Enfortumab Vedotin With or Without Pembrolizumab in Cisplatin-Ineligible Patients With Previously Untreated Locally Advanced or Metastatic Urothelial Cancer

PURPOSE

Patients with locally advanced or metastatic urothelial cancer (la/mUC) who are ineligible for cisplatin-based therapy have limited first-line (1L) treatment options and significant need for improved therapies. Enfortumab vedotin (EV) and pembrolizumab (Pembro) individually have shown a survival benefit in urothelial cancer in second-line + la/mUC settings. Here, we present data from the pivotal trial of EV plus Pembro (EV + Pembro) in the 1L setting.

PATIENTS AND METHODS

In Cohort K of the EV-103 phase Ib/II study, cisplatin-ineligible patients with previously untreated la/mUC were randomly assigned 1:1 to receive EV as monotherapy or in combination with Pembro. The primary end point was confirmed objective response rate (cORR) per blinded independent central review. Secondary end points included duration of response (DOR) and safety. There were no formal statistical comparisons between treatment arms.

RESULTS

The cORR was 64.5% (95% CI, 52.7 to 75.1) and 45.2% (95% CI, 33.5 to 57.3) for patients treated with EV + Pembro (N = 76) and EV monotherapy (N = 73), respectively. The median DOR was not reached for the combination and was 13.2 months for monotherapy; 65.4% and 56.3% of patients who responded to the combination and monotherapy, respectively, maintained a response at 12 months. The most common grade 3 or higher treatment-related adverse events (TRAEs) in patients treated with the combination were maculopapular rash (17.1%), fatigue (9.2%), and neutropenia (9.2%). EV TRAEs of special interest (any grade) in the combination arm included skin reactions (67.1%) and peripheral neuropathy (60.5%).

CONCLUSION

EV + Pembro showed a high cORR with durable responses as 1L treatment in cisplatin-ineligible patients with la/mUC. Patients who received EV monotherapy had a response and safety profile consistent with previous studies. Adverse events for EV + Pembro were manageable, with no new safety signals observed.

Systematic Literature Review (SLR) and Network Meta-Analysis (NMA) of First-Line Therapies (1L) for Locally Advanced/Metastatic Urothelial Carcinoma (la/mUC)

To compare efficacy outcomes for all approved and investigational first-line (1L) treatment regimens for locally advanced or metastatic urothelial carcinoma (la/mUC) with standard of care (SOC), a network meta-analysis (NMA) was conducted. A systematic literature review (SLR) identified phase 2 and 3 randomized trials investigating 1L treatment regimens in la/mUC published January 2001–September 2021. Three networks were formed based on cisplatin (cis) eligibility: cis-eligible/mixed (cis-eligible patients and mixed populations of cis-eligible/ineligible patients), cis-ineligible (strict; exclusively cis-ineligible patients), and cis-ineligible (wide; including studies with investigator’s choice of carbo). Analyses examined comparative efficacy by hazard ratio (HR) for overall survival (OS), and progression-free survival (PFS), and odds ratio (OR) for overall response rate (ORR), with 1L regimens vs. SOC. SOC was gemcitabine + cis (GemCis) or carboplatin (GemCarbo), cis-eligible/mixed network, and GemCarbo cis-ineligible networks. Of 1906 SLR identified citations, 55 trials were selected for data extraction. The NMA comprised 11, 6, and 8 studies in the cis-eligible/mixed, cis-ineligible (strict), cis-ineligible (wide) networks, respectively. In a meta-analysis of SOC control arms, median (95% CI) overall survival (OS) in months varied by network: 13.19 (12.43, 13.95) cis-eligible/mixed, 11.96 (10.43, 13.48) cis-ineligible (wide), and 9.74 (6.71, 12.76) cis-ineligible (strict). Most differences in OS, PFS, and ORR with treatment regimens across treatment networks were not statistically significant compared with SOC. Outcomes with current 1L regimens remain poor, and few significant improvements over SOC have been made, despite inclusion of recent clinical trial data, highlighting an unmet need in the la/mUC patient population.

Reassessment of the Efficacy of Carboplatin for Metastatic Urothelial Carcinoma in the Era of Immunotherapy: A Systematic Review and Meta-analysis

CONTEXT

Platinum-based combination chemotherapy is the standard treatment for advanced or metastatic urothelial carcinoma (AMUC). However, data comparing the efficacy of different platinum agents are limited.

OBJECTIVE

This review aimed to assess the efficacy of carboplatin as a first-line treatment for AMUC using phase 3 randomized trial data.

EVIDENCE ACQUISITION

Multiple databases were searched for articles published until August 2021. Studies that compared overall survival (OS), complete response (CR), and objective response rates (ORRs) in chemotherapy-eligible patients with AMUC were deemed eligible.

EVIDENCE SYNTHESIS

Four studies were included. Compared with immune checkpoint inhibitor (ICI) monotherapy, neither cisplatin- nor carboplatin-based chemotherapy was associated with significant OS (hazard ratio [HR]: 0.97, 95% confidence interval [CI]: 0.85-1.11, p = 0.64 and HR: 0.90, 95% CI: 0.78-1.04, p = 0.16, respectively) and CR (odds ratio [OR]: 1.16, 95% CI: 0.70-1.92, p = 0.57 and OR: 0.89, 95% CI: 0.52-1.53, p = 0.67, respectively benefits, while both were associated with a favorable ORR (OR: 0.54, 95% CI: 0.40-0.74, p < 0.001 and OR: 0.58, 95% CI: 0.42-0.80, p < 0.001, respectively). A network meta-analysis (NMA)-based indirect comparison between carboplatin and cisplatin revealed that while cisplatin was slightly better than carboplatin in terms of OS, CR, and ORR, no significant difference was noted.

CONCLUSIONS

Cisplatin- and carboplatin-based chemotherapies offer similar OS/CR benefits to ICI monotherapy and elicit a greater ORR than ICI monotherapy. Moreover, our NMA demonstrated that both cisplatin- and carboplatin-based chemotherapy have a similar efficacy in terms of OS, CR, and ORR. Given that carboplatin-based chemotherapy is shown to be more effective in contemporary series than in historical controls, it is strongly recommended that carboplatin be re-examined for its value in the era of ICIs and beyond.

PATIENT SUMMARY

Cisplatin- as well as carboplatin-based chemotherapy is as effective as immune checkpoint inhibitors in terms of survival and eliciting a positive response. It is currently believed that cisplatin provides greater benefits than carboplatin; this requires re-evaluation.

Clinical evidence and insights supporting the use of avelumab first-line maintenance treatment in patients with advanced urothelial carcinoma in the Asia-Pacific region

Until recently, international and Asia-specific guidelines for advanced urothelial carcinoma (UC) recommended first-line (1L) platinum-based chemotherapy, followed by second-line (2L) anti-PD-1 or anti-PD-L1 immune checkpoint inhibitor (ICI) therapy where possible, or 1L ICI therapy in cisplatin-ineligible patients with PD-L1+ tumors. However, long-term outcomes remain poor and only a minority of patients receive 2L therapy. The JAVELIN Bladder 100 trial-which assessed avelumab (anti-PD-L1 antibody) as 1L maintenance therapy plus best supportive care (BSC) versus BSC alone in patients with advanced UC that had not progressed with 1L platinum-based chemotherapy-is the only phase 3 trial of ICI-based treatment in the 1L setting to show significantly improved overall survival, and this treatment approach is now recommended in updated treatment guidelines. Available data from the trial suggest that efficacy and safety in patients enrolled in the Asia-Pacific region were similar to findings in the overall population. In this review, we discuss the treatment of advanced UC, with a specific focus on studies in the Asia-Pacific region, and summarize key findings supporting the use of avelumab 1L maintenance as a standard of care in this setting both in cisplatin-eligible and cisplatin-ineligible patients and irrespective of PD-L1 status.

Advances and Controversies With Checkpoint Inhibitors in Bladder Cancer

Immune checkpoint inhibitors have revolutionized the treatment of bladder urothelial cancers and have wide application in almost all disease states. Although several drugs have initially been shown to be beneficial in the second-line metastatic setting, there are still ongoing controversies and debate, including voluntary withdrawals of durvalumab and atezolizumab, along with the approval of agents in the first-line setting in the cisplatin-ineligible state based on inconsistent confirmatory phase III trials. As novel immunotherapy drugs are discovered and studied in various phases of clinical trials, these agents will continue to change the treatment landscape for bladder cancer patients. This review will discuss current available evidence and information and key pivotal trials using checkpoint inhibitors in bladder cancer.

Society for Immunotherapy of Cancer (SITC) clinical practice guideline on immunotherapy for the treatment of urothelial cancer

A number of immunotherapies have been developed and adopted for the treatment of urothelial cancer (encompassing cancers arising from the bladder, urethra, or renal pelvis). For these immunotherapies to positively impact patient outcomes, optimal selection of agents and treatment scheduling, especially in conjunction with existing treatment paradigms, is paramount. Immunotherapies also warrant specific and unique considerations regarding patient management, emphasizing both the prompt identification and treatment of potential toxicities. In order to address these issues, the Society for Immunotherapy of Cancer (SITC) convened a panel of experts in the field of immunotherapy for urothelial cancer. The expert panel developed this clinical practice guideline (CPG) to inform healthcare professionals on important aspects of immunotherapeutic treatment for urothelial cancer, including diagnostic testing, treatment planning, immune-related adverse events (irAEs), and patient quality of life (QOL) considerations. The evidence- and consensus-based recommendations in this CPG are intended to give guidance to cancer care providers treating patients with urothelial cancer.