N-803 Plus BCG Treatment for BCG-Naïve or -Unresponsive Non-Muscle Invasive Bladder Cancer: A Plain Language Review.

WHAT IS THIS SUMMARY ABOUT?: This is a summary of two studies that looked at the safety and effectiveness of a potential new treatment, N-803 (Anktiva), in combination with a standard treatment bacillus Calmette-Guerin (BCG) for people with non-muscle invasive bladder cancer (NMIBC).One study was a Phase 1b study that tested increasing doses of N-803 in combination with the same dose of BCG in people with NMIBC who had never received BCG previously (BCG-naive). The other study is a Phase 2/3 study of N-803 and BCG in people with NMIBC whose cancer wasn't eliminated by BCG alone (BCGunresponsive). WHAT HAPPENED IN THE STUDIES?: In the Phase 1b study, the nine participants were split into three groups of 3 participants who received a dose of 100, 200, or 400 µg N-803 along with a standard 50 mg dose of BCG. In the Phase 2/3 study, one group (cohort A) of participants with carcinoma in situ (CIS) disease and another group (cohort B) with papillary disease were treated with 400 µg N-803 plus 50 mg BCG. There was also a cohort C that received only 400 µg N-803. Treatments were delivered directly into the bladder once a week for 6 weeks in a row. WHAT WERE THE KEY TAKEAWAYS?: N-803 plus BCG eliminated NMIBC in all nine BCG-naive participants and the effects were long-lasting, with participants remaining NMIBC-free for a range of 8.3 to 9.2 years.As reported in 2022, cancer was eliminated in 58 of 82 (71%) participants with BCG-unresponsive CIS disease and the effect was also long-lasting. Importantly, approximately 90% of the successfully treated participants avoided surgical removal of the bladder. In cohort B participants with papillary disease, 40 of 72 (55.4%) were cancer-free 12 months after treatment. N-803 used alone was only effective in 2 of 10 participants. In both studies, the combination of N-803 and BCG was found to be associated with very few adverse events.Based on results from the Phase 2/3 study, the U.S. Food and Drug Association (FDA) approved the use of N-803 plus BCG for the treatment of BCG-unresponsive bladder CIS with or without Ta/T1 papillary disease.Clinical Trial Registration: NCT02138734 (Phase 1b study), NCT03022825 (Phase 2/3 study).

Addition of the IL-15 superagonist N-803 to BCG therapy produces a high rate of success in eliminating non-muscle invasive bladder cancer in both BCG-naive and BCG-unresponsive patients, with long-lasting effects that allow patients to avoid surgical removal of the bladder.

From Detection to Cure - Emerging Roles for Urinary Tumor DNA (utDNA) in Bladder Cancer.

PURPOSE OF REVIEW: This review sought to define the emerging roles of urinary tumor DNA (utDNA) for diagnosis, monitoring, and treatment of bladder cancer. Building from early landmark studies the focus is on recent studies, highlighting how utDNA could aid personalized care. RECENT FINDINGS: Recent research underscores the potential for utDNA to be the premiere biomarker in bladder cancer due to the constant interface between urine and tumor. Many studies find utDNA to be more informative than other biomarkers in bladder cancer, especially in early stages of disease. Points of emphasis include superior sensitivity over traditional urine cytology, broad genomic and epigenetic insights, and the potential for non-invasive, real-time analysis of tumor biology. utDNA shows promise for improving all phases of bladder cancer care, paving the way for personalized treatment strategies. Building from current research, future comprehensive clinical trials will validate utDNA's clinical utility, potentially revolutionizing bladder cancer management.

NCCN Guidelines® Insights: Bladder Cancer, Version 3.2024.

Bladder cancer, the sixth most common cancer in the United States, is most commonly of the urothelial carcinoma histologic subtype. The clinical spectrum of bladder cancer is divided into 3 categories that differ in prognosis, management, and therapeutic aims: (1) non-muscle-invasive bladder cancer (NMIBC); (2) muscle invasive, nonmetastatic disease; and (3) metastatic bladder cancer. These NCCN Guidelines Insights detail recent updates to the NCCN Guidelines for Bladder Cancer, including changes in the fifth edition of the WHO Classification of Tumours: Urinary and Male Genital Tumours and how the NCCN Guidelines aligned with these updates; new and emerging treatment options for bacillus Calmette-Guérin (BCG)-unresponsive NMIBC; and updates to systemic therapy recommendations for advanced or metastatic disease.

Pathogenic Roles for RNASET2 in Clear Cell Renal Cell Carcinoma.

A specific splicing isoform of RNASET2 is associated with worse oncologic outcomes in clear cell renal cell carcinoma (ccRCC). However, the interplay between wild-type RNASET2 and its splice variant and how this might contribute to the pathogenesis of ccRCC remains poorly understood. We sought to better understand the relationship of RNASET2 in the pathogenesis of ccRCC and the interplay with a pathogenic splicing isoform (RNASET2-SV) and the tumor immune microenvironment. Using data from The Cancer Genome Atlas and Clinical Proteomic Tumor Analysis Consortium, we correlated clinical variables to RNASET2 expression and the presence of a specific RNASET2-SV. Immunohistochemical staining with matched RNA sequencing of ccRCC patients was then utilized to understand the spatial relationships of RNASET2 with immune cells. Finally, in vitro studies were performed to demonstrate the oncogenic role of RNASET2 and highlight its potential mechanisms. RNASET2 gene expression is associated with higher grade tumors and worse overall survival in The Cancer Genome Atlas cohort. The presence of the RNASET2-SV was associated with increased expression of the wild-type RNASET2 protein and epigenetic modifications of the gene. Immunohistochemical staining revealed increased intracellular accumulation of RNASET2 in patients with increased RNA expression of RNASET2-SV. In vitro experiments reveal that this accumulation results in increased cell proliferation, potentially from altered metabolic pathways. RNASET2 exhibits a tumor-promoting role in the pathogenesis of ccRCC that is increased in the presence of a specific RNASET2-SV and associated with changes in the cellular localization of the protein.

Comparative Effectiveness of Neoadjuvant Pembrolizumab Versus Cisplatin-based Chemotherapy or Upfront Radical Cystectomy in Patients with Muscle-invasive Urothelial Bladder Cancer.

BACKGROUND: Recent progresses in the use of immune checkpoint inhibitor (ICI) have challenged the therapeutic standards in patients with muscle-invasive urothelial bladder carcinoma (MIBC). OBJECTIVE: To compare neoadjuvant pembrolizumab followed by radical cystectomy (RC) versus neoadjuvant chemotherapy (NAC) and RC or upfront RC, according to cisplatin eligibility. DESIGN, SETTING, AND PARTICIPANTS: We conducted two separate analyses for cisplatin-eligible and cisplatin-ineligible cT2-4N0M0 MIBC patients. We used a propensity score adjustment that relied on inverse probability of treatment-weighting (IPTW). INTERVENTION: Pembrolizumab within the PURE-01 trial, and NAC and RC or upfront RC from a high-volume tertiary care referral center. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary endpoint in both analyses was event-free survival (EFS), defined as freedom from recurrence, and/or death from any cause indexed from the date of treatment initiation or RC. The secondary endpoints included EFS in propensity score-matched patients, pathologic response rate, and recurrence-free survival (RFS) after RC. RESULTS AND LIMITATIONS: A total of 458 patients who underwent RC, with or without NAC, at Moffitt Cancer Center between October 2005 and October 2020, and 146 patients enrolled in PURE-01 were analyzed. In cisplatin-ineligible patients, EFS was superior in those receiving pembrolizumab (p < 0.001). The estimated 3-yr EFS was 77.8% (95% confidence interval [CI]: 63.5-95.2) for pembrolizumab and RC, and 36.1% (95% CI: 28.6-45.5) for upfront RC. EFS remained superior in those receiving neoadjuvant ICI (NICI) following IPTW (p < 0.001). In cisplatin-eligible patients, EFS was superior in those receiving pembrolizumab and RC (p < 0.001). The estimated 3-yr EFS was 86.9% (95% CI: 80.9-93.3) for pembrolizumab and 63.5% (95% CI: 56.5-71.4) for NAC. EFS remained superior in those receiving NICI following IPTW (p < 0.001). Pathologic responses and RFS in pembrolizumab-treated patients were also superior to those in NAC-treated patients. Results are limited by the retrospective nature of the study. CONCLUSIONS: In the first ever reported comprehensive comparison of outcomes between neoadjuvant ICI and NAC, followed by RC, or upfront RC, we report increased responses and improved oncologic outcomes with neoadjuvant ICI in patients with MIBC. PATIENT SUMMARY: We compared the results obtained from the use of pembrolizumab and radical cystectomy with standard-of-care treatments in patients with bladder carcinoma infiltrating the muscle layer. We reported increased response and survival rates possibilities with the use of immunotherapy, anticipating the possibility to set new therapeutic standards in these patients, pending the results of ongoing randomized studies.

The Selection for Cytoreductive Nephrectomy (SCREEN) Score: Improving Surgical Risk Stratification by Integrating Common Radiographic Features.

BACKGROUND: Careful patient selection is critical when considering cytoreductive nephrectomy (CN) for metastatic renal cell carcinoma (mRCC) but few studies have investigated the prognostic value of radiologic features that measure tumor burden. OBJECTIVE: To develop a prognostic model to improve CN selection with integration of common radiologic features with known prognostic factors associated with mortality in the first year following surgery. DESIGN, SETTINGS, AND PARTICIPANTS: Data were analyzed for consecutive patients with mRCC treated with upfront CN at five institutions from 2006 to 2017. Univariable and multivariable models were used to evaluate radiographic features and known risk factors for associations with overall survival. Relevant factors were used to create the SCREEN model and compared to the International mRCC Database Consortium (IMDC) model for predictive accuracy and clinical usefulness. RESULTS AND LIMITATIONS: A total of 914 patients with mRCC were treated with upfront CN during the study period. Seven independently predictive variables were used in the SCREEN score: three or more metastatic sites, total metastatic tumor burden ≥5 cm, bone metastasis, systemic symptoms, low serum hemoglobin, low serum albumin, and neutrophil/lymphocyte ratio ≥4. Predictive accuracy measured as the area under the receiver operating characteristic curves was 0.76 for the SCREEN score and 0.55 for the IMDC model. Decision curve analysis showed that the SCREEN model was useful beyond the IMDC classifier for threshold first-year mortality probabilities between 15% and 70%. CONCLUSIONS: The SCREEN score had higher predictive accuracy for first-year mortality compared to the IMDC scheme in a multi-institutional cohort and may be used to improve CN selection. PATIENT SUMMARY: This study provides a model to improve selection of patients with metastatic kidney cancer who may benefit from surgical removal of the primary kidney tumor. We found that radiographic measurements of the tumor burden predicted the risk of death in the first year after surgery. The model can be used to improve decision-making by these patients and their physicians.

First analysis of the safety and efficacy of UGN-101 in the treatment of ureteral tumors.

OBJECTIVE: UGN-101 has been approved for the chemoablation of low-grade upper tract urothelial cancer (UTUC) involving the renal pelvis and calyces. Herein is the first reported cohort of patients with ureteral tumors treated with UGN-101. PATIENTS AND METHODS: We performed a retrospective review of patients treated with UGN-101 for UTUC at 15 high-volume academic and community centers focusing on outcomes of patients treated for ureteral disease. Patients received UGN-101 with either adjuvant or chemo-ablative intent. Response rates are reported for patients receiving chemo-ablative intent. Adverse outcomes were characterized with a focus on the rate of ureteral stenosis. RESULTS: In a cohort of 132 patients and 136 renal units, 47 cases had tumor involvement of the ureter, with 12 cases of ureteral tumor only (8.8%) and 35 cases of ureteral plus renal pelvic tumors (25.7%). Of the 23 patients with ureteral involvement who received UGN-101 induction with chemo-ablative intent, the complete response was 47.8%, which did not differ significantly from outcomes in patients without ureteral involvement. Fourteen patients (37.8%) with ureteral tumors had significant ureteral stenosis at first post-treatment evaluation, however, when excluding those with pre-existing hydronephrosis or ureteral stenosis, only 5.4% of patients developed new clinically significant stenosis. CONCLUSIONS: UGN-101 appears to be safe and may have similar efficacy in treating low-grade urothelial carcinoma of the ureter as compared to renal pelvic tumors.

Novel Use of Circulating Tumor DNA to Identify Muscle-invasive and Non-organ-confined Upper Tract Urothelial Carcinoma.

BACKGROUND: Optimal patient selection for neoadjuvant chemotherapy prior to surgical extirpation is limited by the inaccuracy of contemporary clinical staging methods in high-risk upper tract urothelial carcinoma (UTUC). OBJECTIVE: To investigate whether the detection of plasma circulating tumor DNA (ctDNA) can predict muscle-invasive (MI) and non-organ-confined (NOC) UTUC. DESIGN, SETTING, AND PARTICIPANTS: Plasma cell-free DNA was prospectively collected from chemotherapy-naïve, high-risk UTUC patients undergoing surgical extirpation and sequenced using a 152-gene panel and low-pass whole-genome sequencing. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: To test for concordance, whole-exome sequencing was performed on matching tumor samples. The performance of ctDNA for predicting MI/NOC UTUC was summarized using the area under a receiver-operating curve, and a variant count threshold for predicting MI/NOC disease was determined by maximizing Youden's J statistic. Kaplan-Meier methods estimated survival, and Mantel-Cox log-rank testing assessed the association between preoperative ctDNA positivity and clinical outcomes. RESULTS AND LIMITATIONS: Of 30 patients enrolled prospectively, 14 were found to have MI/NOC UTUC. At least one ctDNA variant was detected from 21/30 (70%) patients, with 52% concordance with matching tumor samples. Detection of at least two panel-based molecular alterations yielded 71% sensitivity at 94% specificity to predict MI/NOC UTUC. Imposing this threshold in combination with a plasma copy number burden score of >6.5 increased sensitivity to 79% at 94% specificity. Furthermore, the presence of ctDNA was strongly prognostic for progression-free survival (PFS; 1-yr PFS 69% vs 100%, p < 0.001) and cancer-specific survival (CSS; 1-yr CSS 56% vs 100%, p = 0.016). CONCLUSIONS: The detection of plasma ctDNA prior to extirpative surgery was highly predictive of MI/NOC UTUC and strongly prognostic of PFS and CSS. Preoperative ctDNA demonstrates promise as a biomarker for selecting patients to undergo neoadjuvant chemotherapy prior to nephroureterectomy. PATIENT SUMMARY: Here, we show that DNA from upper tract urothelial tumors can be detected in the blood prior to surgical removal of the kidney or ureter. This circulating tumor DNA can be used to predict that upper tract urothelial carcinoma is invasive into the muscular lining of the urinary tract and may help identify those patients who could benefit from chemotherapy prior to surgery.

Effectiveness of perioperative chemotherapy and radical cystectomy in treating bladder cancer.

BACKGROUND: Despite abundant evidence supporting the use of perioperative chemotherapy from clinical trials, no study to date has comprehensively evaluated its use in the treatment of muscle-invasive bladder cancer (MIBC) in the real-world setting. Little is known regarding the impact of pretreatment disease stage and real-world factors such as patient comorbidities preventing timely completion of therapy on its effectiveness. This study aims to assess the usage of perioperative chemotherapy and examines its impact on pathologic downstaging rates and recurrence free survival in patients undergoing radical cystectomy. METHODS: A retrospective review was conducted in 805 patients with muscle invasive bladder cancer undergoing radical cystectomy with no perioperative chemotherapy, 761 with presurgical chemotherapy followed by radical cystectomy, and 134 radical cystectomy followed by adjuvant chemotherapy. Relevant clinicopathologic features were reviewed. Recurrence-free survival and Overall Survival probability estimates were calculated using the Kaplan-Meier method and compared using the Log-rank or Gehan-Breslow tests. The prognostic effects of presurgical chemotherapy and adjuvant chemotherapy regimens were evaluated by estimating hazard ratio and 95% confidence interval from an adjusted Cox proportional hazards model. Statistical tests were 2-sided, and significance was defined as P-value < 0.05. RESULTS: In this contemporary, real-world cohort, 5-yr RFS was found to be 65.6% in pT0, 59.1%in pT2, and 10.8% in pN+ patients. Presurgical chemotherapy increased pathologic downstaging rates from 27.5% to 41.1% in patients with ≥cT2 BCa. Stratified by clinical T-stage, only cT2 patients derived recurrence-free survival (Median 45.3 months vs. 29.0 months, P < 0.01) and overall survival (Median 62.3 months vs. 41.9 months, P < 0.001) benefits.  In patients with adverse pathologic features (≥pT3 or pN+), adjuvant chemotherapy improved recurrence-free survival (Median 22.8 months vs. 10.0 months, P < 0.0001) and overall survival (Median OS 32.4 months vs. 16.3 months, P < 0.0001). CONCLUSIONS: We report real-world outcomes from a large cohort of muscle-invasive bladder cancer patients undergoing surgical treatment with/out perioperative chemotherapy. Pathologic response rates to pre-surgical chemotherapy were modest and led to clinical benefit only in cT2 patients. Adjuvant chemotherapy provided survival benefit for pathologically advanced MIBC patients irrespective of pT/N staging.

Risk Factors for Relapse in Nonseminomatous Testicular Cancer After Postchemotherapy Retroperitoneal Lymph Node Dissection With Viable Residual Cancer.

PURPOSE: No consensus exists on the management of men with nonseminoma and viable nonteratomatous germ cell tumor in the postchemotherapy retroperitoneal lymph node dissection (pcRPLND) specimen after first-line chemotherapy. We analyzed surveillance versus different adjuvant chemotherapy regimens and the influence of time to pcRPLND on oncologic outcomes. METHODS: Data on 117 men treated with cisplatin-based first-line chemotherapy between 1990 and 2018 were collected from 13 institutions. All patients had viable nonteratomatous germ cell tumor in the pcRPLND specimen. Surgery was performed after a median of 57 days, followed by either surveillance (n = 64) or adjuvant chemotherapy (n = 53). Primary end points were progression-free survival (PFS), cancer-specific survival (CSS), and overall survival (OS). RESULTS: After controlling for International Germ Cell Cancer Cooperative Group risk group and percent of viable malignant cells found at RPLND, no difference was observed between men managed with surveillance or adjuvant chemotherapy regarding PFS (hazard ratio [HR], 0.72 [95% CI, 0.32 to 1.6]; P = .4), CSS (HR, 0.69; 95% CI, 0.20 to 2.39; P = .6), and OS (HR, 0.78 [95% CI, 0.25 to 2.44]; P = .7). No statistically significant differences for PFS, CSS, or OS were observed on the basis of chemotherapy regimen or in men treated with pcRPLND ≤57 versus >57 days after first-line chemotherapy. Residual disease with <10% versus ≥10% viable cancer cells were associated with a longer PFS (HR, 3.22 [95% CI, 1.29 to 8]; P = .012). Relapse in the retroperitoneum was observed in 34 (29%) men. CONCLUSION: Men with a complete resection at pcRPLND and <10% viable cells have favorable outcomes without further treatment. Complete retroperitoneal resection seems more important than early pcRPLND.

Contemporary Patients Have Better Perioperative Outcomes Following Cytoreductive Nephrectomy: A Multi-institutional Analysis of 1272 Consecutive Patients.

OBJECTIVE: To evaluate factors associated with perioperative outcomes in a multi-institutional cohort of patients treated with cytoreductive nephrectomy (CN). METHODS: Data were analyzed for metastatic renal cell carcinoma patients treated with CN at 6 tertiary academic centers from 2005 to 2019. Outcomes included: Clavien-Dindo complications, mortality, length of hospitalization, 30-day readmission rate, and time to systemic therapy. Univariate and multivariable models evaluated associations between outcomes and prognostic variables including the year of surgery. RESULTS: A total of 1272 consecutive patients were treated with CN. Patients treated in 2015-2019 vs 2005-2009 had better performance status (P<.001), higher pathologic N stage (P = .04), more frequent lymph node dissections (P<.001), and less frequent presurgical therapy (P = .02). Patients treated in 2015-2019 vs 2005-2009 had lower overall and major complications from surgery, 22% vs 39%, P<.001% and 10% vs 16%, P = .03. Mortality at 90days was higher for patients treated 2005-2009 vs 2015-2019; 10% vs 5%, P = .02. After multivariable analysis, surgical time period was an independent predictor of major complications and 90-day mortality following cytoreductive surgery. CONCLUSION: Postoperative major complications and mortality rates following CN are significantly lower in patients treated within the most recent time period.

A Phase II Study of Durvalumab for Bacillus Calmette-Guerin (BCG) Unresponsive Urothelial Carcinoma In Situ of the Bladder.

PURPOSE: Immune checkpoint blockade holds promise for treating bacillus Calmette-Guerin (BCG)-unresponsive non-muscle-invasive bladder cancer (NMIBC). In this phase II study, we investigated the safety and efficacy of durvalumab, a human IgG1 monoclonal antibody, against BCG-unresponsive carcinoma in situ (CIS). PATIENTS AND METHODS: Patients with BCG-unresponsive CIS-containing NMIBC received durvalumab IV at 1,500 mg every 4 weeks for up to 12 months. The primary endpoint was complete response (CR) rate at month 6, defined by negative cystoscopy, urine cytology, and absence of high-grade recurrence on bladder mapping biopsy. The null hypothesis specified a CR rate of 18% and alternative hypothesis of 40%. According to the Simon two-stage design, if ≤3/13 patients achieved CR during stage 1, the trial is stopped due to futility. RESULTS: Between March 8, 2017, and January 24, 2020, 17 patients were accrued whereas 4 withdrew from study treatment after bladder biopsy at month 3 was positive for CIS. Two of 17 (12%) achieved a CR at month 6, with duration of response of 10 and 18 months, respectively. A single grade 3 lipase elevation was attributed to durvalumab, and immune-related adverse events were observed in 7/17 (41%) patients. Only 1/17 patients had high programmed death-ligand 1 expression pretreatment. On RNA sequencing, complement activation genes were elevated posttreatment, along with enrichment of tumor-associated macrophage signature. CONCLUSIONS: Durvalumab monotherapy conferred minimal efficacy in treating BCG-unresponsive CIS of the bladder, with 6-month CR of 12%. Complement activation is a potential mechanism behind treatment resistance.

Route of Administration for UGN-101 and Impact on Oncological and Safety Outcomes.

BACKGROUND: UGN-101 can be used for chemoablation of low-grade upper tract urothelial carcinoma (UTUC). The gel can be administered via a retrograde route through a ureteral catheter or an antegrade route via a nephrostomy tube. OBJECTIVE: To report outcomes of UGN-101 by route of administration. DESIGN, SETTING, AND PARTICIPANTS: We performed a retrospective review of 132 patients from 15 institutions who were treated with UGN-101 for low-grade UTUC via retrograde versus antegrade administration. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Survival outcomes are reported per patient. Treatment, complications, and recurrence outcomes are reported per renal unit. Statistical analysis was performed for primary endpoints of oncological response and ureteral stricture occurrence. RESULTS AND LIMITATIONS: A total of 136 renal units were evaluated, comprising 78 retrograde and 58 antegrade instillations. Median follow-up was 7.4 mo. There were 120 cases (91%) of biopsy-proven low-grade UTUC. Tumors were in the renal pelvis alone in 89 cases (65%), in the ureter alone in 12 cases (9%), and in both in 35 cases (26%). Seventy-six patients (56%) had residual disease before UGN-101 treatment. Chemoablation with UGN-101 was used in 50/78 (64%) retrograde cases and 26/58 (45%) antegrade cases. A complete response according to inspection and cytology was achieved in 31 (48%) retrograde and 30 (60%) antegrade renal units (p = 0.1). Clavien grade 3 ureteral stricture occurred in 21 retrograde cases (32%) and only six (12%) antegrade cases (p < 0.01). Limitations include treatment bias, as patients in the antegrade group were more likely to undergo endoscopic mechanical ablation before UGN-101 instillation. CONCLUSIONS: These preliminary results show a significantly lower rate of stricture occurrence with antegrade administration of UGN-101, with no apparent impact on oncological efficacy. PATIENT SUMMARY: We compared results for two different delivery routes for the drug UGN-101 for treatment of cancer in the upper urinary tract. For the antegrade route, a tube is inserted through the skin into the kidney. For the retrograde route, a catheter is inserted past the bladder into the upper urinary tract. Our results show a lower rate of narrowing of the ureter (the tube draining urine from the kidney into the bladder) using the antegrade route, with no difference in cancer control.

The ablative effect of mitomycin reverse thermal gel: Expanding the role for nephron preservation therapy in low grade upper tract urothelial carcinoma.

PURPOSE: Assess the real-world ablative effect of mitomycin reverse thermal gel for low-grade upper tract urothelial carcinoma (UTUC) in patients who undergo biopsy only or partial ablation and evaluate utility of complete ablation prior to UGN-101. MATERIAL AND METHODS: We retrospectively reviewed low-grade UTUC patients treated with UGN-101 from 15 high-volume centers. Patients were categorized based on initial endoscopic ablation (biopsy only, partial ablation, or complete ablation) and by size of remaining tumor (complete ablation, <1cm, 1-3cm, or >3cm) prior to UGN-101. The primary outcome was rendered disease free (RDF) rate at first post-UGN-101 ureteroscopy (URS), defined as complete response or partial response with minimal mechanical ablation to endoscopically clear the upper tract of visible disease. RESULTS: One hundred and sixteen patients were included for analysis after excluding those with high-grade disease. At first post-UGN-101 URS, there were no differences in RDF rates between those who at initial URS (pre-UGN-101) had complete ablation (RDF 77.0%), partial ablation (RDF 55.9%) or biopsy only (RDF 66.7%) (P = 0.14). Similarly, a complimentary analysis focusing on tumor size (completely ablated, <1cm, 1-3cm or >3cm) prior to UGN-101 induction did not demonstrate significant differences in RDF rates (P = 0.17). CONCLUSION: The results of the early real-world experience suggest that UGN-101 may play a role in initial chemo-ablative cytoreduction of larger volume low-grade tumors that may not initially appear to be amenable to renal preservation. Further studies will help to better quantify the chemo-ablative effect and to identify clinical factors for patient selection.