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Purpose: On the basis of preclinical evidence of epigenetic contribution to sensitivity and resistance to immune checkpoint inhibitors (ICI), we hypothesized that guadecitabine (hypomethylating agent) and atezolizumab [anti–programmed cell death ligand 1 (PD-L1)] together would potentiate a clinical response in patients with metastatic urothelial carcinoma (UC) unresponsive to initial immune checkpoint blockade therapy. Patients and Methods: We designed a single arm phase II study (NCT03179943) with a safety run-in to identify the recommended phase II dose of the combination therapy of guadecitabine and atezolizumab. Patients with recurrent/advanced UC who had previously progressed on ICI therapy with programmed cell death protein 1 or PD-L1 targeting agents were eligible. Preplanned correlative analysis was performed to characterize peripheral immune dynamics and global DNA methylation, transcriptome, and immune infiltration dynamics of patient tumors. Results: Safety run-in enrolled 6 patients and phase II enrolled 15 patients before the trial was closed for futility. No dose-limiting toxicity was observed. Four patients, with best response of stable disease (SD), exhibited extended tumor control (8–11 months) and survival (>14 months). Correlative analysis revealed lack of DNA demethylation in tumors after 2 cycles of treatment. Increased peripheral immune activation and immune infiltration in tumors after treatment correlated with progression-free survival and SD. Furthermore, high IL6 and IL8 levels in the patients’ plasma was associated with short survival. Conclusions: No RECIST responses were observed after combination therapy in this trial. Although we could not detect the anticipated tumor-intrinsic effects of guadecitabine, the addition of hypomethylating agent to ICI therapy induced immune activation in a few patients, which associated with longer patient survival.

Bladder cancer is an aggressive and lethal disease. Even when presenting as localized muscle-invasive disease, the 5-year survival rate is about 70%, and the recurrence rate after radical cystectomy is approximately 50%. Neoadjuvant chemotherapy (NAC) has the potential to downstage the primary tumor and treat micrometastases, leading to a decrease in recurrence rates and an increase in cure rates. There is level 1 evidence in favor of neoadjuvant cisplatin-based chemotherapy prior to radical cystectomy. However, data from clinical trials evaluating NAC for patients undergoing bladder-sparing treatments are less robust, so this strategy remains controversial. The response to NAC is prognostic and patients with favorable pathological response have better overall survival. Strategies to select patients based on molecular biomarkers have the potential to guide treatment decisions and even de-intensify treatment, avoiding local treatment for those with complete responses to systemic therapy. This review outlines the current literature on the use of NAC in the context of bladder preservation for muscle-invasive bladder cancer, highlights neoadjuvant studies in patients ineligible for cisplatin-based NAC, and discusses novel bladder-preservation strategies, including multimodality combinations and biomarker-driven studies of definitive chemotherapy.

Background Treatment of metastatic renal cell carcinoma (mRCC) is rapidly evolving with new combination therapies demonstrating improved response rates and survival. There are no head-to-head prospective trials comparing an immunotherapy doublet with an immunotherapy/tyrosine-kinase inhibitor-based combination. We compare real-world outcomes in patients treated with axitinib/pembrolizumab (axi/pembro) or ipilimumab/nivolumab (ipi/nivo). The primary endpoints were overall-survival (OS) and real-world progression-free survival (rwPFS). Patients and Methods We used a de-identified database to select patients diagnosed with clear cell mRCC and treated with front-line axi/pembro or ipi/nivo from 2018 to 2022. Analyses are adjusted using propensity score-based inverse probability of treatment weighting, balancing age, gender, insurance, race, IMDC risk, and nephrectomy status. We compared survival by treatment groups using weighted and unweighted Kaplan–Meier curves with log-rank tests and weighted Cox proportional hazards regressions. Results We included a total of 1506 patients with mRCC who received frontline axi/pembro (n = 547) or ipi/nivo (n = 959). Median follow-up time was 20.0 months (range: 0.2-47.6). Baseline demographics were similar between the 2 cohorts. Adjusted median OS for the full population was 28.9 months for axi/pembro and was 24.3 months for ipi/nivo (P = .09). Twenty-four-month survival was 53.8% for axi/pembro treated patients and 50.2% for ipi/nivo treated patients. rwPFS was 10.6 months for axi/pembro treated patients and 6.9 months for ipi/nivo treated patients. Treatment with axi/pembro conferred improved survival in the IMDC favorable risk strata, with no significant difference in survival observed within the full cohort. Conclusions In this retrospective, real-world study of patients treated with front-line combination therapy, patients with IMDC favorable risk disease had better survival when treated with axi/pembro compared to ipi/nivo. However, survival for the entire population and the 24-month median overall survival were not statistically different between treatment groups. Longer follow-up is necessary to discern any emerging significant differences.

BACKGROUND: Predictive immune signatures such as the T-effector, the 26-gene “Renal 101 Immuno signature” and the 18-gene T-cell inflamed gene expression profile were developed in clinical trials enrolling predominantly Caucasians and there is a dearth of literature comparing tumor biology between African American (AA) and Caucasian patients. OBJECTIVE: To compare the immune gene signature expression in AA (n = 55) and Caucasian (n = 457) patients. METHODS: Raw gene expression count data were downloaded from the TCGA KIRC dataset and tumor samples from “white” and “black or AA” patients were selected. The gene expression values of the immune signatures were VST-transformed normalized counts and compared between the groups. RESULTS: There were 457 Caucasian and 55 AA patients in the TCGA. The immune gene expression in all three signatures was significantly lower in AA patients compared to Caucasians (p

The role of cytoreductive nephrectomy (CN) in metastatic renal cell carcinoma (mRCC) was challenged by the results of the CARMENA trial. Here we evaluate the role of CN in mRCC patients, including those receiving modern therapies.We included patients with synchronous mRCC between 2011-2020 from the de-identified nationwide Flatiron Health database. We evaluated 3 groups: systemic therapy alone, CN followed by systemic therapy (up-front CN [uCN]) and systemic therapy followed by CN (deferred CN [dCN]). The primary outcome was median overall survival (mOS) in patients receiving systemic therapy alone vs uCN. Secondary outcome was overall survival in patients receiving uCN vs dCN. First-treatment, landmark and time-varying covariate analyses were conducted to overcome immortal time bias. Weighted Kaplan-Meier curves, log-rank tests and Cox proportional hazards regressions were used to assess the effect of therapy on survival.Of 1,910 patients with mRCC, 972 (57%) received systemic therapy, 605 (32%) received uCN, 142 (8%) dCN and 191 (10%) CN alone; 433 (23%) patients received immunotherapy-based therapy. The adjusted mOS was significantly improved in first-treatment, landmark and time-varying covariate analysis (mOS 26.6 vs 14.6 months, 36.3 vs 21.1 months and 26.1 vs 12.2 months, respectively) in patients undergoing CN. Among patients receiving CN and systemic therapy, the timing of systemic therapy relative to CN was not significantly related to overall survival (HR=1.0, 95% CI 0.76-1.32, p=0.99).Our findings support an oncologic role for CN in select mRCC patients. In patients receiving both CN and systemic therapy, the survival benefit compared to systemic alone was similar for up-front and deferred CN.

Supplementary Figure 12: HLA-DR and NKG2D abundance on peripheral lymphocytes associate with longer progression free survival.

Purpose:On the basis of preclinical evidence of epigenetic contribution to sensitivity and resistance to immune checkpoint inhibitors (ICI), we hypothesized that guadecitabine (hypomethylating agent) and atezolizumab [anti–programmed cell death ligand 1 (PD-L1)] together would potentiate a clinical response in patients with metastatic urothelial carcinoma (UC) unresponsive to initial immune checkpoint blockade therapy.Patients and Methods:We designed a single arm phase II study (NCT03179943) with a safety run-in to identify the recommended phase II dose of the combination therapy of guadecitabine and atezolizumab. Patients with recurrent/advanced UC who had previously progressed on ICI therapy with programmed cell death protein 1 or PD-L1 targeting agents were eligible. Preplanned correlative analysis was performed to characterize peripheral immune dynamics and global DNA methylation, transcriptome, and immune infiltration dynamics of patient tumors.Results:Safety run-in enrolled 6 patients and phase II enrolled 15 patients before the trial was closed for futility. No dose-limiting toxicity was observed. Four patients, with best response of stable disease (SD), exhibited extended tumor control (8–11 months) and survival (>14 months). Correlative analysis revealed lack of DNA demethylation in tumors after 2 cycles of treatment. Increased peripheral immune activation and immune infiltration in tumors after treatment correlated with progression-free survival and SD. Furthermore, high IL6 and IL8 levels in the patients’ plasma was associated with short survival.Conclusions:No RECIST responses were observed after combination therapy in this trial. Although we could not detect the anticipated tumor-intrinsic effects of guadecitabine, the addition of hypomethylating agent to ICI therapy induced immune activation in a few patients, which associated with longer patient survival.

Supplementary TablesSupplementary Table 1: Patient and tumor sample informationSupplementary Table 2: Tumor mutation burdenSupplementary Table 3: Unfiltered whole exome sequencing mutation analysisSupplementary Table 4: Filtered whole exome sequencing mutation analysisSupplementary Table 5: Immunohistochemistry scores of tumorsSupplementary Table 6: FACS panel for PBMC analysisSupplementary Table 7: Geometric mean fluorescence intensity (GMFI) from PBMC FACSSupplementary Table 8: Representativeness of Study Participants

The Cancer Genome Atlas (TCGA) and other large-scale genomic data pipelines have been integral to the current understanding of the molecular events underlying renal cell carcinoma (RCC). These data networks have focused mostly on primary RCC, which often demonstrates indolent behavior. However, metastatic disease is the major cause of mortality associated with RCC and data sets examining metastatic tumors are sparse. Therefore, a more comprehensive analysis of gene expression and DNA methylome profiling of metastatic RCC in addition to primary RCC and normal kidney was performed. Integrative analysis of the methylome and transcriptome identified over 30 RCC-specific genes whose mRNA expression inversely correlated with promoter methylation, including several known targets of hypoxia inducible factors. Notably, genes encoding several metabolism-related proteins were identified as differentially regulated via methylation including hexokinase 2, aldolase C, stearoyl-CoA desaturase, and estrogen-related receptor-γ (ESRRG), which has a known role in the regulation of nuclear-encoded mitochondrial metabolism genes. Several gene expression changes could portend prognosis in the TCGA cohort. Mechanistically, ESRRG loss occurs via DNA methylation and histone repressive silencing mediated by the polycomb repressor complex 2. Restoration of ESRRG in RCC lines suppresses migratory and invasive phenotypes independently of its canonical role in mitochondrial metabolism.Implications:Collectively, these data provide significant insight into the biology of aggressive RCC and demonstrate a novel role for DNA methylation in the promotion of HIF signaling and invasive phenotypes in renal cancer.

Supplemental Table 1. Location of metastasis used for array analysis

1S: Principal component analysis (PCA) of the 44 experimental samples analyzed by array. S2. 2S: TCGA validation of up-regulated RCC associated genes. S3. TCGA validation of down-regulated RCC associated genes. Boxplots show expression level of each gene in 72 kidney normal samples and 533 kidney renal clear cell carcinoma samples. S4. Oncomine analysis of RCC associated genes. S5. Oncomine analysis of RCC associated genes. S6. Oncomine analysis of RCC associated genes. S7. Kaplan meier plots showing effect of gene expression level on overall survival of kidney renal clear cell carcinoma patients.

OBJECTIVES To determine whether patients with carcinoma invading bladder muscle (MIBC) and ureteric obstruction can safely receive cisplatin-based neoadjuvant chemotherapy (C-NAC), and to determine whether such patients require relief of obstruction with a ureteric stent or percutaneous nephrostomy prior to beginning C-NAC. PATIENTS AND METHODS We performed a single-institution retrospective analysis of MIBC patients receiving C-NAC and falling into three groups: no ureteric obstruction (NO); relieved ureteric obstruction (RO); and unrelieved ureteric obstruction (URO). To address whether patients with obstruction can safely receive C-NAC, we compared patients with NO to those with RO, with the primary outcome of premature chemotherapy discontinuation. To investigate whether patients with obstruction should have the obstruction relieved prior to NAC, we compared RO to URO patients using a primary composite outcome of grade ≥ 3 adverse events, premature chemotherapy discontinuation, dose reduction, or dose interruption. The primary outcomes were compared using multivariable logistic regression. Sensitivity analyses were performed for the RO vs URO comparison, in which patients with only mild degrees of obstruction were excluded from the URO group. RESULTS A total of 193 patients with NO, 49 with RO, and 35 with URO were analysed. There were no statistically significant differences between those with NO and those with RO in chemotherapy discontinuation (15% vs 22%; P = 0.3) or any secondary outcome. There was no statistically significant difference between those with RO and URO in the primary composite outcome (51% vs 53%; P = 1) or any secondary outcome. CONCLUSION Patients with ureteric obstruction can safely receive C-NAC. Relief of obstruction was not associated with increased safety of C-NAC delivery.

The standard of care (SOC) for muscle-invasive bladder cancer (MIBC) includes cisplatin-based combination chemotherapy in the neoadjuvant setting followed by radical cystectomy. Older patients often do not receive SOC due to perceived toxicity concerns despite guideline-directed recommendations.To characterize the safety and efficacy of neoadjuvant accelerated methotrexate, vinblastine, adriamycin, and cisplatin (aMVAC) in MIBC patients as a function of age.A retrospective analysis was conducted in 186 MIBC patients treated at Fox Chase Cancer Center between January 1, 2002 and December 31, 2018. Adults with histologically proven muscle-invasive urothelial cancer were eligible. The exclusion criteria included nonurothelial histology, lack of muscularis propria invasion, and primary upper tract or metastatic disease.Neoadjuvant chemotherapy with aMVAC.Patients were stratified by age (65, 65-74, and75 yr old). Renal function was assessed at baseline and at time points after treatment. Clinicopathologic variables were compared between age groups to determine efficacy.There were no statistically significant differences in dose reductions, treatment interruptions, time to surgery, or adverse events when patients were stratified by age in univariate and multivariate analyses. Full safety data were not available due to the retrospective nature of the study. Baseline renal function was significantly worse among older patients, and the percent decline in creatinine clearance was greater with older age. We found comparable efficacy of aMVAC regardless of age.Accelerated MVAC was safe and demonstrated efficacy in MIBC irrespective of age in this single-center, retrospective study. Careful selection based on clinical variables, and not age, should identify patients able to receive neoadjuvant chemotherapy.We examined the feasibility of the standard cisplatin-based chemotherapy regimen given prior to surgery in patients with muscle-invasive bladder cancer. Elderly patients experienced a greater decline in kidney function with treatment but not more complications than younger patients and tolerated therapy with minimal dose changes, resulting in benefit regardless of age.

438 Background: Cisplatin-based neoadjuvant chemotherapy (NAC) followed by cystectomy or chemoradiation is the standard of care for urothelial carcinoma (UC) patients with MIBC. Both cystectomy and chemoradiation have short and long-term toxicity and QOL implications. Mutations in DNA damage repair/response genes are associated with pathologic downstaging after NAC. We hypothesized that a combination of biomarker selection and clinical staging would identify patients prospectively for a cystectomy or chemoradiation avoidance algorithm. Methods: We conducted a single-arm, phase II, non-inferiority trial (NCT02710734) to evaluate a risk-adapted approach for MIBC. Patients with cT2-T3N0M0 UC underwent NAC with accelerated MVAC. Pre-NAC TURBT specimens were sequenced (Caris) for mutations in ATM, ERCC2, FANCC or RB1. Patients with ≥ 1 mutations and no clinical evidence of disease by restaging TUR, urine cytology and imaging post-NAC began pre-defined active surveillance (AS). Remaining patients underwent bladder-directed therapy. The primary endpoint was metastasis-free survival (MFS) at 2 years for the entire cohort. The risk-adapted approach would be declared non-inferior to the standard of care if the lower bound of an exact 1-sided 95% CI for MFS was > 64%. The study required 70 patients with a 4.5% type I error and 81.6% power. Results: 71 (ITT) patients were enrolled over 33 months at four academic centers. Median age was 70 years (47-83), 74% were male, 92% Caucasian, 81% ECOG PS 0 and 79% cT2. 90% completed 3 cycles of MVAC with 17% grade 3-4 TRAEs. In the ITT population, 33 (46%) had a relevant mutation and 26 (37%) began AS. With a median follow-up of 41 months, 47 patients (66%) are metastasis-free (CI 54%-77%). The 2-year MFS for the ITT patients (primary endpoint) was 72% (lower bound exact 1-sided 95% CI=62%). On post hoc analysis, the 2-year MFS was 65% in the AS group (CI 44%-83%) and 76% (CI 60%-87%) in the remaining patients (P=0.42). In the AS group, 18 patients (69%) had some UC recurrence, 8 had a cystectomy, 2 chemoradiation, and 13 (50%) are metastasis-free with an intact bladder. Of the 10 patients (38%) on AS who developed metastatic disease, 9 recurred with localized disease first. The 2-year OS is 83% (CI 72%-90%) and 89% (CI 68%-96%) in the ITT and AS groups, respectively. Associations between mutation presence and MFS or UC recurrence were not observed. Conclusions: The 72% 2-year MFS rate in this MIBC cohort treated with a risk-adapted approach did not satisfy the pre-specified non-inferiority condition. 38% of AS patients developed metastatic disease, with most patients first recurring locally in the bladder. With a median follow-up of 41 months, although 50% of AS patients have been able to avoid cystectomy without metastatic disease, further refinement of this approach is necessary. Clinical trial information: NCT02710734 .

Metformin may have anticancer effects that are independent of its hypoglycemic effects. Retrospective studies have shown that metformin use is associated with decreased incidence of prostate cancer and prostate cancer-specific mortality. Preclinical studies suggesting additive anticancer effects of combining metformin and bicalutamide prompted this clinical trial (NCT02614859).This open-label, randomized, phase 2 trial enrolled non-diabetic patients with biochemically recurrent prostate cancer, a PSADT of 3-9 months, BMI 25 and normal testosterone. Patients were randomized 1:2 to observation for an initial 8 weeks (Arm A) or metformin 1000 mg twice daily (Arm B). Bicalutamide 50 mg/day was added after 8 weeks to both arms. The primary objective was to evaluate the number of patients with undetectable PSA ( 0.2 ng/mL) at the end of 32 weeks. Immune correlatives were assessed as exploratory endpoints.A total of 29 patients were enrolled from March 2015 to January 2020. No difference was seen between the 2 arms in the proportion of patients with undetectable PSA. Modest PSA decrease ranging from 4% to 24% were seen in 40.0% (95% CI: 19.1-64.0%) of patients with metformin monotherapy, compared to 11.1% (95% CI: 0.3-48.3%) in the observation arm. Metformin monotherapy reduced PD-1Although metformin plus bicalutamide was well tolerated, there was no improvement in rates of achieving undetectable PSA at 32 weeks. Metformin monotherapy induced modest PSA declines in 40% of patients after 8 weeks. Metformin, given alone and in combination with bicalutamide, displayed immune modifying effects, primarily within NK and T cells subsets.Trial Registration Number: NCT02614859.

The therapeutic landscape for advanced urothelial carcinoma (mUC) has changed significantly since studies establishing superiority of cisplatin as first-line therapy were conducted. Most patients who are eligible now receive either maintenance or second-line immune checkpoint inhibitors (ICI) and data comparing first-line platinum chemotherapy agents in this setting is limited.The objective of this study was to determine the impact of first-line platinum chemotherapy agent on survival for patients who receive second-line ICI. This is a retrospective cohort study of real-world data, performed from January 1, 2015, to March 21, 2021, included patients with a diagnosis of metastatic or locally advanced urothelial carcinoma. Exposure of interest was first-line platinum-doublet chemotherapy (gemcitabine and/or cisplatin or gemcitabine and/or carboplatin) followed by single-agent second-line ICI. The primary endpoint was overall survival from start of second-line therapy.2,042 patients received either gemcitabine and cisplatin (gem/cis) or gemcitabine and carboplatin (gem/carbo) as first-line therapy. The primary analysis of 890 patients who received second-line single-agent ICI had a median follow-up was 24.2 months from initiation of second-line therapy. Important differences in baseline demographics and/or clinical factors between groups were age, performance status, incidence of upper tract disease, and cisplatin eligibility. Unadjusted overall survival (OS) calculated from start of second-line therapy was longer in patients who received gem/cis compared to gem/carbo followed by ICI (median 9.3 vs. 8.8 months, P = 0.0009). However, OS adjusted for covariates was not significantly different with a hazard ratio (HR) of 0.94 (95% CI, 0.79-1.13; P = 0.50). A separate time-varying covariate model also showed no association between OS and first-line gem/cis (HR 1.00 [95% CI, 0.84-1.19]) while receiving second-line ICI.Survival time on ICI in the second-line setting is the same regardless of choice of prior platinum agent (cisplatin vs. carboplatin) suggesting against specific synergy for one of these agents with ICI. However, a significantly greater proportion of patients in a landmark analysis had long-term benefit with cisplatin strongly supporting it is as the preferred first-line platinum agent.

Concern for discordance between clinical staging and final pathology drives current management of patients deemed appropriate candidates for radical cystectomy. Therefore, we set out to prospectively investigate reliability and shortcomings of cystoscopic evaluation in radical cystectomy candidates.Patients undergoing radical cystectomy for urothelial carcinoma were enrolled in a prospective single-arm study to evaluate reliability of Systematic Endoscopic Evaluation in predicting pT0 urothelial carcinoma (NCT02968732). Systematic Endoscopic Evaluation consisted of cystoscopy and tissue sampling at the time of radical cystectomy. Systematic Endoscopic Evaluation results were compared to radical cystectomy pathology. The primary end point was the negative predictive value of Systematic Endoscopic Evaluation findings in predicting radical cystectomy pathology.A total of 61 patients underwent Systematic Endoscopic Evaluation and radical cystectomy. Indications included muscle invasive bladder cancer in 42 (68.9%) and high risk nonmuscle invasive bladder cancer in 19 (31.1%). In all, 38 (62.3%, 90.5% of patients with muscle invasive bladder cancer) received neoadjuvant chemotherapy. On Systematic Endoscopic Evaluation, 31 (50.8%) patients demonstrated no visual nor biopsy-based evidence of disease (seeT0), yet 16/31 (51.6%) harbored residual disease (pT0), including 8 (8/31, 25.8%) with residual ≥pT2 disease upon radical cystectomy. The negative predictive value of Systematic Endoscopic Evaluation predicting a pT0 bladder was 48.4% (CI 30.2-66.9), which was below our prespecified hypothesis. Therefore, the trial was stopped for futility.Approximately 1 of 4 patients with seeT0 at the time of radical cystectomy harbored residual muscle invasive bladder cancer. These prospective data definitively confirm major limitations of endoscopic assessment for pT0 bladder cancer. Future work should focus on novel imaging and biomarker strategies to optimize evaluations before radical cystectomy for improved decision making regarding bladder preservation.

Background Biomarkers predicting immunotherapy response in metastatic renal cell cancer (mRCC) are lacking. PD-L1 immunohistochemistry is a complementary diagnostic for immune checkpoint inhibitors (ICIs) in mRCC, but has shown minimal clinical utility and is not used in routine clinical practice. Methods Tumor specimens from 56 patients with mRCC who received nivolumab were evaluated for PD-L1, cell proliferation (targeted RNA-seq), and outcome. Results For 56 patients treated with nivolumab as a standard of care, there were 2 complete responses and 8 partial responses for a response rate of 17.9%. Dividing cell proliferation into tertiles, derived from the mean expression of 10 proliferation-associated genes in a reference set of tumors, poorly proliferative tumors (62.5%) were more common than moderately (30.4%) or highly proliferative (8.9%) counterparts. Moderately proliferative tumors were enriched for PD-L1 positive (41.2%), compared to poorly proliferative counterparts (11.4%). Objective response for moderately proliferative (29.4%) tumors was higher than that of poorly (11.4%) proliferative counterparts, but not statistically significant (p = .11). When cell proliferation and negative PD-L1 tumor proportion scores were combined statistically significant results were achieved (p = .048), showing that patients with poorly proliferative and PD-L1 negative tumors have a very low response rate (6.5%) compared to moderately proliferative PD-L1 negative tumors (30%). Conclusions Cell proliferation has value in predicting response to nivolumab in clear cell mRCC patients, especially when combined with PD-L1 expression. Further studies which include the addition of progression-free survival (PFS) along with sufficiently powered subgroups are required to further support these findings.

Update on first-line immunotherapy in metastatic urothelial carcinoma.

4524 Background: TERT is a catalytic subunit of telomerase, the unique enzyme that confers immortality to cells and is expressed in >90% of cancer cells. Mutations in the TERT promoter region (pTERTmut) are the most prevalent noncoding mutations in cancer. Recent data suggest pTERTmut are associated with improved outcomes in patients with UC treated with immune checkpoint inhibitors. We evaluated the molecular and immune landscape of UC with and without pTERTmut. Methods: UC tissue samples were analyzed for DNA alterations (NextSeq, 592 Genes; NovaSeq, WES) and mRNA expression (NovaSeq, WTS). Immune cell fraction was calculated by QuantiSeq (Finotello 2019, Genome Medicine). PD-L1 expression was assessed by immunohistochemistry (IHC) (Caris Life Sciences, Phoenix, AZ). MSI/MMR was tested by fragment analysis, IHC and NGS. TMB-H was based on a cut-off of > 10 mut/MB. We compared alterations between samples with and without detected pathogenic pTERTmut. Significance was determined by Mann–Whitney U, X2, and Fischer-Exact and p adjusted for multiple comparisons (q) was < 0.05 using Benjamini-Hochberg. Results: Overall, 1686 UC samples were analyzed, 1166 from primary lesions and 499 from a lymph node or metastatic site. pTERTmut was present in 68% of primary and 61% of metastatic tumors, and correlated with modest increase of TERT expression (1.18 fold, p=0.015). pTERTmut was associated with less frequent alterations in TP53, KMT2D, CCND1, MYC, KEAP1 and less MSI/dMMR. By contrast, pTERTmut was associated with more frequent alterations in ARID1A, TSC1, PIK3CA and TMB-H (all q

4545 Background: Despite recent advances in the treatment of clear cell RCC, there is a paucity of data to guide management of nccRCC due to the heterogeneity and rarity of these tumors. The clinical activity of combination therapies (including IO-IO, IO-VEGF, VEGF-mTOR) in subtypes of advanced nccRCC is unknown. Methods: In this multicenter retrospective analysis, we evaluated the efficacy of combination systemic therapies in patients with nccRCC. Eligible patients included those with nccRCC as determined by local genitourinary pathology review and receipt of one of three combination regimens during any line treatment (IO-IO, IO-VEGF, mTOR-VEGF). The primary endpoint was objective response rate (ORR) assessed by investigator review. Secondary endpoints were progression- free survival (PFS), disease control rate (DCR), and overall survival (OS). Results: Among 128 included patients, median age was 57 years; 66% were male and 65% white. Histologies included papillary (37%), unclassified (33%), chromophobe (16%), translocation (9%), and other (5 %). Among all patients, 69% had prior nephrectomy; 80% were IMDC intermediate/poor risk; 20% had sarcomatoid and/or rhabdoid differentiation, 27% and 29% had liver and bone metastasis respectively and 63% received combination treatment as first line. Comparison of outcomes based on treatment regimen, line of treatment and subtype is shown in the table. Median PFS and OS were longer with IO/IO and IO/VEGF compared to VEGF/ mTOR at 8.5, 9.5 and 3.7 months and 24.4, 18.2 and 15.4 months respectively. Conclusions: Antitumor activity was observed with novel combinations in nccRCC in both frontline and later line setting. Optimal management of nccRCC remains an unmet need and prospective data is warranted to guide treatment selection for this population. [Table: see text]

5050 Background: PROpel (NCT03732820) is a double-blind, Phase III trial of abiraterone + olaparib vs abiraterone + placebo as first-line treatment in patients with metastatic castration-resistant prostate cancer (mCRPC). Here we report results from the pharmacokinetics (PK) analysis of patients in PROpel. Methods: Patients were randomized 1:1 to receive abiraterone (1000 mg qd) plus prednisone/prednisolone with either olaparib (full monotherapy dose: 300 mg bid) or placebo. Eligible patients were biomarker unselected with confirmed prostate adenocarcinoma and castration-resistant metastatic disease. They had not received prior chemotherapy or next-generation hormonal agents (NHAs) for mCRPC. PK sampling was performed in a subset of patients. Concentrations of olaparib and abiraterone, and its active metabolite Δ4-abiraterone, were measured at steady state predose, at 30 min, 2 h, 3 h, 5 h, and 8 h postdose. The data underwent noncompartmental analysis to evaluate the effect of olaparib on abiraterone PK. The PK of olaparib in the presence of abiraterone was also compared with olaparib PK from other monotherapy studies to evaluate the effect of abiraterone on olaparib PK. Results: The PK analysis included 66 patients from the olaparib + abiraterone arm and 58 patients from the placebo + abiraterone arm. Olaparib absorption was rapid, with median tmax,ss of 2 h. Absorption of abiraterone was rapid in both treatment groups, with median tmax,ss observed between 2.00 and 2.04 h. The steady state exposure of olaparib in the presence of abiraterone, based on AUCss, Cmax,ss and Cmin,ss, was similar to observations for patients receiving olaparib 300 mg bid monotherapy in other Phase III studies, with values of 39.3 μg⋅h/mL, 6.3 μg/mL, and 1.0 μg/mL, respectively. Steady state exposures for abiraterone were similar between the two treatment arms (abiraterone + placebo: AUC(0–8) = 339.5 ng⋅h/mL, Cmax,ss = 105.4 ng/mL, Cmin,ss = 8.5 ng/mL; abiraterone + olaparib: AUC(0–8) = 393.7 ng⋅h/mL, Cmax,ss = 112.6 ng/mL, Cmin,ss = 7.7 ng/mL), and PK data for the abiraterone + olaparib arm were similar to those reported in the literature for abiraterone monotherapy. Conclusions: Combination treatment of olaparib ( full monotherapy dose: 300 mg bid) and abiraterone (1000 mg qd) in patients with mCRPC had no clinically significant effect on the PK profiles of either drug. The steady state exposures for abiraterone were similar between the two treatment arms, indicating that co-administration with olaparib 300 mg bid has no effect on the PK of abiraterone. In line with previous Phase II trial data, results from PROpel confirmed that there were no relevant PK based drug–drug-interactions between olaparib and abiraterone. Clinical trial information: NCT03732820.

The clinical effect of prednisone in metastatic castration-resistant prostate cancer (mCRPC) is unknown. We performed a pooled analysis of control arms of randomized controlled trials that had or had not administered single-agent prednisone. Randomized controlled trials with a control arm that included single-agent placebo (or no anticancer therapy) or single-agent prednisone (with or without placebo) were eligible for analysis. Patients receiving prednisone combined with other agents in the control arm were excluded. The trial characteristics, baseline demographic data, overall survival (OS), progression-free survival (PFS), prostate-specific antigen (PSA) response, Response Evaluation Criteria In Solid Tumors response, and toxicities were recorded. The effect of prednisone was investigated for significance in bivariate models, adjusting for age, pre- and post-docetaxel status, Eastern Cooperative Oncology Group performance status, and trial publication year. Eighteen trials were included; 9 had control arms that contained prednisone (n = 2831) and 9 did not (n = 2784). No significant differences were identified for OS or toxicities of any grade. A significantly greater PSA response rate (18.8% vs. 2.5%; P = .023) and a trend toward more frequent grade ≥ 3 fluid retention (1.0% vs. 0.4%; P = .097) was seen in the prednisone group. Prednisone was also significantly associated with PFS after adjusting for docetaxel status. Single-agent prednisone for mCRPC did not improve OS but was associated with a greater PSA response rate and PFS. Overall and grade ≥ 3 toxicities were not significantly different with prednisone. With the exception of concurrent use with abiraterone or for palliative purposes, the routine use of prednisone for mCRPC appears unnecessary.

291 Background: Combination systemic therapy with tyrosine kinase inhibitors (TKIs) and an immune checkpoint inhibitor (IO) are an established standard of care for patients with metastatic renal cell carcinoma (mRCC). We performed a phase I/II study to investigate the safety and efficacy combining the TKI axitinib (axi) with the IO agent nivolumab (nivo). Methods: This phase I/II study investigated the combination of axi and nivo in an initial dose finding phase I portion with a 3+3 design to determine the recommended phase 2 dose (RP2D) of axi. The phase II portion included 2 parallel arms: treatment naïve mRCC patients and mRCC patients previously treated with TKIs alone or IO/IO combination (NCT03172754). We are presenting results from the treatment naïve arm only. Included patients had to have histology with any clear cell component, ECOG performance status of 0-1, no known or symptomatic brain metastases, and no history of autoimmune disease. The RP2D of axi was 5 mg BID from the phase I portion and patients could be treated for up to 2 years. The primary endpoint of the phase II portion was objective response rate (ORR) per investigator assessment. Results: Forty-four patients were accrued to the treatment naïve arm. One withdrew consent and was replaced but is included in the safety analysis, while 42 patients are evaluable for efficacy. The median age was 65 yrs (range: 42-84 yrs) and the group was predominantly male (83.7%) and white (95.3%). Using the IMDC risk group grading, 18 patients (41.9%) were favorable risk, 22 patients (51.2%) were intermediate risk and 3 patients (7 %) were poor risk. Median follow-up was 11.5 months. Best response data is shown in the table and is notable for an ORR of 69.0%, with only 1 patient (2.4%) experiencing primary progressive disease, for a disease control rate of 97.6%. Median progression free survival was 16.4 months (95% CI: 10.6 - 21.9 mo), and median overall survival (OS) was not reached. OS at 12 months was 86.7%. Adverse event (AE) data was similar to published data for IO/TKI combinations, with no grade 4-5 AEs. Twenty-nine patients experienced a grade 3 AE (70.7%), the most common of which was hypertension, and 14.0% discontinued the study due to treatment-related toxicity. Conclusions: The combination of axi/nivo for treatment naïve patients with mRCC demonstrated efficacy comparable to available IO/TKI combinations with a similar safety profile. Clinical trial information: NCT03172754. [Table: see text]

Background: ccA/ccB classification was developed to classify clear cell renal carcinoma (ccRCC) patients into high and low risk based on gene expression patterns. ClearCode34 is a genetic signature that was developed from the ccA/ccB classification to predict recurrence in localized ccRCC patients. Objective: This review will evaluate the molecular signature ClearCode34, discuss its role in predicting recurrence and consider the rational application of the tool as a strategy to guide future applications of adjunctive therapy in ccRCC. Methods: A review of all the relevant papers in PubMed with the terms “ccA/ccB” or “ClearCode34” in ccRCC were reviewed. Results: Gene expression data was used to model dominant molecular subtypes of ccRCC tumors using consensus clustering methods. The most stable model implied two dominant subgroups – subsequently named ccA and ccB. A 34-gene panel was developed for clinical application, with 10 genes highly expressed corresponding to ccB subtype and 24 from ccA subtype. ClearCode34 independently correlated with cancer-specific survival, overall survival and recurrence in localized ccRCC patients in multiple validations. Conclusions: ClearCode34 is a robust and well validated molecular signature that can identify aggressive ccRCC in primary tumors. Along with basic clinical and pathologic variables like stage, necrosis and grade, robust molecular based prognostic markers are needed that could help better predict groups of patients who will most benefit from risk-adapted treatment approaches.

Five new PD-1/PD-L1 checkpoint inhibitors have been approved for the treatment of metastatic urothelial carcinoma (UC): pembrolizumab, atezolizumab, durvalumab, nivolumab, and avelumab. Although cisplatin-based chemotherapy remains the recommended frontline option for cisplatin-eligible patients with metastatic UC, immunotherapy is now an available option in the second-line setting as well as the frontline setting for selected cisplatin-ineligible patients who are either unable to tolerate chemotherapy or PD-L1–positive. This review describes the updated clinical efficacy of these checkpoint inhibitors in the treatment of advanced UC and suggests how they can be sequenced in the context of available chemotherapeutic options.

The transcriptional events that promote invasive and metastatic phenotypes in renal cell carcinoma (RCC) remain poorly understood. Here we report that the decreased expression of peroxisome proliferator-activated receptor gamma, coactivator 1 alpha (PGC1α) and the increased expression of several genes encoding collagen family members are associated with RCC tumor progression. PGC1α restoration attenuates invasive phenotypes and suppresses tumor progression in vivo. In contrast, collagens produced by RCC cells promote invasive and migratory phenotypes. PGC1α restoration suppresses the expression of collagens and tumor phenotypes via the induction of miR-29a. Furthermore, decreased collagens via the PGC1α/miR-29a axis suppresses collagen-mediated activation of discoidin domain receptor 1 (DDR1)/ERK signaling. In turn, the suppression of collagen/DDR1 signaling by PGC1α leads to decreased levels of the known EMT regulators SNAIL1 and 2. Collectively, our results demonstrate a novel role for PGC1α in the regulation of proinvasive SNAIL proteins.

Level 1 evidence supports cisplatin-based neoadjuvant chemotherapy (NAC) in muscle-invasive urothelial bladder cancer (MIUBC). Recent data from small prospective trials with neoadjuvant immune checkpoint inhibitors are encouraging, but long-term follow-up is required. Randomized trials have failed to accrue a sufficient number of patients and have not demonstrated a survival benefit with adjuvant chemotherapy in MIUBC, but for those with high-risk features at surgery, adjuvant cisplatin-based therapy is appropriate. In upper tract urothelial carcinoma, several retrospective trials and one recent phase 2 prospective trial support the use of NAC, and a randomized trial with adjuvant chemotherapy demonstrated improved disease- and metastasis-free survival and a trend toward improved overall survival.

4551 Background: Front-line treatment for patients (pts) with metastatic clear cell renal cell carcinoma (mRCC) has undergone rapid advances in the last five years. This evolution has led to uncertainty about the optimal first line combination regimen. Herein, we compare real-world outcomes in pts treated with either axitinib/pembrolizumab (A/P) or ipilimumab/nivolumab (I/N) reported by International Metastatic RCC Database Consortium (IMDC) score. Methods: The nationwide Flatiron Health electronic health records-derived database was used to select pts diagnosed with mRCC and treated with front-line A/P or I/N from 2018-2020. The primary endpoints were overall-survival (OS) and real-world progression free survival (rwPFS). The survival analyses were adjusted using propensity score-based Inverse Probability of Treatment weighting, providing balance on age, gender, insurance, race, IMDC, practice type, and nephrectomy. Survival was assessed from beginning of therapy, and survival by treatment groups was compared using weighted and unweighted Kaplan-Meier curves with log-rank tests and weighted Cox proportional hazards regressions. Disease characteristics between the treatment groups were compared using chi-square and T-tests. Results: 821 pts received frontline A/P (n=259) or I/N (n= 562). Demographics and clinical parameters were similar between the two cohorts. Median age was 66 years, 73% were male, and 54.9% had a nephrectomy. 459 pts had all IMDC criteria factors available, 242 pts had missing factors but enough to define as intermediate/poor risk, 120 pts had unknown IMDC risk. Adjusted median OS was not statistically different: mOS for A/P was not reached (NR) while I/N was 22 mo (95% CI, 19.8-NR; p=0.40). Twelve-month survival was 68.5% for A/P treated pts and 65.8% for I/N treated pts (P=0.41). Twelve-month rwPFS was 41.4% for A/P treated pts and 39.7% for I/N treated pts (P=0.14). No statistical difference in survival was seen within IMDC risk strata (see table). Conclusions: In this retrospective, real-world study of pts treated with front-line A/P or I/N, 12-month survival was not statistically different irrespective of IMDC risk. Longer follow-up will be necessary to discern any significant differences.[Table: see text]

4535 Background: Treatment of advanced urothelial carcinoma (mUC) has improved following approvals of PD-1/PD-L1 inhibitors. Platinum chemotherapy remains the standard-of-care in the first-line (1L). Cisplatin (Cis) regimens are accepted to be superior to carboplatin (Carbo) regimens for patients (pts) who are Cis-eligible. We sought to evaluate if differences in efficacy of 1L Cis vs. Carbo have meaningful impact on overall survival (OS) in the era of second-line (2L) immunotherapy (IO). Methods: We conducted a retrospective, observational cohort study to compare OS for pts treated with 1L Cis or Carbo combined with gemcitabine (Gem) followed by 2L IO using patient-level data from the nationwide Flatiron Health electronic health record (EHR)-derived de-identified database. Pts included were diagnosed with mUC between 9/1/2015 and 9/15/2020. 2L IO was defined as single-agent atezolizumab, avelumab, durvalumab, nivolumab, or pembrolizumab. OS was calculated from start of 1L and 2L therapy and compared using Kaplan-Meier curves. Time to 2L IO was calculated from start of 1L to start of IO. Adjusted OS was calculated using multivariable Cox regression models, adjusting for age, gender, race, ECOG performance status, primary site, prior cystectomy, smoking status, and year of diagnosis. Results: A total of 1882 pts were included, 924 (49.1%) received Gem/Cis and 958 (50.9%) received Gem/Carbo in 1L. A similar percentage of pts did not receive any 2L therapy following Gem/Cis (46.4%) or Gem/Carbo (46.0%). Our analysis focused on the 780 pts (41.4%) who received 2L IO—381 after Gem/Cis and 399 after Gem/Carbo. Median follow-up time for the group was 35 months (mo). Pts in the Gem/Cis cohort were younger, had better performance status and lower incidence of upper tract disease (Table). OS from start of 1L therapy was numerically longer in pts who received Gem/Cis compared to Gem/Carbo on unadjusted (median 18.0 v 16.2 mo, p = 0.06) and adjusted analyses (HR = 0.83, 95% CI 0.69-1.00, p = 0.055) but neither result was statistically significant. Time to 2L IO was longer for pts receiving Gem/Cis (6.5 mo) vs Gem/Carbo (5.5 mo, p = 0.008). Survival time on 2L IO did not differ significantly by 1L regimen (Gem/Cis 8.0 mo vs Gem/Carbo 8.2 mo p = 0.36). Conclusions: Real world data suggests that in pts with mUC who are able to receive second-line IO, the choice of first-line platinum chemotherapy may not provide a distinguishable OS benefit. Despite methodologic limitations of this data, a greater focus in discussions with patients on toxicity associated with cisplatin vs carboplatin may be warranted.[Table: see text]