The association of chemotherapy-induced peripheral neuropathy with reduced executive function in chemotherapy-treated cancer survivors: A cross-sectional study

INTRODUCTION

Chemotherapy-induced peripheral neuropathy (CIPN) is common and disabling among cancer survivors. Little is known about the association of CIPN with other measures of the nervous system's integrity, such as executive dysfunction. We compared measures of executive function in older chemotherapy-treated cancer survivors with and without CIPN.

MATERIALS AND METHODS

This cross-sectional study enrolled 50 chemotherapy-treated cancer survivors (65.6 ± 11.5 years, 88% female) post-chemotherapy treatment who were previously referred for outpatient rehabilitation at the request of the cancer survivor or a medical provider. Twenty-two participants (44%) had CIPN defined by patient-reported distal paresthesia or numbness, which began with chemotherapy and continued to the time of cognitive testing. Measures of executive function included Trails-B, Stroop, and rapid reaction accuracy (RRA) and were evaluated between cancer survivors with and without CIPN using t-tests. Multivariable models were then used to determine whether CIPN was an independent determinant of the measures of executive function (Trails-B, Stroop Incongruent, and RRA). Models were adjusted for age, sex, history of anxiety, and benzodiazepine use due to their known associations with CIPN and executive function.

RESULTS

Cancer survivors with CIPN (CIPN+) had reduced executive function compared to survivors without CIPN (CIPN-) on Trails-B (CIPN+: 84.9 s ± 44.1 s, CIPN-: 59.1 s ± 22.5 s, p = 0.01), Stroop (CIPN+: 100.6 s ± 38.2 s, CIPN-: 82.1 s ± 17.3 s, p = 0.03), and RRA (CIPN+: 60.3% ± 12.9%, CIPN-: 70.6% ± 15.7%, p = 0.01). There were no differences in cancer stage severity or functional status by patient report or sit-to-stand function. The association between CIPN and reduced executive function was found in multivariable models after adjusting for age, sex, anxiety, and benzodiazepine use for Trails-B (ß:17.9, p = 0.046), Stroop (ß:16.9, p = 0.02), and RRA (ß:-0.072, p = 0.03).

DISCUSSION

In this population, CIPN is associated with reduced executive function in older cancer survivors treated with chemotherapy. Future research is required to further understand this preliminary association, the causality, and the potential risk factors.

Executive function is associated with balance and falls in older cancer survivors treated with chemotherapy: A cross-sectional study

INTRODUCTION

Balance decrements and increased fall risk in older cancer survivors have been attributed to chemotherapy-induced peripheral neuropathy (CIPN). Cognition is also affected by chemotherapy and may be an additional contributing factor to poor balance through changes in executive functioning. We examined the association of executive function with balance and falls in older cancer survivors who had been treated with chemotherapy.

MATERIALS AND METHODS

Fifty cancer survivors (aged 65.6 ± 11.5 years; 88% female) who were all treated with chemotherapy were included in this cross-sectional study at a tertiary medical center. Executive function was measured by Trails-B, Stroop, and rapid reaction accuracy, a measure emphasizing rapid inhibitory function. Balance was measured by five sit-to-stand time (5STS), repetitions of sit-to-stand in thirty seconds (STS30), and unipedal stance time (UST), which was the primary balance outcome measure. Self-reported falls in the past year were also recorded and was a secondary outcome. Bivariate analyses were conducted between executive function measures and balance variables. Multivariable models were constructed for UST and falls outcomes and included covariates of age and chemotherapy induced peripheral neuropathy status.

RESULTS

Pearson correlations demonstrated significant relationships between two executive function measures (rapid reaction accuracy, Trails-B) and all the balance measures assessed (UST, STS30, and 5STS). Rapid reaction accuracy correlations were stronger than Trails-B. The Stroop measure correlated solely with UST. In multivariable models, rapid reaction accuracy was associated with better UST (standardized regression coefficient: 64.1, p < 0.01), decreased any fall (odds ratio = 0.000901, p = 0.04), and decreased recurrent falls (odds ratio = 0.0000044, p = 0.01). The interaction of CIPN with the inhibitory measures in the prediction of balance was not significant.

DISCUSSION

Measures of executive function were associated with balance, but among the executive function tests, rapid reaction accuracy had the strongest correlations to balance and was independently associated with falls. The findings suggest that executive function should be considered when assessing fall risk and developing interventions intended to reduce fall risk in older chemotherapy-treated cancer survivors.

Circulating and Intratumoral Immune Determinants of Response to Atezolizumab plus Bevacizumab in Patients with Variant Histology or Sarcomatoid Renal Cell Carcinoma

Renal cell carcinoma (RCC) of variant histology comprises approximately 20% of kidney cancer diagnoses, yet the optimal therapy for these patients and the factors that impact immunotherapy response remain largely unknown. To better understand the determinants of immunotherapy response in this population, we characterized blood- and tissue-based immune markers for patients with variant histology RCC, or any RCC histology with sarcomatoid differentiation, enrolled in a phase II clinical trial of atezolizumab and bevacizumab. Baseline circulating (plasma) inflammatory cytokines were highly correlated with one another, forming an "inflammatory module" that was increased in International Metastatic RCC Database Consortium poor-risk patients and was associated with worse progression-free survival (PFS; P = 0.028). At baseline, an elevated circulating vascular endothelial growth factor A (VEGF-A) level was associated with a lack of response (P = 0.03) and worse PFS (P = 0.021). However, a larger increase in on-treatment levels of circulating VEGF-A was associated with clinical benefit (P = 0.01) and improved overall survival (P = 0.0058). Among peripheral immune cell populations, an on-treatment decrease in circulating PD-L1+ T cells was associated with improved outcomes, with a reduction in CD4+PD-L1+ [HR, 0.62; 95% confidence interval (CI), 0.49-0.91; P = 0.016] and CD8+PD-L1+ T cells (HR, 0.59; 95% CI, 0.39-0.87; P = 0.009) correlated with improved PFS. Within the tumor itself, a higher percentage of terminally exhausted (PD-1+ and either TIM-3+ or LAG-3+) CD8+ T cells was associated with worse PFS (P = 0.028). Overall, these findings support the value of tumor and blood-based immune assessments in determining therapeutic benefit for patients with RCC receiving atezolizumab plus bevacizumab and provide a foundation for future biomarker studies for patients with variant histology RCC receiving immunotherapy-based combinations.

Upfront Cytoreductive Nephrectomy for Metastatic Renal Cell Carcinoma Treated with Immune Checkpoint Inhibitors or Targeted Therapy: An Observational Study from the International Metastatic Renal Cell Carcinoma Database Consortium

BACKGROUND

The role of upfront cytoreductive nephrectomy (CN) for metastatic renal cell carcinoma (mRCC) in the era of immune checkpoint inhibitors is unclear.

OBJECTIVE

To evaluate the relationship between upfront CN and clinical outcomes in the setting of mRCC treated with immune checkpoint inhibitors or targeted therapy.

DESIGN, SETTING, AND PARTICIPANTS

Using the International Metastatic RCC Database Consortium, we retrospectively identified patients diagnosed with de novo mRCC treated with immune checkpoint inhibitors or targeted therapy.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Overall survival (OS) was compared between the two groups using the Kaplan-Meier method and multivariable Cox regressions adjusting for known prognostic factors.

RESULTS AND LIMITATIONS

We identified a total of 4639 eligible patients with mRCC. Among the 4202 patients treated with targeted therapy and 437 patients treated with immune checkpoint inhibitors, 2326 (55%) and 234 (54%) patients received upfront CN prior to treatment start. In multivariable analyses, CN was associated with significantly better OS in both the immune checkpoint inhibitor-treated (hazard ratio [HR]: 0.61; 95% confidence interval [CI], 0.41-0.90, p = 0.013) and the targeted therapy treatment (HR: 0.72; 95% CI, 0.67-0.78, p < 0.001) group. There was no difference in OS benefit of CN between the immune checkpoint inhibitor and targeted therapy treatment groups (interaction p = 0.6). Limitations include selection of patients from large academic centers and the retrospective nature of the study.

CONCLUSIONS

Upfront CN is associated with a significant OS benefit in selected patients treated by either immune checkpoint inhibitors or targeted therapy, and still has a role in selected patients in the era of immune checkpoint inhibitors.

PATIENT SUMMARY

Before effective systemic therapies were available for metastatic kidney cancer, surgical removal of the primary (kidney) tumor was the mainstay of treatment. The role of removing the primary tumor has recently been called into question given that more effective systemic therapies have become available. In this study, we find that removal of the primary kidney tumor still has a benefit for selected patients treated with highly effective modern systemic therapies, including targeted therapies and immune checkpoint inhibitors.

Oncology clinical trial disruption during the COVID-19 pandemic: a COVID-19 and cancer outcomes study

Background

COVID-19 disproportionately impacted patients with cancer as a result of direct infection, and delays in diagnosis and therapy. Oncological clinical trials are resource-intensive endeavors that could be particularly susceptible to disruption by the pandemic, but few studies have evaluated the impact of the pandemic on clinical trial conduct.

Patients and methods

This prospective, multicenter study assesses the impact of the pandemic on therapeutic clinical trials at two large academic centers in the Northeastern United States between December 2019 and June 2021. The primary objective was to assess the enrollment on, accrual to, and activation of oncology therapeutic clinical trials during the pandemic using an institution-wide cohort of (i) new patient accruals to oncological trials, (ii) a manually curated cohort of patients with cancer, and (ii) a dataset of new trial activations.

Results

The institution-wide cohort included 4756 new patients enrolled to clinical trials from December 2019 to June 2021. A major decrease in the numbers of new patient accruals (−46%) was seen early in the pandemic, followed by a progressive recovery and return to higher-than-normal levels (+2.6%). A similar pattern (from −23.6% to +30.4%) was observed among 467 newly activated trials from June 2019 to June 2021. A more pronounced decline in new accruals was seen among academically sponsored trials (versus industry sponsored trials) (P < 0.05). In the manually curated cohort, which included 2361 patients with cancer, non-white patients tended to be more likely taken off trial in the early pandemic period (adjusted odds ratio: 2.60; 95% confidence interval 1.00-6.63), and substantial pandemic-related deviations were recorded.

Conclusions

Substantial disruptions in clinical trial activities were observed early during the pandemic, with a gradual recovery during ensuing time periods, both from an enrollment and an activation standpoint. The observed decline was more prominent among academically sponsored trials, and racial disparities were seen among people taken off trial.

Integrative clinical and molecular characterization of translocation renal cell carcinoma

Translocation renal cell carcinoma (tRCC) is a poorly characterized subtype of kidney cancer driven by MiT/TFE gene fusions. Here, we define the landmarks of tRCC through an integrative analysis of 152 patients with tRCC identified across genomic, clinical trial, and retrospective cohorts. Most tRCCs harbor few somatic alterations apart from MiT/TFE fusions and homozygous deletions at chromosome 9p21.3 (19.2% of cases). Transcriptionally, tRCCs display a heightened NRF2-driven antioxidant response that is associated with resistance to targeted therapies. Consistently, we find that outcomes for patients with tRCC treated with vascular endothelial growth factor receptor inhibitors (VEGFR-TKIs) are worse than those treated with immune checkpoint inhibitors (ICI). Using multiparametric immunofluorescence, we find that the tumors are infiltrated with CD8⁺ T cells, though the T cells harbor an exhaustion immunophenotype distinct from that of clear cell RCC. Our findings comprehensively define the clinical and molecular features of tRCC and may inspire new therapeutic hypotheses.

Detecting neuroendocrine prostate cancer through tissue-informed cell-free DNA methylation analysis

PURPOSE

Neuroendocrine prostate cancer (NEPC) is a resistance phenotype that emerges in men with metastatic castration-resistant prostate adenocarcinoma (CR-PRAD) and has important clinical implications, but is challenging to detect in practice. Herein, we report a novel tissue-informed epigenetic approach to non-invasively detect NEPC.

EXPERIMENTAL DESIGN

We first performed methylated immunoprecipitation and high-throughput sequencing (MeDIP-seq) on a training set of tumors, identified differentially methylated regions between NEPC and CR-PRAD, and built a model to predict the presence of NEPC (termed NEPC Risk Score). We then performed MeDIP-seq on cell-free DNA (cfDNA) from two independent cohorts of men with NEPC or CR-PRAD and assessed the accuracy of the model to predict the presence NEPC.

RESULTS

The test cohort comprised cfDNA samples from 48 men, 9 with NEPC and 39 with CR-PRAD. NEPC Risk Scores were significantly higher in men with NEPC than CR-PRAD (P=4.3x10^-7) and discriminated between NEPC and CR-PRAD with high accuracy (AUROC 0.96). The optimal NEPC Risk Score cut-off demonstrated 100% sensitivity and 90% specificity for detecting NEPC. The independent, multi-institutional validation cohort included cfDNA from 53 men, including 12 with NEPC and 41 with CR-PRAD. NEPC Risk Scores were significantly higher in men with NEPC than CR-PRAD (P=7.5x10^-12) and perfectly discriminated NEPC from CR-PRAD (AUROC 1.0). Applying the pre-defined NEPC Risk Score cut-off to the validation cohort resulted in 100% sensitivity and 95% specificity for detecting NEPC.

CONCLUSIONS

Tissue-informed cfDNA methylation analysis is a promising approach for non-invasive detection of NEPC in men with advanced prostate cancer.

Prognostic significance and immune correlates of CD73 expression in renal cell carcinoma

Background

CD73–adenosine signaling in the tumor microenvironment is immunosuppressive and may be associated with aggressive renal cell carcinoma (RCC). We investigated the prognostic significance of CD73 protein expression in RCC leveraging nephrectomy samples. We also performed a complementary analysis using The Cancer Genome Atlas (TCGA) dataset to evaluate the correlation of CD73 (ecto-5′-nucleotidase (NT5E), CD39 (ectonucleoside triphosphate diphosphohydrolase 1 (ENTPD1)) and A2 adenosine receptor (A2AR; ADORA2A) transcript levels with markers of angiogenesis and antitumor immune response.

Methods

Patients with RCC with available archived nephrectomy samples were eligible for inclusion. Tumor CD73 protein expression was assessed by immunohistochemistry and quantified using a combined score (CS: % positive cells×intensity). Samples were categorized as CD73_negative (CS=0), CD73_low or CD73_high (< and ≥median CS, respectively). Multivariable Cox regression analysis compared disease-free survival (DFS) and overall survival (OS) between CD73 expression groups. In the TCGA dataset, samples were categorized as low, intermediate and high NT5E, ENTPD1 and ADORA2A gene expression groups. Gene expression signatures for infiltrating immune cells, angiogenesis, myeloid inflammation, and effector T-cell response were compared between NT5E, ENTPD1 and ADORA2A expression groups.

Results

Among the 138 patients eligible for inclusion, ‘any’ CD73 expression was observed in 30% of primary tumor samples. High CD73 expression was more frequent in patients with M1 RCC (29% vs 12% M0), grade 4 tumors (27% vs 13% grade 3 vs 15% grades 1 and 2), advanced T-stage (≥T3: 22% vs T2: 19% vs T1: 12%) and tumors with sarcomatoid histology (50% vs 12%). In the M0 cohort (n=107), patients with CD73_high tumor expression had significantly worse 5-year DFS (42%) and 10-year OS (22%) compared with those in the CD73_negative group (DFS: 75%, adjusted HR: 2.7, 95% CI 1.3 to 5.9, p=0.01; OS: 64%, adjusted HR: 2.6, 95% CI 1.2 to 5.8, p=0.02) independent of tumor stage and grade. In the TCGA analysis, high NT5E expression was associated with significantly worse 5-year OS (p=0.008). NT5E and ENTPD1 expression correlated with higher regulatory T cell (Treg) signature, while ADORA2A expression was associated with increased Treg and angiogenesis signatures.

Conclusions

High CD73 expression portends significantly worse survival outcomes independent of stage and grade. Our findings provide compelling support for targeting the immunosuppressive and proangiogenic CD73–adenosine pathway in RCC.

Development and initial clinical testing of a multiplexed circulating tumor cell assay in patients with clear cell renal cell carcinoma

Although therapeutic options for patients with advanced renal cell carcinoma (RCC) have increased in the past decade, no biomarkers are yet available for patient stratification or evaluation of therapy resistance. Given the dynamic and heterogeneous nature of clear cell RCC (ccRCC), tumor biopsies provide limited clinical utility, but liquid biopsies could overcome these limitations. Prior liquid biopsy approaches have lacked clinically relevant detection rates for patients with ccRCC. This study employed ccRCC-specific markers, CAIX and CAXII, to identify circulating tumor cells (CTC) from patients with metastatic ccRCC. Distinct subtypes of ccRCC CTCs were evaluated for PD-L1 and HLA-I expression and correlated with patient response to therapy. CTC enumeration and expression of PD-L1 and HLA-I correlated with disease progression and treatment response, respectively. Longitudinal evaluation of a subset of patients demonstrated potential for CTC enumeration to serve as a pharmacodynamic biomarker. Further evaluation of phenotypic heterogeneity among CTCs is needed to better understand the clinical utility of this new biomarker.

Care disruptions among patients with lung cancer: A COVID-19 and cancer outcomes study

Introduction

Patients with lung cancer (LC) are susceptible to severe outcomes from COVID-19. This study evaluated disruption to care of patients with LC during the COVID-19 pandemic.

Methods

The COVID-19 and Cancer Outcomes Study (CCOS) is a prospective cohort study comprised of patients with a current or past history of hematological or solid malignancies with outpatient visits between March 2 and March 6, 2020, at two academic cancer centers in the Northeastern United States (US). Data was collected for the three months prior to the index week (baseline period) and the following three months (pandemic period).

Results

313 of 2365 patients had LC, 1578 had other solid tumors, and 474 had hematological malignancies. Patients with LC were not at increased risk of COVID-19 diagnosis compared to patients with other solid or hematological malignancies. When comparing data from the pandemic period to the baseline period, patients with LC were more likely to have a decrease in in-person visits compared to patients with other solid tumors (aOR 1.94; 95% CI, 1.46–2.58), but without an increase in telehealth visits (aOR 1.13; 95% CI 0.85–1.50). Patients with LC were more likely to experience pandemic-related treatment delays than patients with other solid tumors (aOR 1.80; 95% CI 1.13–2.80) and were more likely to experience imaging/diagnostic procedure delays than patients with other solid tumors (aOR 2.59; 95% CI, 1.46–4.47) and hematological malignancies (aOR 2.01; 95% CI, 1.02–3.93). Among patients on systemic therapy, patients with LC were also at increased risk for decreased in-person visits and increased treatment delays compared to those with other solid tumors.

Discussion

Patients with LC experienced increased cancer care disruption compared to patients with other malignancies during the early phase of the COVID-19 pandemic. Focused efforts to ensure continuity of care for this patient population are warranted.

Abstract S06-02: Disruption to care of patients with thoracic malignancies: A COVID-19 and cancer outcomes study

Introduction: Patients with thoracic malignancies are susceptible to severe outcomes from coronavirus disease 2019 (COVID-19). The aim of this study was to evaluate the disruption to care of patients with thoracic malignancies during the COVID-19 pandemic. Methods: The COVID-19 and Cancer Outcomes Study (CCOS) is a multicenter prospective cohort study comprised of adult patients with a current or past history of hematological malignancy or invasive solid tumor who had an outpatient medical oncology visit on the index week between March 2 and March 6, 2020 at the Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai in New York, NY (MSSM) or the Dana-Farber Cancer Institute in Boston, MA (DFCI). An electronic data capture platform was used to collect patient-, cancer-, and treatment-related variables during the three months prior to the index week (the baseline period) and the following three months (the pandemic period). Two-by-three contingency tables with Fisher’s exact tests were computed. All tests were two-tailed and considered statistically significant for p&lt;0.05. All analyses were done in the R statistical environment (v3.6.1). Results: The overall cohort included 2365 patients, of which 313 had thoracic malignancies, 1578 had other solid tumors, and 474 had hematological malignancies. At a median follow-up of 84 days (95% confidence interval, 82-84), 13 patients with thoracic malignancies (4.1%) had developed COVID-19 (vs. other solid: 63 [4.0%] and hematological: 52 [11.0%]; p&lt;0.001). When comparing data from the pandemic period to the baseline period, patients with thoracic malignancies had a decrease in the number of in-person outpatient visits (thoracic: 209 [66.8%] vs. other solid: 749 [47.5%] vs. hematological: 260 [54.9%]; p&lt;0.001) and an increase in the number of telehealth visits (thoracic: 126 [40.3%] vs. other solid: 465 [29.5%] vs. hematological: 168 [35.4%]; p&lt;0.001). During the pandemic period, 33 (10.5%) patients with thoracic malignancies experienced treatment delays due to the pandemic (vs. other solid: 127 [8.0%] and hematological: 79 [16.7%]; p&lt;0.001), and 26 (8.3%) patients with thoracic malignancies experienced delays in cancer imaging or diagnostic procedures (vs. other solid: 63 [4.0%] and hematological: 26 [5.5%]; p=0.003). Discussion: In this prospective cohort study, patients with thoracic malignancies were not at increased risk of developing COVID-19 compared to patients with other cancers, but experienced significant cancer care disruption during the COVID-19 pandemic with a higher likelihood of decreased in-person visits and increased telehealth visits compared to patients with other malignancies. Focused efforts to ensure continuity of care for this vulnerable patient population are warranted.

Citation Format: Sheena Bhalla, Ziad Bakouny, Andrew L. Schmidt, John A. Steinharter, Douglas A. Tremblay, Mark M. Awad, Alaina J. Kessler, Robert I. Haddad, Michelle Evans, Fiona Busser, Michael Wotman, Catherine R. Curran, Brittney S. Zimmerman, Gabrielle Bouchard, Tomi Jun, Pier V. Nuzzo, Qian Qin, Laure Hirsch, Jonathan Feld, Kaitlin M Kelleher, Danielle Seidman, Hsin-Hui Huang, Chris Labaki, Heather M. Anderson-Keightly, Sarah Abou Alaiwi, Talia D. Rosenbloom, Penina S. Stewart, Matthew D. Galsky, Toni K. Choueiri, Deborah B. Doroshow. Disruption to care of patients with thoracic malignancies: A COVID-19 and cancer outcomes study [abstract]. In: Proceedings of the AACR Virtual Meeting: COVID-19 and Cancer; 2021 Feb 3-5. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(6_Suppl):Abstract nr S06-02.

Integrative molecular characterization of sarcomatoid and rhabdoid renal cell carcinoma

Sarcomatoid and rhabdoid (S/R) renal cell carcinoma (RCC) are highly aggressive tumors with limited molecular and clinical characterization. Emerging evidence suggests immune checkpoint inhibitors (ICI) are particularly effective for these tumors, although the biological basis for this property is largely unknown. Here, we evaluate multiple clinical trial and real-world cohorts of S/R RCC to characterize their molecular features, clinical outcomes, and immunologic characteristics. We find that S/R RCC tumors harbor distinctive molecular features that may account for their aggressive behavior, including BAP1 mutations, CDKN2A deletions, and increased expression of MYC transcriptional programs. We show that these tumors are highly responsive to ICI and that they exhibit an immune-inflamed phenotype characterized by immune activation, increased cytotoxic immune infiltration, upregulation of antigen presentation machinery genes, and PD-L1 expression. Our findings build on prior work and shed light on the molecular drivers of aggressivity and responsiveness to ICI of S/R RCC.

Sarcomatoid and rhabdoid tumours are highly aggressive forms of renal cell carcinoma that are also responsive to immunotherapy. In this study, the authors perform a comprehensive molecular characterization of these tumours discovering an enrichment of specific alterations and an inflamed phenotype.

The COVID-19 and Cancer Consortium: A Collaborative Effort to Understand the Effects of COVID-19 on Patients with Cancer

National and international consortia will play a key role in understanding the effects of the coronavirus disease 2019 (COVID-19) pandemic on cancer patients. The COVID-19 and Cancer Consortium (CCC19) aims to collect and analyze observational data at scale to inform clinical practice in real-time.

Detection of urothelial carcinoma using plasma cell-free methylated DNA

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Background: Methylation profiling of circulating cell-free DNA (cfDNA) is a promising approach for non-invasive tumor detection due to the presence of tissue-specific epigenetic signatures that are detectable in cfDNA. Cell-free methylated DNA immunoprecipitation and high-throughput sequencing (cfMedDIP-seq) is a sensitive, low-input, cost-effective, bisulfite-free approach to profiling cfDNA methylomes, capable of detecting and classifying various tumor types. We tested the feasibility of cfMeDIP-seq to detect urothelial carcinoma (UC) in plasma samples. Methods: We performed cfMeDIP-seq on plasma samples from 43 patients (pts): 18 metastatic UC (UC) pts, 12 pre-cystectomy non-metastatic UC pts, and 13 cancer-free controls. Six (50%) of pre-cystectomy cases were non-muscle invasive UC. cfDNA was immunoprecipitated and enriched using an antibody targeting 5-methylcytosine and PCR-amplified to create a sequence-ready library. The top differentially methylated regions (DMRs) between UC and control samples were used to train a regularized binomial generalized linear model using 80% of the samples as a training set. The 20% of withheld test samples were then assigned a probability of being UC or control. This process was repeated 100 times. Results: The average amount (standard deviation) of cfDNA isolated from 1 ml of UC plasma samples was 29.2 (27.4) ng/µL and 8.02 (3.58) ng/µL in cancer-free controls. We identified 9,826 DMRs in plasma samples at an adjusted p-value of < 0.01, which partitioned UC and control samples. Iterative training and classification of held out samples using the top 300 DMRs resulted in a mean AUROC of 0.987. Conclusions: cfMeDIP-seq is an interesting new approach for non-invasive detection of UC. cfMeDIP-seq demonstrates high sensitivity to detect UC across all stages of UC, including non-muscle invasive disease.

Plasma IL-8 and PD-L1 and overall survival in metastatic castration-resistant prostate cancer patients (mCRPC)

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Background: We previously reported the significant prognostic and predictive utility of pretreatment serum PD-L1 in the CCTG MA.31 breast cancer serum bank (SABCS 2018, abstr PD3-10). IL-8 (CXCL8) is a pro-inflammatory cytokine that binds to CXCR1 and CXCR2 and promotes tumor immune escape and progression. High serum IL-8 levels are associated with poor prognosis in many cancers, and have recently been reported to predict for reduced overall survival (OS) to nivolumab in lung cancer and melanoma (ASCO 2018, abstr #3025). Here we correlated plasma IL-8 and PD-L1 levels with OS in mCRPC patients. Methods: 201 metastatic CRPC patients had EDTA plasma available for this retrospective analysis. Patient eligibility included chemotherapy-naive mCRPC patients. The ELLA immunoassay platform (ProteinSimple, San Jose, CA) was utilized to quantitate plasma IL-8 and PD-L1. Cox regression assessed hazard ratio (HR) for OS using both categorical (median) and continuous (log-transformed) biomarkers. Results: In univariate analysis, higher plasma IL-8 levels were significantly associated with reduced OS when analyzed as a continuous variable (HR = 1.53; p = 0.003) and were of borderline significance at the median cutpoint (HR = 1.32; p = 0.069; 20.9 vs 31.5 mos median OS). Plasma PD-L1 levels were not significantly associated with OS when analyzed as a continuous variable (p = 0.17), but increased levels were significant when analyzed at the median cutpoint (HR = 1.36; p = 0.044; 21.9 vs 29.0 mos median OS). When plasma IL-8 and PD-L1 levels were combined (median cutpoints), plasma IL-8 high / PD-L1 high patients (n = 58) had a significantly shorter OS vs the plasma IL-8 low / PD-L1 low patients (n = 58) (HR = 1.69; p = 0.009; 19.3 vs 32.9 mos median OS, respectively). In multivariate analysis, when adjusted for biopsy Gleason score, age, PSA, and ECOG PS (all at time of blood draw), only high plasma IL-8 (on a continuous basis) was significantly associated with reduced OS (HR = 1.43; p = 0.019). Conclusions: In mCRPC patients, high plasma IL-8 and PD-L1 levels were associated with reduced OS (separately and combined). Circulating IL-8 and PD-L1 evaluation may inform prognosis in mCRPC and could be considered as biomarkers in future studies determining response to immune checkpoint inhibitor and anti-IL8 therapy.

Mammalian SWI/SNF Complex Genomic Alterations and Immune Checkpoint Blockade in Solid Tumors

Prior data have variably implicated the inactivation of the mammalian SWItch/Sucrose Non-Fermentable (mSWI/SNF) complex with increased tumor sensitivity to immune checkpoint inhibitors (ICI). Herein, we examined the association between mSWI/SNF variants and clinical outcomes to ICIs. We correlated somatic loss-of-function (LOF) variants in a predefined set of mSWI/SNF genes (ARID1A, ARID1B, SMARCA4, SMARCB1, PBRM1, and ARID2) with clinical outcomes in patients with cancer treated with systemic ICIs. We identified 676 patients from Dana-Farber Cancer Institute (DFCI, Boston, MA) and 848 patients from a publicly available database from Memorial Sloan Kettering Cancer Center (MSKCC, New York, NY) who met the inclusion criteria. Multivariable analyses were conducted and adjusted for available baseline factors and tumor mutational burden. Median follow-up was 19.6 (17.6-22.0) months and 28.0 (25.0-29.0) months for the DFCI and MSKCC cohorts, respectively. Seven solid tumor subtypes were examined. In the DFCI cohort, LOF variants of mSWI/SNF did not predict improved overall survival (OS), time-to-treatment failure (TTF), or disease control rate. Only patients with renal cell carcinoma with mSWI/SNF LOF showed significantly improved OS and TTF with adjusted HRs (95% confidence interval) of 0.33 (0.16-0.7) and 0.49 (0.27-0.88), respectively, and this was mostly driven by PRBM1 In the MSKCC cohort, where only OS was captured, LOF mSWI/SNF did not correlate with improved outcomes across any tumor subtype. We did not find a consistent association between mSWI/SNF LOF variants and improved clinical outcomes to ICIs, suggesting that mSWI/SNF variants should not be considered as biomarkers of response to ICIs.

Integrative molecular characterization of sarcomatoid and rhabdoid renal cell carcinoma (S/R RCC) to reveal potential determinants of poor prognosis and response to immune checkpoint inhibitors (ICI)

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Background: S/R RCC are highly aggressive tumors but recent pilot clinical data have suggested that these tumors respond well to ICI. Our aim was to perform integrative molecular characterization of S/R RCC tumors in order to characterize potential features that underlie their poor prognosis and responses to ICI. Methods: We compared genomic (1), transcriptomic (2) and immune microenvironment (3) data between S/R and non-S/R tumors. (1) S/R patients from 3 cohorts [N = 209]: The Cancer Genome Atlas [TCGA], CheckMate 010/025 & panel sequencing from Dana-Farber/Harvard Cancer Center [DF/HCC]. (2) RNA-seq on S/R from 2 cohorts [N = 98]: TCGA & CheckMate 010/025. (3) Immunofluorescence for CD8+ T cells [N = 17] & Immunohistochemistry for PD-L1 expression on tumor cells [N = 118] from CheckMate 010/025. Overall Response Rate (ORR), Progression Free Survival (PFS), and Overall Survival (OS) in S/R RCC was compared between ICI and non-ICI in clinical cohorts (Table). Results: S/R tumors were significantly enriched in mutations in BAP1, NF2, RELN, and MUTYH, deletions of CDKN2A/B & amplifications of EZH2 (q < 0.05) compared to non-S/R tumors. Gene Set Enrichment Analysis showed upregulation of epithelial-mesenchymal transition, immune pathways, and proliferation programs compared to non-S/R tumors in both RNA-seq cohorts independently (q < 0.25). S/R tumors exhibited greater infiltration by CD8+ T cells at the tumor margin (p = 0.048) and PD-L1 expression on tumor cells (43.2% vs 21.0%, p < 0.01) compared to non-S/R. S/R had improved ORR, PFS, and OS on ICI vs. non-ICI (Table). Conclusions: S/R RCC tumors have distinctive molecular features that may account for their association with poor prognosis and outcomes on ICI.[Table: see text]

Cytoreductive nephrectomy (CN) for metastatic renal cell carcinoma (mRCC) treated with immune checkpoint inhibitors (ICI) or targeted therapy (TT): A propensity score-based analysis

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Background: The role of CN for mRCC treated with ICI is not well defined. Our aim was to evaluate the role of CN for mRCC treated by ICI or TT using a propensity score-based analysis. Methods: We retrospectively assessed patients who were diagnosed with de novo mRCC and who had started first line systemic therapy (ICI or TT) between 2009 and 2019 using the International Metastatic RCC Database Consortium (IMDC). Overall Survival (OS) was compared between patients receiving CN and those treated by systemic therapies alone, using the Kaplan-Meier method and Cox regressions, in the TT and ICI arms separately. In order to account for treatment selection bias, inverse probability of treatment weighting (IPTW) of propensity scores, based on 14 confounding variables, was used and variables were considered balanced if standardized mean difference (SMD) < 0.1. For variables with SMD≥0.1, residual confounding was adjusted for using multivariable models. Results: 3856 patients had been treated by TT (2470 CN+ & 1386 CN-) and 198 by ICI (143 CN+ & 55 CN-). Median follow-up was 38.5 months. After IPTW, baseline characteristics were largely balanced between the CN+ and CN- arms, in the TT and ICI groups (14/14 and 12/14 with SMD < 0.1, respectively). CN was associated with significantly improved OS in both the ICI (Hazard Ratio [HR] = 0.39 [0.19-0.83]) and TT (HR = 0.56 [0.51-0.62]) groups. The interaction term between CN and therapy type (ICI vs TT) was not statistically significant (p = 0.43). The point estimates of the HRs were consistent in sensitivity analyses using multivariable models. Conclusions: In a propensity score-based analysis, CN was found to be associated with a significant OS benefit in patients treated by either ICI or TT. While this study is not a substitute for randomized controlled trials (e.g. CARMENA), the results suggest that CN may still play a role in selected patients in the ICI era.[Table: see text]

Circulating immune cell populations and cytokines in patients with metastatic variant histology renal cell carcinoma (vRCC) treated with atezolizumab plus bevacizumab (AB): Dynamic changes on therapy and association with outcomes from a phase II trial

740

Background: Metastatic vRCC are aggressive tumors with poor prognosis. Our phase 2 trial of AB in vRCC showed a response rate of 33%. We investigated on-therapy changes in circulating immune cells and cytokines and their association with outcomes. Methods: Blood was collected at baseline (C1D1) and on-therapy (C3D1). Peripheral blood mononuclear cells were analyzed for cell type, expression of immune checkpoints, markers of activation, proliferation and function using flow cytometry; circulating cytokines by multiplex immunoassay. Relationship with progression-free (PFS) and overall survival (OS) was assessed by cox regression models. Results: Baseline and on-therapy samples were collected from all 60 patients. High baseline levels of immunosuppressive cytokines IL1α, IL6, CCL4 and IL13, as well as high baseline levels of CD4+ lymphocytes expressing CD69, were associated with inferior PFS and OS (Table). However, a decline in these markers on-therapy was not predictive of outcomes. On-therapy assessments showed an increase in the IFN-γ inducible cytokine CXCL10 (p<0.0001) as well as an increase in VEGF-A (p<0.0001) consistent with induction of antitumor immunity and inhibition of angiogenesis. A decrease in PD-L1 expression on circulating CD8+ lymphocytes was associated with shorter PFS and OS (Table), suggesting a potential resistance mechanism. Conclusions: High baseline levels of immunosuppressive cytokines and CD4+ CD69+ lymphocytes portended worse survival in patients treated with AB. Early changes in PD-L1 expression on circulating CD8+ lymphocytes may inform resistance to therapy. Correlation of circulating and tissue-based biomarkers is ongoing. Clinical trial information: NCT02724878. [Table: see text]

Safety and efficacy of restarting immune checkpoint inhibitors after clinically significant immune-related adverse events in metastatic renal cell carcinoma

BACKGROUND

Immune checkpoint inhibitors (ICI) induce a range of immune-related adverse events (irAEs) with various degrees of severity. While clinical experience with ICI retreatment following clinically significant irAEs is growing, the safety and efficacy are not yet well characterized.

METHODS

This multicenter retrospective study identified patients with metastatic renal cell carcinoma treated with ICI who had >1 week therapy interruption for irAEs. Patients were classified into retreatment and discontinuation cohorts based on whether or not they resumed an ICI. Toxicity and clinical outcomes were assessed descriptively.

RESULTS

Of 499 patients treated with ICIs, 80 developed irAEs warranting treatment interruption; 36 (45%) of whom were restarted on an ICI and 44 (55%) who permanently discontinued. Median time to initial irAE was similar between the retreatment and discontinuation cohorts (2.8 vs 2.7 months, p=0.59). The type and grade of irAEs were balanced across the cohorts; however, fewer retreatment patients required corticosteroids (55.6% vs 84.1%, p=0.007) and hospitalizations (33.3% vs 65.9%, p=0.007) for irAE management compared with discontinuation patients. Median treatment holiday before reinitiation was 0.9 months (0.2-31.6). After retreatment, 50% (n=18/36) experienced subsequent irAEs (12 new, 6 recurrent) with 7 (19%) grade 3 events and 13 drug interruptions. Median time to irAE recurrence after retreatment was 2.8 months (range: 0.3-13.8). Retreatment resulted in 6 (23.1%) additional responses in 26 patients whose disease had not previously responded. From first ICI initiation, median time to next therapy was 14.2 months (95% CI 8.2 to 18.9) and 9.0 months (5.3 to 25.8), and 2-year overall survival was 76% (95%CI 55% to 88%) and 66% (48% to 79%) in the retreatment and discontinuation groups, respectively.

CONCLUSIONS

Despite a considerable rate of irAE recurrence with retreatment after a prior clinically significant irAE, most irAEs were low grade and controllable. Prospective studies are warranted to confirm that retreatment enhances survival outcomes that justify the safety risks.

Real-World Assessment of Clinical Outcomes Among First-Line Sunitinib Patients with Clear Cell Metastatic Renal Cell Carcinoma (mRCC) by the International mRCC Database Consortium Risk Group

BACKGROUND

International Metastatic Renal Cell Carcinoma (mRCC) Database Consortium (IMDC) risk groups are important when considering therapeutic options for first-line treatment.

MATERIALS AND METHODS

Adult patients with clear cell mRCC initiating first-line sunitinib between 2010 and 2018 were included in this retrospective database study. Median time to treatment discontinuation (TTD) and overall survival (OS) were estimated using Kaplan-Meier analysis. Outcomes were stratified by IMDC risk groups and evaluated for those in the combined intermediate and poor risk group and separately for those in the intermediate risk group with one versus two risk factors.

RESULTS

Among 1,769 patients treated with first-line sunitinib, 318 (18%) had favorable, 1,031 (58%) had intermediate, and 420 (24%) had poor IMDC risk. Across the three risk groups, patients had similar age, gender, and sunitinib initiation year. Median TTD was 15.0, 8.5, and 4.2 months in the favorable, intermediate, and poor risk groups, respectively, and 7.1 months in the combined intermediate and poor risk group. Median OS was 52.1, 31.5, and 9.8 months in the favorable, intermediate, and poor risk groups, respectively, and 23.2 months in the combined intermediate and poor risk group. Median OS (35.1 vs. 21.9 months) and TTD (10.3 vs. 6.6 months) were significantly different between intermediate risk patients with one versus two risk factors.

CONCLUSION

This real-world study found a median OS of 52 months for patients with favorable IMDC risk treated with first-line sunitinib, setting a new benchmark on clinical outcomes of clear cell mRCC. Analysis of intermediate risk group by one or two risk factors demonstrated distinct clinical outcomes.

IMPLICATIONS FOR PRACTICE

This analysis offers a contemporary benchmark for overall survival (median, 52.1 months; 95% confidence interval, 43.4-61.2) among patients with clear cell metastatic renal cell carcinoma who were treated with sunitinib as first-line therapy in a real-world setting and classified as favorable risk according to International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) risk group classification. This study demonstrates that clinical outcomes differ between IMDC risk groups as well as within the intermediate risk group based on the number of risk factors, thus warranting further consideration of risk group when counseling patients about therapeutic options and designing clinical trials.

Results of a Multicenter Phase II Study of Atezolizumab and Bevacizumab for Patients With Metastatic Renal Cell Carcinoma With Variant Histology and/or Sarcomatoid Features

PURPOSE

In this multicenter phase II trial, we evaluated atezolizumab combined with bevacizumab in patients with advanced renal cell carcinoma (RCC) with variant histology or any RCC histology with ≥ 20% sarcomatoid differentiation.

PATIENTS AND METHODS

Eligible patients may have received previous systemic therapy, excluding prior bevacizumab or checkpoint inhibitors. Patients underwent a baseline biopsy and received atezolizumab 1,200 mg and bevacizumab 15 mg/kg intravenously every 3 weeks. The primary end point was overall response rate (ORR) by RECIST version 1.1. Additional end points were progression-free survival (PFS), toxicity, biomarkers of response as determined by programmed death-ligand 1 (PD-L1) status, and on-therapy quality-of-life (QOL) metrics using the Functional Assessment of Cancer Therapy Kidney Symptom Index-19 and the Brief Fatigue Inventory.

RESULTS

Sixty patients received at least 1 dose of either study agent; the majority (65%) were treatment naïve. The ORR for the overall population was 33% and 50% in patients with clear cell RCC with sarcomatoid differentiation and 26% in patients with variant histology RCC. Median PFS was 8.3 months (95% CI, 5.7 to 10.9 months). PD-L1 status was available for 36 patients; 15 (42%) had ≥ 1% expression on tumor cells. ORR in PD-L1-positive patients was 60% (n = 9) v 19% (n = 4) in PD-L1-negative patients. Eight patients (13%) developed treatment-related grade 3 toxicities. There were no treatment-related grade 4-5 toxicities. QOL was maintained throughout therapy.

CONCLUSION

In this study, atezolizumab and bevacizumab demonstrated safety and resulted in objective responses in patients with variant histology RCC or RCC with ≥ 20% sarcomatoid differentiation. This regimen warrants additional exploration in patients with rare RCC, particularly those with PD-L1-positive tumors.

Atezolizumab plus bevacizumab in non-clear cell renal cell carcinoma (NccRCC) and clear cell renal cell carcinoma with sarcomatoid differentiation (ccRCCsd): Updated results of activity and predictive biomarkers from a phase II study

4583

Background: NccRCC and ccRCCsd are aggressive tumors associated with poor prognosis and response to therapy. Combination strategies co-targeting VEGF signaling and inhibitory immune checkpoints are highly active in clear-cell renal cell carcinoma, but data is lacking in NccRCC and ccRCCsd. We conducted a multicenter, open-label, single arm phase II trial of atezolizumab plus bevacizumab in NccRCC and ccRCCsd. Methods: Patients with NccRCC and ccRCCsd ( > 20% sarcomatoid differentiation), and ECOG performance status of 0-2 were eligible. Prior systemic treatment was allowed with the exception of prior PD-1/PD-L1-directed therapy. Atezolizumab 1200mg and bevacizumab 15mg/kg were administered every 3 weeks until progression, unacceptable toxicity, or patient withdrawal. Primary endpoint was objective response rate (ORR) per RECIST 1.1. Exploratory biomarker analyses included PD-L1 expression on tumor (TC) and immune cells (IC), and spatial analysis of the immune infiltrate. Results: Sixty patients received at least 1 cycle of treatment, among whom 56 were evaluable for response (17 ccRCCsd and 39 NccRCC). ORR was 34% in the overall population, 53% in ccRCCsd and 26% in NccRCC. Median progression-free survival was 8.4 months (95%CI, 6.9-16.5). Baseline tumor tissue was available for 36 patients. TC PD-L1 expression ≥1% was associated with improved ORR (9/14, 64%) compared to patients with PD-L1 expression < 1% (4/20, 20%). Patients with TC PD-L1 expression ≥1% who experienced progressive disease as best response had shorter average distance between tumor cells and nearest neighboring immune cells at baseline. Further analysis of the immune tumor microenvironment on an expanded cohort, including IC PD-L1 expression and correlation with clinical outcomes, is ongoing and will be updated. Conclusions: The combination of atezolizumab plus bevacizumab is active in NccRCC and ccRCCsd. Candidate predictive biomarkers include PD-L1 expression in TC and topological analysis of the immune infiltrate. Clinical trial information: NCT02724878.

Association of polybromo-associated BAF (PBAF) complex mutations with overall survival (OS) in cancer patients (pts) treated with checkpoint inhibitors (ICIs)

103

Background: ICIs have shown benefit across several metastatic carcinomas, yet predictive biomarkers are still lacking. 20% of malignancies harbor alterations in ≥1gene that is part of PBAF complex. With recent data suggesting an association between PBRM1 mutations (mts) and outcomes in renal cell carcinoma (RCC) pts treated with ICIs (Miao, Science, 2018), we examined the association between PBAF mts and OS in ICI-treated patients across several solid cancer (ca) types. Methods: Of 6007 pts with different ca histologies and targeted exome sequencing (Oncopanel) at Dana Farber Cancer institute (DFCI), 138 pts had truncating mts in any PBAF gene (SMARCA4, PBRM1, and ARID2) or oncogenic missense mts in SMARCA4 and were treated with ICIs. 138 histology-matched DFCI pts had none. A publicly-available cohort (2:1 histology matched) from Memorial Sloan Kettering (MSKCC) (Samstein et al., Nature Genetics, 2019) of 621 ca pts (PBAF mutant [MT] = 207, PBAF wild type [WT] = 414) treated with ICIs was analyzed for association between PBAF mts and OS. OS was defined from time from ICI initiation. OS was compared by Cox regression between PBAF MT and PBAF WT. Hazard ratio (HR) was derived using univariable and multivariable analysis (MVA) adjusted for ICI regimen (single vs combination) and age. Results: Median (Md) follow-up for the combined cohort (n = 897) was 27 months (m). Major histologies were non-small cell lung ca (268; 29.9%), melanoma (220; 24.5%), RCC (181; 20.2%), and bladder ca (65; 7.2%). Results on univariable and MVA analyses from individual and combined cohorts are presented below. Conclusions: PBAF mts are associated with survival in ICI-treated ca pts. Work in progress with non-ICI treated pts will determine if this is prognostic or predictive of response. [Table: see text]

Cell-free methylated DNA (cfMeDNA) immunoprecipitation and high throughput sequencing technology (cfMeDIP-seq) in patients with clear cell renal cell carcinoma (ccRCC)

3052

Background: CfmeDNA is a promising biomarker for non-invasive assessment of solid tumors: i) MeDNA is tissue- and tumor-specific ii) cfDNA methylation changes are stable unlike DNA alterations iii) ‘methylation target size’ is larger than identifying specific genomic alterations and, therefore, more sensitive. CfMeDIP-seq is a sensitive assay for genome-wide bisulfite-free cfMeDNA profiling, that requires 1-10 ng input DNA. We tested the feasibility of cfMeDIP-seq to detect ccRCC across TNM stages. Methods: We evaluated plasma cfDNA collected prior to nephrectomy in 46 pts with ccRCC: 25 stage I, 7 stage II, 6 stage III, 8 stage IV. cfMeDIP-seq involves four steps: 1) cfDNA end-repair, A-tailing, and adapter ligation 2) cfMeDNA immunoprecipitation and enrichment using an Ab targeting 5-methylcytosine (quality control by qPCR to ensure <1% of unMeDNA and >99% reaction specificity) 3) adapter-mediated PCR to amplify cfMeDNA 4) high-throughput NGS for cfMeDNA data. A previously-derived model (Shen et al, Nature, 2018) was used to classify pts as having ccRCC or not based on cfMeDNA. cfMeDIP-seq paired end data was reduced to 300 bp windows of the genome that map to CpG islands, shores, shelves, and FANTOM5 enhancers; a classifier was then built using the top 1,000 most variable fragments between pts with ccRCC and cancer-free controls. Statistical comparisons were performed in the R statistical environment, with the caret package being used for classifier construction and evaluation. Results: The average amount of cfDNA isolated from 1 ml of ccRCC plasma was 19.8±39.8 ng/µL [1.95-260]. Greater than 99% specificity of reaction and <1% of unMeDNA was achieved in 46/46 samples (100%). The previously-derived classifier of ccRCC correctly predicted 46/46 pts (100%) as having ccRCC. Across 3 rounds of 5-fold cross-validation, the classifier performed with a Cohen’s Kappa of 0.93. Conclusions: CfMeDIP-seq is a non-invasive, cost-effective, and sensitive assay to detect cancer-specific cfmeDNA in ccRCC pts prior to nephrectomy. With further validation, cfmeDNA may detect minimal residual disease after nephrectomy for ‘precision’ adjuvant therapy.

Prognostic significance of CD73 expression in localized renal cell carcinoma (RCC)

4582

Background: CD73 or ecto-5'-nucleotidase mediates the de-phosphorylation of adenosine monophosphate to adenosine which promotes immunosuppression in the tumor microenvironment. Its prognostic significance in localized RCC has not been well characterized. Methods: We assessed CD73 protein expression using immunohistochemistry (Cell Signaling Technology, D7F9A, 1:25) on tissue microarrays (TMAs) containing tumor tissue from patients with pT1-4,N0-1, M0 RCC who underwent nephrectomy.CD73 expression was quantified using a combined score (CS: intensity x percentage of cells staining positive). CD73 positivity was defined as any CD73 expression on tumor cells (CS > 0). Patients were categorized into CD73 negative (CS = 0), low ( < median CS) and high (≥ median CS) groups. Clinical data was collected retrospectively.Baseline patient characteristics were compared between CD73 negative and positive (high + low) groups using the Cochran-Armitage trend test. Multivariable Cox regression evaluated associations of CD73 expression with disease-free and overall survival (DFS, OS) after adjusting for other baseline prognostic variables. Results: Of the 112 patients included, clear cell was the most common histology (70%) followed by chromophobe (12.5%), and papillary (12%) RCC. CD73 expression (CS > 0) was noted in 22% (n = 25) of tumors and was associated with more advanced stage (T3-4/N+: 37.5% vs. 25%; p = 0.02) and a trend towards higher nuclear grade (≥3: 48% vs. 35%; p = 0.07). Median follow-up from nephrectomy was 9.7 yrs. In multivariable analysis adjusting for nuclear grade ( < 3 vs. ≥3) and stage (T1-2, N0 vs. T3-4/N+), tumors with high CD73 expression had significantly worse DFS and OS (Table). Conclusions: CD73 expression was found in 22% of RCC patients and was associated with adverse pathologic features and poor prognosis independent of tumor stage and histologic grade. Our results provide strong rationale for further investigation of the CD73/adenosine pathway as a therapeutic target in RCC. [Table: see text]

Efficacy of immune checkpoint inhibitors (ICI) and genomic characterization of sarcomatoid and/or rhabdoid (S/R) metastatic renal cell carcinoma (mRCC)

4514

Background: S/R mRCC are poorly characterized rapidly progressing tumors associated with poor prognosis. Although conventional therapies are less effective for these tumors, emerging data suggests that ICIs may be especially effective. Our aim was to characterize the genomic alterations (GA) in S/R mRCC tumors and evaluate their response to ICIs. Methods: We retrospectively compared the activity of first-line ICIs to non-ICI-based therapies for S/R mRCC patients (pts) treated at DFCI and analyzed sequencing data from an NGS panel (275-447 genes) on a subset of these patients (matched by histology to non-S/R mRCC). For S/R mRCC pts treated with ICI vs non-ICI therapies, overall survival (OS) and time to treatment failure (TTF) were compared by Cox regression and objective response rate (ORR) by logistic regression. GA frequencies were compared by Fisher’s test and tumor mutational burden (TMB) by Mann Whitney U between S/R and non-S/R mRCC. Results were considered statistically significant if p < 0.05 or q < 0.10. Results: 125 S/R mRCC pts were included (88 S, 23 R, 14 S&R) among which 103 were clear cell and 48 had sequencing data. GA in BAP1 were significantly more frequent in S/R vs non-S/R (25% vs 4.3%; q = 0.096) while other GA had similar frequencies and TMB (median [IQR]) was similar (7.2 [5.2-8.4] vs 6.8 [5.3-9.1] mut/Mb; p = 0.98). Median follow-up was 35.4 (95% CI = 24.9 – 46.0) months (m). On multivariable analysis, S/R mRCC pts treated with ICI had significantly better clinical outcomes (Table). Conclusions: Pts with S/R mRCC have a higher frequency of BAP1 GA and better outcomes on ICIs compared to non-ICI-based therapies. Future studies should determine the molecular mechanisms underlying the improved response to ICIs in S/R mRCC. [Table: see text]

Efficacy of first-line immune checkpoint inhibitors in patients with sarcomatoid and/or rhabdoid (S/R) metastatic renal cell carcinoma (mRCC)

66

Background: Patients with mRCC with S/R components tend to have a poor prognosis with few therapeutic options available. Recent data suggest that immune checkpoint inhibitor (ICI)-based therapies may be especially effective for these patients. Our aim was to evaluate the efficacy of ICI-based therapies in patients with S/R mRCC. Methods: We retrospectively assessed objective response rate (ORR), progression free survival (PFS) & overall survival (OS) of patients with S/R mRCC treated at our institution with first-line ICI-based therapies and compared these to those of patients treated with first-line non-ICI-based therapies. Univariable and multivariable (adjusted for IMDC group) Cox and logistic regressions were performed. Results: 92 patients (70 S, 9 R, and 13 S&R) patients were included, of which 74 with a clear-cell component. For all patients (regardless of therapy), 74 (80.4%) patients experienced a PFS event (progression or death) and 52 (56.5%) died at 25.3 months (m) median follow-up. Overall median PFS was 5.3 m (95% CI= 3.4–7.2) and 24 m OS rate was 39.5% (27.4–51.7). Out of 78 patients in whom response was evaluable, ORR was 30.8% (20.4–41.2). Patients treated with ICI-based therapies had significantly better ORR, PFS, and OS on multivariable analysis (table). Conclusions: mRCC patients with S/R components have significantly better ORR, PFS, and OS with first-line ICI-based compared to non-ICI-based therapies. These data support the use of ICI-based therapies for patients with S/R mRCC. [Table: see text]

Real-world assessment of clinical outcomes among first-line (1L) sunitinib (SUN) patients (pts) with metastatic renal cell carcinoma (mRCC) by the international mRCC database consortium (IMDC) risk group

610

Background: Prognostic factors such as the IMDC criteria have included all types of targeted therapy. This study assesses clinical outcomes and provide benchmarks for mRCC pts treated specifically with 1L SUN in the real world to provide contemporary benchmarks for outcomes and survival. Methods: Clear cell mRCC pts initiating SUN as 1L therapy between 2010-2018 were included in a retrospective database study. Kaplan Meier analysis was used to estimate median time to treatment discontinuation (TTD) and overall survival (OS: time to death) by IMDC risk groups based on Karnofsky Performance Status < 80%, diagnosis to treatment interval < 1 year, anemia, neutrophilia, hypercalcemia and thrombocytosis. Results: Among 1,769 1L SUN pts with clear cell in the RW clinical database, 318 (18%) had favorable, 1,031 (58%) had intermediate and 420 (24%) had poor IMDC risk. Across the favorable, intermediate, and poor risk groups, pts had similar mean age in years, gender distribution, and year of SUN initiation (age: 63.8, 62.9 and 62.6; male: 74%, 75%, and 72%; SUN initiation year of 2010-2013: all 71%). In the favorable risk group, 99% received nephrectomy vs 88% in intermediate and 66% in poor risk group. Median TTD was 15.0, 8.5, and 4.2 months (mos) in the favorable, intermediate, and poor risk groups, respectively, and was 7.1 mos in the combined intermediate/poor risk groups. Median OS was 52.1, 31.5, and 9.8 mos in the favorable, intermediate, and poor risk groups, respectively, and was 23.2 mos in the combined intermediate/poor risk groups. Conclusions: This real world study based on a contemporary cohort of 1L SUN mRCC pts found a median OS of 52 mos which sets a new benchmark for clear cell mRCC in the favorable risk group. OS in the intermediate and poor risk groups are similar to previous reports. This affects pt counselling and clinical trial design.

Impact of body mass index (BMI) on treatment outcomes to immune checkpoint blockade (ICB) in metastatic renal cell carcinoma (mRCC)

566

Background: An elevated BMI is associated with improved survival in mRCC patients treated with oral targeted therapies (TT); however, this relationship in the contemporary treatment landscape is unknown. We investigated the effect of BMI on outcomes in mRCC patients treated with PD-1/PD-L1 ICB. Methods: We analyzed 147 patients with mRCC who received ICB alone or in combination with VEGF or other therapies. The association of BMI with objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) was evaluated using logistic and Cox regression models, adjusted for known prognostic factors including International Metastatic RCC Database Consortium (IMDC) risk groups, line of therapy, ECOG (0 vs ≥1), and histology. Results: Median follow up was 25.5 (4.3-78.6) months (mos). Median time on ICB was 5.1 ( < 0.1-69.7) mos. Overall, most patients were male (71%), had clear cell histology (85%), and were intermediate risk (60%). 43% received first-line ICB and 45% received ICB in combination therapy (37% with VEGF inhibition, 8% with other therapies). At ICB initiation, 46 (31%) patients were considered underweight/normal weight (BMI < 25 kg/m2), 56 (38%) overweight (BMI 25-30 kg/m2), and 45 (31%) obese (BMI > 30 kg/m2). Patients with high BMI (≥ 25) had improved OS (median 34.3 vs 16.7 mos, 2-yr OS 61 vs 42%, p = 0.016) compared to those with low BMI ( < 25), with an adjusted hazard ratio (HR) = 0.74 (0.44-1.26). ORR (33 vs 28%, p = 0.7) and PFS (median 8.2 vs 5.9 mos, p = 0.4) did not statistically differ. Patients who experienced a BMI change from ≥ 25 at start of first-line TT to < 25 at start of subsequent-line ICB displayed shorter OS (adjusted HR = 2.25 (0.94-5.35)) compared to those with no change. Conclusions: High BMI appears to be associated with improved OS in mRCC patients treated with ICB. This contemporary data is consistent with the “obesity paradox” demonstrated in the TT era. Validation with the IMDC database and examination of underlying mechanisms are ongoing.

Results of a phase II study of atezolizumab and bevacizumab in non-clear cell renal cell carcinoma (nccRCC) and clear cell renal cell carcinoma with sarcomatoid differentiation (sccRCC)

548

Background: NccRCC and sccRCC have historically been underrepresented in clinical trials. Even with targeted therapy, most patients have inferior survival compared to clear cell renal cell carcinoma. The combination of atezolizumab and bevacizumab has demonstrated safety and efficacy in ccRCC. In this multicenter, phase II, open-label, single arm trial we evaluate the efficacy of atezolizumab and bevacizumab in patients with nccRCC and sccRCC with >20% sarcomatoid differentiation. Methods: Eligible patients had an ECOG performance status of 0-2 and may have received prior therapy. Prior PD-1/PD-L1 therapy was not allowed. Patients underwent a mandatory baseline biopsy and subsequently received atezolizumab 120 mg and bevacizumab 15 mg/kg intravenously every 3 weeks. Patients remained on therapy until radiographic progression, unacceptable adverse events, or withdrawal. The primary end point was overall response rate (ORR) as determined by RECIST version 1.1. Results: 65 patients were enrolled of whom 52 had ≥1 response assessment and were included in this analysis. 36 patients had nccRCC (papillary n=14, chromophobe n=8, unclassified RCC n=3, collecting duct n=3, translocation n=3, other n=5), and 16 patients had sccRCC. 17 patients received prior systemic therapy, 16 of whom had nccRCC. The ORR was 31% in the overall cohort (Table 1). 10 patients (19%) developed grade 3 treatment-related adverse events (AEs), half of which were immune-related. There were no grade 4-5 AEs. Conclusions: In this study, we show that therapy with atezolizumab and bevacizumab was safe and demonstrated anti-tumor activity in nccRCC and sccRCC. Further analyses will report ORR by histologic subtype and PD-L1 expression status. Analysis of tissue and blood-based biomarkers of response are ongoing. Clinical trial information: NCT02724878. [Table: see text]

Safety and efficacy of restarting immune checkpoint inhibitors (CPI) after immune-related adverse events (irAEs) in metastatic renal cell carcinoma (mRCC)

652

Background: CPI can induce a range of irAEs with various degrees of severity. Clinical experience with retreatment following clinically significant irAEs is growing. Methods: We retrospectively reviewed mRCC patients treated with CPI-based regimens who had >1 week therapy delay for irAEs at Dana Farber and Emory to characterize the safety and outcomes of retreatment. Toxicity was graded by CTCAEv5. Patients were divided into retreatment (R) and discontinuation (D) cohorts. Patient characteristics were compared by Fisher’s exact test or Wilcoxon’s rank sum test. ORR, OS and PFS were assessed descriptively. Results: Of 339 treated with CPI, 53 (16%) had irAEs warranting treatment interruption: 24 (45%) in R and 29 (55%) in D. Median (med) time to drug interruption was 2.0 (<0.1-74) months (mos) in D and 3.2 (<0.1-21) mos in R (p=0.89). Prior to irAE onset, 8 (28%) of cohort D and 5 (21%) of cohort R experienced partial responses (PR). While type of irAEs were balanced across D and R, initial irAEs were less severe in R vs D (all p<0.05) with fewer grade (gr) 3-4 events (29% vs 66%), less hospitalizations (25% vs 69%), and lower steroid requirements (>40 mg: 29% vs 79%). The most common irAEs in R were transaminitis, pancreatitis and dermatitis with 7 gr 3/4 events (pancreatitis, colitis, adrenal insufficiency and dermatitis). Median drug break before retreatment was 1.2 (0.3-4.8) mo. Subsequent irAEs occurred in 42% (n=10) after restarting (8 new, 2 recurrent) with 2 discontinuations; 6/10 were gr 3 with no gr 4/5 events. Median interval to irAE recurrence after retreatment was 2.1 (0.5-3.3) mos. Retreatment resulted in 4 (17%) PRs in patients whose disease had not responded prior to irAE (med time to PR from R = 2 mos). Conclusions: Despite a significant rate of irAE recurrence, most patients with prior clinically significant irAEs can be safely retreated. Retreatment can induce responses in an appreciable proportion of patients with no response prior to irAE. Larger studies are warranted to confirm these findings. [Table: see text]

Antibiotic use and outcomes with systemic therapy in metastatic renal cell carcinoma (mRCC)

607

Background: Antibiotic (Abx) use is shown to alter commensal gut microbiota, a key regulator of immune homeostasis. We conducted the largest investigation to date on the impact of Abx use on outcomes in mRCC patients treated with systemic agents. Methods: Two cohorts were analyzed: an institutional cohort (DFCI, n = 146) of patients receiving PD-1/PD-L1-based immune checkpoint inhibitors (ICI), and an external cohort from pooled phase II/III clinical trials (Pfizer, n = 4144) of patients treated with interferon (IFN, n = 510), mTOR inhibitors (n = 660), and VEGF inhibitors (n = 2974). Abx use was defined as Abx treatment at any time between 8-weeks pre- and 4-weeks post the start of systemic therapy. We examined the associations of Abx use and objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) using Cox/logistic regression models, adjusted for prognostic factors including risk groups. Results: In the DFCI cohort, 15% had non-clear cell histology, 43% had first-line ICI, 45% had combotherapy. Baseline characteristics were balanced between Abx users (n = 31, 21%) and non-users (p > 0.15). Abx users had a lower ORR (12.9 vs 34.8%, p = 0.026) and shorter PFS compared to non-users (Table). In the external cohort, Abx users (n = 709) had lower ORR (19.3 vs 24.2%, p = 0.005). IFN treated patients (current or prior cytokines) had worse OS if they received Abx compared to those who did not. However, there was no OS difference by Abx use in mTOR or VEGF treated patients without prior cytokines. Conclusions: Abx use was independently associated with worse outcomes in mRCC patients receiving contemporary ICI or historic cytokine immunotherapy. We hypothesize that concurrent use of Abx may reduce the efficacy of ICI due to a complex interplay with the host microbiome. [Table: see text]

Durable Clinical Benefit in Metastatic Renal Cell Carcinoma Patients Who Discontinue PD-1/PD-L1 Therapy for Immune-Related Adverse Events

The current standard of care for treatment of metastatic renal cell carcinoma (mRCC) patients is PD-1/PD-L1 inhibitors until progression or toxicity. Here, we characterize the clinical outcomes for 19 mRCC patients who experienced an initial clinical response (any degree of tumor shrinkage), but after immune-related adverse events (irAE) discontinued all systemic therapy. Clinical baseline characteristics, outcomes, and survival data were collected. The primary endpoint was time to progression from the date of treatment cessation (TTP). Most patients had clear cell histology and received anti-PD-1/PD-L1 therapy as second-line or later treatment. Median time on PD-1/PD-L1 therapy was 5.5 months (range, 0.7-46.5) and median TTP was 18.4 months (95% CI, 4.7-54.3) per Kaplan-Meier estimation. The irAEs included arthropathies, ophthalmopathies, myositis, pneumonitis, and diarrhea. We demonstrate that 68.4% of patients (n = 13) experienced durable clinical benefit off treatment (TTP of at least 6 months), with 36% (n = 7) of patients remaining off subsequent treatment for over a year after their last dose of anti-PD-1/PD-L1. Three patients with tumor growth found in a follow-up visit, underwent subsequent surgical intervention, and remain off systemic treatment. Nine patients (47.4%) have ongoing irAEs. Our results show that patients who benefitted clinically from anti-PD-1/PD-L1 therapy can experience sustained beneficial responses, not needing further therapies after the initial discontinuation of treatment due to irAEs. Investigation of biomarkers indicating sustained benefit to checkpoint blockers are needed. Cancer Immunol Res; 6(4); 402-8. ©2018 AACR.

Change in Neutrophil-to-lymphocyte ratio (NLR) in response to immune checkpoint blockade for metastatic renal cell carcinoma

Background

An elevated Neutrophil-to-lymphocyte ratio (NLR) is associated with worse outcomes in several malignancies. However, its role with contemporary immune checkpoint blockade (ICB) is unknown. We investigated the utility of NLR in metastatic renal cell carcinoma (mRCC) patients treated with PD-1/PD-L1 ICB.

Methods

We examined NLR at baseline and 6 (±2) weeks later in 142 patients treated between 2009 and 2017 at Dana-Farber Cancer Institute (Boston, USA). Landmark analysis at 6 weeks was conducted to explore the prognostic value of relative NLR change on overall survival (OS), progression-free survival (PFS), and objective response rate (ORR). Cox and logistic regression models allowed for adjustment of line of therapy, number of IMDC risk factors, histology and baseline NLR.

Results

Median follow up was 16.6 months (range: 0.7–67.8). Median duration on therapy was 5.1 months (<1–61.4). IMDC risk groups were: 18% favorable, 60% intermediate, 23% poor-risk. Forty-four percent were on first-line ICB and 56% on 2nd line or more. Median NLR was 3.9 (1.3–42.4) at baseline and 4.1 (1.1–96.4) at week 6. Patients with a higher baseline NLR showed a trend toward lower ORR, shorter PFS, and shorter OS. Higher NLR at 6 weeks was a significantly stronger predictor of all three outcomes than baseline NLR. Relative NLR change by ≥25% from baseline to 6 weeks after ICB therapy was associated with reduced ORR and an independent prognostic factor for PFS (p < 0.001) and OS (p = 0.004), whereas a decrease in NLR by ≥25% was associated with improved outcomes.

Conclusions

Early decline and NLR at 6 weeks are associated with significantly improved outcomes in mRCC patients treated with ICB. The prognostic value of the readily-available NLR warrants larger, prospective validation.

Response to single agent PD-1 inhibitor after progression on previous PD-1/PD-L1 inhibitors: a case series

Background

Monoclonal antibodies targeting the PD-1/PD-L1 axis have gained increasing attention across many solid tumors and hematologic malignancies due to their efficacy and favorable toxicity profile. With more than 1 agent now FDA-approved in a wide variety of tumor types, and with others in clinical trials, it is becoming more common that patients present to clinic for potential treatment with a second PD-1/PD-L1 inhibitor.

Case presentation

In this report, we present two patients with renal cell carcinoma and one with melanoma who received PD-1/PD-L1 inhibitors. Upon progression on their first-line PD-1/PD-L1 inhibitors, these patients received a different PD-1 inhibitor (nivolumab in all cases) and all had progressive disease as their best response to the subsequent PD-1 inhibitor. The reported clinical information focuses on the course of the disease and the responses to all treatment regimens.

Conclusions

Clinicians should refrain from using multiple PD-1/PD-L1 inhibitors sequentially outside of clinical trials until there is sufficient data to support this practice routinely. Prospective studies that allow prior treatment with PD-1/PD-L1 are needed to validate the efficacy and safety of these drugs in the second line or later setting. Furthermore, ongoing efforts that aim to identify mechanisms of resistance to immunotherapy will be informative and may ultimately assist physicians in select the optimal treatment following progression on PD-1/PD-L1 inhibitor.