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.

Precision Medicine in Bladder Cancer: Present Challenges and Future Directions

Bladder cancer (BC) is characterized by significant histopathologic and molecular heterogeneity. The discovery of molecular pathways and knowledge of cellular mechanisms have grown exponentially and may allow for better disease classification, prognostication, and development of novel and more efficacious noninvasive detection and surveillance strategies, as well as selection of therapeutic targets, which can be used in BC, particularly in a neoadjuvant or adjuvant setting. This article outlines recent advances in the molecular pathology of BC with a better understanding and deeper focus on the development and deployment of promising biomarkers and therapeutic avenues that may soon make a transition into the domain of precision medicine and clinical management for patients with BC.

The Impact of Systemic Medications on Retinal Function

This study will provide a thorough review of systemic (and select intravitreal) medications, along with illicit drugs that are capable of causing various patterns of retinal toxicity. The diagnosis is established by taking a thorough medication and drug history, and then by pattern recognition of the clinical retinal changes and multimodal imaging features. Examples of all of these types of toxicity will be thoroughly reviewed, including agents that cause retinal pigment epithelial disruption (hydroxychloroquine, thioridazine, pentosan polysulfate sodium, dideoxyinosine), retinal vascular occlusion (quinine, oral contraceptives), cystoid macular edema/retinal edema (nicotinic acid, sulfa-containing medications, taxels, glitazones), crystalline deposition (tamoxifen, canthaxanthin, methoxyflurane), uveitis, miscellaneous, and subjective visual symptoms (digoxin, sildenafil). The impact of newer chemotherapeutics and immunotherapeutics (tyrosine kinase inhibitor, mitogen-activated protein kinase kinase, checkpoint, anaplastic lymphoma kinase, extracellular signal-regulated kinase inhibitors, and others), will also be thoroughly reviewed. The mechanism of action will be explored in detail when known. When applicable, preventive measures will be discussed, and treatment will be reviewed. Illicit drugs (cannabinoids, cocaine, heroin, methamphetamine, alkyl nitrite), will also be reviewed in terms of the potential impact on retinal function.

Update on Retinal Drug Toxicities

Purpose of Review

This review aims to provide an update on the clinical presentations and diagnostic findings of drug-induced retinal toxicities.

Recent Findings

Several newly FDA-approved medications have been associated with acute retinal toxicities, including brolucizumab, MEK inhibitors, ulixertinib, and FGFR inhibitors. Additionally, as previously believed-to-be well-tolerated medications, such as pentosan sulfate sodium, anti-retroviral therapies, and certain intraoperative ocular medications, are used more frequently or for longer periods of time, associated toxic retinopathies and inflammatory reactions have been reported. Finally, advances in ocular imaging have revealed novel findings in hydroxychloroquine and tamoxifen maculopathies.

Summary

Discovery of new medications, increased frequency of use, and longer-term use have led to increased reports of retinal toxicities. Advances in retinal imaging have allowed for earlier detection of subclinical changes associated with these medications, which may help prevent progression of disease. However, more research is needed to determine the point at which vision loss becomes irreversible. Risks and benefits must be assessed prior to discontinuation of the offending, but potentially lifesaving, therapy.

Efficacy of enfortumab vedotin in advanced urothelial cancer: Analysis from the Urothelial Cancer Network to Investigate Therapeutic Experiences (UNITE) study

BACKGROUND

Enfortumab vedotin (EV) is a novel antibody-drug conjugate approved for advanced urothelial cancer (aUC) refractory to prior therapy. In the Urothelial Cancer Network to Investigate Therapeutic Experiences (UNITE) study, the authors looked at the experience with EV in patient subsets of interest for which activity had not been well defined in clinical trials.

METHODS

UNITE was a retrospective study of patients with aUC treated with recently approved agents. This initial analysis focused on patients treated with EV. Patient data were abstracted from chart reviews by investigators at each site. The observed response rate (ORR) was investigator-assessed for patients with at least 1 post-baseline scan or clear evidence of clinical progression. ORRs were compared across subsets of interest for patients treated with EV monotherapy.

RESULTS

The initial UNITE analysis included 304 patients from 16 institutions; 260 of these patients were treated with EV monotherapy and included in the analyses. In the monotherapy cohort, the ORR was 52%, and it was >40% in all reported subsets of interest, including patients with comorbidities previously excluded from clinical trials (baseline renal impairment, diabetes, and neuropathy) and patients with fibroblast growth factor receptor 3 (FGFR3) alterations. Progression-free survival and overall survival were 6.8 and 14.4 months, respectively. Patients with a pure urothelial histology had a higher ORR than patients with a variant histology component (58% vs 42%; P = .06).

CONCLUSIONS

In a large retrospective cohort, responses to EV monotherapy were consistent with data previously reported in clinical trials and were also observed in various patient subsets, including patients with variant histology, patients with FGFR3 alterations, and patients previously excluded from clinical trials with an estimated glomerular filtration rate < 30 mL/min and significant comorbidities.

LAY SUMMARY

Enfortumab vedotin, approved by the Food and Drug Administration in 2019, is an important new drug for the treatment of patients with advanced bladder cancer. This study looks at the effectiveness of enfortumab vedotin as it has been used at multiple centers since approval, and focuses on important patient populations previously excluded from clinical trials. These populations include patients with decreased kidney function, diabetes, and important mutations. Enfortumab vedotin is effective for treating these patients. Previously reported clinical trial data have been replicated in this real-world setting, and support the use of this drug in broader patient populations.

Targeted therapies: Expanding the role of FGFR3 inhibition in urothelial carcinoma

The management of urothelial carcinoma (UC) has rapidly advanced in recent years with new approvals for immune checkpoint inhibitors and antibody-drug conjugates. However, while many UC tumors contain potentially actionable mutations, the role for targeted small molecule inhibitors has been limited. One such target is the fibroblast growth factor receptor (FGFR) family of proteins. Activating mutations and amplifications of FGFR3 are common in UC with higher incidences seen in upper tract as compared to lower tract disease. Consequently, multiple FGFR-directed targeted therapies have been developed and trialed in both UC and other solid tumors harboring FGFR mutations. At current, erdafitinib, an inhibitor of FGFR1-4, is the only approved targeted therapy in metastatic UC following the BLC2001 study, which demonstrated a 49% overall response rate in patients with UC harboring an FGFR3 mutation. Additional FGFR-directed agents also continue to be investigated across multiple disease stages in FGFR-mutated UC including infigratinib, rogaratinib, and AZD4547, among others. Ongoing trials are combining these agents with immune checkpoint inhibitors and chemotherapy regimens. The precision medicine revolution has begun in UC, and FGFR3 inhibitors are leading the charge toward a more personalized, biomarker-driven treatment paradigm.

Fibroblast Growth Factor Inhibitors for Treating Locally Advanced/Metastatic Bladder Urothelial Carcinomas via Dual Targeting of Tumor-Specific Oncogenic Signaling and the Tumor Immune Microenvironment

Locally advanced or metastatic urothelial bladder cancer (a/m UBC) is currently treated using platinum-based combination chemotherapy. Immune checkpoint inhibitors (ICIs) are the preferred second-line treatment options for cisplatin-eligible a/m UBC patients and as first-line options in cisplatin-ineligible settings. However, the response rates for ICI monotherapy are modest (~20%), which necessitates the exploration of alternative strategies. Dysregulated activation of fibroblast growth factor receptor (FGFR) signaling enhances tumor proliferation, survival, invasion, angiogenesis, and immune evasion. The recent U.S. Food and Drug Administration approval of erdafitinib and the emergence of other potent and selective FGFR inhibitors (FGFRis) have shifted the treatment paradigm for patients with a/m UBC harboring actionable FGFR2 or FGFR3 genomic alterations, who often have a minimal-to-modest response to ICIs. FGFRi-ICI combinations are therefore worth exploring, and their preliminary response rates and safety profiles are promising. In the present review, we summarize the impact of altered FGFR signaling on a/m UBC tumor evolution, the clinical development of FGFRis, the rationale for FGFRi-ICI combinations, current trials, and prospective research directions.

Erdafitinib treatment in Brazilian patients with metastatic urothelial carcinoma (mUC): real-world evidence from an Expanded Access Program

Background

Erdafitinib is the first targeted therapy approved for the treatment of patients with metastatic urothelial carcinoma (mUC). Approval was based on a phase II single-arm trial that demonstrated significant activity of erdafitinib in patients with tumors harboring FGFR2/3 alterations. In Brazil, an Expanded Access Program (EAP) provided patients with early access to erdafitinib prior to market authorization. The current report describes characteristics and outcomes of patients with mUC on erdafitinib therapy.

Methods

Patients with mUC that failed first- and second-line systemic therapies were screened for FGFR2/3 alterations in primary or metastatic tumor tissues. Patients with FGFR2/3 alterations were selected to receive erdafitinib at the standard dosing schedule and were followed prospectively to evaluate the efficacy and safety outcomes.

Results

From 19 April 2019, through 13 March 2020, 47 patients with mUC from 10 Brazilian centers were tested for FGFR2/3 alterations. Alterations in FGFR2/3 were found in 12 patients (25.5%) and all of them were eligible for the EAP. Four patients (33%) had partial response, while two patients (17%) had stable disease. Progressive disease, the best response, was observed in five patients (42%). At a median follow-up of 16.2 months, the median time to treatment failure (TTF) was 2.8 months. When considering only patients with objective response, the median TTF was 5.3 months. Adverse events (AEs) were reported for any grade and grade 3 or higher in 10 patients (83%) and 5 patients (42%), respectively. The most common AE was hyperphosphatemia.

Conclusion

This first real-world evidence report of heavily treated patients with mUC confirms the efficacy and safety of erdafitinib in a disease setting with a lack of treatment options.

Emerging Targeted Therapy for Bladder Cancer

For the last decade, biology of urothelial tumorigenesis has been widely explored, helping to better understand the molecular pathways in urothelial carcinoma (UC). Until recently, no targeted therapies have been approved in UC. However, several new molecules have shown promising results in metastatic UC: fibroblast growth factor receptor inhibitors, conjugated antibodies, PARP inhibitors, and antiangiogenics. In this article, the authors review the targeted therapies that are being evaluated in bladder UC.

Emerging agents for the treatment of metastatic urothelial cancer

Over the past few decades, platinum-based combination chemotherapy (PBCC) has been the preferred initial therapy for metastatic urothelial cancer (mUC). However, despite a response rate of approximately 50%, a small proportion of patients with distant metastases may be cured by cisplatin-based combination chemotherapy (CBCC). In addition, up to 50% of patients are not eligible for CBCC due to age or comorbidities. Furthermore, adverse effects from PBCC are a major concern. The emergence of check-point inhibitors (CPIs), particularly those with antibodies directed against programmed cell death 1 protein (PD-1) or its ligand (PD-L1), advanced the treatment of mUC. Avelumab switch-maintenance therapy is recommended in patients with locally advanced or mUC who did not progress on initial PBCC. With the recent advances in tumor molecular biology and the discovery of actionable therapeutic targets, the clinical application of targeted therapy is now being explored for mUC. Erdafitinib, a tyrosine kinase inhibitor of FGFR1-4, has shown positive outcomes in patients with advanced UC with FGFR alterations. Another recent technological development is antibody-drug conjugates (ADCs), which are complex molecules composed of an antibody linked to a biologically active cytotoxic drug (payload) that targets and kills tumor cells while sparing healthy cells. Enfortumab vedotin, a monoclonal antibody targeting nectin-4 conjugated to monomethyl auristatin E, has demonstrated clinically significant efficacy in patients who do not respond to both cytotoxic chemotherapy and CPIs. In this review, we describe switch-maintenance therapies using CPI, various targeted agents, and ADCs that have been investigated for mUC treatment.

Novel Tyrosine Kinase Targets in Urothelial Carcinoma

Urothelial carcinoma represents one of the most prevalent types of cancer worldwide, and its incidence is expected to grow. Although the treatment of the advanced disease was based on chemotherapy for decades, the developments of different therapies, such as immune checkpoint inhibitors, antibody drug conjugates and tyrosine kinase inhibitors, are revolutionizing the therapeutic landscape of this tumor. This development coincides with the increasing knowledge of the pathogenesis and genetic alterations in urothelial carcinoma, from the non-muscle invasive setting to the metastatic one. The purpose of this article is to provide a comprehensive review of the different tyrosine kinase targets and their roles in the therapeutic scene of urothelial carcinoma.

Practice change in the management of metastatic urothelial carcinoma after ASCO 2020

Metastatic urothelial carcinoma (mUC) is an incurable and aggressive disease. In the past decades there have been few effective treatment options that have impacted the prognosis of mUC patients. However, in the last few years, several drugs have emerged as new treatment choices that are changing the therapeutic landscape of mUC. Immune checkpoint inhibitors (ICIs) and targeted agents are useful treatment strategies that have been incorporated into our clinical practice. Nevertheless, cisplatin-based chemotherapy is still the standard of care in the first-line of metastatic disease. The results of the JAVELIN Bladder 100 phase 3 trial were presented at ASCO 2020, this trial evaluated the role of avelumab, an ICI, as maintenance therapy in patients who had not progressed after first-line platinum-based chemotherapy. The trial met its primary endpoint demonstrating an overall survival benefit with avelumab maintenance. In addition, new drugs and combinations are being evaluated to improve the outcomes of second and subsequent lines. Fibroblast growth factor receptor (FGFR) inhibitors and immunotherapy combinations were some of the strategies presented at ASCO 2020 that have shown promising results. Finally, the development of predictive biomarkers that help us in the decision-making process will be one of the most important challenges in the next years.

New and Emerging Therapies in the Management of Bladder Cancer

The treatment landscape for bladder cancer has undergone a rapid evolution in the past five years with the approval of seven new agents. New classes of medications have improved outcomes for many patients who previously had limited treatment options, but there is still much to learn about how to optimize patient selection for these agents and the role of combination therapies. The aims of this review are to discuss these newly approved agents for bladder cancer and to feature promising drugs and combinations—including immune checkpoint inhibitors, targeted therapies, and antibody–drug conjugates—that are in development.