Uchio, Edward

4601 Background: Cretostimogene grenadenorepvec is a type-5 oncolytic adenovirus designed to selectively replicate in bladder cancer cells with alterations in the retinoblastoma pathway. Additionally, the virus is engineered to express the GM-CSF transgene, resulting in a potent oncolytic immunotherapy mode of action. Cretostimogene monotherapy recently received Food and Drug Administration (FDA) Fast Track and Breakthrough Therapy Designations (BTD) in the BCG-Unresponsive, High-Risk, non-Muscle Invasive Bladder Cancer with Carcinoma in Situ (BCG-UR HR NMIBC with CIS) indication with a Complete Response (CR) at any time rate of 76%. This phase-2 study assessed the potential synergy between intravesical cretostimogene and pembrolizumab in patients with BCG-UR, HR NMIBC, with CIS, with or without Ta/T1 tumors. This combination has also received BTD from the FDA. Methods: 35 pts were treated with cretostimogene (1x1012 viral particles) in combination with pembrolizumab at a dose of 400 mg IV q6 weeks. Cretostimogene induction was given as 6 weekly intravesical instillations followed by 3 weekly maintenance doses at months 3, 6, 9, 12, and 18. Pts with persistent CIS or high-grade Ta tumors at the 3mo assessment were eligible for re-induction. Pembrolizumab was administered for up to 24mo. Response assessments included cystoscopy, urine cytology, cross-sectional imaging, and mandatory bladder mapping biopsies at 12mo. The primary endpoint was CR at 12mo. Secondary endpoints included CR at any time, duration of response (DOR), CR at 24mo, cystectomy-free survival, and safety. Exploratory endpoints included analyses of baseline viral receptor expression, free E2F levels, PD-L1 status, urinary cytokine panels and measures of viral replication. Results: 30/35 pts are evaluable per protocol for the primary endpoint. Five pts discontinued prior to the 12mo time point. The CR rate in the Intention to Treat (ITT) population at 12mo and any time, was 57% (20/35) (95% CI 40-73%) and 83% (29/35) (95% CI 66-93%), respectively. Median DOR has not been reached but exceeds 21mo. The current CR rate in the ITT population at 24mo is 46% (16/35) (95% CI 29-63%). Three pts have yet to reach the 24mo time point. Cystectomy-free survival at 21mo is 80%. Complete data on the ITT and evaluable patient cohorts will be presented. Analyses of treatment-related adverse events (AE) are consistent with the individual agents and demonstrate no synergistic toxicity. Conclusions: The efficacy and safety of cretostimogene plus pembrolizumab for treatment of BCG-UR, HR NMIBC with CIS demonstrates best-in-class CR and DOR compared to current FDA-approved therapies, with an acceptable AE profile. Further investigation of this promising combination therapy is warranted and may serve to address a considerable unmet need. Clinical trial information: NCT04387461 .

The PRESERVE study (NCT04972097) aims to evaluate the safety and effectiveness of the NanoKnife System to ablate prostate tissue in patients with intermediate-risk prostate cancer (PCa). The NanoKnife uses irreversible electroporation (IRE) to deliver high-voltage electrical pulses to change the permeability of cell membranes, leading to cell death. A total of 121 subjects with organ-confined PCa ≤ T2c, prostate-specific antigens (PSAs) ≤ 15 ng/mL, and a Gleason score of 3 + 4 or 4 + 3 underwent focal ablation of the index lesion. The primary endpoints included negative in-field biopsy and adverse event incidence, type, and severity through 12 months. At the time of analysis, the trial had completed accrual with preliminary follow-up available. Demographics, disease characteristics, procedural details, PSA responses, and adverse events (AEs) are presented. The median (IQR) age at screening was 67.0 (61.0–72.0) years and Gleason distribution 3 + 4 (80.2%) and 4 + 3 (19.8%). At 6 months, all patients with available data (n = 74) experienced a median (IQR) percent reduction in PSA of 67.6% (52.3–82.2%). Only ten subjects (8.3%) experienced a Grade 3 adverse event; five were procedure-related. No Grade ≥ 4 AEs were reported. This study supports prior findings that IRE prostate ablation with the NanoKnife System can be performed safely. Final results are required to fully assess oncological, functional, and safety outcomes.

TPS582 Background: The majority of patients with bladder cancer present with non-muscle invasive disease (Chang 2016; Woldu 2017; Kates 2020; Li 2020). The standard of care for treatment of high risk NMIBC involves transurethral resection of the bladder tumor (TURBT) followed by intravesical Bacillus Calmette-Guerin (BCG) or chemotherapy. Although the response rate to BCG therapy is high, many patients recur within 1–5 years (Matulay JU 2021). For patients who have BCG unresponsive disease after adequate course of BCG, there are limited options. While radical cystectomy (RC) is still considered the standard of care, most patients are reluctant to undergo RC and their options are limited to intravesical chemotherapy or pembrolizumab. Enfortumab vedotin (EV) is an antibody-drug conjugate directed to Nectin-4, which is highly expressed in bladder tumors. In EV-301, a phase 3 study, EV showed an OS benefit vs chemotherapy in patients with locally advanced or metastatic urothelial carcinoma (la/mUC) who had previously received platinum-based therapy and a PD-1 or PD-L1 inhibitor (Powles NEJM 2021). Based on its demonstrated benefit in la/mUC, EV is currently being evaluated in earlier UC settings. The purpose of this study is to investigate the intravesical administration of EV for patients with NMIBC. Methods: EV-104 (NCT05014139) is a phase 1, open-label, multicenter, dose-escalation and dose-expansion study designed to evaluate the safety, tolerability, PK, and antitumor activity of intravesical EV in adults with high-risk BCG-unresponsive NMIBC (carcinoma in situ with or without papillary disease) who are ineligible for or refuse RC. The dose escalation part of the trial aims to identify the maximum tolerated dose (MTD) and/or recommended dose of intravesical EV. The dose expansion part will evaluate patients at the MTD or recommended dose and further characterize safety and antitumor activity of intravesical EV. The study treatment regimen will include an induction phase, where patients will receive intravesical EV weekly for 6 weeks followed by monthly maintenance for a total of 9 additional EV doses. Patients will be assessed for response every 3 months by cystoscopy and urine cytology, while on study. Safety and antitumor activity endpoints will be summarized using descriptive statistics. The study is currently enrolling in the US with additional sites planned in Canada and the EU. Clinical trial information: NCT05014139 .

4597 Background: CG0070, is an Ad5-based oncolytic vaccine engineered to express GM-CSF and replicate selectively in tumor cells with mutated or deficient RB. The CG0070 mechanism of action includes cell lysis and immunogenic cell death which is enhanced in the presence of GM-CSF. In an open label ph. 2 study, an overall CR rate of 62% and a CR at 12 months (m) of 29% have been observed in patients with high risk NMIBC previously treated with BCG. IV pembrolizumab, was recently approved by the FDA for patients with BCG-unresponsive CIS (with or without papillary tumors) with an overall complete RR of 41% and a 12 m CR rate of ̃20%. This ph. 2 study will assess the potential synergy of the two agents in the treatment of BCG-unresponsive NMIBC. Methods: 35 pts with BCG-unresponsive CIS with or without concurrent Ta or T1 disease will be treated with intravescical CG0070 (1x1012 vp) in combination with pembrolizumab at a dose of 400 mg IV q6 weeks. CG0070 will be administered weekly x 6 as induction followed by weekly x 3 maintenance instillations at months 3, 6, 9, 12, and 18. Pts with persistent CIS or HG Ta at 3 m may receive re-induction with weekly x 6 of CG0070. Pembrolizumab will be administered up to 24 m. Assessment of response will include q 3 m cystoscopy with biopsy of areas suspicious for disease, urine cytology, CTU/MRU, and mandatory bladder mapping biopsies at 12 m. Recurrence of HG disease will be enumerated as disease recurrence. The primary endpoint of the study is CR at 12 m. Secondary endpoints will include CR at any time, progression free survival, duration of response, cystectomy free survival and the safety. Correlate assessments will include changes in the tumor immune microenvironment, systemic immune induction,viral replication and transgene expression. Baseline expression of PD-L1, coxsackie adenovirus receptor, E2F transcription factor as well as anti-Ad5 Ab titer will be correlated with tumor response. Results: A CR rate of 87.5% (14/16) at the 3 m assessment timepoint has been observed thus far. All patients in CR at 3 m remain in CR at downstream timepoints including: 9/9 at 6 m, 6/6 at 9 m, and 3/3 at 12 m. Treatment related AE have been generally limited to transient grade 1-2 local-regional genitourinary adverse events with no reports of grade 3, 4 or SAE attributed to treatment with CG0070/Pembroluzimab. Conclusions: This initial data on the efficacy and safety of CG0070 plus pembrolizumab for the treatment of BCG unresponsive NMIBC is encouraging. Additional data on efficacy as well as safety and biomarker (CAR, E2F, and PDL1) assessment will be presented for at least 25 of the projected 35 patients at the time of the conference. Clinical trial information: NCT04387461.

TPS598 Background: CG0070 is a serotype 5 adenovirus engineered to express GM-CSF and replicate in cells with mutated or deficient RB, with response rates (RR) of approximately 45% observed in patients with recurrent NMIBC after BCG (J Urol. 2012;188:2391–7; Urol Oncol. 2018;36(10):440–7). This single arm phase 3 study (NCT04452591) was launched to confirm the clinical activity of CG0070 in patients with BCG Unresponsive NMIBC. Methods: 110 patients with BCG-unresponsive CIS with or without concurrent Ta or T1 disease will be treated with intravesical (IVe) CG0070 at a dose of 1x1012 vp. CG0070 will be administered as follows: induction weekly x 6 followed by weekly x 3 maintenance instillations at months 3, 6, 9, 12, and 18. Patients with persistent CIS or HG Ta at 3 months (m) may receive re-induction with weekly x 6 CG0070. Assessment of response will include q 3 m cystoscopy with biopsy of areas suspicious for disease, urine cytology, CTU/MRU, and mandatory bladder mapping at 12 m. Detection of high grade disease within the bladder will be enumerated as recurrence or non-response. The primary endpoint of the study is CR at any time on study as assessed by biopsy (directed to cystoscopic abnormalities and mandatory mapping at 12 m), urine cytology, and radiography, as above. Secondary endpoints include CR at 12 m, duration of response, progression free survival, cystectomy free survival and safety. Correlative assessments include changes in the tumor immune microenvironment, systemic immune induction as reflected in the peripheral blood and urine, as well as viral replication and transgene expression. Baseline expression of coxsackie adenovirus receptor, E2F transcription factor as well as anti-adenovirus antibody titer will be correlated with tumor response. Study enrollment globally is ongoing including in North America, Taiwan, Japan, and South Korea. Refs. Burke JM, Lamm DL, Meng MV, Nemunaitis JJ, Stephenson JJ, Arseneau JC, Aimi J, Lerner S, Yeung AW, Kazarian T, Maslyar DJ, McKiernan JM. A first in human phase 1 study of CG0070, a GM-CSF expressing oncolytic adenovirus, for the treatment of nonmuscle invasive bladder cancer. Clinical trial information: NCT04452591.

AbstractObjectiveThe objective of this study is to determine if Aquablation therapy can maintain its effectiveness in treating men with lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH) with large‐volume (80–150 cc) prostates at 3 years.Subjects and MethodsOne hundred one men with moderate‐to‐severe BPH symptoms and prostate volumes between 80 and 150 cc were enrolled in a prospective, nonrandomized, multicenter, international clinical trial in late 2017. Baseline, procedural, and follow‐up parameters were recorded at baseline and scheduled postoperative visits. IPSS, Qmax, and treatment failure are reported at 3 years.ResultsThe mean prostate volume was 107 cc (range 80–150). Mean IPSS improved from 23.2 at baseline to 6.5 at 3 years (16.3‐point improvement, p < 0.0001). Mean IPSS quality of life improved from 4.6 at baseline to 1.1 at 3 years (improvement of 3.4 points, p < 0.0001). Maximum urinary flow increased from 8.7 to 18.5 cc/s. At 3 year follow‐up, 6% of treated patients needed BPH medication and an additional 3% required surgical retreatment for LUTS.ConclusionsThree‐year follow‐up demonstrates a sustained symptom reduction response along with low irreversible complications to Aquablation in men with LUTS due to BPH and prostates of 80–150 cc. Current treatment options available for men with prostates of this size have similar efficacy outcomes but are burdened with high rates of irreversible complications. There are now numerous clinical studies with Aquablation used in various prostates sizes, and it should be offered as an option to men with LUTS due to BPH.

Objective To present 6‐month safety and effectiveness data from a multicentre prospective study of aquablation in men with lower urinary tract symptoms (LUTS) attributable to benign prostatic hyperplasia ( BPH ) with prostate volumes between 80 and 150 mL. Methods Between September and December 2017, 101 men with LUTS attributable to BPH were prospectively enrolled at 16 centres in Canada and the USA. Results The mean prostate volume was 107 mL. The mean length of hospital stay after the aquablation procedure was 1.6 days (range: same day to 6 days). The primary safety endpoint (Clavien–Dindo grade 2 or higher or any grade 1 event resulting in persistent disability) at 3 months occurred in 45.5% of men, which met the study design goal of < 65% ( P < 0.001). At 6 months, 22% of the patients had experienced a Clavien–Dindo grade 2, 14% a grade 3 and 5% a grade 4 adverse event. Bleeding complications requiring intervention and/or transfusion were recorded in eight patients prior to discharge and in six patients after discharge. The mean International Prostate Symptom Score improved from 23.2 ± 6.3 at baseline to 6.7 ± 5.1 at 3 months, meeting the study's primary efficacy endpoint goal ( P < 0.001). The maximum urinary flow rate increased from 8.7 to 18.8 mL/s ( P < 0.001) and post‐void residual urine volume decreased from 131 at baseline to 47 at 6 months ( P < 0.0001). At 6 months, prostate‐specific antigen concentration reduced from 7.1 ± 5.9 ng/mL at baseline to 4.0 ± 3.9 ng/mL, a 44% reduction. Conclusions Aquablation is safe and effective in treating men with larger prostates (80–150 mL), without significant increase in procedure or resection time.