Miest, Tanner

509 Background: Bladder cancer is a leading cause of cancer death in the United States. The histology in > 90% of cases is urothelial carcinoma (UC). Tumors may present either as non-muscle-invasive (NMIBC) or muscle-invasive disease (MIBC). Current standard of care for patients with high risk NMIBC includes transurethral resection of bladder tumor (TURBT) followed by intravesical immunotherapy with Bacillus Calmette-Guerin (BCG). Meanwhile, patients with BCG unresponsive NMIBC or MIBC are recommended to undergo radical cystectomy (RC), which adversely impacts quality of life and is associated with significant morbidity. MV-NIS is an investigational oncolytic measles virus with an excellent clinical safety profile. This ongoing phase I clinical study is designed to test the safety, efficacy and identify the recommended phase 2 dose (RP2D) of intravesical MV-NIS in patients with NMIBC or MIBC who are scheduled for RC and not eligible for neoadjuvant chemotherapy. Methods: Bladder UC patients were evaluated for eligibility and provided informed consent prior to enrolling. To date 8 patients have been enrolled: 4 to the single dose safety cohort, and 4 to the multi-dose expansion cohort. Patients were administered intravesical ̃1x109 TCID50 MV-NIS once at least 1 week prior to RC (safety cohort), or twice at 4 and 2 weeks prior to RC (expansion cohort). Patients were closely monitored during the 2-hour instillation period. Tumor specimens from the pre-treatment TURBT and post-treatment RC were analyzed to determine pre- and post-treatment pathological stage and evaluate tumor killing and immune cell infiltrate. Results: Intravesical MV-NIS treatment was well tolerated in all patients. Only a single Adverse Event (AE) attributable to MV-NIS treatment (Grade 1 hematuria). AEs Grade > 2 were related to post-surgical complications. Tumor downstaging was observed in 4 of 8 patients. Among 4 patients in the expansion cohort, 2 had no residual disease (pT0). Central assessment of RC tissues showed significant inflammatory infiltrate in all treated bladder specimens. Detailed analyses are ongoing to characterize MV infection and immune infiltrate in bladder tissue. Conclusions: The higher-than-expected rate of tumor downstaging and pT0 pathology, paired with the significant immune infiltrate observed in post-treatment bladder tissue, provide compelling evidence that intravesical MV-NIS has clinical activity against UC. These results support the use of two doses of ̃1x109 TCID50 as the RP2D in future clinical studies for BCG unresponsive NMIBC or MIBC patients. MV-NIS induced inflammation may act synergistically with checkpoint blockade therapies. Clinical trial information: NCT03171493.

Abstract Background: Bladder cancer is a leading cause of cancer death in the United States1. The histology in > 90% of cases is urothelial carcinoma (UC). Tumors may present either as non-muscle-invasive (NMIBC) or muscle-invasive disease (MIBC). Current standard of care for patients with high risk NMIBC includes transurethral resection of bladder tumor (TURBT) followed by intravesical immunotherapy with Bacillus Calmette-Guerin (BCG)2. Meanwhile, patients with BCG unresponsive NMIBC or MIBC are recommended to undergo radical cystectomy (RC), which adversely impacts quality of life and is associated with significant morbidity3. MV-NIS is an investigational oncolytic measles virus with an excellent clinical safety profile4. This ongoing phase I clinical study is designed to test the safety, efficacy and identify the recommended phase 2 dose (RP2D) of intravesical MV-NIS in patients with NMIBC or MIBC who are scheduled for RC and not eligible for neoadjuvant chemotherapy. Methods: Bladder UC patients were evaluated for eligibility and provided informed consent prior to enrolling. To date 8 patients have been enrolled: 4 to the single dose safety cohort, and 4 to the multi-dose expansion cohort. Patients were administered intravesical ~1x109 TCID50 MV-NIS once at least 1 week prior to RC (safety cohort), or twice at 4 and 2 weeks prior to RC (expansion cohort). Patients were closely monitored during the 2-hour instillation period. Tumor specimens from the pre-treatment TURBT and post-treatment RC were analyzed to determine pre- and post-treatment pathological stage and evaluate tumor killing and immune cell infiltrate. Results: Intravesical MV-NIS treatment was well tolerated in all patients. Only a single Adverse Event (AE) attributable to MV-NIS treatment (Grade 1 hematuria). AEs Grade>2 were related to post-surgical complications. Tumor downstaging was observed in 4 of 8 patients. Among 4 patients in the expansion cohort, 2 had no residual disease (pT0). Central assessment of RC tissues showed significant inflammatory infiltrate in all treated bladder specimens. Detailed analyses are ongoing to characterize MV infection and immune infiltrate in bladder tissue. Conclusions: The higher-than-expected rate of tumor downstaging and pT0 pathology, paired with the significant immune infiltrate observed in post-treatment bladder tissue, provide compelling evidence that intravesical MV-NIS has clinical activity against UC. These results support the use of two doses of ~1x109 TCID50 as the RP2D in future clinical studies for BCG unresponsive NMIBC or MIBC patients. MV-NIS induced inflammation may act synergistically with checkpoint blockade therapies. References 1. Siegel, R.L., Miller, K.D. & Jemal, A. CA Cancer J Clin 69, 7-34 (2019). 2. Knowles, M.A. & Hurst, C.D. Nature reviews. Cancer 15, 25-41 (2015). 3. Zakaria, A.S., et al. Can Urol Assoc J 8, 259-267 (2014). 4. Galanis, E., et al. Cancer research 75, 22-30 (2015). Citation Format: Tanner S. Miest, Bradley Leibovich, Stephen Bardot, Paul R. Young, Stephen A. Boorjian, Mark Gonzalgo, Loren Herrera-Hernandez, Matthew K. Tollefson, Jeffrey Karnes, Paige Nichols, Tessa Kroeninger, Rachel Graham, Carole Lahana, Monica Reckner, Alysha Newsom, Nandakumar Packiriswamy, Janice Anoka, Kah Whye Peng, Erol Wiegert, Alice Bexon, Shruthi Naik. Safety and efficacy of neoadjuvant intravesical oncolytic MV-NIS in patients with urothelial carcinoma [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P190.

405 Background: The diagnosis of upper tract urothelial carcinoma (UTUC) is frequently obtained via diagnostic ureteroscopy (URS) with biopsy. In a recent meta-analysis of five retrospective series comparing UTUC RNU patients with and without prior diagnostic URS, prior URS was associated with intravesical recurrence of urothelial carcinoma. However, there remains an incomplete understanding of the risks of URS on intravesical recurrence after RNU, and existing studies have not examined the risks of URS without endoscopic biopsy or percutaneous biopsy alone. Here, we query our institutional RNU registry to determine if UTUC diagnostic modality influences post-RNU intravesical recurrence risk. Methods: Years 1995 to 2019 of our institutions RNU registry were queried. Patients with UTUC were divided into four groups: 1) URS with endoscopic biopsy; 2) URS without endoscopic biopsy (visual confirmation alone); 3) percutaneous biopsy without any URS; 4) no URS and no percutaneous biopsy. Exclusion criteria included pure non-urothelial histology, RNU for benign indications, and prior/concomitant cystectomy. The primary outcome was intravesical recurrence of urothelial carcinoma compared across the four groups using Kaplan-Meier log-rank analyses and Cox-proportional hazard modeling (hazard ratio = HR). Results: In a cohort of 878 patients (mean post-RNU follow-up 43 months), 461 (53%) had URS with biopsy, 130 (15%) had URS without biopsy, 229 (26%) had no URS or percutaneous biopsy, and 58 (7%) had percutaneous biopsy alone. The 3-year intravesical recurrence rate was 27%, 22%, 18%, 12% for groups 1-4, respectively. Covariates associated with intravesical recurrence on univariable analysis included age (HR 1.03, p < 0.01), female gender (HR 0.76, p = 0.06), history of bladder cancer (HR 1.39, p = 0.01), current smoker (HR 1.49, p = 0.04), and multifocality (HR 1.34, p = 0.03). After adjusting for these covariates, multivariable analysis found that group 1 (URS with biopsy) was associated with increased intravesical recurrence (HR 1.41, p = 0.03) relative to group 3 (no URS or percutaneous biopsy). Compared to group 1, the hazard ratio for intravesical recurrence was not significantly different for group 2 (HR 1.18, p = 0.45) or group 4 (HR 1.11, p = 0.79). Conclusions: Patients undergoing ureteroscopic biopsy to diagnose UTUC prior to RNU had a higher risk of intravesical recurrence after RNU compared to patients who did not undergo any URS or percutaneous biopsy. This agrees with prior literature and suggests that aggressive ureteroscopic manipulation of UTUC tumors via biopsy may promote shedding of urothelial carcinoma cells capable of seeding the bladder. Our study does support the initiation of a randomized trial to determine if intravesical chemotherapy after ureteroscopic biopsy can reduce intravesical urothelial carcinoma recurrences.

TPS3172 Background: Bladder cancer is a leading cause of cancer death in the United States. Over 90% of bladder cancer cases are urothelial carcinomas (UC) that may present as a non-muscle-invasive (NMIBC) or muscle-invasive disease (MIBC). Standard of care for NMIBC includes transurethral resection of bladder tumor (TURBT), intravesical chemotherapy and immunotherapy with Bacillus Calmette-Guerin (BCG). Patients (pts) with high-grade BCG-refractory NMIBC or MIBC undergo RC, which involves complete bladder removal and pelvic lymphadenectomy. RC severely impacts quality of life with significant morbidity. Oncolytic viruses are showing promise in UC, and MV-NIS has proven efficacy in other tumor types. MV-NIS is an investigational oncolytic measles virus with an excellent safety profile, irrespective of route of administration (n > 100). MV-NIS-related adverse events are limited to infusion reactions and transient CBC changes, and little local toxicity is anticipated with intravesical therapy. Clinical efficacy of this oncolytic may be related to absence of measles immunity. Based on this, the clinical strategy for MV-NIS is focused on targeting immune-privileged sites via intra-tumoral or intravesical routes, alone or in combination with checkpoint inhibitors. We hypothesize that intravesical therapy with oncolytic MV-NIS can improve clinical outcomes for (a) BCG refractory NMIBC pts to avoid or delay the need for RC; and (b) MIBC pts undergoing RC. Methods: This study is enrolling pts undergoing RC who are ineligible to receive neoadjuvant chemotherapy. The trial has 2 stages to (a) determine the safety and tolerability of intravesical MV-NIS, and (b) assess preliminary efficacy. Part (a) includes 4-24 pts in a timing cohort with doses administered at increasing durations (1-4 weeks) prior to RC to establish safety of a single MV-NIS dose. Part (b) includes an expansion cohort (n = 12) to evaluate the safety and efficacy of 2 intravesical doses of MV-NIS at 2-week intervals prior to RC. Safety is assessed using NCI-CTCAE V5 and Clavien-Dindo grading of operative complications. The efficacy endpoint is pathologic stage at time of RC (pT0 rate), which can be compared to pre-study TURBT stage. Additional exploratory studies include PK and PD analyses in urine, blood and tumor. Enrollment is ongoing at 2 Mayo Clinic sites (Rochester, MN and Jacksonville, FL) and the study has now progressed from the timing cohort into the expansion cohort. Clinical trial information: NCT03171493 .

ObjectivesTo evaluate the timing and distribution of first renal cell carcinoma metastasis after nephrectomy stratified by nodal status.MethodsWe evaluated patients treated with nephrectomy for sporadic, unilateral renal cell carcinoma between 1970 and 2011 who subsequently developed distant metastasis to three or fewer sites. Site‐specific metastases‐free 2‐year survival rates were estimated using the Kaplan–Meier method. Associations of nodal status with time to metastasis were evaluated using multivariable Cox regression models.ResultsA total of 1049 patients met the inclusion criteria (135 pN1, 914 pN0/x patients). The median time to identification of first distant metastasis for pN1 patients was 0.4 years (interquartile range 0.2–1.1 years) versus 2.2 years (interquartile range 0.6–6.0 years) in pN0/x patients. The most common site of metastasis was to the lung, but this occurred earlier in pN1 patients (median 0.3 years vs 2.0 years). pN1 was associated with significantly lower site‐specific 2‐year metastases‐free survival when compared with pN0/x for lung (37% vs 70%, P < 0.001), bone (63% vs 87%, P < 0.001), non‐regional lymph nodes (60% vs 96%, P < 0.001) and liver metastases (79% vs 91%, P < 0.001). On multivariable analysis, pN1 status remained significantly associated with lung, bone, and non‐regional lymph node (all P < 0.001) metastases, but it was no longer associated with liver metastases (P = 0.3).ConclusionspN1 nodal status in M0 patients treated with nephrectomy for renal cell carcinoma is associated with more frequent early metastasis to sites conferring poor prognosis when compared with pN0/x. Our findings highlight the importance of rigorous, early surveillance though the multimodal use of a comprehensive history, physical, laboratory and radiological studies, as outlined in societal guidelines.

430 Background: Malignant melanoma of the female urethra accounts for less than 1% of all melanoma and less than 4% of urethral cancer. Due to limited data regarding management and outcomes of this condition, we evaluated the management and outcomes of urethral melanoma in females over the last 20 years at our institution. Methods: Patients were identified via retrospective review of the medical record. Those with metastatic disease at initial diagnosis were excluded. We evaluated primary and adjuvant treatments, disease recurrence and overall survival. Results: Fifteen women (median age 71, range 55, 82) were identified. Majority of masses involved the distal urethra (86.6%). All patients underwent primary surgical resection (60.0% partial urethrectomy, 40.0% radical urethrectomy). Disease recurrence and metastatic spread occurred in 73.3% (median 7 months, IQR 4, 12) and 60% (median 6 months, IQR 3, 9) of patients, respectively. 90.9% of patients with recurrence received adjuvant therapy: 5 chemotherapy and radiation, 4 chemotherapy only, 1 anterior exenteration. Of the 9 patients undergoing chemotherapy, treatment regimens were varied and included checkpoint inhibitors (2/9), platinum-based chemotherapy (3/9), tyrosine kinase inhibitors (2/9), taxels (2/9), and alkylating agents (1/9). Median overall survival was 27 months (IQR 7.5, 57.5). Conclusions: Malignant melanoma of the urethra is locally aggressive with a high likelihood of recurrence and metastases resulting in poor long-term survival. Despite high recurrence rates, our data highlight the lack of consensus adjuvant treatment regimens. Future research is required to identify neoadjuvant, combination, and adjuvant treatment approaches to improve disease outcomes.