HER2 expression in urothelial carcinoma, a systematic literature review

Immune Checkpoint Inhibitors and Antibody-Drug Conjugates in Urothelial Carcinoma: Current Landscape and Future Directions

BACKGROUND/OBJECTIVES

Urothelial carcinoma (UC) treatment has been transformed by immunotherapy and antibody-drug conjugates (ADCs). This review evaluates the current evidence for these approaches and identifies future directions.

METHODS

We conducted a structured review of clinical trials, meta-analyses, and guidelines published until early 2025.

RESULTS

Immune checkpoint inhibitors have established benefits across multiple settings: post-platinum therapy (pembrolizumab, nivolumab), maintenance therapy (avelumab), adjuvant settings for high-risk muscle-invasive disease (nivolumab), and BCG-unresponsive non-muscle-invasive disease (pembrolizumab). Enfortumab vedotin (targeting Nectin-4) has proven effective in post-platinum/post-immunotherapy. Most significantly, enfortumab vedotin plus pembrolizumab has redefined first-line treatment with unprecedented survival benefits (median OS 31.5 months vs. 16.1 months with chemotherapy; HR 0.47), and nivolumab plus gemcitabine-cisplatin improved outcomes in cisplatin-eligible patients. Key challenges include managing unique toxicity profiles, optimizing treatment sequencing, and developing reliable biomarkers.

CONCLUSIONS

Combination approaches offer the most promising path forward, with future research needed on resistance mechanisms, biomarker development, and expanding these therapies to earlier disease stages.

Antibody-drug conjugates in urothelial carcinoma: current status and future

PURPOSE OF REVIEW

Antibody-drug conjugates (ADCs) are quickly becoming frontline standard of care in many tumor types, including urothelial carcinoma. This review summarizes recent clinical investigations into the use of ADCs targeting nectin-4, trophoblast cell surface antigen-2 (Trop-2), human epidermal growth factor receptor 2 (HER-2), and other antigens in urothelial carcinoma.

RECENT FINDINGS

This review covers efficacy and toxicity data of ADCs alone and in combination with immunotherapy; mechanisms of resistance; and preclinical studies that provide biological basis for clinical approaches.

SUMMARY

Enfortumab vedotin and sacituzumab govitecan can be used in an unselected group of patients with urothelial carcinoma whereas HER-2 ADCs have only been administered in those with high expression or amplification. Most are being studied in combination with immune checkpoint inhibitors. Data supports use of enfortumab vedotin in combination with pembrolizumab as first-line therapy in metastatic/unresectable locally advanced urothelial carcinoma. Sacituzumab govitecan may be used as later-line option in these patients. HER-2 therapy is still under investigation but has many recent promising results.

Testing and Interpretation of Human Epidermal Growth Factor Receptor 2 Protein Expression and ERBB2 Gene Amplification in Advanced Urothelial Carcinoma

PURPOSE

The aim of this study was to assess the prevalence of human epidermal growth factor receptor 2 (HER2) protein expression and ERBB2 gene amplification in a large cohort of tumor samples from patients with advanced urothelial carcinoma (UC).

MATERIALS AND METHODS

Testing was performed on formalin-fixed, paraffin-embedded tissue from commercially sourced primary advanced or metastatic UC using an anti-HER2/neu (4B5) rabbit monoclonal antibody immunohistochemistry (IHC) assay (detects HER2 protein) and HER2 dual in situ hybridization (DISH) DNA probe cocktail assay (detects ERBB2 gene and the centromere of its residing chromosome 17). The HER2 clinical status was classified as HER2-zero (IHC 0), HER2-low (IHC 1+ or IHC 2+/DISH nonamplified), or HER2-positive (IHC 2+/DISH amplified or IHC 3+).

RESULTS

Of the 2,024 UC samples, HER2 protein expression was IHC 0 for 962 (47.5%), IHC 1+ for 297 (14.7%), IHC 2+ for 498 (24.6%), and IHC 3+ for 267 (13.2%). The percentage of HER2-expressing tumors (IHC 1+, 2+, and 3+) was similar between primary (52.2%, 1,028/1,968) and metastatic UC samples (60.7%, 34/56; P = .26). The ERBB2 gene was amplified in 235 cases (11.6%), including 2.7%/3.7%/9.6%/56.2% scored as IHC 0/1+/2+/3+, respectively. Overall, HER2 clinical status was HER2-zero for 962 UC tissue samples (47.5%; 95% CI, 45.4 to 49.7), HER2-low for 747 (36.9%; 95% CI, 34.8 to 39.0), and HER2-positive for 315 (15.6%; 95% CI, 14.0 to 17.2).

CONCLUSION

We observed that more than 50% of 2,024 advanced UC tumors demonstrated some degree of HER2 protein expression detected using a standardized IHC method, whereas about 12% of specimens had ERBB2 gene amplification, including about 3% of those scored as either IHC 0 or 1+. Continued development of optimized and standardized HER2 testing methods is warranted to identify patients with HER2-expressing UC who may benefit from novel HER2-targeting therapies.

Efficacy and safety of DV in HER2-negative and HER2-low locally advanced or metastatic urothelial carcinoma: Results of a phase 2 study

BACKGROUND

Human epidermal growth factor receptor 2 (HER2) has emerged as a new target for metastatic urothelial carcinomas (mUCs). Disitamab vedotin (DV), an anti-HER2 antibody-drug conjugate (ADC), demonstrates a promising efficacy in patients with HER2-positive mUC. However, the role of DV in HER2-negative and HER2-low mUCs remains unknown.

METHODS

Patients with HER2-negative and HER2-low (immunohistochemistry [IHC] 0 or 1+) mUCs who received ≥1 line of systemic chemotherapy were included. Patients received 2 mg/kg DV intravenously once every 2 weeks. The primary endpoint was the objective response rate (ORR). Secondary endpoints included progression-free survival (PFS), overall survival (OS), and safety.

FINDINGS

Nineteen patients with UC were enrolled from September 2019 to December 2021. The median age was 64.0 years. 15 patients (79%) had visceral metastases. HER2 IHC 0 and 1+ were detected in 6 and 13 patients, respectively. As of September 30, 2022, the confirmed ORR was 31.6% (95% confidence interval [CI]: 12.6, 56.6), and the disease control rate was 94.7% (18/19). The median PFS and OS were 5.5 (95% CI: 3.9, 5.7) and 16.4 (6.8, 26.8) months, respectively. Common treatment related adverse events were mostly grade 1 or 2, including leukopenia (52.6%) and hypoesthesia (47.4%).

CONCLUSIONS

This is the first exploratory trial demonstrating substantial anti-tumor activity and a manageable safety profile using a HER2-targeting agent in patients with HER2-low mUC. This study was registered at ClinicalTrials.gov (ClinicalTrials.gov: NCT04073602).

FUNDING

The study was funded by the Natural Science Foundation of China, the Natural Science Foundation of Tibet Autonomous Region, the Beijing Xisike Clinical Oncology Research Foundation, and RemeGen, Ltd.

Prevalence and Clinical Outcomes of Human Epidermal Growth Factor Receptor 2 Expression in Patients With Advanced Urothelial Carcinoma

Background

The prognosis for urothelial carcinoma remains poor, with limited therapeutic options, emphasizing the need for further research into targeted therapies. The prognostic and predictive significance of human epidermal growth factor receptor 2 (HER2) expression in urothelial carcinoma remains unclear, with previous studies reporting conflicting results.

Methods

We conducted a retrospective analysis of advanced urothelial carcinoma cases diagnosed between January 2017 and December 2022. HER2 status was prospectively determined using the Leica CB11 antibody on available biopsy specimens. Patient data, tumor characteristics, and survival outcomes were retrieved from hospital records for analysis.

Results

Of the 84 patients initially identified with muscle-invasive disease, HER2 immunohistochemistry (IHC) was performed on 50 samples. Among these, 54% exhibited HER2 scores ≥ 1+, with 22% classified as HER2-positive (3+ score by IHC), 10% as equivocal (2+ score by IHC), and 22% as HER2-low (1+ score by IHC). The distribution of HER2 score ≥ 1+ tumors included 25.7% in the bladder, 20.0% in the renal pelvis, and none in the ureter. HER2-positive (3+ score by IHC) tumors were all histological grade 3. Among these patients, 13.4% presented with localized disease, 20% with locally advanced disease, and 50% with metastatic disease at the time of diagnosis. Notably, 42.8% of recurrent tumors originating from the renal pelvis and 62.5% of those from the bladder exhibited HER2 scores ≥ 1+. Among patients diagnosed with non-metastatic disease, 100% with renal pelvis tumors and 75% with bladder tumors experienced metastatic recurrence if they were HER2-positive (3+ score by IHC). The overall survival for HER2-negative patients was 31.0 months (95% confidence interval (CI): 15.29 - 66.70) compared to 13.0 months (95% CI: 7.32 - 18.68) in the HER2 score ≥ 1+ population (P = 0.0029).

Conclusions

In this cohort of Mexican patients with urothelial carcinoma, HER2 expression was observed in 54.4% of cases. HER2-positive (+3 by IHC) tumors were associated with higher histological grade and worse prognostic outcomes, including increased recurrence, progression, and mortality.

The biologic landscape and therapeutic implications of upper tract urothelial cancer

PURPOSE OF REVIEW

Management of upper tract urothelial cancer (UTUC) has been largely extrapolated from bladder cancer due to its rarity; however, unique biological and clinical differences between UTUC and bladder cancer have been uncovered. The purpose of this review is to present the current therapeutic landscape of UTUC with an emphasis on biologically driven rationale.

RECENT FINDINGS

Prospective trials for patients with high-risk localized UTUC have shown improved outcomes with adjuvant and neoadjuvant platinum-based chemotherapy. However, the timing of therapy relative to nephroureterectomy may impact platinum eligibility due to renal functional decline following surgery. In recent years, emerging therapeutic classes including immune checkpoint inhibition, antibody drug conjugates, and targeted therapies have emerged as tolerable alternatives to platinum-based chemotherapy in treating metastatic disease. Biomarker-selected therapies, including those targeting HER2 and FGFR3, have shown encouraging results and are relevant to UTUC based on increased expressions of these targets; however, no prospective study to date has been powered to assess the effect of these modern treatments on patients with UTUC specifically.

SUMMARY

Unique biological insights into UTUC pathogenesis and risk factors have expanded the therapeutic landscape for these patients beyond conventional platinum-based chemotherapeutic approaches. Novel therapeutic classes have emerged to guide more precise approaches in treating patients with urothelial cancer, with a need for further trials powered specifically to the UTUC population.

The Role of Antibody-Drug Conjugates in Urothelial Cancer: A Review of Recent Advances in the Treatment of Locally Advanced and Metastatic Urothelial Cancer

Locally advanced and metastatic urothelial cancer (la/mUC) is an aggressive disease with poor prognosis. Platinum-based chemotherapy has remained the first-line treatment for decades and until recently no other treatment options existed. Today, novel agents called antibody drug conjugates (ADCs), including enfortumab vedotin (EV) and sacituzumab govitecan (SG), have been approved for la/mUC offering patients treatment options following or instead of traditional chemotherapy. The EV consists of the chemotherapy monomethyl auristatin E linked to anti-nectin-4 antibody. Single-agent response rates for EV are 40% to 52% including activity in patients with liver metastases, a phenotype associated with worse outcomes. In 2023, EV in combination with pembrolizumab almost doubled progression-free and overall survival versus platinum-based chemotherapy, which led to accelerated FDA approval as first-line treatment for all patients with la/mUC. Safety profile of EV monotherapy and combination with pembrolizumab is generally manageable with peripheral neuropathy and cutaneous toxicity among the most common treatment-related adverse events (TRAEs). The SG is another ADC targeting TROP-2 with SN-38 as payload. It is approved as late-line treatment for la/mUC with ORR 27% and most common TRAEs include gastrointestinal symptoms and neutropenia. Finally, a recent cancer agnostic accelerated approval for trastuzumab deruxtecan (T-DXd) in HER2-positive (IHC3+) solid tumors provides another active ADC option for biomarker-selected patients with treatment refractory la/mUC. Several new ADCs are being investigated in urothelial cancer (UC) clinical trials. This review summarizes the clinical studies and real-world data regarding the use of ADCs in UC.

Clinical significance of HER2 in urothelial carcinoma and analysis of its correlation with glycolytic metabolic characteristics

Objective

This study aimed to explore the clinical relevance of Human Epidermal Growth Factor Receptor 2 (HER2) in urothelial carcinoma (UC) and its association with glycolytic metabolic markers, insulin resistance, and beta-cell function, shedding light on potential therapies targeting both HER2 pathways and cancer metabolism.

Methods

In this retrospective analysis, 237 UC patients from the Departments of Urology and Pathology at Shandong Provincial Hospital were examined. From 1 January 2023, to 1 October 2024, patients underwent HER2 testing using immunohistochemistry (IHC). We investigated the relationships between HER2 expression and metabolic indicators such as the Homeostatic Model Assessment for insulin resistance (HOMA-IR), beta-cell function (HOMA-β), the triglyceride-glucose (TyG) index, and lactate dehydrogenase (LDH) levels. HER2 status was determined using a standardized scoring system from the 2021 Clinical Pathological Expert Consensus on HER2 Testing in UC, China. Statistical analysis followed CDC guidelines, using multivariate logistic regression to assess the independent impacts of HER2 on metabolic traits.

Results

Of the 237 evaluated UC samples, 87.76% exhibited positive HER2 expression. A significant correlation was found between positive HER2 status, advanced tumor stages, and increased LDH levels, suggesting a link between HER2 expression and heightened glycolytic activity. No significant relationships were observed between HER2 status and TyG levels, HOMA-IR, or HOMA-B. Subgroup analyses confirmed the consistency of the relationship between HER2 expression and LDH levels across different demographics and lifestyle factors.

Conclusion

Our findings confirm the significant role of HER2 as a prognostic marker and therapeutic target in UC. The association of HER2 positivity with advanced tumor stages and high LDH levels underscores its complex involvement in disease progression. This study highlights the need to explore HER2's biological mechanisms further and pursue combined therapeutic strategies.

Precision medicine for urothelial carcinoma: An international perspective

The treatment landscape of urothelial cancers has evolved in the last decade with the approval of chemotherapy, immune checkpoint inhibitors, targeted therapies, and antibody drug conjugates. Although improvements in response and survival have been achieved with these strategies, in some scenarios their benefit is still questionable. Current efforts to identify prognostic and predictive biomarkers are crucial for better patient selection and treatment outcomes. In this paper we will review the most promising biomarkers under investigation, such as molecular classifiers, genomic alterations, programmed cell death ligand 1 expression, tumor mutational burden, circulating tumor DNA, urinary biomarkers among others, for muscle invasive bladder cancer and metastatic urothelial cancers. Deeper understanding of these biomarkers will aid clinical decision-making and help tailor treatment strategies.

Performance of a HER2 testing algorithm tailored for urothelial bladder cancer: A Bi-centre study

Aims

This study aimed to develop an AI algorithm for automated HER2 scoring in urothelial bladder cancer (UBCa) and assess the interobserver agreement using both manual and AI-assisted methods based on breast cancer criteria.

Methods and Results

We utilized 330 slides from two institutions for initial AI development and selected 200 slides for the ring study, involving six pathologists (3 senior, 3 junior). Our AI algorithm achieved high accuracy in two independent tests, with accuracies of 0.94 and 0.92. In the ring study, the AI-assisted method improved both accuracy (0.66 vs 0.94) and consistency (kappa=0.48; 95 % CI, 0.443-0.526 vs kappa=0.87; 95 % CI, 0.852-0.885) compared to manual scoring, especially in HER2-low cases (F1-scores: 0.63 vs 0.92). Additionally, in 62.3 % of heterogeneous HER2-positive cases, the interpretation accuracy significantly improved (0.49 vs 0.93). Pathologists, particularly junior ones, experienced enhanced accuracy and consistency with AI assistance.

Conclusions

This is the first study to provide a quantification algorithm for HER2 scoring in UBCa to assist pathologists in diagnosis. The ring study demonstrated that HER2 scoring based on breast cancer criteria can be effectively applied to UBCa. Furthermore, AI assistance significantly improves the accuracy and consistency of interpretations among pathologists with varying levels of experience, even in heterogeneous cases.

Phase 2 Trial of Enfortumab Vedotin in Patients With Previously Treated Locally Advanced or Metastatic Urothelial Carcinoma in China

BACKGROUND

Enfortumab vedotin, a fully human monoclonal antibody-drug conjugate (ADC) directed to Nectin-4, prolonged overall survival (OS) versus standard chemotherapy in patients with previously treated locally advanced or metastatic urothelial carcinoma (mUC) previously receiving a programmed cell death protein 1/ligand 1 (PD-1/L1) inhibitor and platinum-based chemotherapy in the pivotal, phase 3 EV-301 clinical trial, supporting global approvals of enfortumab vedotin monotherapy. This bridging study was the first to evaluate enfortumab vedotin monotherapy in previously treated Chinese patients with locally advanced or mUC.

METHODS

EV-203 was a multicenter, open-label, phase 2 study (NCT04995419) assessing efficacy, safety/tolerability, pharmacokinetics (PK), and immunogenicity of enfortumab vedotin in 40 Chinese patients (PK analysis set, n = 13) with previously treated locally advanced or mUC. Patients received enfortumab vedotin 1.25 mg/kg (Days 1, 8, and 15). Primary endpoints included confirmed objective response rate (ORR) by the independent review committee (IRC) and PK parameters of ADC, total antibody (TAb), and free monomethyl auristatin E (MMAE). Secondary endpoints included investigator-assessed confirmed ORR; investigator-/IRC-assessed duration of response (DOR), disease control rate (DCR), and progression-free survival (PFS); OS; immunogenicity; and safety/tolerability.

RESULTS

As of May 13, 2022, the median follow-up was 6.5 months. Confirmed ORR was 37.5% (n/N = 15/40; 95% CI: 22.7%-54.2%) by IRC and 42.5% (n/N = 17/40; 95% CI: 27.0%-59.1%) by investigator assessment. By IRC, DCR was 72.5% (n = 29), median DOR was not reached, and median PFS was 4.7 months. Median OS was not reached. Endpoints assessed by investigators were consistent with IRC assessments. Two patients discontinued treatment for treatment-related adverse events. No new safety signals were identified. ADC, TAb, and free MMAE were characterized in Chinese patients and consistent with previously characterized populations. The incidence of positive antitherapeutic antibodies postbaseline was 0%.

CONCLUSION

Enfortumab vedotin demonstrated meaningful clinical activity with a manageable safety profile in Chinese patients with previously treated locally advanced or mUC.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT04995419.

Advances, recognition, and interpretation of molecular heterogeneity among conventional and subtype histology of urothelial carcinoma (UC): a survey among urologic pathologists and comprehensive review of the literature

AIMS

Urothelial carcinoma (UC) demonstrates significant molecular and histologic heterogeneity. The WHO 2022 classification has hinted at adding molecular signatures to the morphologic diagnosis. As morphology and associated molecular repertoire may potentially translate to choices of and response to therapy and relapse rate, broader acceptability of recognizing these key features among uropathologists is needed. This prompted an international survey to ascertain the practice patterns in classical/subtype UC among uropathologists across the globe.

METHODS AND RESULTS

A survey instrument was shared among 98 uropathologists using SurveyMonkey software. Anonymized respondent data were analysed. The response rate was 85%. A majority were in concordance with the profiles of luminal (93%) and basal (82%) types. Opinion on the FGFR3 testing platform was variable. While 95% concurred that TERT promoter mutation is the key driver in UC, 72% had the opinion that APOBEC mutagenesis is the main signature in muscle invasive bladder cancer (MIBC). Uropathologists have divergent opinions on MIBC and ERCC2 mutations. Among the participants, 94% would quantify aggressive micropapillary and sarcomatoid histology, while 88% would reevaluate another transurethral resection of the bladder tumour specimen in nonmuscle invasive tumour with micropapillary, small cell, or sarcomatoid histology. A leading number agreed to specific molecular signatures of micropapillary (93%), plasmacytoid (97%), and small cell (86%) subtypes. Ninety-six percent of participants agreed that a small-cell component portends a more aggressive course and should be treated with neoadjuvant chemotherapy and 63% would perform HER2/neu testing only on oncologist's request in advanced tumours. Ninety percent agreed that microsatellite instability testing, although not a standard protocol, should be considered in young patients with upper tract UC. Eighty-six percent agreed that UC with high tumour mutational burden would be a better candidate for immunotherapy.

CONCLUSION

In the era of precision medicine, enhanced understanding of molecular heterogeneity of UC will contribute to better therapeutic options, novel biomarker discovery, innovative management protocols, and outcomes. Our survey provides a broad perspective of pathologists' perceptions and experience regarding incorporation of histomolecular approaches to "personalize" therapy. Due to variable clinical adoption, there is a need for additional data using uniform study criteria. This will drive generation of best practice guidelines in this area for widespread and consistent clinical utility.

HER2 expression in upper tract urothelial carcinoma and the relationship with clinicopathological characteristics-an analysis of 155 patients in Southwest China

OBJECTIVE

We aimed to evaluate the expression of HER2 in patients with upper tract urothelial carcinoma (UTUC) in Southwest China by using a relatively large cohort, and to determine the relationship between HER2 expression and clinicopathological characters.

MATERIALS AND METHODS

We retrospectively enrolled the clinical data of 155 UTUC patients who have undergone radical nephroureterectomy (RNU) from March 2019 to September 2022. HER2 expression was assessed using immunohistochemistry and scored according to the HercepTest (Scores of 0 or 1 + were considered as negative and 2 + or 3 + as positive). Tumor molecular phenotype was classified by the panel of CK20, CK5/6, and CD44.

RESULTS

HER2 was overexpressed in 55 (35.5%) patients. It was associated with pathologic characteristics such as grade (p = 0.017), tumor molecular phenotype (p < 0.001) and Ki-67 expression (p = 0.017). On univariate and multivariable logistic regression analysis, HER2 overexpression remained associated with higher grade (HR, 10.6; 95% CI 1.0-112.6; p = 0.050) and luminal molecular phenotype (HR, 8.0; 95% CI 1,6-38.4; p = 0.010). During disease progression after nephroureterectomy, the phenotype of the tumor might change and a switch phenomenon in phenotype after recurrence in the bladder was reported.

CONCLUSION

According to our study, in Southwest China, one-third of UTUC patients overexpressed HER2. Tumors with high grade or luminal phenotype tended to be HER2 positive. HER2 may represent a promising target for therapy in UTUC.

Prognostic and Predictive Roles of HER2 Status in Non-Breast and Non-Gastroesophageal Carcinomas

The oncogene ERBB2, also known as HER2 or c-ERB2, is located on chromosome 17 (q12). It encodes a tyrosine kinase receptor, the human epidermal growth factor receptor 2 (HER2), involved in neoplastic proliferation, tumor angiogenesis, and invasiveness. Over the past years, the introduction of various anti-HER2 therapies has significantly improved outcomes for patients with HER2-positive breast and gastroesophageal carcinomas. More recently, the introduction of a new antibody-drug conjugate, that is trastuzumab deruxtecan, expanded the therapeutic options to low-HER2 breast and gastroesophageal tumors. HER2 protein overexpression is investigated using immunohistochemistry, gene amplification using fluorescence in situ hybridization, and gene mutation using next-generation sequencing. This review evaluated the predictive and prognostic role of HER2 status in various types of epithelial malignant cancers beyond breast and gastroesophageal cancers. We critically analyzed the key published studies, focusing on utilized scoring systems and assays used, and analyzed clinical parameters and therapeutic approaches. Although the evidence about prognostic and predictive roles of HER2 in carcinomas other than breast and gastroesophageal has been widely increasing over the last decade, it still remains investigational, revealing a tumor site-related prognostic and predictive value of the different types of HER2 alterations. However, standardized and validated scoring system assays have not been well-established for many organs.

HER2-targeted therapies beyond breast cancer - an update

The receptor tyrosine-kinase HER2 (also known as ErbB2) is a well-established therapeutic target in patients with breast or gastric cancer selected on the basis of HER2 overexpression on immunohistochemistry and/or ERBB2 amplification on in situ hybridization. With advances in cancer molecular profiling and increased implementation of precision medicine approaches into oncology practice, actionable HER2 alterations in solid tumours have expanded to include ERBB2 mutations in addition to traditional HER2 overexpression and ERBB2 amplification. These various HER2 alterations can be found in solid tumour types beyond breast and gastric cancer, although few HER2-targeted therapeutic options have been established for the other tumour types. Nevertheless, during the 5 years since our previous Review on this topic was published in this journal, obvious and fruitful progress in the development of HER2-targeted therapies has been made, including new disease indications, innovative drugs with diverse mechanisms of action and novel frameworks for approval by regulatory authorities. These advances have culminated in the recent histology-agnostic approval of the anti-HER2 antibody-drug conjugate trastuzumab deruxtecan for patients with HER2-overexpressing solid tumours. In this new Review, we provide an update on the current development landscape of HER2-targeted therapies beyond breast cancer, as well as anticipated future HER2-directed treatment strategies to overcome resistance and thereby improve efficacy and patient outcomes.

Immunohistochemical markers in predicting behavior of bladder urothelial carcinoma

Background

Bladder cancer is the 5th most prevalent cancer among Iranian men. Finding prognostic markers to predict behavior of this cancer can help us to choose the best treatment for patients from the first place. We aimed to evaluate the correlation of immunohistochemical markers with tumor stage, grade and prognosis of disease.

Methods

In this study, we reassessed the specs of proven UC among Iranian patients. Sixty specimens were collected, contained of 30 low grade and 30 high grade urothelial carcinomas. All slides were assessed by immunohistochemistry study for p21, p27, Her-2/neu, E-cadherin, and CD10. Data were analyzed by SPSS 18.0 and a p-value < 0.05 was considered significant.

Results

We evaluated 60 patients in this study with mean age of 66±11 years and majority of them are men. High expression of p27 showed significant correlation with LGUC (P=0.030). HGUC related with high expression of Her-2/neu, CD10 and aberrant expression of E-Cadherin (P<0.0001). Aberrant E-Cadherin and high expression of CD10 are associated with higher tumor stage (P=0.000). CD10 intensity was the only immunohistochemical markers to predict prognosis (P=0.010).

Conclusion

In the present study, CD10 intensity is the only marker that directly predicts the prognosis. The higher intensity leads to poor prognosis (recurrence or metastasis). More studies must be done in this aspect to resolve the controversies and clarify the role of immunohistochemical markers in predicting BC behaviors.

Expression and clinicopathologic significance of HER2 and PD-L1 in high grade urothelial carcinoma of the urinary tract

BACKGROUND

Urothelial carcinoma (UC) is an aggressive tumor with high recurrence rates and poses a great challenge for clinical management. Programmed death ligand-1 (PD-L1) inhibitors and human epidermal growth factor receptor 2 (HER2) blockers have been approved for the treatment of advanced urothelial carcinoma. PD-L1 and HER2 expression in UC will determine whether patients are likely to respond to these targeted treatments. This study assessed the expressions of HER2 and PD-L1 in UC at our institution and investigated their correlations with gender, tumor location (upper genitourinary (GU) tract vs. lower GU tract), tumor stage, and histologic divergent subtypes.

DESIGN

Patients with UC who had PD-L1 or HER2 immunostains performed in the past 3 years at our institution were included in our analysis. A total of 97 cases were identified. PD-L1 and HER2 scores were provided by two experienced GU pathologists. HER2 scores were given according to the criteria used in breast cancer, while PD-L1 scores were reported as the combined positive score. We assessed correlation of the scores with the patients' gender, tumor location, tumor stage, and histologic divergent subtypes. The data for PD-L1 expression were analyzed using the Mann-Whitney U Test for gender and urinary tract location, and one-way analysis of variance (ANOVA) for stage and histology. The data for HER2 expression were analyzed using the chi-square test. For all analyses, significance was set at P<0.05.

RESULTS

Of the 97 patients, the average age was 69 years. There were 95 patients who had previously reported HER2 results and 86 patients who had PD-L1 results. PD-L1 expression did not show a significant difference among the histological divergent subtypes (P=0.36). However, HER2 status exhibited a significant difference, with more HER2-positive cases observed in the conventional histology (P=0.008). No correlation between HER2 status and either gender or tumor stage was identified. The median PD-L1 combined positive score was significantly higher in lower urinary tract UC than upper (10 and 2, respectively; P=0.049). No significant differences were observed for gender or pathologic stage.

CONCLUSION

Our data suggest that HER2 is more frequently expressed in conventional UC than in divergent subtypes. Additionally, PD-L1 has a higher expression level in lower urinary tract UC compared to upper. However, PD-L1 and HER2 expression are not related to gender or tumor stage in UC.

HER2 overexpression in urothelial carcinoma with GATA3 and PPARG copy number gains

HER2, encoded by the ERBB2 gene, is an important druggable driver of human cancer gaining increasing importance as a therapeutic target in urothelial carcinoma (UC). The genomic underpinnings of HER2 overexpression in ERBB2 nonamplified UC are poorly defined. To address this knowledge gap, we investigated 172 UC tumors from patients treated at the University of California San Francisco, using immunohistochemistry and next-generation sequencing. We found that GATA3 and PPARG copy number gains individually predicted HER2 protein expression independently of ERBB2 amplification. To validate these findings, we interrogated the Memorial Sloan Kettering/The Cancer Genome Atlas (MSK/TCGA) dataset and found that GATA3 and PPARG copy number gains individually predicted ERBB2 mRNA expression independently of ERBB2 amplification. Our findings reveal a potential link between the luminal marker HER2 and the key transcription factors GATA3 and PPARG in UC and highlight the utility of examining GATA3 and PPARG copy number states to identify UC tumors that overexpress HER2 in the absence of ERBB2 amplification. In summary, we found that an increase in copy number of GATA3 and PPARG was independently associated with higher ERBB2 expression in patient samples of UC. This finding provides a potential explanation for HER2 overexpression in UC tumors without ERBB2 amplification and a way to identify these tumors for HER2-targeted therapies.

Making Multiplexed Imaging Flexible: Combining Essential Markers With Established Antibody Panels

Multiplexed immunofluorescence (IF) can be achieved using different commercially available platforms, often making use of conjugated antibodies detected in iterative cycles. A growing portfolio of pre-conjugated antibodies is offered by the providers, as well as the possibility for in-house conjugation. For many conjugation methods and kits, there are limitations in which antibodies can be used, and conjugation results are sometimes irreproducible. The conjugation process can limit or slow down the progress of studies requiring conjugation of essential markers needed for a given project. Here, we demonstrate a protocol combining manual indirect immunofluorescence (IF) of primary antibodies, followed by antibody elution and staining with multiplexed panels of commercially pre-conjugated antibodies on the PhenoCycler platform. We present detailed protocols for applying the workflow on fresh frozen and formalin fixed paraffin embedded tissue sections. We also provide a ready to use workflow for coregistration of the images and demonstrate this for two examples.

A single-arm, multicenter, phase 2 clinical study of recombinant humanized anti-HER2 monoclonal antibody-MMAE conjugate (MRG002) in HER2-positive unresectable locally advanced or metastatic urothelial carcinoma

BACKGROUND

MRG002 is a novel HER2-targeted antibody-drug conjugate being investigated in the MRG002-006 trial to evaluate the efficacy and safety in HER2-positive urothelial carcinoma patients.

METHODS

This is an open-label, single-arm, multicenter phase II study. Eligibility criteria included: histologically confirmed HER2 IHC 2 + or 3 + UC, prior received ≥ 1 standard treatment. Patients in this study received MRG002 every 3 weeks until progressive disease or unacceptable toxicity. The primary endpoint was confirmed ORR per RECIST 1.1.

RESULTS

As of February 24, 2023, a total of 43 patients were enrolled. The median age was 60. 9 patients were dosed at 2.6 mg/kg and 34 patients were dosed at 2.2 mg/kg. At baseline, most patients (29/43) received ≥ 2 lines of treatment and 35 (81.4%) patients had prior ICI therapy. FISH test was performed in 41 patients and 9 (22.0%) were positive. By the cut-off date, 41 patients were evaluable and the ORR was 53% (95%CI：38.9%-67.5%), with 6.9% CR, and the DCR was 83.7% (95%CI：70.0%-91.9%). The median PFS and OS for the 43 patients were 7.0 months (95%CI：5.4-NE) and 14.9 months (95%CI：11.9-NE), respectively. The ORR was 77.8% in 9 patients with positive HER2 FISH results. Most common treatment-related AEs were anemia (51.2%), alopecia (44.2%) and neutropenia (39.5%); most were grade 1 or 2.

CONCLUSION

Preliminary results of MRG002 demonstrated a clinically meaningful response in pretreated HER-2 positive unresectable locally advanced or metastatic UC patients. MRG002 at 2.2 mg/kg was well tolerated with a manageable toxicity.

Antibody-drug conjugates targeting HER2 for the treatment of urothelial carcinoma: potential therapies for HER2-positive urothelial carcinoma

Urothelial carcinoma (UC) is a common cancer characterized by high morbidity and mortality rates. Despite advancements in treatment, challenges such as recurrence and low response rates persist. Antibody-drug conjugates (ADCs) have emerged as a promising therapeutic approach for various cancers, although their application in UC is currently limited. This review focuses on recent research regarding ADCs designed to treat UC by targeting human epidermal growth factor receptor 2 (HER2), a surface antigen expressed on tumor cells. ADCs comprise three main components: an antibody, a linker, and a cytotoxic payload. The antibody selectively binds to tumor cell surface antigens, facilitating targeted delivery of the cytotoxic drug, while linkers play a crucial role in ensuring stability and controlled release of the payload. Cleavable linkers release the drug within tumor cells, while non-cleavable linkers ensure stability during circulation. The cytotoxic payload exerts its antitumor effect by disrupting cellular pathways. HER2 is commonly overexpressed in UCs, making it a potential therapeutic target. Several ADCs targeting HER2 have been approved for cancer treatment, but their use in UC is still being tested. Numerous HER2 ADCs have demonstrated significant growth inhibition and induction of apoptosis in translational models of HER2-overexpressing bladder cancer. Ongoing clinical trials are assessing the efficacy and safety of ADCs targeting HER2 in UC, with the aim of determining tumor response and the potential of ADCs as a treatment option for UC patients. The development of effective therapies with improved response rates and long-term effectiveness is crucial for advanced and metastatic UC. ADCs targeting HER2 show promise in this regard and merit further investigation for UC treatment.

Predictive and prognostic biomarkers in urological tumours

Advancements in cutting-edge molecular profiling techniques, such as next-generation sequencing and bioinformatic analytic tools, have allowed researchers to examine tumour biology in detail and stratify patients based on factors linked with clinical outcome and response to therapy. This manuscript highlights the most relevant prognostic and predictive biomarkers in kidney, bladder, prostate and testicular cancers with recognised impact in clinical practice. In bladder and prostate cancer, new genetic acquisitions concerning the biology of tumours have modified the therapeutic scenario and led to the approval of target directed therapies, increasing the quality of patient care. Thus, it has become of paramount importance to choose adequate molecular tests, i.e., FGFR screening for urothelial cancer and BRCA1-2 alterations for prostate cancer, to guide the treatment plan for patients. While no tissue or blood-based biomarkers are currently used in routine clinical practice for renal cell carcinoma and testicular cancers, the field is quickly expanding. In kidney tumours, gene expression signatures might be the key to identify patients who will respond better to immunotherapy or anti-angiogenic drugs. In testicular germ cell tumours, the use of microRNA has outperformed conventional serum biomarkers in the diagnosis of primary tumours, prediction of chemoresistance, follow-up monitoring, and relapse prediction.

Revisiting Treatment of Metastatic Urothelial Cancer: Where Do Cisplatin and Platinum Ineligibility Criteria Stand?

Cisplatin-based chemotherapy has been the standard of care in metastatic urothelial cancer (mUC) for more than two decades. However, many patients with comorbidities cannot receive cisplatin or its alternative, carboplatin. 'Cisplatin-ineligible' and 'platinum-ineligible' patients lacked effective therapy options. However, the recent combination of enfortumab vedotin (EV), an antibody-drug conjugate targeting Nectin-4, with pembrolizumab (P), an antibody targeting the programmed death-1 (PD-1) immune checkpoint, is changing the status quo of frontline mUC treatment, with potential synergy seen in the EV-103 and EV-302 clinical trials. First, we review the working definitions of 'cisplatin ineligibility' and 'platinum ineligibility' in mUC clinical trials and the standard of care in both categories. Then, we review select clinical trials for frontline treatment of cisplatin- and platinum-ineligible mUC patients on ClinicalTrials.gov. We classify the investigated drugs in these trials by their therapeutic strategies. Alongside chemotherapy combinations, the field is witnessing more immunotherapy combinations with fibroblast growth factor receptor (FGFR) inhibitors, bicycle toxin conjugates, bispecific antibodies, innovative targeted therapies, and many others. Most importantly, we rethink the value of classifying patients by cisplatin or platinum ineligibility in the frontline setting in the post-EVP era. Lastly, we discuss new priority goals to tailor predictive, monitoring, and prognostic biomarkers to these emergent therapies.

Expression of HER2 in high-grade urothelial carcinoma based on Chinese expert consensus and the clinical effects of disitamab vedotin-tislelizumab combination therapy in the treatment of advanced patients

Background: A vast number of researchers have discovered high levels of human epidermal growth factor receptor-2 (HER2) expression in urothelial carcinoma (UC), but they do not use a uniform scoring system. Based on the 2021 edition of clinical pathological expert consensus on HER-2 testing in UC in China, we investigated the expression level and clinical significance of HER2 in high-grade UC. Furthermore, we looked at the prognosis of patients with locally advanced/metastatic UC after combining HER2 targeting antibody-drug conjugates (ADC) medication disitamab vedotin (DV) with programmed cell death protein 1 (PD-1) inhibitor tislelizumab. Patients and methods: From 2019 to 2022, we collected paraffin specimens of UC from the Department of Urology at the Provincial Hospital Affiliated to Shandong First Medical University. HER2 expression-related factors were investigated. Patients with advanced UC who have failed systemic chemotherapy at least once and had received immune checkpoint inhibitor (ICI) medication during second-line treatment were selected and treated with DV in combination with tislelizumab. We assessed the therapy's efficacy and safety. Results: 185 patients with high-grade UC were included in this investigation. 127 patients (68.7%) were HER2 positive (IHC 2+/3+) according to the 2021 Clinical pathological expert consensus on HER2 testing in UC in China. The clinical stage of UC differed statistically significantly between the HER2-and HER2+ groups (p = 0.019). Sixteen advanced UC patients were treated with DV and tislelizumab for a median of 14 months. The disease control rate was 87.5%, while the objective response rate (ORR) was 62.5%. The ORR of HER2+ individuals was higher than that of HER2-individuals (70.0% vs. 50.0%). The median progression-free survival or overall survival was not reached. In this study, the incidence of treatment-related adverse events was 68.8% (11/16), with all of them being grade 1 or 2 adverse reactions. Conclusion: HER2 protein expressed at a high percentage in UC, and 68.7% patients expressed HER2 positive (IHC 2+/3+). HER2+ expression is positively correlated with higher clinical stage of UC. HER2 targeted ADC drug disitamab vedotin combining with PD-1 inhibitor tislelizumab has shown efficacy, safety and controllable adverse reactions in the treatment of advanced UC.

A Comprehensive Review of Immunotherapy Clinical Trials for Metastatic Urothelial Carcinoma: Immune Checkpoint Inhibitors Alone or in Combination, Novel Antibodies, Cellular Therapies, and Vaccines

Urothelial cancer is an immune-responsive cancer, but only a subset of patients benefits from immune checkpoint inhibition. Currently, single-agent immune checkpoint inhibitors (ICIs) and the combination of pembrolizumab with the antibody-drug conjugate enfortumab vedotin are approved to treat patients with metastatic UC (mUC). Approval of first-line nivolumab in combination with gemcitabine and cisplatin is expected imminently. Many treatment approaches are being investigated to better harness the immune system to fight mUC. In this review, we summarize the landmark clinical trials of ICIs that led to their incorporation into the current standard of care for mUC. We further discuss recent and ongoing clinical trials in mUC, which are investigating ICIs in combination with other agents, including chemotherapy, antibody-drug conjugates, tyrosine kinase inhibitors, and novel antibodies. Lastly, we review novel approaches utilizing bispecific antibodies, cellular therapies, and vaccines. The landscape of immunotherapy for mUC is rapidly evolving and will hopefully lead to better outcomes for patients.

The Genomic Landscape of Urothelial Carcinoma with High and Low ERBB2 Expression

BACKGROUND

Recent data suggests that HER2-targeted treatment is efficacious in urothelial carcinoma (UC). We investigated the genomic, transcriptomic, and immune landscapes and clinical outcomes in UC segmented by ERBB2 expression.

METHODS

NextGen DNA/RNA sequencing was performed for 4743 UC tumors. A total of 3% (124/4125) of tumors had HER2 IHC and whole transcriptome sequencing (WTS) data. ERRB2-high and -low tumors were defined by ≥75th and <25th percentiles of ERBB2 expression, respectively. PD-L1 (SP142) positive staining was defined as ≥2+ and ≥5%. HER2 (4B5) positive staining was defined as ≥3+ and >10% or 2+ and >10% with positive HER2 in situ hybridization (ISH).

RESULTS

Of the patients who were ERBB2-high, 79% (61/77) were HER2 positive via IHC. Tumors from lower tract UC had higher ERBB2 expression compared to upper tract UC (50 v 40 median TPM (mTPM), p < 0.001). ERBB2 expression was similar between primary and metastatic tumors (47 v 47 mTPM, p = 0.95). ERBB2-high tumors had a higher prevalence of pathogenic mutations in pTERT, ERBB2, and ELF3 versus ERBB2-low tumors, p < 0.001. ERBB2-high tumors had higher expressions of ADC target genes NECTIN4 (12 v 8 mTPM) and TACSTD2 (366 v 74 mTPM) versus ERBB2-low (p < 0.001), as well as better overall survival from time of tissue sampling than ERBB2-low (HR 1.71, p < 0.001).

CONCLUSION

Our study demonstrated a high concordance between HER2 expression by IHC and ERBB2 gene expression by WTS in UC. Differences in ADC target expression between ERBB2-high vs. ERBB2-low UC may provide a rationale for combination treatment strategies with HER2-ADC. The association between high ERBB2 expression and survival advantage warrants further investigation.

Systemic treatment of advanced and metastatic urothelial cancer: The landscape in Australia

The 5-year survival rate of metastatic urothelial carcinoma (mUC) is estimated to be as low as 5%. Currently, systemic platinum-based chemotherapy followed by avelumab maintenance therapy is the only first-line treatment for mUC that has an overall survival benefit. Cisplatin-based chemotherapy (usually in combination with gemcitabine) is the preferred treatment but carboplatin is substituted where contraindications to cisplatin exist. Treatment with immune checkpoint inhibitors, antibody-drug conjugates, and kinase inhibitors has not yet demonstrated superiority to chemotherapy as first-line therapy and remains investigational in this setting. A recent media release indicates that chemotherapy plus nivolumab gives an OS advantage as first-line treatment but results of this study have not yet been made public. Pembrolizumab remains an option in those having primary progression on first-line chemotherapy or within 12 months of neoadjuvant chemotherapy. The antibody-drug conjugate, enfortumab vedotin has TGA approval for patients whose cancer has progressed following chemotherapy and immunotherapy and has just received a positive Pharmaceutical Benefits Scheme recommendation. The use of molecular screens for somatic genetic mutations, gene amplifications, and protein expression is expanding as drugs that target such abnormalities show promise. However, despite these advances, a substantial proportion of patients with mUC have significant barriers to receiving any treatment, including advancing age, frailty, and comorbidities, and less toxic, effective therapies are needed.

Opportunities and Challenges for a Histology-Agnostic Utilization of Trastuzumab Deruxtecan

PURPOSE OF REVIEW

This review delves into the prospects and challenges offered by a potential pan-histological utilization of trastuzumab deruxtecan (T-DXd) in patients with advanced solid tumors.

RECENT FINDINGS

The HER2-targeted antibody-drug conjugate (ADC) T-DXd has shown broad activity across cancer types, with current indications for patients with biomarker-selected breast, gastric, and non-small-cell lung cancer and relevant activity observed in multiple histology-specific trials. Moreover, two recently reported phase 2 trials (DESTINY-Pantumor02 and HERALD) have supported the potential for a pan-cancer utilization of this ADC in patients with advanced cancers expressing HER2 or with HER2 amplifications. By improving the delivery of cytotoxic chemotherapy, ADCs have allowed for meaningful clinical advantages in broad populations of cancer patients, often leading to survival advantages over conventional chemotherapy. Notably, the broad spectrum of activity of certain ADCs has led to the hypothesis of a histology-agnostic utilization based on detecting specific biomarkers, similar to what is already established for certain targeted treatments and immunotherapy. To date, T-DXd has shown the broadest activity across cancer types, with current approvals in breast, gastric, and lung cancer, and relevant antitumor activity observed in a multiplicity of additional cancer types. The optimization of the drug dose, identification of predictive biomarkers, and clarification of mechanisms of resistance will be critical steps in view of a pan-histological expansion in the use of T-DXd.

Advanced renal pelvis carcinoma patient with an ERBB2 insertion mutation: a case report

The prognosis of renal pelvis cancer is poor and therapeutic options are limited, especially for patients with advanced disease. In this report, we present a case of advanced renal pelvis carcinoma in a male patient in his 60s, characterized by an activating mutation in ERBB2. Clinical evaluation resulted in a pathological diagnosis of renal pelvis carcinoma with liver metastasis. Immunohistochemistry staining results suggested that CK, P63, and PAX8 were positively expressed, while Sy, CK7, CK20, S100, PAX8, and HEP1 were negatively expressed. Furthermore, next-generation sequencing results showed an activating mutation in the ERBB2 gene. The patient initially received a trastuzumab-based combination therapy, which led to a significant reduction in ERBB2 mutation frequency and a stable condition after three treatment cycles. However, following continuous treatment for 4 months, the patient developed drug resistance that resulted in disease relapse. Subsequently, the patient received apatinib treatment, but the therapeutic response was not satisfactory. The patient's condition underwent rapid deterioration and he ultimately succumbed to the disease. This case underscores the potential benefit of trastuzumab for treating ERBB2-mutated advanced renal pelvis cancer, but further highlights that overcoming drug resistance remains a crucial challenge for long-term efficacy.

Navigating the Rapidly Evolving Advanced Urothelial Carcinoma Treatment Landscape: Insights from Italian Experts

PURPOSE OF REVIEW

To discuss recent advances in the treatment of advanced urothelial carcinoma (UC) and how best to incorporate new therapies into clinical practice.

RECENT FINDINGS

There have been several recent practice-changing phase 2 and 3 trials of immune checkpoint inhibitors (ICIs), antibody-drug conjugates (ADCs), and targeted agents in advanced UC. Based on data from these trials, ICIs can be used as first-line maintenance therapy in patients who do not progress on platinum-based chemotherapy, second-line therapy for those with progression, and first-line therapy in cisplatin-ineligible patients with PD-L1 expression; ADCs and targeted agents provide later-line treatment options. Despite substantial progress in the treatment of advanced UC, there are still many uncertainties, including the optimal treatment sequence for novel agents, and reliable predictive biomarkers to aid in treatment selection. There is also an unmet need for effective treatment options in patients unfit for any platinum-based chemotherapy.

Impact of Squamous Histology on Clinical Outcomes and Molecular Profiling in Metastatic Urothelial Carcinoma Patients Treated With Immune Checkpoint Inhibitors or Enfortumab Vedotin

INTRODUCTION

Urothelial carcinoma with squamous differentiation (UCS) is associated with increased resistance to chemotherapy, but outcomes associated with newer therapies approved in this space over the last 5 to 10 years are less well defined. We investigated clinical outcomes and molecular profiling of patients with UCS treated with an immune checkpoint inhibitor (ICI) and/or Enfortumab vedotin (EV).

PATIENTS AND METHODS

We undertook a retrospective analysis of UC patients treated with ICI and/or EV. Objective response rate (ORR), progression free survival (PFS) and overall survival (OS) were compared between pure UC (pUC) and UCS using X2 and log-rank tests, respectively. Prevalence of the most commonly detected somatic alterations were also compared between the 2 histologic subgroups.

RESULTS

A total of 160 patients (40 UCS, 120 pUC) were identified for this analysis. Among 151 patients treated with ICI (38 UCS, 113 pUC), UCS patients had a shorter mPFS (1.9 vs. 4.8 months, P < 0.01) and mOS (9.2 vs. 20.7 months, P < 0.01) compared to pUC. Among 37 patients treated with EV (12 UCS, 25 pUC), UCS patients had a lower ORR (17% vs. 70%, P < 0.01) and shorter mPFS (3.4 vs. 15.8 months, P < 0.01). UCS samples were enriched for CDKN2A, CDKN2B, PIK3CA, while pUC samples were enriched for ERBB2 alterations.

CONCLUSION

In this single-center retrospective analysis, patients with UCS had a distinct somatic genomic profile relative to patients with pUC. Patients with UCS also had inferior outcomes to ICIs and EV compared to patients with pUC.

Systemic Treatment-Decision Algorithms in Muscle-Invasive Bladder Cancer: Clinical Complexities and Navigating for Improved Outcomes

Muscle-invasive bladder cancer has poor prognosis. If organ confined, it is potentially curable; however, across all prognostic groups, approximately half of patients will relapse. For patients with advanced disease, the median overall survival remains under two years. Systemic treatment options are centered on the use of platinum-based combination chemotherapy, with the choice of cisplatin- or carboplatin-based regimens determined on the basis of criteria including performance status and renal function. PD-1/PD-L1 checkpoint-directed immunotherapy has been established for use in advanced disease with modest overall improvements in survival outcomes. Based on current data, optimal utilization appears to be a switch maintenance strategy on completion of chemotherapy. In the curative setting, cisplatin-based chemotherapy provides modest improvements in cure rates in those fit to receive it. Data on the use of adjuvant immunotherapy are currently contradictory, with disease-free survival demonstrated for adjuvant nivolumab, but not atezolizumab, and no overall survival benefit has yet been confirmed. The Nectin-4 directed antibody drug conjugate enfortumab vedotin is an established treatment option for patients previously treated with both chemotherapy and immunotherapy. The emerging therapeutic targets under evaluation include Trop-2 with sacituzumab govitecan, fibroblast growth factor receptors, HER2, and DNA repair deficiency in biomarker-selected patients. The development of properly validated predictive biomarkers has proven challenging for this disease and should be a central priority in the future development of treatment options. This review summarizes the available systemic treatment options in both palliative and curative disease settings, and highlights the available evidence and current limitations for making treatment recommendations.

HER2-targeting antibody-drug conjugate RC48 alone or in combination with immunotherapy for locally advanced or metastatic urothelial carcinoma: a multicenter, real-world study

BACKGROUND

Phase II trials showed the efficacy of anti-HER2 RC48-ADC (disitamab vedotin) for HER2-positive metastatic urothelial carcinoma (UC). This study evaluated RC48 alone verses in combination with immunotherapy for locally advanced or metastatic UC using real-world data.

METHODS

This retrospective, multicenter, real-world study included patients with locally advanced or metastatic UC who received RC48 in five hospitals in China between July 2021 and April 2022. The outcomes were progression-free survival (PFS), overall survival (OS), objective response rate (ORR), disease control rate (DCR), and adverse events.

RESULTS

Thirty-six patients were included. The patients were 47-87 years, and 26 (72.2%) were male. Eighteen patients received RC48 alone, and 18 received RC48 combined with a programmed death-1 antibody. The median PFS was 5.4 months. The median OS was not reached. The 6-month and 1-year PFS rates were 38.8% and 15.5%, respectively. The 1-year OS rate was 79.6%. Fourteen (38.9%) patients achieved a partial response, and the ORR was 38.9%. Eleven patients had stable disease, and the DCR was 69.4%. The median PFS for patients who received RC48 combined with immunotherapy and those who received RC48 alone was 8.5 and 5.4 months, respectively. The main treatment-related adverse events included anemia, hypoesthesia, fatigue, and elevated transaminase. No treatment-related death occurred.

CONCLUSION

RC48 alone or combined with immunotherapy might benefit patients with locally advanced or metastatic UC, regardless of impaired renal function.

The Many Faces of Urothelial Carcinomas: An Update From Pathology to Clinical Approach and Challenges in Practice

Urothelial carcinoma is a heterogeneous disease with histomorphological and genomic variations throughout the same tumor or between tumors from different patients. It has been shown that most of these histologic and genetic differences have prognostic significance and may have a guiding role in determining the appropriate treatment choice for the patient. Therefore, it is crucial for both the pathologist and the clinician to be conscious of these variations and to consider them in patient management. Recently, a consensus molecular classification has been developed and categorized urothelial carcinomas into 6 subclasses. These molecular subclasses seem to be associated with prognosis and/or response to certain therapeutic approaches like chemotherapy or immune checkpoint inhibitory therapy; however, it has not yet been sufficiently validated and has some limitations for routine application. As is well known, there are therapeutic limitations in locally advanced or metastatic urothelial carcinomas, especially those inappropriate for standard therapy with platinum-based chemotherapy regimens. Emerging new therapeutic approaches and testing for appropriate patient selection for those are discussed in this article.