Novel Tyrosine Kinase Targets in Urothelial Carcinoma

Enfortumab vedotin and pembrolizumab as monotherapies and combination treatment in locally advanced or metastatic urothelial carcinoma: A narrative review

Background

Bladder cancer is the 10th most common cancer globally. The majority of bladder cancers are urothelial carcinomas (UCs), which, if locally advanced or metastatic, carry poor long-term prognosis. Cancer cells can evade the immune system by expressing the programmed cell death ligand 1 protein (PD-L1). Programmed cell death ligand 1 protein binds to programmed cell death protein 1 (PD-1) on T cells, inhibiting their antitumor action. Bladder tumor cells also overexpress nectin-4, a cell adhesion polypeptide that contributes to metastasis, worsening prognosis. Current platinum-based chemotherapy treatments are suboptimal. This review aimed to assess novel treatments for locally advanced or metastatic UC that specifically target PD-L1 or nectin-4, namely, the PD-1 inhibitor pembrolizumab and the anti-nectin-4 antibody-drug conjugate enfortumab vedotin (EV).

Materials and methods

Relevant English-language peer-reviewed articles and conference abstracts from the last 5 years were identified through MEDLINE and EMBASE database searches. A narrative review was performed, with key results outlined below.

Results

Pembrolizumab was demonstrated to be superior to chemotherapy as a second-line treatment for platinum-unresponsive participants in the KEYNOTE-045 trial, resulting in its Food and Drug Administration (FDA) approval. Enfortumab vedotin therapy resulted in superior outcomes compared with chemotherapy in the EV-301 trial, resulting in FDA approval for its use for patients with locally advanced or metastatic UC who had previously undergone treatment with platinum-based chemotherapy and PD-1/PD-L1 inhibitors. Positive preliminary results for pembrolizumab and EV combination therapy have led to FDA approval in patients with locally advanced or metastatic UC who are not eligible for platinum chemotherapy.

Conclusions

Pembrolizumab and EV represent novel treatment options for patients with locally advanced or metastatic UC with documented superior outcomes and tolerability as compared with standard chemotherapy.

Precision Medicine in Urothelial Carcinoma: Current Markers to Guide Treatment and Promising Future Directions

OPINION STATEMENT

The treatment landscape for urothelial cancer has changed dramatically in the last 10 years, with the approval of several new treatments. At the same time, profiling of individual tumors has become more commonplace with widespread availability of molecular testing and immunohistochemistry. For urothelial cancer, this has led to current guidelines recommending that molecular testing be obtained in the metastatic setting, and that it be considered in the setting of locally advanced disease. Between molecular testing and immunohistochemistry testing of tumors, the only current guideline-directed application of these tests is in the identification of FGFR3 or FGFR2 alterations for use of FGFR inhibitors. While additional recurrent molecular alterations linked to the pathogenesis of urothelial cancer have been identified, the ability to successfully "drug" the pathways association with such alterations remains limited. There has been extensive research into whether expression of particular proteins might inform specific treatment approaches such as the use of PD-L1 testing to guide immune checkpoint blockade. With the integration of antibody-drug conjugates into the treatment armamentarium for urothelial cancer, ongoing research is seeking to determine whether expression of the targets of these therapies, such as Nectin 4, Trop-2, or HER2, could help to guide treatment.

Current and Emerging Strategies to Treat Urothelial Carcinoma

Urothelial cell carcinoma (UCC, bladder cancer, BC) remains a difficult-to-treat malignancy with a rising incidence worldwide. In the U.S., UCC is the sixth most incident neoplasm and ~90% of diagnoses are made in those >55 years of age; it is ~four times more commonly observed in men than women. The most important risk factor for developing BC is tobacco smoking, which accounts for ~50% of cases, followed by occupational exposure to aromatic amines and ionizing radiation. The standard of care for advanced UCC includes platinum-based chemotherapy and programmed cell death (PD-1) or programmed cell death ligand 1 (PD-L1) inhibitors, administered as frontline, second-line, or maintenance therapy. UCC remains generally incurable and is associated with intrinsic and acquired drug and immune resistance. UCC is lethal in the metastatic state and characterized by genomic instability, high PD-L1 expression, DNA damage-response mutations, and a high tumor mutational burden. Although immune checkpoint inhibitors (ICIs) achieve long-term durable responses in other cancers, their ability to achieve similar results with metastatic UCC (mUCC) is not as well-defined. Here, we discuss therapies to improve UCC management and how comprehensive tumor profiling can identify actionable biomarkers and eventually fulfill the promise of precision medicine for UCC patients.

Emerging monoclonal antibody therapies in the treatment of metastatic urothelial carcinoma

INTRODUCTION

The treatment landscape for advanced-stage, unresectable or metastatic urothelial carcinoma (mUC) has shifted dramatically over a short period of time, with new therapeutic agents available for clinical use. However, despite these recent advances in the field, mUC continues to be a disease with significant morbidity and mortality and remains generally incurable. While platinum-based therapy remains the backbone of therapy, many patients are ineligible for chemotherapy or have failed initial chemotherapy treatment. In post-platinum treated patients, immunotherapy and antibody drug conjugates have provided incremental advances, but agents with better therapeutic index guided by precision medicine are needed.

AREAS COVERED

This article covers the available monoclonal antibody therapies in mUC excluding immunotherapy and antibody drug conjugates. Included are a review of data utilizing monoclonal antibodies targeting VEG-F, HER-2, FGFR, and KIR-2 in the setting of mUC. A literature search from 6/2022- 9/2022 was performed utilizing PubMed with key terms including urothelial carcinoma, monoclonal antibody, VEG-F, HER-2, FGFR.

EXPERT OPINION

Often used in combination with immunotherapy or other therapeutic agents, monoclonal antibody therapies have exhibited efficacy in mUC in early trials. Upcoming clinical trials will further explore their full clinical utility in treating mUC patients.

Recent Advances in Kinase Drug Discovery Part I: The Editors' Take

This special issue on Advances in Kinase Drug Discovery provides a selection of research articles and topical reviews covering all aspects of drug discovery targeting the phosphotransferase enzyme family [...].