (mUC-non-EV, n = 103). Furthermore, we queried The Cancer Genome Atlas (TCGA) data sets (10,712 patients across 32 cancer types) for NECTIN4 CNVs. RESULTS: NECTIN4 amplifications are frequent genomic events in muscle-invasive bladder cancer (TCGA bladder cancer data set: approximately 17%) and mUC (approximately 26% in our mUC cohorts). In mUC-EV, NECTIN4 amplification represents a stable genomic alteration during metastatic progression and associates with enhanced membranous NECTIN4 protein expression. Ninety-six percent (27 of 28) of patients with NECTIN4 amplifications demonstrated objective responses to EV compared with 32% (24 of 74) in the nonamplified subgroup ( P < .001). In multivariable Cox analysis adjusted for age, sex, and Bellmunt risk factors, NECTIN4 amplifications led to a 92% risk reduction for death (hazard ratio, 0.08 [95% CI, 0.02 to 0.34]; P < .001). In the mUC-non-EV, NECTIN4 amplifications were not associated with outcomes. TCGA Pan-Cancer analysis demonstrated that NECTIN4 amplifications occur frequently in other cancers, for example, in 5%-10% of breast and lung cancers. CONCLUSION: NECTIN4 amplifications are genomic predictors of EV responses and long-term survival in patients with mUC.

30 March 2022 in European Journal of Cancer
Verified
Journal Article
Open access
NKNiklas Klümper
Niklas Klümper
DSDanijel Sikic
Danijel Sikic
JSJonas Saal
Jonas Saal
TBThomas Büttner
Thomas Büttner
FGFranziska Goldschmidt
Franziska Goldschmidt
Markus EcksteinMarkus Eckstein
Markus Eckstein
Robust biomarkers to predict response to immune checkpoint blockade (ICB) in metastatic urothelial carcinoma (mUC) are still in demand. Recently, early C-reactive protein (CRP) kinetics and especially the novel CRP flare-response phenomenon has been associated with immunotherapy response. We conducted a multicentre observational study comprising 154 patients with mUC treated with ICB to evaluate the predictive value of a previously described on-treatment CRP kinetics: CRP flare responders (at least doubling of baseline CRP within the first month after initiation of ICB followed by a decline below baseline within three months), CRP responders (decline in baseline CRP by ≥ 30% within three months without a prior flare) and the remaining patients as CRP non-responders. CRP kinetics groups were correlated with baseline parameters, PD-L1 status, progression-free survival (PFS) and overall survival (OS). Objective response was observed in 57.1% of CRP responders, 45.8% of CRP flare responders and 17.9% of CRP non-responders (P < 0.001). CRP flare response was associated with prolonged PFS and OS (P < 0.001). In multivariable Cox regression analysis, CRP flare responders showed a risk reduction of ∼70% for tumour progression and death compared to CRP non-responders. Subgroup analysis of CRP flare responders revealed that patients with a long-flare response (completed flare-response kinetics ≥6 weeks on-treatment) showed even more favourable outcomes following ICB (HR = 0.18, 95%-CI: 0.07-0.48, P < 0.001). CRP (flare)response robustly predicts immunotherapy response and outcomes in mUC independent of PD-L1 status. Thus, early on-treatment CRP kinetics is a promising low-cost and easy-to-implement biomarker to optimise therapy monitoring in patients with mUC treated with ICB.

20 March 2023 in Clinical Genitourinary Cancer
Verified
Journal Article
Closed access
MSMatteo Santoni
Matteo Santoni
Francesco MassariFrancesco Massari
Francesco Massari
ZMZin W. Myint
Zin W. Myint
RIRoberto Iacovelli
Roberto Iacovelli
MPMartin Pichler
Martin Pichler
CPCamillo Porta
Camillo Porta

26 August 1992 in Cerebrovascular Diseases
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Journal Article
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CHClaus R. Hornig
Claus R. Hornig
TBThomas Büttner
Thomas Büttner
OHOskar Hoffmann
Oskar Hoffmann
WDWolfgang Dorndorf
Wolfgang Dorndorf
Clinical, CT, Doppler, and angiographic findings of 404 consecutive patients with brainstem/cerebellar strokes were registered in a data bank. One hundred and sixty-nine of the patients (41.8%) had a minor stroke, 160 patients (39.6%) a disabling event, and 75 patients (18.6%) died during stay at the hospital. Early recurrence rate was low with 1.7%. In a forward stepwise logistic regression analysis independent variables of a disabling or fatal outcome were age, diabetes mellitus, initial somnolence or coma, tetraparesis, certain pupil abnormalities, dysarthria, an infratentorial infarct in CT, and a bilateral vertebral artery stenosis or occlusion in angiography. Independent variables of a fatal outcome were an initial decreased consciousness, tetraparesis, and a basilar artery occlusion in angiography. Without prognostic relevance in either multivariate or univariate statistical analysis were previous stroke, evidence of concomitant carotid artery disease by Doppler or CT, and unilateral vertebral artery stenosis or occlusion.

7 September 2022 in Cancers
Verified
Journal Article
Open access
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PKPhilipp Krausewitz
Philipp Krausewitz
NKNiklas Klümper
Niklas Klümper
ARAyk-Peter Richter
Ayk-Peter Richter
TBThomas Büttner
Thomas Büttner
GKGlen Kristiansen
Glen Kristiansen
Jörg EllingerJörg Ellinger
Jörg Ellinger
Background: The methylation status of Septin 9 (SEPT9) and short stature homeobox 2 (SHOX2) in circulating cell-free DNA (ccfDNA) are validated pan-cancer biomarkers. The present proof-of-concept study aimed to investigate the potential and dynamics of quantitative SEPT9 and SHOX2 methylation in prostate cancer (PCa) patient tissue and ccfDNA during prostate biopsy as a diagnostic tool. Methods: The methylation patterns of SEPT9 and SHOX2 in prostate tissue were analyzed using The Cancer Genome Atlas data set (n = 498 PCa and n = 50 normal adjacent prostate tissue (NAT)). Next, dynamic changes of ccfDNA methylation were quantified in prospectively enrolled patients undergoing prostate biopsy (n = 72), local treatment for PCa (n = 7; radical prostatectomy and radiotherapy) as well as systemic treatment for PCa (n = 6; chemotherapy and 177-Lu-PSMA-therapy). Biomarker levels were correlated with clinicopathological parameters. Results: SEPT9 and SHOX2 were hypermethylated in PCa tissue (p < 0.001) and allowed discrimination of PCa and non-tumor prostate tissue (mSEPT9: AUC 0.87, 95%CI [0.82–0.92]; mSHOX2: AUC 0.89, 95%CI 0.84–0.94). SHOX2 methylation and mRNA levels were significantly higher in PCa tissue and increased with tumor stage and grade, as well as in patients suffering from biochemical recurrence following radical prostatectomy. SEPT9 and SHOX2 ccfDNA methylation allowed distinguishing patients with localized and metastatic disease (p < 0.001 for both). In addition, methylation levels increased shortly after prostate biopsy only in patients with PCa (ΔmSEPT9: p < 0.001 and ΔmSHOX2: p = 0.001). Conclusions: The early dynamics of methylated SEPT9 and SHOX2 in ccfDNA allow differentiation between PCa patients and patients without PCa and is a promising marker for tumor monitoring in the metastatic stage to determine tumor burden under systemic therapy.