Heterogenous NECTIN4 expression in urothelial high-risk non-muscle-invasive bladder cancer

Multimodal Diffusion MRI Synergized with VI-RADS for Precision Grading of Bladder Urothelial Carcinoma: A Prospective Diagnostic Model Validation

RATIONALE AND OBJECTIVES

To evaluate the diagnostic performance of diffusion tensor imaging (DTI), diffusion kurtosis imaging (DKI), mean apparent propagator (MAP), neurite orientation dispersion and density imaging (NODDI), and the Vesical Imaging-Reporting and Data System (VI-RADS) in discriminating the pathological grade of bladder urothelial carcinoma (UCB).

MATERIALS AND METHODS

This prospective study enrolled patients with pathologically confirmed UCB between May 2023 and December 2023. Preoperative MRI protocols included spin-echo echo-planner imaging (SE-EPI) and conventional DWI. Quantitative parameters from SE-EPI (DTI, DKI, MAP, NODDI) and apparent diffusion coefficient (ADC) values were measured. Group comparisons between low-grade and high-grade UCB were performed using t-tests or Mann-Whitney U tests. Receiver operating characteristic (ROC) analysis and DeLong's test were used to evaluate diagnostic performance.

RESULTS

A total of 50 patients with UCB (low-grade/ high-grade = 16/34) were included. VI-RADS score and mean kurtosis (MK) derived from DKI emerged as independent predictors for differentiating low-grade and high-grade UCB (area under the curve (AUC): 0.692 and 0.865, respectively). The combination of VI-RADS and DKI-MK achieved superior diagnostic performance (AUC: 0.915, sensitivity: 0.941) compared to VI-RADS alone (AUC: 0.692, sensitivity: 0.471; p < 0.001) or ADC alone (AUC: 0.787, sensitivity: 0.813; p < 0.05).

CONCLUSION

Integrating VI-RADS with DKI-MK significantly enhances preoperative assessment of UCB pathological grading, demonstrating higher accuracy and sensitivity than VI-RADS or ADC alone. This approach improves diagnostic objectivity by combining qualitative imaging criteria with quantitative diffusion metrics, offering potential clinical utility for treatment stratification.

Nectin-4 Expression in Prostatic Adenocarcinoma: An Immunohistochemical Study

BACKGROUND

The Nectin-4 directed antibody drug conjugate enfortumab vedotin (EV) has emerged as frontline systemic therapy in combination with immune checkpoint blockade for urothelial carcinoma (UC), capitalizing on the ubiquitous expression of this protein in UC. There is limited data available regarding expression of Nectin-4 by immunohistochemistry in prostate cancer, but this is of interest as a substantial number of UC patients likely to receive EV have concomitant prostate cancer.

METHODS

Nectin-4 protein expression was evaluated by immunohistochemistry in tissue microarrays encompassing a cohort of 302 prostatic adenocarcinomas spanning Grade Groups 1-5. Intensity of expression was scored from 1 (weak) to 3 (intense staining readily apparent at low magnification). H-scores were calculated by multiplying the percentage of cells staining by the intensity of expression.

RESULTS

Nectin-4 expression was frequently observed in benign prostate tissue (86% of cases, mean H-score of 40, median 20, interquartile range [IQR]: 10-60) and in prostatic adenocarcinoma (91% of cases, mean H-score of 90, median 70, IQR: 20-150). Significant differences in Nectin-4 expression among prostatic adenocarcinoma Grade Groups 1-5 were not observed. Across all prostatic adenocarcinomas evaluated, the mean Nectin-4 H-score of 90 was statistically significantly higher than the mean H-score of 40 observed in benign prostate tissue (p < 0.001). Three of four prostatic ductal adenocarcinomas showed Nectin-4 expression, with a median H-score of 250 (IQR: 152-300).

CONCLUSIONS

Nectin-4 protein expression is common in benign prostate tissue and prostatic adenocarcinoma. These findings provide a rationale for future studies investigating potential activity of EV in prostate cancer.

Mechanistic Insights into the Successful Development of Combination Therapy of Enfortumab Vedotin and Pembrolizumab for the Treatment of Locally Advanced or Metastatic Urothelial Cancer

Antibody-drug conjugates (ADCs) consist of an antibody backbone that recognizes and binds to a target antigen expressed on tumor cells and a small molecule chemotherapy payload that is conjugated to the antibody via a linker. ADCs are one of the most promising therapeutic modalities for the treatment of various cancers. However, many patients have developed resistance to this form of therapy. Extensive efforts have been dedicated to identifying an effective combination of ADCs with other types of anticancer therapies to potentially overcome this resistance. A recent clinical study demonstrated that a combination of the ADC enfortumab vedotin (EV) with the immune checkpoint inhibitor (ICI) pembrolizumab can achieve remarkable clinical efficacy as the first-line therapy for the treatment of locally advanced or metastatic urothelial carcinoma (la/mUC)-leading to the first approval of a combination therapy of an ADC with an ICI for the treatment of cancer patients. In this review, we highlight knowledge and understanding gained from the successful development of EV and the combination therapy of EV with ICI for the treatment of la/mUC. Using urothelial carcinoma as an example, we will focus on dissecting the underlying mechanisms necessary for the development of this type of combination therapy for a variety of cancers.

Proteomic analysis of the urothelial cancer landscape

Urothelial bladder cancer (UC) has a wide tumor biological spectrum with challenging prognostic stratification and relevant therapy-associated morbidity. Most molecular classifications relate only indirectly to the therapeutically relevant protein level. We improve the pre-analytics of clinical samples for proteome analyses and characterize a cohort of 434 samples with 242 tumors and 192 paired normal mucosae covering the full range of UC. We evaluate sample-wise tumor specificity and rank biomarkers by target relevance. We identify robust proteomic subtypes with prognostic information independent from histopathological groups. In silico drug prediction suggests efficacy of several compounds hitherto not in clinical use. Both in silico and in vitro data indicate predictive value of the proteomic clusters for these drugs. We underline that proteomics is relevant for personalized oncology and provide abundance and tumor specificity data for a large part of the UC proteome ( www.cancerproteins.org ).

First-in-Human Study of the Radioligand 68Ga-N188 Targeting Nectin-4 for PET/CT Imaging of Advanced Urothelial Carcinoma

PURPOSE

Nectin-4 is an emerging biomarker for cancer diagnosis and therapy. Recently, enfortumab vedotin (EV) was approved by the FDA as the first nectin-4 targeting antibody-drug conjugate for treating advanced urothelial carcinoma (UC). A PET imaging method to noninvasively quantify nectin-4 expression level would potentially help to select patients most likely to respond to EV and predict the response.

EXPERIMENTAL DESIGN

In this study, we designed a bicyclic peptide-based nectin-4 targeting radiotracer 68Ga-N188. Initially, we performed preclinical evaluations of 68Ga-N188 in UC cell lines and xenograft mouse models. Next, we performed the translational study in healthy volunteers and a pilot cohort of patients with advanced UC on uEXPLORER total-body PET/CT.

RESULTS

In the preclinical study, 68Ga-N188 showed high affinity to nectin-4, specific uptake in a nectin-4(+) xenograft mouse model, and suitable pharmacokinetic and safety profiles. In the translational study, 2 healthy volunteers and 14 patients with advanced UC were enrolled. The pharmacokinetic profile was determined for 68Ga-N188, and the nectin-4 relative expression level in different organs was quantitatively imaged.

CONCLUSIONS

A clear correlation between PET SUV value and nectin-4 expression was observed, supporting the application of 68Ga-N188 PET as a companion diagnostic tool for optimizing treatments that target nectin-4. See related commentary by Jiang et al., p. 3259.

Antibody-Drug Conjugates in the Treatment of Urothelial Cancer

Antibody-drug conjugates (ADCs) have transformed the treatment landscape in oncology and become an essential therapeutic modality. In urothelial carcinoma (UC), the two ADCs that have been especially successful in clinical practice are enfortumab vedotin and sacituzumab govitecan. These drugs are currently approved as monotherapy for later lines of treatment in locally advanced or metastatic UC and have had a significant impact for patients with limited treatment options. Combinational trials, as well as additional ADCs, are currently being investigated in the treatment of UC for subsequent lines of therapy as overall survival rates remain dismal.

Nectin-4: a Tumor Cell Target and Status of Inhibitor Development

PURPOSE OF REVIEW

This study aims to gather the current state of the literature about anti-Nectin-4 innovative associations in solid tumors and to investigate underlying resistance mechanisms.

RECENT FINDINGS

Antibody-drug conjugate (ADC) targeting Nectin-4 efficacy gained attention and offers a promising association with other antineoplastic drugs especially in urothelial carcinoma. The heterogeneity of Nectin-4 expression across the molecular subtypes was highlighted especially in urothelial cancers. A unique study using preclinical models demonstrated an upregulation of P-gp expression, which may explain the anti-Nectin-4 resistance mechanisms. Further studies are urgently needed to understand anti-Nectin-4 sensitivity and resistance phenomenon. The growing therapeutic associations of enfortumab vedotin offer optimistic opportunities in management and treatment of wide range of solid tumors including rare aggressive malignancies.