Avelumab Maintenance for Urothelial Carcinoma

The role of switch maintenance therapy in urothelial cancers

Maintenance therapy with immune checkpoint inhibitors (ICIs) has changed the treatment paradigm of metastatic urothelial carcinoma (mUC). The JAVELIN Bladder 100 trial established avelumab, one of several ICIs in use today, as a life-prolonging maintenance therapy for patients with advanced urothelial carcinoma. Platinum-based chemotherapy is most often used in the first-line treatment of mUC, and while response rates approach about 50%, disease control is usually short-lived upon completion of the standard three to six cycles of chemotherapy. Much progress has been made in recent years in the second-line space and beyond with the use of ICIs, antibody-drug conjugates (ADCs), and tyrosine kinase inhibitors (TKIs) in eligible patients at the time of disease progression post-platinum-based chemotherapy. However, many patients with progressive mUC after first-line chemotherapy suffer from rapid progression of disease, treatment toxicity with subsequent lines of therapy, and a limited life expectancy. Until the results of the JAVELIN Bladder 100 trial were presented in 2020, there were no maintenance strategies proven to be beneficial over best supportive care after disease control is achieved with first-line platinum-based chemotherapy. To date, standard of care frontline treatment of metastatic urothelial cancer remains to be four to six cycles of platinum-based chemotherapy followed by maintenance avelumab. This review summarizes the current evidence available on maintenance therapies in mUC, as well as several highly anticipated clinical trials that we hope will result in further progress in the management of this aggressive cancer and improve patient outcomes.

Impact of clinicopathological features on immune-based combinations for advanced urothelial carcinoma: a meta-analysis

Aims: Immune checkpoint inhibitors (ICIs) have recently revolutionized the treatment landscape of metastatic urothelial carcinoma. The authors performed a meta-analysis aiming to evaluate the predictive value of Eastern Cooperative Oncology Group performance status, age, sex, liver metastasis and histology in trials comparing first-line ICI-based combinations with chemotherapy in metastatic urothelial carcinoma patients. Methods: Hazard ratios were analyzed. Results: ICI-based combinations significantly decreased the risk of death in several clinicopathological subgroups, including patients with no liver metastases (hazard ratio: 0.84; 95% CI: 0.74-0.95) and those with an Eastern Cooperative Oncology Group performance status of 0 (hazard ratio: 0.84; 95% CI: 0.72-0.97). Conclusion: The benefit of ICI-based combinations over chemotherapy in metastatic urothelial carcinoma was consistent across several clinicopathological subgroups, although a proportion of patients responded to chemotherapy alone.

Immunotherapy and Sonpavde score validation in advanced upper tract urothelial carcinoma: a retrospective study by the Italian Network for Research in Urologic-Oncology

Background: Few data are available regarding the effectiveness of immune checkpoint inhibitors in advanced upper tract urothelial carcinoma (UTUC) patients. Methods: To provide a real-world experience with anti-PD-1/PD-L1-based therapy in UTUC patients, we involved an Italian network in a multicenter retrospective analysis. Results: A total of 78 UTUC patients were enrolled. The median follow-up was 25.1 months. The median progression-free survival (mPFS) was 2.2 months (95% CI 1.8-2.6), and the median OS (mOS) was 6.0 months (95% CI 3.6-8.4). The Sonpavde score (including performance status > 0, hemoglobin < 10 g/dl, liver metastases, time from prior chemotherapy ≥ 3 months) split the patients into three groups (0 vs 1 vs 2-4 factors), efficiently predicting the OS and PFS outcome at the multivariate analyses (p < 0.0001). Conclusion: The prognosis of unselected UTUC patients is still unsatisfactory. The Sonpavde score was validated for the first time in an UTUC population, as a useful tool for the treatment decision-making process.

Metastatic Urothelial Cancer: a rapidly changing treatment landscape

Despite significant progress, metastatic urothelial cancer remains an incurable condition with a limited life expectancy. Platinum-based chemotherapy is still the mainstay of treatment for metastatic disease, but immunotherapy, antibody drug conjugates, and targeted agents have shown encouraging results in several recent practice changing trials. In this review, we discuss the standard of care, recent therapeutic advances, ongoing clinical trials, and future perspectives in metastatic urothelial carcinoma.

Impact of the objective response to and number of cycles of platinum-based first-line chemotherapy for metastatic urothelial carcinoma on overall survival of patients treated with pembrolizumab

OBJECTIVES

To investigate the impact of the number of cycles and objective response to chemotherapy on overall survival in patients with metastatic urothelial carcinoma treated with pembrolizumab.

METHODS

This multicenter, retrospective study included 755 patients from 59 institutions with advanced, chemoresistant urothelial carcinoma who received pembrolizumab. The associations of the overall survival with the number of cycles and best objective response were investigated using Cox multiple regression analysis.

RESULTS

Overall, 391 patients received standard first-line chemotherapy and pembrolizumab as a second-line treatment, and were included in the final analysis. Of the 391 patients, 185 received less than four cycles, 134 received four to six cycles and 72 received more than six cycles of first-line chemotherapy. An objective response (complete or partial response) to chemotherapy was observed in 145 patients (37.1%). Univariate analysis showed that the overall survival of patients who received more than six cycles or responded to chemotherapy (complete or partial response) was significantly longer than that of patients who received less than four cycles or did not respond to chemotherapy (stable or progressive disease). At multivariate levels, no correlations were observed between overall survival and the number of cycles of or the response to chemotherapy.

CONCLUSIONS

Therapeutic benefit of pembrolizumab can be expected irrespective of the objective response to and number of cycles of platinum-based first-line chemotherapy.

PD-L1 testing in urothelial bladder cancer: essentials of clinical practice

PURPOSE

While immunotherapy has become an increasingly attractive strategy in patients with urothelial bladder cancer, the need for a biomarker to identify patients whose cancer is the most likely to respond has never been more crucial. This review systematically evaluates evidence regarding PD-L1 as a predictive biomarker of response to anti-PD(L)1 monoclonal antibodies in patients with urothelial bladder carcinoma, and discusses its current limits in routine clinical practice.

METHODS

We performed a critical review of PubMed/Medline according to the Preferred Reporting Items for Systematic Review and Meta-analyses (PRISMA) statement. Prospective clinical trials evaluating anti-PD(L)1 monoclonal antibodies in urothelial bladder carcinoma together with retrospective studies evaluating PD-L1 expression in patients with bladder cancer were included.

RESULTS

Evidence data related to PD-L1 as a predictive biomarker of response to immune checkpoint blockade monotherapy across clinical trials are detailed in this review. The different companion diagnostic assays, and the methods for PD-L1 scoring in urothelial bladder carcinoma are reported. Additionally, the issues related to the implementation of PD-L1 testing in clinical practice are discussed.

CONCLUSIONS

PD-(L)1 monoclonal antibodies atezolizumab and pembrolizumab are restricted to patients with PD-L1 positive status in the first-line setting in patients with advanced or metastatic urothelial bladder carcinoma who are ineligible to cisplatin-based chemotherapy. Importantly, the use of anti-PD(L)1 mAb in the other clinical settings is not based on PD-L1 status, but rather on patients' clinical characteristics. Further identification of biomarkers with high negative predictive value will also be of utmost importance to identify patients who may not respond to such immunotherapies.