Accelerating Early Access to Immunotherapies for Advanced Urothelial Carcinoma

Report From the International Society of Urological Pathology (ISUP) Consultation Conference On Molecular Pathology Of Urogenital Cancers. II. Molecular Pathology of Bladder Cancer: Progress and Challenges

During the 2019 International Society of Urological Pathology Consultation Conference on Molecular Pathology of Urogenital Cancer, the Working Group on Bladder Cancer presented the current status and made recommendations on the diagnostic use of molecular pathology, incorporating a premeeting survey. Bladder cancers are biologically diverse and can be separated into "molecular subtypes," based on expression profiling. These subtypes associate with clinical behavior, histology, and molecular alterations, though their clinical utility has not been demonstrated at present and use in bladder cancer is not recommended. Mutations in the TERT promoter are present in the majority of bladder cancers, including the noninvasive stage of tumor evolution, but not in reactive conditions. Mutational analysis of the TERT promoter thus distinguishes histologically deceptive cancers from their benign mimics in some cases. A minority of pathologists employ this test. FGFR3 mutations are common in bladder cancer, and metastatic urothelial carcinoma (UC) with such mutations frequently responds to erdafitinib, an FGFR inhibitor. Testing for FGFR3 alterations is required before using this drug. Metastatic UC responds to immune-oncology (IO) agents in 20% of cases. These are approved as first and second-line treatments in metastatic UC. Several biological parameters associate with response to IO agents, including tumor mutational burden, molecular subtype, and infiltration by programmed death-ligand 1-positive lymphocytes, detected by immunohistochemistry. Programmed death-ligand 1 immunohistochemistry is mandatory before administering IO agents in the first-line setting. In conclusion, much has been learned about the biology of bladder cancer, and this understanding has improved the care of patients with the disease.

Optimal Management of Upper Tract Urothelial Carcinoma: an Unmet Need

OPINION STATEMENT

Upper tract urothelial carcinoma (UTUC) is a rare genitourinary entity of the renal pelvis and the ureter characterized by a more aggressive disease phenotype when compared with urothelial carcinoma of the bladder (UCB) with more than half of UTUC cases presenting with invasive disease at diagnosis compared to 20% for bladder tumors. There is growing evidence suggesting that its distinct natural history from that of bladder cancer can be related to several genetic and epigenetic differences. Treatment of low-risk disease consists of kidney-sparing surgeries such as ureteroscopic and percutaneous treatments, segmental ureterectomy, and adjuvant topical and intracavitary chemo-immunotherapies. The standard of care for high-risk non-metastatic disease remains radical nephroureterectomy and bladder cuff excision with increasing utilization rates of minimally invasive approaches leading to reduced morbidity without compromising outcomes while the role of lymphadenectomy is still being investigated. The prognosis of UTUC has been stagnant over the past decade highlighting the need for further studies on the role of multimodal therapy (neoadjuvant/adjuvant chemotherapy, immunotherapy, targeted therapy) to optimize management and improve outcomes.

FDA Approval Summary: Atezolizumab or Pembrolizumab for the Treatment of Patients with Advanced Urothelial Carcinoma Ineligible for Cisplatin-Containing Chemotherapy

This article summarizes the data supporting FDA approval of atezolizumab and pembrolizumab for the treatment of patients with advanced urothelial carcinoma ineligible for cisplatin‐based chemotherapy and the subsequent revision of the indications for both agents.

The U.S. Food and Drug Administration (FDA) granted accelerated approval to atezolizumab and pembrolizumab in April and May 2017, respectively, for the treatment of patients with locally advanced or metastatic urothelial carcinoma who are not eligible for cisplatin‐containing chemotherapy. These approvals were based on efficacy and safety data demonstrated in the two single‐arm trials, IMvigor210 (atezolizumab) and KEYNOTE‐052 (pembrolizumab). The primary endpoint, confirmed objective response rate, was 23.5% (95% confidence interval [CI]: 16.2%–32.2%) in patients receiving atezolizumab and 28.6% (95% CI: 24.1%–33.5%) in patients receiving pembrolizumab. The median duration of response was not reached in either study and responses were seen regardless of PD‐L1 status. The safety profiles of both drugs were generally consistent with approved agents targeting PD‐1/PD‐L1. Two ongoing trials (IMvigor130 and KEYNOTE‐361) are verifying benefit of these drugs. Based on concerning preliminary reports from these trials, FDA revised the indications for both agents in cisplatin‐ineligible patients. Both drugs are now indicated for patients not eligible for any platinum‐containing chemotherapy or not eligible for cisplatin‐containing chemotherapy and whose tumors/infiltrating immune cells express a high level of PD‐L1. The indications for atezolizumab and pembrolizumab in patients who have received prior platinum‐based therapy have not been changed. This article summarizes the FDA thought process and data supporting the accelerated approval of both agents and the subsequent revision of the indications.

Implications for Practice.

The accelerated approvals of atezolizumab and pembrolizumab for cisplatin‐ineligible patients with advanced urothelial carcinoma represent the first approved therapies for this patient population. These approvals were based on single‐arm trials demonstrating reasonable objective response rates and favorable durations of response with an acceptable toxicity profile compared with available non‐cisplatin‐containing chemotherapy regimens. However, based on concerning preliminary reports from two ongoing phase III trials, the FDA revised the indication for both agents in cisplatin‐ineligible patients. Both are now indicated either for patients not eligible for any platinum‐containing chemotherapy or not eligible for cisplatin‐containing chemotherapy and whose tumors have high expression of PD‐L1.

Clinical Development and Initial Approval of Novel Immune Checkpoint Inhibitors in Oncology: Insights From a Global Regulatory Perspective

Immune checkpoint inhibitors (ICI) have demonstrated meaningful patterns of clinical efficacy across various cancers. During their development, novel regulatory strategies and clinical design approaches were explored. This metrics-based narrative review examines submission strategies and clinical evidence expectations of the US, European, and Japanese drug agencies, as well as their impact on approval and overall development times. Also discussed is the role of emerging clinical science and biomarker evaluation to get the first six ICI initially approved.