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701 Background: In patients with clear cell renal cell carcinoma (ccRCC), progressive local dysfunction in the tumor immune microenvironment (TIM) has been shown to play a significant role in clinical outcomes and response to therapy. Patients with oligometastatic ccRCC may particularly benefit from localized treatment such as radiation therapy. However, immune cell dysfunction in TIM and its influence on patient outcomes in oligometastatic ccRCC has yet to be defined. To address this unmet need we conducted spatially resolved immune profiling on longitudinally collected patient samples from our ongoing prospective phase II trial (NCT03575611) of radiation therapy in oligometastatic ccRCC. This methodology offers a unique multidimensional evaluation of TIM in relation to histological architecture. Methods: Thirty-seven FFPE tumor samples from 32 patients with ccRCC (primary, 21; oligometastatic, 16) were obtained to construct a tissue microarray (TMA) and assess tumor immune activation biomarkers using the nanoString GeoMx Digital Spatial Profiler (DSP). We used the pan-cytokeratin, CD3, CD68, and SYTO13 as morphology biomarkers to profile, in each TMA core, a panel of 49 protein immune biomarkers in each of these compartments (DSP areas of illumination/AOI): tumor (panCK+), T-cell (CD3+), and macrophage (CD68+). In addition, DSP Immunofluorescence images were used to calculate cell density, and cell-to-cell distances of T cell and Macrophage. A median of 7 AOIs (range 3-9) were assessed in each tissue. Comparisons were made between primary and metastatic tissues by Mann-Whitney test with correction false discovery rate of 1%. Regression models were used to evaluate association between protein counts within each compartment and clinical outcomes. Results: In T-cells, CD127 was significantly higher in primary ccRCC tissue (p=0.00009) while FOXP3 and LAG3 were significantly increased in oligometastatic tissue (p=0.001). Macrophages in oligometastatic tissue expressed higher CD163 and ARG1 (p=0.01 and 0.02, respectively), compared to those in primary tissue. Average distances between macrophage and the nearest T cell were significantly shorter in oligometastatic tumor tissue compared to those in primary ccRCC (22.9 vs 28.8 µm, p=0.04). Higher PD-1 (R2=0.26) with lower CD127 (R2=0.22) and CD27 (R2=0.21) expression in T cells in primary tumor predicted earlier time to first diagnosis of metastases after nephrectomy (all p

TPS749 Background: Complete response (CR) is still a rare event in patients with advanced clear cell renal cell carcinoma (ccRCC). The combination of nivolumab plus cabozantinib was recently approved for the first-line treatment of ccRCC based on the CheckMate 9ER phase 3 study demonstrating improved progression-free survival (PFS) and objective response rate (ORR) in comparison to sunitinib. However, the CR rate was only 9%. Since the anti-tumor effects of immune checkpoint inhibitors are dependent on the presence of activated tumor-infiltrating T cells, drugs that could synergize with T cells’ anti-tumor activity can allow us to improve CR rates. Activation of the cGAS-STING pathway which is induced by radiation-induced DNA damage, is one promising mechanism that has been investigated. Many studies have shown that radiation treatment augments immune checkpoint inhibition. However, it is not always possible to radiate all metastatic lesions. Therefore, targeted peptide receptor radionuclide therapies, have been developed by conjugating radioisotopes to receptor binding analogs targeting specific cancer cell surface proteins, thereby delivering targeted radiation to cancer cells in the body with minimal damage to surrounding healthy cells. 177Lu girentuximab is the first antibody-radioisotope designed for ccRCC, targeting carbonic anhydrase 9-expressing cells, which includes >90% of ccRCC. It has been tested in metastatic ccRCC as a single agent and shown to be safe and effective in stabilizing disease in 57% of pts. In this study, we hypothesize that 177Lu girentuximab-induced DNA damage will potentiate the STING pathway, and this activation will synergize with nivolumab and cabozantinib to promote trafficking and infiltration of activated T cells to tumors and achieve higher CR rates. Methods: Up to 100 patients with treatment naïve, biopsy-proven ccRCC with adequate organ/marrow function with ≥1 evaluable lesion by RECIST 1.1 will be enrolled. A 5-patient safety lead-in will evaluate myelosuppression. Ongoing safety, and futility monitoring will employ a Bayesian approach. The sample size was chosen for reasonable operating characteristics to distinguish a CR rate (primary endpoint) of 18% as better than 9% using a beta(0.09, 0.91) prior. Secondary endpoints are ORR, PFS by RECIST 1.1, and overall survival. 177Lu-girentuximab 1480 MBq/m2 (61% of single agent MTD) will be administered every 12 weeks for up to 3 cycles. Starting with the second cycle, nivolumab and cabozantinib will be added at standard dose. To explore the effects of the treatment on inducing activated T cell infiltration, patients will undergo pre/post-treatment PET scan with [18F]F-AraG radiotracer as well as biopsies for single cell, spatial transcriptomics and proteomics studies. This investigator initiated trial is supported by Telix Pharmaceuticals and DOD grant W81XWH-22-1-0456.

TPS745 Background: A SEER analysis from 2010 to 2013 demonstrated that the incidence of brain metastases(mets) at the diagnosis of renal cell carcinoma(RCC) is 1.51%, and around 12% of patients(pts) with advanced RCC (aRCC) also had mets to the brain. Brain mets confer a poor prognosis. Local management strategies for brain mets from RCC include surgical resection, stereotactic radiosurgery and whole brain radiation therapy. Although systemic therapies including tyrosine kinase inhibitors and immune checkpoint inhibitors have been explored in aRCC pts with brain mets, prospective data is lacking. Cabozantinib is a potent small molecule inhibitor of multiple tyrosine kinases that was approved by FDA for pts with aRCC alone or in combination with nivolumab. Cabozantinib has demonstrated activity in patients with intracranial tumors. A phase III trial (COSMIC-313) recently evaluated cabozantinib in combination with nivolumab and ipilimumab compared to nivolumab plus ipilimumab and demonstrated significantly improved progression-free survival (PFS) in previously untreated pts with aRCC. The combination was found to be safe as frontline systemic treatment. The role of this combination in patients with aRCC with brain mets remains undefined. As such, we propose a study to assess the safety and efficacy of cabozantinib in combination with nivolumab/ipilimumab in RCC pts with untreated brain mets. We believe the results from this trial could provide additional treatment options for pts with RCC brain mets who are typically excluded from clinical trials. Methods: This is a phase II study to assess the safety and efficacy of the combination of nivolumab with ipilimumab and cabozantinib in pts with untreated brain mets from RCC until disease progression or intolerable toxicities or patient withdrawal. Planned accrual is 40 pts. Pts will be treated with nivolumab (3mg/kg) and ipilimumab (1mg/kg) IV every 3 weeks for 4 doses and cabozantinib 40mg daily. Then pts will be treated with nivolumab 480mg IV Q 4 weeks and cabozantinib 40mg daily until progression or intolerable toxicities or patient’s withdrawal. A lead-in group of 6 pts will be closely monitored for dose limiting toxicities(DLT). If stopping criteria (>3 patients develop DLTs) is met, then treatment will be switched to nivolumab plus cabozantinib omitting ipilimumab. The primary objective is intracranial progression free survival(PFS). Secondary objectives include intracranial safety, objective response rate (intracranial + extracranial) by modified RECIST v1.1 and RECIST v1.1, extracranial PFS and overall survival. This phase II trial is currently enrolling pts. Clinical trial information: NCT05048212 .

653 Background: Kidney cancer (renal cell carcinoma, RCC) has shown a sustained increase in its global prevalence thereby presenting increasing burden to health systems, and most of all, to individual patients and their families. Little is known about the variations in the patient experience and best practices among countries. Although individual national surveys have been held, no conclusions could be drawn about country-level variation in patient experience or best practice. Here, we report on the 3rd biennial Global Patient Survey on the diagnosis, management, and burden of Renal Cell Carcinomas conducted by the International Kidney Coalition (IKCC) and involving its Affiliate Organisations worldwide in 15 languages. The aim of the survey was to improve collective understanding and to contribute toward the reduction of the burden of kidney cancer around the world. Methods: A 35-question survey on the diagnosis, management, and burden of RCC was designed by a multi-country steering committee of patient leaders to identify geographic variations in 6 key dimensions: patient education, experience and awareness, access to care and clinical trials, best practices, quality of life, and unmet psychosocial needs. EAU, ESMO, ASCO and NCCN Guidelines committees provided topics of interest to support evidence-based medicine (eg patient perspective on active surveillance, biopsies, etc) . The survey was distributed to patients with kidney cancer and their caregivers in 15 languages, through social media and IKCC’s 49 Affiliate Organizations and/or allied organizations who are not formal affiliates. It was completed online or in paper form between 26 September 2022 and 31 October 2022. At the time of this abstract submission, the survey was still open for completion. Results: We will present the top-line results of the 2022 survey for the very first time. Survey results will be analyzed using cross-tabulations by an independent third-party organization, and multi-variate analysis of predetermined variable will be performed. The full global report will be presented, as well as individual country reports where at least 100 responses were received. Conclusions: The IKCC and its global affiliates will be using the results to ensure that patients’ voices are heard. Actionable points will suggest future projects. Furthermore, individual countries can use their reports to advance their understanding of patient experiences and to drive improvements in care provision locally.

Anti-angiogenic agents, such as vascular endothelial growth factor (VEGF) receptor tyrosine kinase inhibitors and anti-VEGF antibodies, and immune checkpoint inhibitors (CPIs) are standard treatments for advanced renal cell carcinoma (aRCC). In the past, these agents were administered as sequential monotherapies. Recently, combinations of anti-angiogenic agents and CPIs have been approved for the treatment of aRCC, based on evidence that they provide superior efficacy when compared with sunitinib monotherapy. Here we explore the possible mechanisms of action of these combinations, including a review of relevant preclinical data and clinical evidence in patients with aRCC. We also ask whether the benefit is additive or synergistic, and, thus, whether concomitant administration is preferred over sequential monotherapy. Further research is needed to understand how combinations of anti-angiogenic agents with CPIs compare with CPI monotherapy or combination therapy (e.g., nivolumab and ipilimumab), and whether the long-term benefit observed in a subset of patients treated with CPI combinations will also be realised in patients treated with an anti-angiogenic therapy and a CPI. Additional research is also needed to establish whether other elements of the tumour microenvironment also need to be targeted to optimise treatment efficacy, and to identify biomarkers of response to inform personalised treatment using combination therapies.

The International Kidney Cancer Coalition (IKCC) is a federation of 46 affiliated patient organisations representing 1.2 million patients worldwide that is committed to reducing the global burden of kidney cancer. A large-scale global survey of patients with renal cell carcinoma (RCC) to capture real-world experiences has never been undertaken. The 35-question survey was designed to identify geographic variations in patient education, experience, awareness, access to care, best practices, quality of life, and unmet psychosocial needs. A total of 1983 responses were recorded from 43 countries in 14 languages. Analysis revealed key findings. (1) At diagnosis, 43% of all respondents had no understanding of their RCC subtype. (2) Shared decision-making remains aspirational: globally, 29% of all patients reported no involvement in their treatment decision, responding “My doctor decided for me”. (3) While 96% of respondents reported psychosocial impacts, surprisingly, only 50% disclosed them to their health care team. (4) Lastly, 70% of patients were not asked to participate in a clinical trial, although 90% indicated they would be interested. The survey reflects patient perspectives from diverse clinical scenarios in which different treatment options are available. The data point to actionable deficits in the fields of clinical trials, psychosocial support, and shared decision-making. Patient summary: In this brief report, we highlight the key results from the first large-scale global survey of patients with kidney cancer to capture real-world experiences. This survey reflects patient perspectives from diverse clinical scenarios in which different treatment options are available. We conclude that there is a need for improvement in the fields of clinical trials, psychosocial support, and shared decision-making.

Treatment with immune checkpoint blockade (ICB) has resulted in durable responses for a subset of patients with cancer, with predictive biomarkers for ICB response originally identified largely in the context of hypermutated cancers. Although recent clinical data have demonstrated clinical responses to ICB in certain patients with non-hypermutated cancers, previously established ICB response biomarkers have failed to accurately identify which of these patients may benefit from ICB. Here, we demonstrate that a replication stress response (RSR) defect gene expression signature, but not other proposed biomarkers, is associated with ICB response in 12 independent non-hypermutated cohorts of patients with cancer across 7 tumor types, including those of the breast, prostate, kidney, and brain. Induction or suppression of RSR deficiencies was sufficient to modulate response to ICB in pre-clinical models of breast and renal cancers. Mechanistically, we find that despite robust activation of checkpoint kinase 1 (Chk1) signaling in RSR-deficient cancer cells, aberrant replication origin firing causes exhaustion of replication protein A, resulting in accumulation of immunostimulatory cytosolic DNA. We further found that deficient RSR coincided with increased intratumoral dendritic cells in both mouse cancer models and human tumors. Together, this work demonstrates the RSR defect gene signature can accurately identify patients who may benefit from ICB across numerous non-hypermutated tumor types, and pharmacological induction of RSR defects may further expand the benefits of ICB to more patients.

INTRODUCTION AND OBJECTIVE:Tumor shrinkage of ≥10% with presurgical targeted molecular therapy (TMT) in renal cell carcinoma (RCC) was associated with improved overall survival (OS). We characteriz...

Background In the phase 3 METEOR trial, cabozantinib improved progression-free survival (PFS) and overall survival (OS) versus everolimus in patients with advanced RCC after prior antiangiogenic therapy. Methods In this exploratory analysis, plasma biomarkers from baseline and week 4 from 621 of 658 randomized patients were analyzed for CA9, HGF, MET, GAS6, AXL, VEGF, VEGFR2, and IL-8. PFS and OS were analyzed by baseline biomarker levels as both dichotomized and continuous variables using univariate and multivariable methods. For on-treatment changes, PFS and OS were analyzed using fold change in biomarker levels at week 4. Biomarkers were considered prognostic if p interaction Results Hazard ratios for PFS and OS favored cabozantinib versus everolimus for both low and high baseline levels of all biomarkers (hazard ratios ≤0.78). In univariate analyses, low baseline HGF, AXL, and VEGF were prognostic for improvements in both PFS and OS with cabozantinib, and low HGF was prognostic for improvements in both PFS and OS with everolimus. Low AXL was predictive of relative improvement in PFS for cabozantinib versus everolimus. Results were generally consistent when baseline biomarkers were expressed as continuous variables, although none were predictive of benefit with treatment. In multivariable analysis, low baseline HGF was independently prognostic for improved PFS for both cabozantinib and everolimus; low HGF, GAS6, and VEGF were independently prognostic for improved OS with cabozantinib. No biomarkers were independently prognostic for OS with everolimus. On-treatment increases in some biomarkers appeared prognostic for PFS or OS with cabozantinib in univariate analyses; however, none were independently prognostic in multivariable analysis. Conclusions PFS and OS were improved with cabozantinib versus everolimus at high and low baseline levels of all biomarkers. Low baseline HGF was consistently identified as a prognostic biomarker for improved PFS or OS with cabozantinib or everolimus, supporting further prospective evaluation of the prognostic significance of HGF in advanced RCC. Trial registration ClinicalTrials.gov NCT01865747 (registered on 05/31/2013).

Background Although renal cell carcinoma (RCC) is believed to have a strong hereditary component, there is a paucity of published guidelines for genetic risk assessment. A panel of experts was convened to gauge current opinions. Methods A North American multidisciplinary panel with expertise in hereditary RCC, including urologists, medical oncologists, clinical geneticists, genetic counselors, and patient advocates, was convened. Before the summit, a modified Delphi methodology was used to generate, review, and curate a set of consensus questions regarding RCC genetic risk assessment. Uniform consensus was defined as ≥85% agreement on particular questions. Results Thirty-three panelists, including urologists (n = 13), medical oncologists (n = 12), genetic counselors and clinical geneticists (n = 6), and patient advocates (n = 2), reviewed 53 curated consensus questions. Uniform consensus was achieved on 30 statements in specific areas that addressed for whom, what, when, and how genetic testing should be performed. Topics of consensus included the family history criteria, which should trigger further assessment, the need for risk assessment in those with bilateral or multifocal disease and/or specific histology, the utility of multigene panel testing, and acceptance of clinician-based counseling and testing by those who have experience with hereditary RCC. Conclusions In the first ever consensus panel on RCC genetic risk assessment, 30 consensus statements were reached. Areas that require further research and discussion were also identified, with a second future meeting planned. This consensus statement may provide further guidance for clinicians when considering RCC genetic risk assessment. Lay summary The contribution of germline genetics to the development of renal cell carcinoma (RCC) has long been recognized. However, there is a paucity of guidelines to define how and when genetic risk assessment should be performed for patients with known or suspected hereditary RCC. Without guidelines, clinicians struggle to define who requires further evaluation, when risk assessment or testing should be done, which genes should be considered, and how counseling and/or testing should be performed. To this end, a multidisciplinary panel of national experts was convened to gauge current opinion on genetic risk assessment in RCC and to enumerate a set of recommendations to guide clinicians when evaluating individuals with suspected hereditary kidney cancer.

Chronic Hepatitis C virus (HCV) infection has been associated with extrahepatic cancers. Few studies have reported associations between HCV and genitourinary cancers such as kidney and prostate cancers with inconsistent findings. We sought to study associations between HCV and the most common genitourinary cancers including kidney, prostate and urinary bladder.This case-control study included adult (≥18 years at diagnosis) cancer patients who were screened for HCV antibody (anti-HCV) at MD Anderson Cancer Center from June 2004 through January 2018. Cases had incident primary genitourinary cancers (cancers of the kidney, prostate, renal pelvis and ureter, or urinary bladder). Controls had smoking-associated cancers (esophagus, lung and pancreas). Multivariate logistic regression models were used.Among 42,244 patients screened for anti-HCV, 1,493 cases (527 kidney, 691 prostate, 58 renal pelvis and ureter, and 217 urinary bladder cancer) and 1,187 controls (242 esophagus, 709 lung, and 236 pancreas cancer) were studied. In the univariate analysis, the prevalence of anti-HCV positivity did not differ significantly between the controls and the cases with cancers of the renal pelvis and ureter (8% v9%, P = .81), prostate (10% v8%, P = .34), or urinary bladder (8% v 6%, P = .18). In contrast, the prevalence of anti-HCV positivity was lower among the cases with kidney cancer than among the controls (4% v 8%, P.001). However, in the multivariate analyses after adjustment for cofounders, no significant association between anti-HCV positivity and any genitourinary cancer we evaluated.Our results do not support an association between chronic HCV and common genitourinary cancers.

Cancer-derived small extracellular vesicles (sEVs) induce stromal cells to become permissive for tumor growth. However, it is unclear whether this induction solely occurs through transfer of vesicular cargo into recipient cells. Here we show that cancer-derived sEVs can stimulate endothelial cell migration and tube formation independently of uptake. These responses were mediated by the 189 amino acid isoform of vascular endothelial growth factor (VEGF) on the surface of sEVs. Unlike other common VEGF isoforms, VEGF189 preferentially localized to sEVs through its high affinity for heparin. Interaction of VEGF189 with the surface of sEVs profoundly increased ligand half-life and reduced its recognition by the therapeutic VEGF antibody bevacizumab. sEV-associated VEGF (sEV-VEGF) stimulated tumor xenograft growth but was not neutralized by bevacizumab. Furthermore, high levels of sEV-VEGF were associated with disease progression in bevacizumab-treated cancer patients, raising the possibility that resistance to bevacizumab might stem in part from elevated levels of sEV-VEGF., Song Yi Ko et al. show that cancer cell-derived small extracellular vesicles (sEVs) stimulate endothelial cell migration and tube formation through heparin-bound VEGF on the surface of sEVs. The authors find that interaction of VEGF with the sEV surface increases stability of VEGF and reduces its recognition by bevacizumab.

One-carbon metabolism plays a central role in a broad array of metabolic processes required for the survival and growth of tumor cells. However, the molecular basis of how one-carbon metabolism may influence RNA methylation and tumorigenesis remains largely unknown. Here we show MTHFD2, a mitochondrial enzyme involved in one-carbon metabolism, contributes to the progression of renal cell carcinoma (RCC) via a novel epitranscriptomic mechanism that involves HIF-2α. We found that expression of MTHFD2 was significantly elevated in human RCC tissues, and MTHFD2 knockdown strongly reduced xenograft tumor growth. Mechanistically, using an unbiased methylated RNA immunoprecipitation sequencing (meRIP-Seq) approach, we found that MTHFD2 plays a critical role in controlling global N(6)-methyladenosine (m(6)A) methylation levels, including the m(6)A methylation of HIF-2α mRNA, which results in enhanced translation of HIF-2α. Enhanced HIF-2α translation, in turn, promotes the aerobic glycolysis, linking one-carbon metabolism to HIF-2α-dependent metabolic reprogramming through RNA methylation. Our findings also suggest that MTHFD2 and HIF-2α form a positive feedforward loop in RCC, promoting metabolic reprograming and tumor growth. Taken together, our results suggest that MTHFD2 links RNA methylation status to the metabolic state of tumor cells in RCC.

Background Immune checkpoint inhibitors (ICIs) are being increasingly utilised in the front-line (1L) setting of metastatic clear-cell renal cell carcinoma (mccRCC). Limited data exist on responses and survival on second-line (2L) vascular endothelial growth factor–receptor tyrosine kinase inhibitor (VEGFR-TKI) therapy after 1L ICI therapy. Patients and methods This is a retrospective study of mccRCC patients treated with 2L VEGFR-TKI after progressive disease (PD) with 1L ICI. Patients were treated at MD Anderson Cancer Center or Memorial Sloan Kettering Cancer Center between December 2015 and February 2018. Objective response was assessed by blinded radiologists' review using Response Evaluation Criteria in Solid Tumours v1.1. Descriptive statistics and Kaplan–Meier method were used. Results Seventy patients were included in the analysis. Median age at mccRCC diagnosis was 59 years; 8 patients (11%) had international metastatic database consortium favourable-risk disease, 48 (69%) had intermediate-risk disease and 14 (20%) had poor-risk disease. As 1L therapy, 12 patients (17%) received anti–programmed death ligand-1 (PD-(L)1) monotherapy with nivolumab or atezolizumab, 33 (47%) received nivolumab plus ipilimumab and 25 (36%) received combination anti–PD-(L)1 plus bevacizumab. 2L TKI therapies included pazopanib, sunitinib, axitinib and cabozantinib. On 2L TKI therapy, one patient (1.5%) achieved a complete response, 27 patients (39.7%) a partial response and 36 patients (52.9%) stable disease. Median progression-free survival (mPFS) was 13.2 months (95% confidence interval: 10.1, NA). Forty-five percent of subjects required a dose reduction, and twenty-seven percent of patients discontinued treatment because of toxicity. Conclusions In this retrospective study of patients with mccRCC receiving 2L TKI monotherapy after 1L ICI, we observed 2L antitumour activity and tolerance comparable to historical data for 1L TKI.

Low oxygen or hypoxia is a feature of all solid tumors and has been associated with aggressive disease. Here, we describe a novel mechanism for the hypoxia-dependent degradation of the Ras-GTPase–activating protein neurofibromin, by hypoxia-associated factor (HAF). We have previously characterized HAF as an oxygen-independent ubiquitin ligase for HIF-1α. Here, we show that HAF promotes neurofibromin ubiquitination and degradation independently of oxygen and pVHL, resulting in Ras–ERK pathway activation. Hypoxia enhanced HAF:neurofibromin binding independently of HAF-SUMOylation, whereas HAF knockdown increased neurofibromin levels primarily in hypoxia, supporting the role of HAF as a hypoxia-specific neurofibromin regulator. HAF overexpression increased p-ERK levels and promoted resistance of clear cell kidney cancer (ccRCC) cells to sorafenib and sunitinib in both normoxia and hypoxia. However, a greater-fold increase in sorafenib/sunitinib resistance was observed during hypoxia, particularly in pVHL-deficient cells. Intriguingly, HAF-mediated resistance was HIF-2α–dependent in normoxia, but HIF-2α–independent in hypoxia indicating two potential mechanisms of HAF-mediated resistance: a HIF-2α–dependent pathway dominant in normoxia, and the direct activation of the Ras–ERK pathway through neurofibromin degradation dominant in hypoxia. Patients with ccRCC with high HAF transcript or protein levels showed significantly decreased overall survival compared with those with low HAF. Thus, we establish a novel, nonmutational pathway of neurofibromin inactivation through hypoxia-induced HAF-mediated degradation, leading to Ras–ERK activation and poor prognosis in ccRCC. Implications: We describe a novel mechanism of neurofibromin degradation induced by hypoxia that leads to activation of the prooncogenic Ras–ERK pathway and resistance to therapy.

Tumour hypoxia is a major contributor to resistance to anticancer therapies. Given that the results of hypoxia-targeted therapy trials have been disappointing, a more personalized approach may be needed. Here, we characterize multi-omic molecular features associated with tumour hypoxia and identify molecular alterations that correlate with both drug-resistant and drug-sensitive responses to anticancer drugs. Based on a well-established hypoxia gene expression signature, we classify about 10,000 tumour samples into hypoxia score-high and score-low groups across different cancer types from The Cancer Genome Atlas (TCGA) and demonstrate their prognostic associations. Then, we identify various types of molecular features associated with hypoxia status that correlate with drug resistance but, in some cases, also with drug sensitivity, contrasting the conventional view that hypoxia confers drug resistance. We further show that 110 out of 121 (90.9%) clinically actionable genes can be affected by hypoxia status and experimentally validate the predicted effects of hypoxia on the response to several drugs in cultured cells. Our study provides a comprehensive molecular-level understanding of tumour hypoxia and may have practical implications for clinical cancer therapy. The conventional view holds that hypoxia confers drug resistance. In contrast, here the authors use a multilayer ‘omics data approach to characterize the molecular features associated with tumour hypoxia and identify molecular alterations that correlate with both drug-resistant and drug-sensitive responses to approved drugs.

In this roundtable discussion, nation's leading cancer experts from across the country share their perspectives on current changes, challenges and opportunities for delivering cancer care during the COVID-19 era. The roundtable panel examines long-term implications of the pandemic on the management and treatment of cancer especially focusing on significant issues in patient safety, toxicities associated with the use of immunotherapy, COVID-19 vaccination, and clinical trial designs. In this discussion, experts also brainstorm a range of recommendations focusing especially on how the cancer community can capitalize on lessons learned from the pandemic to develop creative approaches that can be taken forward.

Objectives Multimodal kidney‐preserving (MKP) strategies may be an option for patients with localised or locally advanced high‐risk upper tract urothelial carcinoma (UTUC) who have a relative contraindication for nephroureterectomy (NU). Materials and methods We studied patients with UTUC who were managed with MKP strategies, consisting of systemic anticancer therapy, with or without local/topical strategies after endoscopic control of intraluminal tumours. Primary end points were overall survival (OS) and progression‐free survival (PFS). Results Fourteen patients received MKP treatment between August 2013 and April 2020. Median baseline estimated glomerular filtration rate was 43 mL/min/1.73m2. MKP was mainly pursued to avoid dialysis (10/14, 71%), followed by low performance status and/or comorbidities (2/14, 14%). All patients had received systemic therapy: chemotherapy (64%) and immunotherapy (36%). Endoscopic control and/or laser ablation was feasible in 7 (50%) patients. Calculated overall risk of non‐organ confined disease was 35%. Predicted 2‐year and 5‐year relapse‐free probability (RFP) was 74% (24–92%) and 62% (10–85%), respectively. Median follow‐up was 31 months (95% CI: 22.6, NE), median OS was 48.1 months (95% CI: 48.1, NE) and 2‐year OS probability was 0.89 (95% CI: 0.71, 1). Median metastases‐free survival was 48.1 months (95% CI: 26.8, NE), median PFS was 22.4 months (95% CI: 15.6, NE) and 2‐year PFS probability was 0.48 (0.26, 0.89). Conclusion Management of high‐risk localised or locally advanced UTUC with MKP strategies was associated with good tolerance, preservation of renal function, and comparable PFS and OS to predicted in vulnerable patients. Prospective studies with more patients are needed to evaluate these possible benefits relative to current standards.

BACKGROUND: High tumor mutation burden (TMB-H) has been proposed as a predictive biomarker for response to immune checkpoint blockade (ICB), largely due to potential for tumor mutations to generate immunogenic neoantigens. Despite recent pan-cancer approval of ICB treatment for any TMB-H tumor, as assessed by the targeted Foundation One CDx assay in 9 tumor types, the utility of this biomarker has not been fully demonstrated across all cancers. PATIENTS AND METHODS: Data from over 10,000 patient tumors included in The Cancer Genome Atlas were used to compare approaches to determine TMB and identify the correlation between predicted neoantigen load and CD8 T cells. Association of TMB with ICB treatment outcomes was analyzed by both objective response rates (ORRs, N=1551) and overall survival (OS, N=1936). RESULTS: In cancer types where CD8 T cell levels positively correlated with neoantigen load, such as melanoma, lung, and bladder cancers, TMB-H tumors exhibited a 39.8% ORR to ICB (95% CI 34.9–44.8), which was significantly higher than that observed in low TMB (TMB-L) tumors (odds ratio (OR) = 4.1, 95% CI 2.9–5.8, P < 2×10(−16)). In cancer types that showed no relationship between CD8 T cell levels and neoantigen load, such as breast cancer, prostate cancer, and glioma, TMB-H tumors failed to achieve a 20% ORR (ORR = 15.3%, 95% CI 9.2–23.4, P = 0.95), and also exhibited a significantly lower ORR relative to TMB-L tumors (OR = 0.46, 95% CI 0.24–0.88, P = 0.02). Bulk ORRs were not significantly different between the two categories of tumors (P = 0.10) for patient cohorts assessed. Equivalent results were obtained by analyzing OS and by treating TMB as a continuous variable. CONCLUSIONS: Our analysis failed to support application of TMB-H as a biomarker for treatment with ICB in all solid cancer types. Further tumor type specific studies are warranted.

Simple Summary Renal medullary carcinoma (RMC) is a rare and highly aggressive renal cell carcinoma, with a median survival of 13 months. Platinum-based chemotherapy is the recommended standard of care for RMC, but no effective salvage regimens have been established to date. Previous comprehensive molecular characterization of RMC tissues revealed a reliance on aerobic glycolysis, suggesting that bevacizumab plus erlotinib may be an effective regimen against RMC. The aim of our retrospective study was to evaluate the efficacy and safety of bevacizumab plus erlotinib in patients with RMC. In ten patients, the combination was safe and effective, establishing bevacizumab plus erlotinib as a new salvage regimen in RMC. Abstract Purpose: To assess the efficacy and safety of bevacizumab plus erlotinib in patients with RMC. Methods: We retrospectively reviewed the records of patients with RMC treated with bevacizumab plus erlotinib at our institution. Results: Ten patients were included in the study. Two patients achieved a partial response (20%) and seven patients achieved stable disease (70%). Tumor burden was reduced in seven patients (70%) in total, and in three out of five patients (60%) that had received three or more prior therapies. The median progression-free survival (PFS) was 3.5 months (95% CI, 1.8–5.2). The median overall survival (OS) from bevacizumab plus erlotinib initiation was 7.3 months (95% CI, 0.73–13.8) and the median OS from diagnosis was 20.8 months (95% CI, 14.7–26.8). Bevacizumab plus erlotinib was well tolerated with no grade ≥4 adverse events and one grade 3 skin rash. Dose reduction was required in one patient (10%). Conclusions: Bevacizumab plus erlotinib is clinically active and well tolerated in heavily pre-treated patients with RMC and should be considered a viable salvage strategy for this lethal disease.

Somatic copy number aberrations (CNAs) have been associated with clear-cell renal carcinoma (ccRCC) pathogenesis and are a potential source of new diagnostic, prognostic and therapeutic biomarkers. Recurrent CNAs include loss of chromosome arms 3p, 14q, 9p, and gains of 5q and 8q. Some of these regional CNAs are suspected of altering gene expression and could influence clinical outcomes. Despite many studies of CNAs in RCC, there are currently no descriptions of genomic copy number alterations in a Brazilian ccRCC cohort. This study was designed to evaluate the chromosomal profile of CNAs in Brazilian ccRCC tumors and explore clinical associations. A total of 92 ccRCC Brazilian patients that underwent nephrectomy at Barretos Cancer Hospital were analyzed for CNAs by array comparative genomic hybridization. Most patients in the cohort had early-stage localized disease. The most significant alterations were loss of 3p (87.3%), 14q (35.8%), 6q (29.3%), 9p (28.6%) and 10q (25.0%), and gains of 5q (59.7%), 7p (29.3%) and 16q (20.6%). Bioinformatics analysis revealed 19 genes mapping to CNA significant regions, including SETD2, BAP1, FLT4, PTEN, FGFR4 and NSD1. Moreover, gain of 5q34-q35.3 (FLT4 and NSD1) and loss of 6q23.2-q23.3 (MYB) and 9p21.3 (MLLT3) had gene expression levels that correlated with TCGA data and was also associated with advanced disease features, such as larger tumors, Fuhrman 3, metastasis at diagnosis and death. The loss of region 14q22.1 which encompasses the NIN gene was associated with poor overall survival. Overall, this study provides the first CNA landscape of Brazilian patients and pinpoints genomic regions and specific genes worthy of more detailed investigations. Our results highlight important genes that are associated with copy number changes involving large chromosomal regions that are potentially related to ccRCC tumorigenesis and disease biology for future clinical investigations.

Introduction Two separate antiangiogenic tyrosine kinase inhibitors (TKIs) and immunotherapy (IO) combinations are FDA‐approved as front‐line treatment for metastatic renal cell carcinoma (mRCC). Little is known about off‐protocol and post‐front‐line experience with combination TKI–IO approaches. Methods We conducted a retrospective analysis of mRCC patients who received combination TKI–IO post‐first‐line therapy between November 2015 and January 2019 at MD Anderson Cancer Center and Duke Cancer Institute. Chart review detailed patient characteristics, treatments, toxicity, and survival. Independent radiologists, blinded to clinical data, assessed best radiographic response using RECIST v1.1. Results We identified 48 mRCC patients for inclusion: median age 65 years, 75.0% clear cell histology, 68.8% IMDC intermediate risk, and median two prior systemic therapies. TKI–IO combinations included nivolumab–cabozantinib (N +C; 24 patients), nivolumab–pazopanib (N+P; 13), nivolumab–axitinib (6), nivolumab–lenvatinib (2), and nivolumab–ipilimumab–cabozantinib (3). The median progression‐free survival was 11.6 months and the median overall survival was not reached. Response data were available in 45 patients: complete response (CR; n = 3, 6.7%), partial response (PR; 20, 44.4%), stable disease (SD; 19, 42.2%), and progressive disease (3, 6.7%). Overall response rate was 51% and disease control rate (CR+PR+SD) was 93%. Only one patient had a grade ≥3 adverse event. Conclusion To our knowledge, this is the first case series reporting off‐label use of combination TKI–IO for mRCC. TKI–IO combinations, particularly N+P and N+C, are well tolerated and efficacious. Although further prospective research is essential, slow disease progression on IO or TKI monotherapy may be safely controlled with addition of either TKI or IO., Real world use of combination anti‐angiogenic tyrosine kinase inhibitor (TKI)—anti‐PD1 immunotherapy (IO) is feasible, well tolerated and efficacious for metastatic renal cell carcinoma in the second line setting and beyond. Although further prospective research is essential to define optimal use of salvage TKI‐IO, slow disease progression on IO or TKI monotherapy may be safely controlled with addition of either a TKI or IO.

Introduction Lenvatinib (Len) plus everolimus (Eve) is an approved therapy for metastatic renal cell carcinoma (mRCC) after first-line vascular endothelial growth factor receptor-tyrosine kinase inhibitors (VEGFR-TKIs), but limited data exist on the efficacy of Len ± Eve after progression on immune checkpoint inhibitors (ICIs) and VEGFR-TKIs. Methods We retrospectively reviewed the records of patients with mRCC at our institution who were treated with Len ± Eve after ICI and VEGFR-TKI. A blinded radiologist assessed objective response as defined by RECIST version 1.1. Descriptive statistics and the Kaplan-Meier method were used. Results Fifty-five patients were included in the analysis. Of these patients, 81.8% had clear-cell histology (ccRCC), and 76.4% had International Metastatic RCC Database Consortium intermediate-risk disease. Median number of prior therapies was four (range, 2–10); all patients had prior ICIs and VEGFR-TKIs, and 80% were previously treated with ICI and at least two VEGFR-TKIs, including cabozantinib. One patient (1.8%) achieved a complete response, and 11 patients (20.0%) achieved a partial response, for an overall response rate (ORR) of 21.8%; 35 patients (63.6%) achieved stable disease. In all patients, median progression-free survival (PFS) was 6.2 months (95% confidence interval [CI], 4.8–9.4) and median overall survival (OS) was 12.1 months (95% CI, 8.8–16.0). In patients with ccRCC, ORR was 24.4%, PFS was 7.1 months (95% CI, 5.0–10.5), and OS was 11.7 months (95% CI, 7.9–16.1). 50.9% of patients required dose reductions and 7.3% discontinued treatment because of toxicity. Conclusion Len ± Eve demonstrated meaningful clinical activity and tolerability in heavily pretreated patients with mRCC after disease progression with prior ICIs and VEGFR-TKIs. Implications for Practice As the therapeutic landscape for patients with metastatic renal cell carcinoma continues to evolve, this single-center, retrospective review highlights the real-world efficacy of lenvatinib with or without everolimus in heavily pretreated patients. This article supports the use of lenvatinib with or without everolimus as a viable salvage strategy for patients whose disease progresses after treatment with immune checkpoint inhibitors and vascular endothelial growth factor receptor-tyrosine kinase inhibitor therapies, including cabozantinib.

Introduction: Clear cell renal cell carcinoma (ccRCC) displays genomic instability, but lacks mutations in canonical DNA damage response (DDR) genes. Bi-allelic loss of VHL is a near ubiquitous, truncal event in ccRCC development. Herein, we performed preclinical and clinical analysis to understand how VHL loss impacts DDR pathway activity and how specific DDR deficiencies (DDR-D) may be targeted in ccRCC. Methods: We performed DNA whole exome sequencing (WES) and reverse phase protein array (RPPA) early stage ccRCC tumors. All patients were consented under an IRB-approved protocol for the use of tissue. Transcriptomic and protein analyses of select DDR pathways was performed on in silico data (TCGA). DDR functional assays and ATR inhibitor treatment were performed on preclinical cell line models, and in vivo ATR inhibitor treatment in ccRCC xenografts with varying VHL status. Results: Bi-allelic loss of VHL via mutation in one allele and copy number loss of chromosome 3p was observed in 13/13 patient tumors. Mutations in other genes associated with ccRCC and/or canonical DDR genes were not observed. Despite VHL loss being the only driver mutation, these early stage tumors displayed tumor mutational burden (TMB) similar to ccRCC across all tumor stages (1.1 ± 0.5 mut/Mb). Proteomic analysis of patient tumor versus normal tissue (N=12) revealed significantly different (P Conclusions: Here we show in patient tissue and preclinical models that VHL biallelic loss results in genomic instability and functional impairment of ATM kinase activity; furthermore, we provide preclinical evidence for selectively targeting the ATR signaling cascade in patients with VHL-deficient kidney cancer. Clinical trials of ATR inhibitor based therapy in patients with advanced cancer, including ccRCC, are underway (e.g. NCT04266912). Citation Format: Patrick G. Pilie, Lijun Zhou, Yan-Ting Zhang, Christine Peterson, Daniel McGrail, Yang Peng, Guang Peng, Xiande Liu, Xuesong Zhang, Eric Jonasch. VHL-deficient renal cell carcinoma displays defective ATM activation and sensitivity to ATR inhibition [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr LB039.

4539 Background: VHL disease is an inherited condition associated with tumors in multiple organs; RCC may affect up to 70% of patients with VHL. Patients often need many tumor reduction procedures (TRP) to manage renal neoplasms. This study evaluated TRP treatment patterns, costs, and complications among patients with VHL-RCC. Methods: Using an algorithm based on VHL manifestations, patients with VHL were identified from the Optum Clinformatics claims database. Patients were then selected with a prior RCC diagnosis. Minimum continuous enrollment of 12 months before and 3 months after first observed RCC diagnosis was required. TRPs for RCC included nephrectomy, renal ablation, and cryotherapy. Time to first TRP from initial observed RCC diagnosis was estimated using Kaplan-Meier analysis. Mean hospitalization costs per TRP type were estimated. Costs associated with TRP complications were estimated via linear regression; the explanatory variable was the presence of a given complication. Short-term complications were evaluated for 4 weeks post-TRP; long-term ones were evaluated over 6 months. Renal function was evaluated using chronic kidney disease (CKD) stages before and after TRPs, using diagnosis codes and eGFR lab values. Results: 160 patients with VHL-RCC were identified; mean follow-up time was 34.1 months. 115 (71.8%) patients incurred ≥1 RCC TRP over their study period. 68.4% had a TRP in the first year after RCC diagnosis and 76.5% had TRPs by year 5. Of the 125 observed TRPs, 97 (77.6%) were nephrectomies and 28 (22.4%) were ablation/cryotherapy. The mean costs for nephrectomy were nominally higher vs. ablation/cryotherapy ($29,313 vs. $18,290). The most common short-term complications were respiratory related (20.8%) and vascular injury/anemia (13.6%). The most common long-term complications were CKD stage 1-5 (24.0%) and end-stage renal disease (chronic dialysis dependence) (4.0%). The most expensive complications were related to impaired renal function: acute renal failure ($21,013 over 4 weeks), CKD ($26,032 over 6 months) and end stage renal disease ($65,338 over 6 months). At baseline, the proportion of patients with a diagnosis of CKD ≥ stage 3 was similar between patients who had TRPs (n = 115) and those who did not have TRPs (n = 45): 24.3% and 24.4%, respectively. After the first TRP, the proportion of patients with CKD ≥ stage 3 increased from 24.3% to 41.7%. Conclusions: Patients with VHL-RCC incur a significant clinical and economic burden related to TRPs for managing their renal tumors. This is in addition to the burden that VHL-RCC patients incur from the management of other VHL tumors. This study underscores the need for novel effective therapies to prevent or delay the recurrence of VHL-related renal neoplasms to mitigate the burden of morbidity and long-term medical management related to VHL.

4525 Background: Approximately 30% of renal cell carcinoma (RCC) cases present as stage IV at the time of diagnosis. Metastatic RCC (mRCC) is associated with poor outcomes, with a five-year survival rate below 50%. Tools to evaluate the efficacy of novel systemic regimens are needed. Biomarkers like ctDNA can accurately and non-invasively assess molecular residual disease (MRD) in response to therapy and monitor disease status over time to predict disease progression. Here, we aimed to determine the feasibility of performing personalized and tumor-informed ctDNA testing in mRCC patients enrolled on a study integrating systemic therapy with surgical cytoreduction, as well as to measure patient response to sunitinib by assessing ctDNA dynamics. Methods: We analyzed a cohort of 21 mRCC patients with median age of 59.5 (43-76) years who were treated with sunitinib, and had planned cytoreductive nephrectomy during their second cycle of therapy. Baseline and post-first cycle ctDNA levels were measured using a personalized and tumor-informed ctDNA assay (SignateraTM bespoke mPCR NGS assay). Changes in ctDNA levels from baseline to the best response time point were correlated with disease status as assessed by radiological imaging. Results: In this cohort, baseline ctDNA was detected in 81% (17/21) of patients, with higher ctDNA concentrations observed in patients who presented with multiple distant metastases (n = 11) compared to the 10 cases with a single metastatic mass (median 5.8 vs 1.3 mean tumor molecules/mL, not statistically significant). Of those with baseline ctDNA measurement, 12% (2/17) cleared their ctDNA, 24% (4/17) had a decrease in ctDNA, and 59% (10/17) had an increase in ctDNA after 4 weeks of sunitinib. During the course of treatment, patients whose ctDNA concentration increased from baseline were more likely to experience a disease progression (HR: 3.9 95% CI 1.13-13.7; p = 0.032) compared to those whose ctDNA decreased. In addition, higher ctDNA concentration before surgery after initial treatment with sunitinib correlated with shorter time to progression (p = 0.04). Conclusions: Our results demonstrate the feasibility and prognostic value of personalized and tumor-informed ctDNA testing for determining response to systemic therapy in patients with mRCC. Early signs of unfavorable ctDNA kinetics can provide rationale for modification of systemic therapy in order to enhance response. Future work exploring the clinical utility of ctDNA testing in larger mRCC cohorts is warranted.

4546 Background: VHL disease is associated with malignant or benign tumors, including renal cell carcinoma (RCC), pancreatic neuroendocrine tumors (pNETs), and hemangioblastomas. Alterations in the VHL gene cause aberrant stabilization and accumulation of HIF-2α, leading to activation of genes associated with tumor growth. Antitumor activity observed in the ongoing open-label phase 2 study, LITESPARK-004 (NCT03401788), led to the approval of belzutifan for the treatment of patients (pts) with VHL disease who require therapy for associated RCC, CNS hemangioblastomas, or pNETs not requiring immediate surgery. Updated results are presented after > 2 years of follow-up. Methods: Pts (≥18 years) with germline VHL alterations, ≥1 measurable nonmetastatic RCC tumor, no tumor of > 3 cm that necessitated immediate surgery, no prior anticancer systemic treatment, and an ECOG PS score of 0 or 1 received oral belzutifan 120 mg once daily until disease progression, unacceptable toxicity, or pt withdrawal. The primary end point was objective response rate (ORR) in VHL disease–associated RCC per RECIST v1.1 by independent central review (ICR). Secondary end points were safety, ORR in non-RCC neoplasms, and duration of response (DOR) in renal and nonrenal neoplasms, per RECIST v1.1 by ICR. Results: Of 61 pts, 50 were on treatment as of July 15, 2021; the primary reasons for discontinuation were disease progression in RCC neoplasms (n = 4) and pt decision to withdraw (n = 4). Twenty pts (33%) had ≥1 pNET and 50 (82%) had ≥1 CNS hemangioblastoma evaluable by ICR at baseline. At baseline, 97% of pts (n = 59) had prior VHL-related surgery; 38 pts had ≥1 VHL-related surgery within 3 years before starting belzutifan. Median time from first dose to database cutoff date was 29.3 mo (range, 27.6-37.5). ORR in RCC was 59% (n = 36), with 2 CRs (3%) and 34 PRs (56%). Median DOR was not reached (range, 8.3+ to 27.6+ mo). ORR in CNS hemangioblastomas was 38% (n = 19; 3 CRs; 16 PRs); median DOR was not reached (range, 3.7+ to 28.0+ mo). ORR in pNETS was 90% (n = 18; 3 CRs; 15 PRs); median DOR was not reached (range, 11.0+ to 31.0+ mo). Three pts (5%) underwent VHL-related surgeries after starting belzutifan. Grade 3 treatment-related adverse events (TRAEs) were reported in 10 pts (16%); the most common was anemia (n = 6 [10%]). No pt had a grade 4 or 5 TRAE. Two pts (3%) stopped treatment because of TRAEs (grade 1 dizziness and grade 2 intracranial hemorrhage). Conclusions: After a median follow-up of 29.3 mo, belzutifan continued to show antitumor activity in VHL disease–related neoplasms, including RCC, pNETs, and CNS hemangioblastomas, whereas the safety profile remained consistent with that of previous reports. These results support the use of belzutifan as a systemic treatment for VHL disease. Clinical trial information: NCT03401788.

4509 Background: Hypoxia-inducible factor 2α (HIF-2α) is a key oncogenic driver in RCC. Antitumor activity of the HIF-2α inhibitor belzutifan has been observed in RCC and is approved for treatment in patients (pts) with VHL disease who require therapy for associated RCC, CNS hemangioblastomas, or pNETs not requiring immediate surgery. Previous data from the phase 1 LITESPARK-001 trial (NCT02974738) designed to evaluate belzutifan in heavily pretreated RCC showed durable antitumor activity and an acceptable safety profile. After more than 3 years of follow-up for pts with ccRCC still receiving treatment, updated data are presented. Methods: Pts enrolled in the ccRCC cohort were previously treated with ≥1 therapy, had RECIST-measurable disease, ECOG PS score of 0 or 1, adequate organ function, and life expectancy of ≥6 months. Pts received oral belzutifan 120 mg once daily. The primary end point was safety. Secondary end points were ORR, DCR (CR + PR + SD), PFS, and DOR per RECIST v1.1 by investigator. The data cutoff date was July 15, 2021. Results: Of 55 pts enrolled in the ccRCC cohort, 9 (16%) remain on treatment as of the data cutoff date of July 15, 2021; the primary reason for discontinuation was progressive disease (n = 34; 62%). Pts received a median of 3 prior therapies (range, 1-9); 39 (71%) received prior VEGF and immunotherapy. Pts were followed while on treatment and for 30 days after the last dose for a median of 41.2 months (range, 38.2-47.7). Twenty-two pts (40%) experienced grade 3 TRAEs. The most common (≥10%) grade 3 TRAEs were anemia (n = 13; 24%) and hypoxia (n = 7; 13%). There were no grade 4 or 5 TRAEs. ORR was 25%, with 1 confirmed CR (2%) and 13 PRs (24%); DCR was 80%. Median DOR was not reached (range, 3.1+ to 37.9+ months); 8 of 14 responding pts (57%) remain in response as of the data cutoff date. Per IMDC risk, 4 of 13 pts with favorable risk achieved response (ORR = 31%; all PRs) and 10 of 42 pts with intermediate/poor risk achieved response (ORR = 24%; 1 CR, 9 PRs). DCR was 92% for pts with favorable risk and 76% for pts with intermediate/poor risk. For pts who received prior VEGF and immunotherapy, 8 of 39 pts achieved response (ORR = 21%; 1 CR; 7 PR); DCR was 74%. For the 16 pts who did not receive prior VEGF/immunotherapy, 6 achieved response (ORR = 38%; all PRs); DCR was 94%. Median PFS for the total cohort was 14.5 months (95% CI, 7.3-22.1); PFS rate at 156 weeks (̃36 months) was 34%. Conclusions: As seen after a median follow-up of > 3 years for pts still receiving treatment, belzutifan monotherapy continued to show a high rate of disease control and durable responses in previously treated pts with advanced ccRCC. Belzutifan exhibited a favorable safety profile, and no new safety signals were observed. In several phase 3 studies, belzutifan is being evaluated as monotherapy and combined therapy for ccRCC. Clinical trial information: NCT02974738.

Dedifferentiation and acquisition of chromosomal instability in renal cell carcinoma portends dismal prognosis and aggressive clinical behavior. However, the absence of reliable experimental models dramatically impacts the understanding of mechanisms underlying malignant progression. Here we established an in vivo genetic platform to rapidly generate somatic mosaic genetically engineerd immune-competent mouse models of renal tumors, recapitulating the genomic and phenotypic features of these malignancies. Leveraging somatic chromosomal engineering, we demonstrated that ablation of the murine locus syntenic to human 9p21 drives the rapid expansion of aggressive mesenchymal clones with prominent metastatic behavior, characterized by early emergence of chromosomal instability, whole-genome duplication, and conserved patterns of aneuploidy. This model of punctuated equilibrium provides a remarkable example of cross-species convergent evolution.SignificanceTo better understand the role of 9p21 in malignant progression, we generated a somatic mosaic GEMM of renal cancer, capturing the histological, genomic and evolutionary features of human disease. With this technology we demonstrated a critica role of 9p21 loss in metastatic evolution of RCC and provide a unique tool for testing new therapeutic treatments.

The NCCN Guidelines for Kidney Cancer provide multidisciplinary recommendations for diagnostic workup, staging, and treatment of patients with renal cell carcinoma (RCC). These NCCN Guidelines Insights focus on recent updates to the guidelines, including changes to certain systemic therapy recommendations for patients with relapsed or stage IV RCC. They also discuss the addition of a new section to the guidelines that identifies and describes the most common hereditary RCC syndromes and provides recommendations for genetic testing, surveillance, and/or treatment options for patients who are suspected or confirmed to have one of these syndromes.

Investigations into the function of non-promoter DNA methylation have yielded new insights into epigenetic regulation of gene expression. Previous studies have highlighted the importance of distinguishing between DNA methylation in discrete functional regions; however, integrated non-promoter DNA methylation and gene expression analyses across a wide number of tumor types and corresponding normal tissues have not been performed. Through integrated analysis of gene expression and DNA methylation profiles, we examined 32 tumor types and identified 57 tumor suppressors and oncogenes out of 260 genes exhibiting a correlation of > 0.5 between gene body methylation and gene expression in at least 1 tumor type. The lymphocyte-specific gene CARD11 exhibits robust association between gene body methylation and expression across 19 of 32 tumor types examined. It is significantly overexpressed in kidney renal cell carcinoma (KIRC) and lung adenocarcinoma (LUAD) tumor tissues in comparison to respective control samples; and is significantly associated with lower overall survival in KIRC. Contrary to its canonical function in lymphocyte NF-kB activation, CARD11 activates the mTOR pathway in KIRC and LUAD, resulting in suppressed autophagy. Furthermore, demethylation of a CpG island within the gene body of CARD11 decreases gene expression. Collectively, our study highlights how DNA methylation outside the promoter region can impact tumor progression.

Introduction Metastatic renal cell carcinoma with sarcomatoid dedifferentiation (sRCC) is associated with poor survival outcomes. We aimed to analyze the efficacy and safety of immune checkpoint inhibitors (ICI) in patients with sRCC comparing clear-cell (sccRCC) to non-clear cell epithelial histology (snccRCC). Methods We performed retrospective analysis of sRCC patients who received ICI at MD Anderson Cancer Center (n = 48, 41 with ccRCC and 7 with nccRCC) to determine the overall survival (OS), progression-free survival (PFS), and objective response rate (ORR). Additionally, we performed a prespecified multivariable Cox regression comparing survival outcomes between sccRCC and snccRCC. Results The ORR for the entire cohort was 35.4% (95% confidence interval [CI]: 23.4%, 49.6%), including 8 (16.7%) patients (95% CI: 8.7%, 29.6%) who achieved a complete remission. The disease control rate was 52% (95% CI: 38.3%, 65.5%). In patients with sccRCC, the ORR was 39% (95% CI: 25.7%, 54.3%) and disease control rate 58.5% (43.4%, 72.2%). Among 7 snccRCC patients, only one (14.3%) achieved an objective partial response. At a median follow-up of 51.1 months, the median PFS was 4.9 months (95% CI: 2.7, 16.3) and the median OS was 28.4 months (95% CI: 15.8, NA) for the entire cohort. For patients with sccRCC, the median PFS was 8.9 months, with median OS of 30.1 months, compared with median PFS of 2.3 months (HR 0.25 [95% CI: 0.08, 0.78]; P= 0.0145) and median OS of 6.7 months (HR 0.13 [95% CI 0.04, 0.44]; P=0.0009) for patients with snccRCC. Conclusion ICIs appear to be effective in sccRCC while the treatment of snccRCC remains challenging.

Clear Cell Renal Carcinoma (ccRCC) is a heterogeneous disease with a variable post-surgical course. To assemble a comprehensive ccRCC tumor microenvironment (TME) atlas, we performed single-cell RNA sequencing (scRNASeq) of hematopoietic and non-hematopoietic subpopulations from tumor and tumor-adjacent tissue of treatment-naïve ccRCC resections. We leveraged the VIPER algorithm to quantitate single-cell protein activity, and validated this approach by comparison to flow cytometry. The analysis identified key TME sub-populations, as well as their master regulators and candidate cell-cell interactions, revealing clinically-relevant populations, undetectable by gene expression analysis. Specifically, we uncovered a tumor-specific macrophage subpopulation characterized by upregulation of TREM2/APOE/C1Q - validated by spatially-resolved, quantitative multispectral immunofluorescence. In a large clinical validation cohort, these markers were significantly enriched in tumors from patients who recurred following surgery. The study thus identifies TREM2/APOE/C1Q-positive macrophage infiltration as a potential prognostic biomarker for ccRCC recurrence, as well as a candidate therapeutic target.

A non-immunogenic tumor microenvironment (TME) is a significant barrier to immune checkpoint blockade (ICB) response. The impact of Polybromo-1 (PBRM1) on TME and response to ICB in renal cell carcinoma (RCC) remains to be resolved. Here we show that PBRM1/Pbrm1 deficiency reduces the binding of brahma-related gene 1 (BRG1) to the IFNγ receptor 2 (Ifngr2) promoter, decreasing STAT1 phosphorylation and the subsequent expression of IFNγ target genes. An analysis of 3 independent patient cohorts and of murine pre-clinical models reveals that PBRM1 loss is associated with a less immunogenic TME and upregulated angiogenesis. Pbrm1 deficient Renca subcutaneous tumors in mice are more resistance to ICB, and a retrospective analysis of the IMmotion150 RCC study also suggests that PBRM1 mutation reduces benefit from ICB. Our study sheds light on the influence of PBRM1 mutations on IFNγ-STAT1 signaling and TME, and can inform additional preclinical and clinical studies in RCC., PBRM1, encoding for a subunit of the SWI/SNF complex, is the second most frequently mutated gene in clear cell renal cell carcinoma (ccRCC). Here, the authors show that PBRM1 loss reduces IFNγ-mediated signalling resulting in a less immunogenic tumor microenvironment and that PBRM1 mutations correlate with lack of response to checkpoint inhibitor therapy in ccRCC patients..

Second-line targeted therapies for metastatic renal cell carcinoma (mRCC) include mammalian target of rapamycin (mTOR) inhibitors and tyrosine kinase inhibitors (TKIs). This study compares the effectiveness of these therapies in a multi-practice chart review and synthesizes the findings with those of a similarly designed study. Medical oncologists/hematologists (N = 36) were recruited to review charts for patients aged ≥18 years, received a first-line TKI and initiated second-line targeted therapy in 2010 or later. The primary outcome was time from second-line initiation to treatment failure (TTF; discontinuation, physician-assessed progression, or death, whichever occurred first). TTF was compared among patients receiving second-line everolimus (EVE), temsirolimus (TEM), or TKI as a class, using a Cox proportional hazards model adjusting for type of initial TKI and response, histological subtype, performance status, and sites of metastasis. Hazard ratios (HRs) for TTF were pooled, in a meta-analysis, with previously reported HRs for progression-free survival from a chart review with a similar design. A total of 138, 64 and 79 patients received second-line therapy with EVE, TEM or a TKI, respectively. Adjusting for baseline characteristics, EVE was associated with numerical, but not statistically significant, reductions of 28% (HR = 0.72; 95% CI [0.45–1.16]) and 26% (HR = 0.74; 95% CI [0.48–1.15]) in the hazard of TTF compared to TEM and TKI, respectively. After pooling the HRs from both studies, EVE was associated with significantly reduced hazards of TTF compared to TEM and TKI (HR = 0.73; 95% CI [0.57–0.93]; and HR = 0.75; 95% CI [0.57–0.98], respectively). Limitations include retrospective analyses with possible missing or erroneous chart data, confounding of unobserved factors due to non-randomization, and limited data for axitinib during the study period. In pooled results from two independent multi-practice chart reviews of second-line mRCC treatment, EVE was associated with significantly reduced hazards of treatment failure compared to TEM and to TKIs as a class.

305 Background: VHL disease is an inherited condition characterized by the formation of benign and malignant tumors in multiple organs, and RCC affects up to 40-70% of patients with VHL disease. However, real-world evidence on HRU and direct healthcare costs related to VHL-RCC is lacking. This study sought to address the gap in the literature by evaluating HRU and healthcare costs associated with the disease. Methods: Patients with VHL disease were identified from the Optum Clinformatics claims data using an algorithm based on combinations of manifestations of the disease. Among the patients identified, those with at least 1 diagnosis of RCC were further selected. The index date was defined as the date of first observed RCC diagnosis in the data, and the study period extends up to 5 years after index date or the end of continuous enrollment, whichever was earlier. A minimum continuous enrollment of 12 months prior to and 3 months after the index date was required. All-cause and RCC-related HRU and healthcare costs were evaluated among eligible patients with VHL-RCC. HRU was expressed as events per person-month and cost was expressed as average monthly cost. HRU and healthcare costs related to other VHL disease-related tumors were also assessed, including central nervous system (CNS) hemangioblastomas (Hb), retinal Hb, and pancreatic neuroendocrine tumors (pNETs). Results: 160 patients with VHL-RCC were included in the analyses. Mean age of the patients was 51.5 years and 89 (56%) were male. During the study period, patients with VHL-RCC incurred 0.10 hospitalizations (0.52 inpatient days), 1.49 outpatient visits, 0.09 emergency department (ED) visits, and 0.17 other medical visits per person-month on average. This translated to a monthly all-cause healthcare cost of $4,276, which included $2,222 inpatient, $1,318 outpatient, $188 ED, $63 other medical visits, and $485 pharmacy costs. $1,627 out of the all-cause cost per month was RCC-related, which was mainly driven by inpatient costs for RCC ($1,184/month). There were also notable costs associated with other tumor types: $2,159/month for CNS Hb, $601/month for retinal Hb, and $3,306/month for pNETs on average. Among patients with VHL-RCC who received surgical procedures for different tumors, the average hospitalization or outpatient visit costs were $28,356 for nephrectomies, $70,515 for CNS Hb surgeries, $2,887 for laser therapy of retinal Hb, and $81,825 for pNET surgeries. Conclusions: VHL-RCC is associated with significant HRU and healthcare costs due to the needs of managing RCC as well as tumors in other organs caused by VHL disease. This highlights the multi-disciplinary nature of VHL disease and the need for novel effective therapies to prevent or delay the recurrence of VHL-related tumors in order to mitigate the economic burden related to the disease.

356 Background: Pembrolizumab monotherapy recently showed promising efficacy in nccRCC. The objective response rate (ORR) by histology was 28.8% for papillary, 9.5% for chromophobe, and 30.8% for unclassified RCC (McDermott, JCO 2021). However, combination immunotherapy data are limited in nccRCC. Methods: We retrospectively evaluated the efficacy and safety of nivo-ipi in pts with nccRCC treated at our institution. ORR and progression-free survival (PFS) were determined using RECIST. Overall survival (OS) was measured from therapy start to death or last follow up. Results: Between November 2017 and July 2020, 27 pts with nccRCC were treated with nivo-ipi at our institution; 25 pts (93%) received nivo-ipi as first-line therapy and 14 pts (52%) had prior nephrectomy. Histology subtypes included 13 (48%) papillary (4 with sarcomatoid features [SF]), 7 (26%) chromophobe (4 with SF), and 7 (26%) unclassified. Sites of metastases included lung in 52%, bone in 37%, and liver in 22% of pts. IMDC risk was favorable (8%), intermediate (48%) and poor (44%). ORR in all pts was 30%; 7 pts achieved a partial response (PR), and 1 patient achieved a complete response (CR). ORR by histology subtype was 54% for papillary, 14% for chromophobe, and 0% for unclassified (table). Clinical benefit (defined as PR, CR, or stable disease [SD] for > 6 months) was achieved in 62% for papillary, 57% for chromophobe, and 29% for unclassified. At a median follow-up time of 17.1 months, for all 27 pts, median PFS was 7.2 months, and median OS was 18.5 months. Median OS per each variant histology subtype was not reached in papillary, 25.7 months in chromophobe, and 7.4 months in unclassified. Median PFS per variant histology subtype was 11.8 months in papillary, 4.0 months in chromophobe, and 2.8 months in unclassified. Seven pts (26%) developed Grade ≥3 toxicity: pneumonitis (2), colitis (2), hepatitis (1), rash (1), and immune-mediated glomerulonephritis (1). Conclusions: In this small retrospective study, nivo-ipi was well-tolerated in pts with nccRCC and yielded high ORR and prolonged PFS in papillary RCC but disappointing efficacy results in chromophobe and unclassified RCC. Molecular studies are ongoing to understand the mechanisms of response and resistance to nivo-ipi in these tumor subtypes.[Table: see text]

306 Background: Renal cell carcinoma (RCC) is increasing in global prevalence, thereby increasing burden to health systems, and most of all, to individual patients and their families. Little is known about the variations in patient experience and best practices among countries. Here, we report on the second biennial Global Patient Survey on the diagnosis, management, and burden of Renal Cell Carcinomas conducted by the International Kidney Coalition (IKCC) worldwide in 13 languages. The aim of the survey was to improve collective understanding and to contribute toward the reduction of the burden of kidney cancer around the world. Methods: A 35-question survey on the diagnosis, management, and burden of RCC was designed by a multi-country steering committee to identify geographic variations in 6 topics: patient education, experience and awareness, access to care and clinical trials, best practices, quality of life, and unmet psychosocial needs. The survey was distributed to patients with kidney cancer and their caregivers in 13 languages, through IKCC’s 46 Affiliate Organisations and social media from 29 Oct 2020 to 5 Jan 2021. Results: 2,012 responses came from 41 countries. Survey results were analysed using cross-tabulations by an independent third-party organisation. The full global report is publicly available, as well as 7 individual country reports where at least 100 responses were received. 42% reported that the likelihood of surviving their cancer beyond 5 years was not explained Just over half (51%) reported that they were involved as much as they wanted to be in developing their treatment plan. 56% experienced barriers to their treatment 41% indicated that “No one” discussed cancer clinical trials with them 31% were invited to take part in a clinical trial 45% self-reported that they were insufficiently active 50% indicated that they ‘very often’ or ‘always’ experienced disease-related anxiety. 26% ‘very often’ or ‘always’ experienced stress related to financial issues 55% indicated that they ‘very often’ or ‘always’ experienced a fear of recurrence 52% reported having talked to their doctor/healthcare professional about their concerns 48% had been offered a biopsy in the past with only 3% refusing; 47% would be willing to undergo biopsy in the future Patients aged ≤65 experienced more barriers to quality care, understood their disease less well, and experienced a longer time to diagnosis. Conclusions: The IKCC and its global affiliates will be using the results to ensure that patients’ voices are heard. Actionable points will suggest future projects. Individual countries can use their reports to advance their understanding of patient experiences and to improve local care.

351 Background: S/R mRCC is an aggressive disease that is associated with improved response to ICT. Studies performed prior to the approval of ICT demonstrated poor outcomes of S/R RCC with VEGF targeted therapies (TT). Here, we report outcomes of pts with S/R mRCC treated with VEGF TT after PD on ICT. Methods: We retrospectively reviewed the records of pts with mRCC with sarcomatoid (S), rhabdoid (R), or sarcomatoid plus rhabdoid (S+R) features who received VEGF TT after PD on ICT. Clinical endpoints of interest were time on VEGF TT and OS from treatment initiation. Directed acyclic graphs were used to identify confounders for adjustment in regression models. Hazard ratios (HR) and 95% confidence intervals (95% CI) were calculated using multivariable Cox regression. Multivariable models adjusted for epithelial histology, IMDC risk, prior VEGF TT, and inclusion of cabozantinib in the post-ICT VEGF TT regimen. Results: 57 pts with metastatic S/R RCC (52 with clear cell and 5 with non-clear cell histology) received a VEGF TT after PD on ICT. 46% of pts received a VEGF TT prior to ICT. After PD on ICT, 67% of pts had IMDC intermediate-risk disease; the most commonly used VEGF TT were cabozantinib (44%), either sunitinib, pazopanib, or axitinib (24%), and a VEGF TT in combination with an ICT (21%). Pts with R RCC had significantly longer time on VEGF TT compared with S RCC (adjusted HR = 0.45, 95% CI 0.21-0.94, p = 0.034), whereas the OS comparison was inconclusive (adjusted HR = 0.77, 95% CI 0.36-1.62, p = 0.486). IMDC risk classification following ICT progression was predictive of OS (adjusted HR = 2.22, 95% CI 1.07-4.61, p = 0.032), whereas, its association with time on VEGF TT was less conclusive (adjusted HR = 1.78, 95% CI 0.88-3.60, p = 0.107). Conclusions: Patients with S/R mRCC derive clinical benefit from VEGF TT after progression on ICT, and it is similar to the benefit previously described for patients without S/R features. Our findings suggest that the type of S/R features present and IMDC risk score inform the clinical benefit that VEGF TT will produce in this setting.[Table: see text]

Summary Background No approved systemic therapy exists for von Hippel-Lindau disease, an autosomal dominant disorder with pleiotropic organ manifestations that include clear cell renal cell carcinomas; retinal, cerebellar, and spinal haemangioblastomas; pheochromocytomas; pancreatic serous cystadenomas; and pancreatic neuroendocrine tumours. We aimed to assess the activity and safety of pazopanib in patients with von Hippel-Lindau disease. Methods In this non-randomised, single-centre, open-label, phase 2 trial, adult patients with clinical manifestations of von Hippel-Lindau disease were recruited from the University of Texas MD Anderson Cancer Center (Houston, TX, USA) and were treated with pazopanib (800 mg orally daily) for 24 weeks, with an option to continue treatment if desired by the patient and treating physician. Primary endpoints were the proportion of patients who achieved an objective response and safety in the per-protocol population. The objective response was measured for each patient and each lesion type. Radiographic assessments were done at baseline and every 12 weeks throughout the study. Activity and safety were assessed with continuous monitoring and a Bayesian design. This study is registered with ClinicalTrials.gov, number NCT01436227, and is closed to accrual. Findings Between Jan 18, 2012, and Aug 10, 2016, we screened 37 patients with genetically confirmed or clinical features consistent with von Hippel-Lindau disease, of whom 31 eligible patients were treated with pazopanib. The proportion of patients who achieved an objective response was 42% (13 of 31 patients). By lesion sites responses were observed in 31 (52%) of 59 renal cell carcinomas, nine (53%) of 17 pancreatic lesions, and two (4%) of 49 CNS haemangioblastomas. Seven (23%) of 31 patients chose to stay on the treatment after 24 weeks. Four (13%) of 31 patients withdrew from the study because of grade 3 or 4 transaminitis, and three (10%) discontinued study treatment because of treatment intolerance with multiple intercurrent grade 1–2 toxicities. Treatment-related serious adverse events included one case each of appendicitis and gastritis and one patient had a fatal CNS bleed. Interpretation Pazopanib was associated with encouraging preliminary activity in von Hippel-Lindau disease, with a side-effect profile consistent with that seen in previous trials. Pazopanib could be considered as a treatment choice for patients with von Hippel-Lindau disease and growing lesions, or to reduce the size of unresectable lesions in these patients. The safety and activity of pazopanib in this setting warrants further investigation. Funding Novartis Inc and NIH National Cancer Institute core grant.

Pancreatic neuroendocrine tumors (PanNETs) are rare in von Hippel–Lindau disease (VHL) but cause serious morbidity and mortality. Management guidelines for VHL-PanNETs continue to be based on limited evidence, and survival data to guide surgical management are lacking. We established the European-American-Asian-VHL-PanNET-Registry to assess data for risks for metastases, survival and long-term outcomes to provide best management recommendations. Of 2330 VHL patients, 273 had a total of 484 PanNETs. Median age at diagnosis of PanNET was 35 years (range 10–75). Fifty-five (20%) patients had metastatic PanNETs. Metastatic PanNETs were significantly larger (median size 5 vs 2 cm; P P = 0.001). All metastatic tumors were ≥2.8 cm. Codons 161 and 167 were hotspots for VHL germline mutations with enhanced risk for metastatic PanNETs. Multivariate prediction modeling disclosed maximum tumor diameter and TVDT as significant predictors for metastatic disease (positive and negative predictive values of 51% and 100% for diameter cut-off ≥2.8 cm, 44% and 91% for TVDT cut-off of ≤24 months). In 117 of 273 patients, PanNETs >1.5 cm in diameter were operated. Ten-year survival was significantly longer in operated vs non-operated patients, in particular for PanNETs P = 0.020; 80% vs 50% at 10 years; P = 0.030). This study demonstrates that patients with PanNET approaching the cut-off diameter of 2.8 cm should be operated. Mutations in exon 3, especially of codons 161/167 are at enhanced risk for metastatic PanNETs. Survival is significantly longer in operated non-metastatic VHL-PanNETs.

Purpose Standard frontline treatment of patients with metastatic renal cell carcinoma currently includes sunitinib. A barrier to long-term treatment with sunitinib includes the development of significant adverse effects, including diarrhea, hand-foot syndrome (HFS), and fatigue. This trial assessed the effect of an alternate 2 weeks on, 1 week off (2/1) schedule of sunitinib on toxicity and efficacy in previously untreated patients with metastatic renal cell carcinoma. Methods Patients started with oral administration of 50 mg sunitinib on a 2/1 schedule and underwent schedule and dose alterations if toxicity developed. The primary end point was < 15% grade ≥ 3 fatigue, diarrhea, or HFS. With 60 patients, the upper bound of the CI would fall below the published 4/2 schedule grade ≥ 3 toxicity rate of 25% to 30%. Results Fifty-nine patients were treated between August 2014 and March 2016. Seventy-seven percent were intermediate or poor risk per Memorial Sloan Kettering Cancer Center criteria. With a median follow-up of 17 months, 25% of patients experienced grade 3 fatigue, HFS, or diarrhea; 37% required a dose reduction, and 10% discontinued because of toxicity. The overall response rate was 57%, median progression-free survival was 13.7 months, and median overall survival was not reached. At 12 weeks, Functional Assessment of Cancer Therapy–General scores dropped between 0% and 10% from baseline, with less reduction in patients who continued treatment longer. Conclusion The primary end point of decreased grade 3 toxicity was not met; however, treatment with a 2/1 sunitinib schedule is associated with a lack of grade 4 toxicity, a low patient discontinuation rate, and high efficacy.

Von Hippel-Lindau (VHL) disease is an autosomal dominant disease occurring in 1 in 35,000 births and leads to an increased risk of a phenotypically diverse array of tumor types including, but not limited to, clear cell renal cell carcinoma (ccRCC) and hemangioblastomas (HBs). Previous studies of patients with VHL disease treated with the tyrosine kinase inhibitor (TKI) sunitinib did not show clinical response in HBs. Interestingly, VHL-related HBs displayed increased fibroblast growth factor receptor 3 (FGFR3) protein expression when compared to VHL-related ccRCCs. Therefore, in this pilot study, we assessed the safety and efficacy profile of TKI 258 (dovitinib), a multi-tyrosine kinase inhibitor of VEGF receptor and fibroblast growth factor (FGF), in patients with VHL disease who had measureable HBs. The trial was stopped after six patients enrolled after the toxicity stopping rule was triggered. With regards to safety, 6/6 subjects had at least one adverse event (AE). Best response in 6/6 subjects was stable disease (SD) in HBs. While the negative safety and efficacy results of this pilot study do not favor the use of dovitinib for the treatment of asymptomatic HBs in VHL disease patients, further investigation into alternative scheduling and other FGFR inhibitors for the treatment of HBs in VHL disease patients is warranted given the promising pre-clinical and molecular data.

BACKGROUND : Bone metastasis is common in renal cell carcinoma (RCC), and the lesions are mainly osteolytic. The mechanism of bone destruction in RCC bone metastasis is unknown. METHODS : We used a direct intrafemur injection of mice with bone-derived 786-O RCC cells (Bo-786) as an in vivo model to study if inhibition of osteoblast differentiation is involved in osteolytic bone lesions in RCC bone metastasis. RESULTS : We showed that bone-derived Bo-786 cells induced osteolytic bone lesions in the femur of mice. We examined the effect of conditioned medium of Bo-786 cells (Bo-786 CM) on both primary mouse osteoblasts and MC3T3-E1 preosteoblasts and found that Bo-786 CM inhibited osteoblast differentiation. Secretome analysis of Bo-786 CM revealed that BIGH3 (Beta ig h3 protein), also known as TGFBI (transforming growth factor beta-induced protein), is highly expressed. We generated recombinant BIGH3 and found that BIGH3 inhibited osteoblast differentiation in vitro . In addition, CM from Bo-786 BIGH3 knockdown cells (786-BIGH3 KD) reduced the inhibition of osteoblast differentiation compared to CM from vector control. Intrafemural injection of mice with 786-BIGH3 KD cells showed a reduction in osteolytic bone lesions compared to vector control. Immunohistochemical staining of 18 bone metastasis specimens from human RCC showed strong BIGH3 expression in 11/18 (61%) and moderate BIGH3 expression in 7/18 (39%) of the specimens. CONCLUSIONS: These results suggest that suppression of osteoblast differentiation by BIGH3 is one of the mechanisms that enhance osteolytic lesions in RCC bone metastasis, and raise the possibilty that treatments that increase bone formation may improve therapy outcomes.

OBJECTIVE: Tumor shrinkage of at least 10% after presurgical targeted molecular therapy (TMT) in renal cell carcinoma (RCC) patients has been associated with better overall survival (OS) outcomes. We characterized primary and metastatic tumor diameter response and OS in patients with metastatic clear cell RCC (ccRCC) who received preoperative TMT, immunotherapy, or both followed by deferred cytoreductive nephrectomy (dCN). MATERIALS AND METHODS: Patients with metastatic ccRCC (n = 198) who underwent preoperative therapy and dCN from 2005 to 2019 were identified retrospectively. Longest primary and metastatic tumor diameters were calculated using cross-sectional images obtained before systemic therapy and dCN using the Response Evaluation Criteria in Solid Tumors. Patients were stratified by tumor shrinkage of at least 10% in the primary and/or metastatic tumors after systemic therapy. The Kaplan-Meier method was used to estimate OS, and Cox proportional hazards models were used to assess the association of patient characteristics with OS. RESULTS: In total, 31.31% of patients had only metastatic tumor shrinkage (MTS) ≥ 10%, 8.08% had only primary tumor shrinkage (PTS) ≥ 10%, 32.32% had PTS and MTS ≥ 10%, and 28.28% had PTS/MTS < 10%. The median OS, number of patients with tumor shrinkage ≥ 10%, and International Metastatic Database Consortium (IMDC) scores were similar among the three systemic therapy groups (all P ≥ 0.80). Patients with MTS ≥ 10%, PTS ≥ 10%, and PTS/MTS ≥ 10% had significantly longer median OS compared to patients with PTS/MTS < 10% (P < 0.01). Patients with intermediate-risk IMDC scores had significantly longer median OS compared to patients in the poor-risk group. After adjusting for preoperative therapy and IMDC risk group, MTS ≥ 10%, PTS ≥ 10%, and PTS/MTS ≥ 10% were associated with better OS outcomes (HR 0.48 95% CI 0.32–0.73, P < 0.001; HR 0.48, 95% CI 0.23–0.98, P = 0.04; HR 0.44, 95% CI 0.29–0.67, P < 0.001, respectively). CONCLUSIONS: Intermediate risk score and shrinkage of at least 10% in the primary tumor, metastases, or both were associated with better OS outcomes in patients with metastatic ccRCC who underwent dCN independent of the type of preoperative systemic therapy.

The presence of sarcomatoid features and/or lymph node-positive disease may be associated with a worse prognosis in chromophobe renal cell carcinoma (ChRCC). We sought to better characterize patients' long-term outcomes with these features compared with those without these features.We identified 300 patients treated for sporadic, unilateral, nonmetastatic ChRCC between 1993 and 2019. Clinical and pathologic features were summarized, and cancer-specific survival (CSS) and recurrence-free survival (RFS) were analyzed using Kaplan-Meier plots. Cox regression analysis was performed to determine factors associated with recurrence. Patients with sarcomatoid features and/or nodal disease were grouped as high-risk in a secondary analysis.The median age was 60 years, 43.7% were female, 29.3% had pT3/T4 disease, 3.3% had sarcomatoid features, and 4% had pathologic N1 disease. Sixteen patients were categorized as high-risk based on the presence of sarcomatoid features (n = 4), pathologic N1 disease (n = 6), or both (n = 6). There were 22 recurrences; the recurrence rate in the low-risk group was 4.9% and 50% in the high-risk group. 10-year RFS was 91.4% in the low-risk group and 34.4% in the high-risk group (P0.001). 10-year CSS was 96.4% in the low-risk group and 54.3% in the high-risk group (P0.001). In multivariable analysis, sarcomatoid features (HR 5.5, CI 1.5-20.2, P = 0.01) and pN1 disease (HR 16.5, CI 5.3-51.4, P0.0001) were independently associated with RFS.The presence of sarcomatoid features and/or lymph node-positive disease portends a poor prognosis in ChRCC. Further studies evaluating the impact of novel therapeutic agents in these patients are warranted.

BackgroundIn clear cell renal cell carcinoma (ccRCC) the constitutive expression of hypoxia induced factor 1-α leads to increased expression of AXL. AXL overexpression has been associated with the development of resistance to VEGF inhibitors and suppression of the innate immune response through inhibition of macrophage-driven inflammation. AVB-S6-500 (AVB-500) is recombinant fusion protein dimer containing an extracellular region of human AXL combined with the human immunoglobulin G1 heavy chain (Fc), which demonstrates highly potent, specific AXL inhibition. In mouse ccRCC xenograft models, AVB-500 showed significantly more tumor reduction in combination with pazopanib versus pazopanib alone. In a Ph1b study of AVB-500 plus chemotherapy in platinum-resistant ovarian cancer (NCT03639246), no dose limiting toxicity (DLT) or treatment discontinuation due to adverse events was observed. The recommended phase 2 dose (RP2D) of 15 mg/kg was established by a model-informed drug development (MIDD) approach.MethodsThe P1b portion of this trial is a 3+3 dose escalation study to evaluate safety, pharmacokinetics, and pharmacodynamics of AVB 500 in combination with cabozantinib 60 mg daily. Dose levels of AVB-500 may include 15, 20, and 25 mg/kg every two weeks. The primary objective is to evaluate safety and tolerability. Secondary objectives include identification of the RP2D of AVB-500 and clinical activity. Key eligibility criteria include clear cell histology RCC and at least one prior line of therapy administered in the advanced or metastatic setting.ResultsAs of July 21, 2021, seven patients have received at least one dose of AVB-500 15 mg/kg and cabozantinib, with six patients ongoing treatment. No DLTs were observed. Trough levels at C1D15 were above the minimally efficacious concentration (MEC) identified from MIDD and GAS6 (AXL ligand) levels were suppressed prior to C2D1. Partial responses were observed in 3 of 5 patients (table 1); all patients demonstrated tumor decrease from baseline.Abstract 424 Table 1Preliminary clinical activity in NCT04300140ConclusionsAVB-500 in combination with cabozantanib demonstrates promising preliminary clinical activity and tolerability in patients with ccRCC. AVB-500 15 mg/kg is the presumptive RP2D with C1D15 AVB-500 troughs consistently above MECs observed. Safety, PK/PD and clinical activity will be updated at the time of presentation. (NCT04300140)Ethics ApprovalThis study has obtained ethics approval from WIRB Institutional Review Board®, Protocol ID #20200159, and all subjects provided informed consent prior to taking part in this study.