Immune Checkpoint Inhibitors in Metastatic Bladder and Other Solid Malignancies: How Long is Enough?

Abstract: 

The introduction of T-cell targeted immunomodulators blocking the PD-1 and PD-L1 axis is unquestionably one of the most notable advancements in the treatment of advanced or metastatic solid malignancies, including bladder cancer. Immune checkpoint antibodies are now widely utilized as monotherapies or in combination with other systemic therapies in the first or subsequent lines of treatment in approximately 50 cancer types. Deep and durable responses and long tails of survival curves are hallmarks of patients treated with immune checkpoint inhibitors. However, treatment can have negative impacts, including serious treatment-related side effects as well as a high financial burden to individual patients and the healthcare system. There is increasing data that the benefit of immune checkpoint treatment may persist after treatment is discontinued for reasons other than progressive disease, particularly in patients who have achieved a durable complete response. However, the optimal treatment duration and activity after treatment reinitiation remains undefined and will likely be influenced by disease biology (histology and genomics), treatment (monotherapy or combination therapy), and disease context (depth and duration of response). Well-designed prospective clinical trials and the development and validation of biomarkers that predict outcomes after treatment cessation are needed to move the field forward.

Historical Pathogen-Driven Selection May Contribute to Contemporary Ethnic Difference in Bladder Cancer Susceptibility

ABSTRACT:

BACKGROUND: The rationale for ethnic differences in bladder cancer (BCa) susceptibility is an important open question. In this study, we raised the hypothesis that the APOBEC3-rs1014971 variant associated with BCa risk and APOBEC-mutagenesis probably contribute to ethnic differences.

METHODS: We calculated the ethnicity-stratified 5-year age-adjusted incidence rates of BCa using the US SEER database. We performed somatic mutational-signature analyses and compared the APOBEC-related mutational contribution across BCa tumors in patients of different ethnicities. We analyzed the allele frequency distribution of APOBEC3-related rs1014971 in contemporary populations of different ethnicities and in ancient human genomes. We also analyzed the natural selection profiles and ages of the investigated SNPs.

RESULTS: We validated the ethnic difference in BCa risk using US SEER data, revealing Caucasians to be at >2-fold greater risk than Asians / Pacific islanders. In contemporary populations, we observed a coherent ethnic distribution in terms not only of the allele frequency of APOBEC3-related rs1014971, but also the mutational contribution of APOBEC-mediated mutagenesis in BCa tumors. Population genetics and ancient genome analyses further suggested that the diverse ethnic distribution of rs1014971 could be rooted in human evolution.

CONCLUSIONS: It is possible that APOBEC3-related rs1014971 is involved in the different BCa incidence across ethnic groups, and this difference is potentially derived from human evolution. Our findings suggested an evolutionary link between contemporary population-level variations in malignancy susceptibility and pathogen-driven selection in the past, not unlike previously reported cases of certain autoimmune and metabolic disorders.

Impact of Adjuvant Gemcitabine Containing Chemotherapy Following Radical Nephroureterectomy for Patients with Upper Tract Urothelial Carcinoma: Results from a Propensity-Score Matched Cohort Study

Abstract: 

BACKGROUND: The evidence regarding perioperative adjuvant chemotherapy and personalized surveillance strategies for upper tract urothelial carcinoma is limited.

OBJECTIVE: To evaluate whether adjuvant gemcitabine containing chemotherapy affects the oncological outcomes of advanced upper tract urothelial carcinoma (UTUC).

METHODS: The CROES-UTUC registry is an observational, international, multi-center study on patients diagnosed with UTUC. Patient and disease characteristics from 2380 patients with UTUC were collected, and finally 738 patients were included in this analysis. The primary outcome of this study was recurrence-free survival. Propensity score matching was performed. Kaplan-Meier and multivariate Cox regression analyses were performed by stratifying patients according to the treatment of adjuvant chemotherapy.

RESULTS: A total of 738 patients were included in this analysis, and 59 patients received adjuvant chemotherapy (AC), including 50 patients who received gemcitabine. A propensity score matching was performed, including 50 patients who received gemcitabine containing treatment and 50 patients without adjuvant chemotherapy. Disease recurrence occurred in 34.0% of patients. The recurrence rate in the AC group was 22.0%, which was significantly lower than the non-AC group (46.0%). Kaplan-Meier analyses also showed that AC was associated with a lower likelihood of tumor recurrence (p = 0.047). However, AC was not significantly associated with a higher overall survival (OS) (p = 0.908) and cancer-specific survival (CSS) (p = 0.979). Upon multivariate Cox regression analysis, AC was associated with a lower risk of tumor recurrence (HR = 0.297, p = 0.028).

CONCLUSION: The present study confirms that adjuvant gemcitabine containing chemotherapy could decrease the risk of tumor recurrence in patients with locally advanced UTUC following nephroureterectomy. However, more studies are need to draw a clearer image of the value of this treatment method.

The Impact of Dose Reduction of Bacillus Calmette–Guerin on Oncological Outcomes and Toxicity in Non-Muscle Invasive Bladder Cancer: A Systematic Review and Meta-Analysis

Abstract: 

BACKGROUND: Bacillus Calmette–Guerin (BCG) is the standard adjuvant treatment for intermediate and high-risk non-muscle invasive bladder cancer (NMIBC) following transurethral resection of the bladder (TURB). However, the optimal dose, strain, and schedule of BCG remain unclear.

OBJECTIVE: To evaluate the impact of BCG dose reduction on oncological outcomes and toxicity in patients with non-muscle invasive bladder cancer.

METHODS: We performed a systematic review of the literature in PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov databases. Selected studies were analyzed for Meta Analysis using PRISMA criteria. The study focused on disease recurrence, progression, and toxicity. We also compared the oncological outcomes of the different BCG strains.

RESULTS: A total of 2963 patients in 13 randomized controlled trials were included. In recurrence analysis, we found a non-significant difference between the full dose and any dose reduction of BCG (RR = 1.17, [1.06–1.28], I2 = 0%, p = 0.7). In terms of progression, the difference was also non-statistically significant (RR: 1.12 [0.89 – 1.41], I2 = 0%, p = 0.93). In the toxicity analysis, there were more local (RR: 0.81 [0.67–0.99] I2 = 76%; p < 0.01) and systemic (RR: 0.53 [0.34–0.82] I2 = 83%; p < 0.01) side effects in the full dose group than in the dose reduction group. There were no statistically significant differences in oncological outcomes between the analyzed BCG strains.

CONCLUSIONS: Dose reduction did not affect the oncological outcomes of patients with NMIBC who received adjuvant therapy with BCG. On the other hand, dose reduction showed a significant trend towards fewer systemic and local side effects. Further studies comparing oncological and toxicity outcomes using different strains are needed.

New Intravesical Agents for BCG-Unresponsive High-Risk Non-Muscle Invasive Bladder Cancer

Abstract: 

BACKGROUND: With the exception of the FDA-approved valrubicin and pembrolizumab, there are no standard second-line treaments for BCG-unresponsive high-risk non-muscle invasive bladder cancer (NMIBC).

OBJECTIVES: To provide a systematic review of the novel intravesically administered therapeutic agents for the salvage treatment of BCG-unresponsive NMIBC.

METHODS: Online search of the PubMed, EMBASE and Web of Science databases was performed. The endpoints of this review were to evaluate the efficacy of the agents in terms of complete response rates (CR) and durability of CR, overall survival, recurrence-free survival and cancer-specific survival and to report on their toxicity profile. A search on Clinicaltrials.gov was performed to identify ongoing clinical trials.

RESULTS: 14 studies were included in this review. The critical clinical need for the development of an effective, safe and durable intravesical drug for the salvage treatment of high-risk NMIBC seems to be met mainly by intravesical gene therapy; in fact, data support the FDA-approved nadofaragene firadenovec as a potentially important therapeutic advancement in this context. Promising results are also being obtained by the combination of N-803/BCG and by innovative drug delivery systems.

CONCLUSIONS: Considering the plethora of novel intravesical treatments that have completed phase II evaluation, one can reasonably expect that clinicians will soon have at their disposal new agents and treatment options for BCG-unresponsive NMIBC. In the near future, it will be up to the urologist to identify, for each specific patient, the right agent to use, based on safety, results and cost-effectiveness.

Comparison of Robotic vs Open Cystectomy: A Systematic Review

Abstract: 

BACKGROUND: The benefits of a robot-assisted radical cystectomy (RARC) compared to an open approach is still under debate. Initial data on RARC were from trials where urinary diversion was performed by an extracorporeal approach, which does not represent a completely minimally invasive procedure. There are now updated data for RARC with intracorporeal urinary diversion that add to the evidence profile of RARC.

OBJECTIVE: To perform a systematic review and meta-analysis of the effectiveness of RARC compared with open radical cystectomy (ORC).

MATERIALS AND METHODS: Multiple databases were searched up to May 2022. We included randomised trials in which patients underwent RARC and ORC. Oncological and safety outcomes were assessed.

RESULTS: Seven trials of 907 participants were included. There were no differences seen in primary outcomes: disease progression [RR 0.98, 95% CI 0.78 to 1.23], major complications [RR 0.95, 95% CI 0.72 to 1.24] and quality of life [SMD 0.05, 95% CI -0.13 to 0.38]. RARC resulted in a decreased risk of perioperative blood transfusion [RR 0.57, 95% CI 0.43 to 0.76], wound complications [RR 0.34, 95% CI 0.21 to 0.55] and reduced length of hospital stay [MD -0.62 days, 95% CI -1.11 to -0.13]. However, there was an increased risk of developing a ureteric stricture [RR 4.21, 95% CI 1.07 to 16.53] in the RARC group and a prolonged operative time [MD 70.4 minutes, 95% CI 34.1 to 106.7]. The approach for urinary diversion did not impact outcomes.

CONCLUSION: RARC is an oncologically safe procedure compared to ORC and provides the benefits of a minimally invasive approach. There was an increased risk of developing a ureteric stricture in patients undergoing RARC that warrants further investigation. There was no difference in oncological outcomes between approaches.

Advancing Clinical Trial Design for Non-Muscle Invasive Bladder Cancer

Abstract: 

BACKGROUND: Despite recent drug development for non-muscle invasive bladder cancer (NMIBC), few therapies have been approved by the US Food and Drug Administration (FDA), and there remains an unmet clinical need. Bacillus Calmette-Guerin (BCG) supply issues underscore the importance of developing safe and effective drugs for NMIBC.

OBJECTIVE: On November 18–19, 2021, the FDA held a public virtual workshop to discuss NMIBC research needs and potential trial designs for future development of effective therapies.

METHODS: Representatives from various disciplines including urologists, oncologists, pathologists, statisticians, basic and translational scientists, and the patient advocacy community participated. The workshop format included invited lectures, panel discussions, and opportunity for audience discussion and comment.

RESULTS: In a pre-workshop survey, 92% of urologists surveyed considered the development of alternatives to BCG as a high drug development priority for BCG-naïve high-risk patients. Key topics discussed included definitions of disease states; trial design for BCG-naïve NMIBC, BCG-unresponsive carcinoma in situ, and BCG-unresponsive papillary carcinoma; strengths and limitations of single-arm trial designs; assessing patient-reported outcomes; and considerations for assessing avoidance of cystectomy as an efficacy measure.

CONCLUSIONS: The workshop discussed several important opportunities for trial design refinement in NMIBC. FDA encourages sponsors to meet with the appropriate review division to discuss trial design proposals for NMIBC early in drug development.

Y Chromosome Loss and Bladder Cancer

The Y-chromosome until recently had not been regarded to be as consequential as other chromosomes in mammalian development. However, it is needed for male sex determination and spermatogenesis [1], and a variety of other functions [2]. This work has been facilitated greatly by advances in molecular genetic methodologies, particularly the development of CRISPR/Cas9- mediated knockout of parts, or all of entire chromosomes [3]. Indeed, loss of the Y chromosome (LOY) has been identified in many cancer types and as many as 10–40% of human bladder cancers [4–8]. Now a recent publication sheds some light on how LOY potentially drives cancer growth and progression and focuses on bladder cancer [9].