Recent advances in immune checkpoint inhibitors in the treatment of urothelial carcinoma: A review

Treatment options for urothelial carcinoma were limited until the emergence of immune checkpoint inhibitors, and even now, the prognosis of metastatic disease is poor compared with the other two major genitourinary cancers, renal cell carcinoma and prostate cancer. Despite the increasing use of immune checkpoint inhibitors in the sequential treatment of urothelial carcinoma, conflicting results from similar randomized clinical trials call into question the efficacy of this treatment. In addition, physicians must be aware of the clinical characteristics of immune checkpoint inhibitors, including immune-related adverse events, pseudo- and hyperprogression. This review summarizes the conflicting results of recent clinical trials and provides insights into the role of immune checkpoint inhibitors in the treatment of urothelial carcinoma.

Current Status of Perioperative Therapy in Muscle-Invasive Bladder Cancer and Future Directions

PURPOSE OF REVIEW

Cisplatin-based combination chemotherapy has been a standard of care in the perioperative management of muscle-invasive bladder cancer for years, but several novel therapies are under active investigation. This review aims to provide an update on recent relevant literature and a forward look at the future landscape of adjuvant and neoadjuvant therapy in muscle-invasive bladder cancer patients who opt for radical cystectomy.

RECENT FINDINGS

The recent approval of nivolumab as adjuvant therapy established a new treatment option for high-risk patients with muscle-invasive bladder cancer after radical cystectomy. Several phase II studies of chemo-immunotherapy combinations and immunotherapy alone have reported pathological complete responses in the 26-46% range, including studies in cisplatin-ineligible patients. Randomized studies of perioperative chemo-immunotherapy, immunotherapy alone, and enfortumab vedotin are ongoing. Muscle-invasive bladder cancer remains a challenging disease associated with significant morbidity and mortality; however, increasing options in systemic therapy and an increasingly personalized approach to cancer treatment suggest continued future improvements in patient care.

Disparities in access to novel systemic therapies in patients with urinary tract cancer: Propagating access, policies and resources uniformly

After several decades of therapeutic stagnation, the treatment of patients with urothelial carcinoma has met a revolutionary wave, anticipated by the advent of immune-checkpoint inhibitors (ICI) and followed by newer therapeutic options in the post-ICI setting. These achievements were made in a very short time-frame, thus making the treatment of this disease particularly susceptible to geographical health disparity due to the differences in healthcare systems and approval processes of the regulatory authorities. Furthermore, additional barriers to access innovative care are represented by a limited coverage of clinical trials availability, that is consistent in focusing on selected geographical areas, across trials and clinical settings. Here, we present the current picture of new drug approvals in urothelial carcinoma worldwide, and we also focus our considerations onto the spectrum of ongoing trial inclusion possibilities, trying to understand what are the current gaps in clinical research and routine practice, identifying a way to move forward.

Neoadjuvant Atezolizumab With Gemcitabine and Cisplatin in Patients With Muscle-Invasive Bladder Cancer: A Multicenter, Single-Arm, Phase II Trial

PURPOSE

Neoadjuvant gemcitabine and cisplatin (GC) followed by radical cystectomy (RC) is standard for patients with muscle-invasive bladder cancer (MIBC). On the basis of the activity of atezolizumab (A) in metastatic BC, we tested neoadjuvant GC plus A for MIBC.

METHODS

Eligible patients with MIBC (cT2-T4aN0M0) received a dose of A, followed 2 weeks later by GC plus A every 21 days for four cycles followed 3 weeks later by a dose of A before RC. The primary end point was non-muscle-invasive downstaging to < pT2N0.

RESULTS

Of 44 enrolled patients, 39 were evaluable. The primary end point was met, with 27 of 39 patients (69%) < pT2N0, including 16 (41%) pT0N0. No patient with < pT2N0 relapsed and four (11%) with ≥ pT2N0 relapsed with a median follow-up of 16.5 months (range: 7.0-33.7 months). One patient refused RC and two developed metastatic disease before RC; all were considered nonresponders. The most common grade 3-4 adverse event (AE) was neutropenia (n = 16; 36%). Grade 3 immune-related AEs occurred in five (11%) patients with two (5%) requiring systemic steroids. The median time from last dose of chemotherapy to surgery was 7.8 weeks (range: 5.1-17 weeks), and no patient failed to undergo RC because of AEs. Four of 39 (10%) patients had programmed death-ligand 1 (PD-L1)-positive tumors and were all < pT2N0. Of the patients with PD-L1 low or negative tumors, 23 of 34 (68%) achieved < pT2N0 and 11 of 34 (32%) were ≥ pT2N0 (P = .3 for association between PD-L1 and < pT2N0).

CONCLUSION

Neoadjuvant GC plus A is a promising regimen for MIBC and warrants further study. Patients with < pT2N0 experienced improved relapse-free survival. The PD-L1 positivity rate was low compared with published data, which limits conclusions regarding PD-L1 as a predictive biomarker.

Adjuvant immunotherapy for muscle-invasive urothelial carcinoma of the bladder

INTRODUCTION

There are substantial unmet needs with regards to adjuvant therapy for muscle-invasive urothelial carcinoma (UC) of the bladder, including patients with persistent disease histologically following neoadjuvant platinum-based therapy and radical resection, as well as patients who are not eligible for or refuse cytotoxic chemotherapy. As such, increased interest has been developed in advancing the use of systemic immunotherapy in the postoperative setting.

AREAS COVERED

We begin by examining current uses of systemic immunotherapy in the treatment of advanced UC. We also review emerging neoadjuvant data and describe current adjuvant approaches. We then report and analyze data on adjuvant immunotherapy, including the recent randomized trials on adjuvant nivolumab and atezolizumab, and conclude with a discussion on the available evidence and likely directions of the field.

EXPERT OPINION

Systemic immunotherapy can serve to enhance postoperative therapies for muscle-invasive bladder UC, as exemplified by the recent approval of nivolumab. Further research will serve to define optimal immunotherapy timing and combinations with other systemic therapies, as well as identify predictive biomarkers to allow effective tailoring of therapy for each patient.

Bladder-Sparing Chemoradiotherapy Combined with Immune Checkpoint Inhibition for Locally Advanced Urothelial Bladder Cancer-A Review

Simple Summary

Immunotherapy with immune checkpoint inhibition (ICI) has provided durable treatment responses in advanced, metastatic, bladder cancer patients. The first trials using checkpoint inhibitors before surgery, when the cancer is still confined to the pelvis, without signs of metastasis, have reported promising results. We reviewed the literature to identify clinical trials combining ICI with bladder-sparing chemoradiotherapy (CRT). Radiotherapy stimulates the immune system, thereby possibly inducing an additive effect in combination with checkpoint inhibition. Currently, twelve trials are treating patients with this immunochemoradiotherapy (iCRT) combination treatment. Several combinations with different chemotherapeutics and ICI added to CRT appear safe and feasible. Further research and comparative trials are needed to prove whether iCRT has additional clinical value for bladder cancer patients.

Abstract

Despite current treatment strategies, the 5-year overall survival of muscle-invasive bladder cancer (MIBC) is approximately 50%. Historically, radical cystectomy (RC) with neoadjuvant chemotherapy has been the first-choice treatment for this patient group. Recently, several studies have reported encouraging results of using immune checkpoint inhibitors (ICI) prior to RC. However, in recent years, bladder-sparing alternatives such as CRT have gained popularity. The effect of radiotherapy on the tumor microenvironment is an important rationale for combining CRT with ICI therapy. Worldwide, twelve immunochemoradiotherapy (iCRT) trials are ongoing. Each study employs a different chemotherapy and radiotherapy regimen and varies the timing of ICI administration concurrent to radiotherapy, adjuvant, or both. Five studies have presented (preliminary) results showing promising safety and short-term survival data. The first peer-reviewed publications are expected in the near future. The preclinical evidence and preliminary patient data demonstrate the potential of iCRT bladder-sparing treatment for bladder cancer.

Role of immunotherapy in bladder cancer

The role of immunotherapy in bladder urothelial cancers is rapidly expanding. Since the initial second-line therapy approval for patients who fail prior platinum-based chemotherapy, the use of immunotherapy with checkpoint inhibitors has been rapidly evolving. There are approved indications for first-line metastatic disease in the platinum-ineligible patients or the cisplatin-ineligible PD-L1 positive patients, and there is a label for high-risk non-muscle-invasive bladder cancer who are BCG-refractory. In addition, a trial on maintenance immunotherapy with avelumab showed positive findings with improvement in overall survival that has also changed standard of care for these patients. There are ongoing clinical trials evaluating its use in the neoadjuvant and adjuvant perioperative muscle-invasive bladder cancer setting. The pivotal trials that led to these FDA approvals and promising and ongoing trials are discussed herein.

Cutting-edge Management of Muscle-invasive Bladder Cancer in 2020 and a Glimpse into the Future

This case-based discussion describes the clinical course of a 63-yr-old patient who presented with gross hematuria and was diagnosed with a muscle-invasive bladder cancer at transurethral resection. Computed tomography revealed a locally advanced tumor, and the patient underwent neoadjuvant chemotherapy followed by open radical cystectomy with standard pelvic lymph node dissection. In a step-by-step fashion, we elaborate on diagnostic and therapeutic treatment options from two different vantage points: (1) guideline-adherent treatment with the state-of-the-art standard of care, and (2) a glimpse into the future discussing the evidence of potential additional or alternative approaches based on recent scientific advances. PATIENT SUMMARY: In this case-based discussion, we follow the clinical course of a patient with advanced bladder cancer and elaborate how the state-of-the-art treatment looks like in 2020, based on the best available evidence. This is compared with potential future treatment strategies, which may change and alternate our understanding of optimal bladder cancer care.