Clinical outcomes and safety of immune checkpoint inhibitors in patients with solid tumors and paraneoplastic syndromes

BACKGROUND

Patients with paraneoplastic syndromes (PNS) are excluded from clinical trials involving immune checkpoint inhibitors (ICIs) due to safety concerns. Moreover, real-world data on efficacy and safety is scarce.

METHODS

In this retrospective study, data were collected on patients with PNS and solid tumors receiving ICI between 2015 and 2022 at nine institutions. Patients were classified into: Cohort 1 (pre-existing PNS before ICI initiation), cohort 2 (PNS during ICI treatment), and cohort 3 (PNS after ICI discontinuation). Patients with metastatic non-small cell lung cancer (NSCLC) (mNSCLC) from cohort 1 were matched to patients who were PNS-free at each institution up to a 1:3 ratio for age, sex, type of ICI, use of concurrent chemotherapy, and number of lines of systemic therapy prior to ICI initiation. Kaplan-Meier method was used to assess overall survival (OS) and time-to-next treatment (TTNT).

RESULTS

Among 109 patients with PNS treated with ICIs, median age at ICI initiation was 67 years (IQR: 58-74). The most represented cancer type was NSCLC (n=39, 36%). In cohort 1 (n=55), PNS exacerbations occurred in 16 (29%) patients with median time to exacerbation after ICI of 1.1 months (IQR: 0.7-3.3). Exacerbation or de novo PNS prompted temporary/permanent interruption of ICIs in 14 (13%) patients. For cohort 2 (n=16), median time between ICI initiation and de novo PNS was 1.2 months (IQR: 0.4-3.5). Treatment-related adverse events (trAEs) occurred in 43 (39%) patients. Grade ≥3 trAEs occurred in 18 (17%) patients. PNS-directed immunosuppressive therapy was required in 55 (50%) patients. We matched 18 patients with mNSCLC and PNS (cohort 1) to 40 without PNS, treated with ICIs. There was no significant difference in OS or TTNT between patients with mNSCLC with and without PNS, although a trend was seen towards worse outcomes in patients with PNS. TrAEs occurred in 6/18 (33%) and 14/40 (35%), respectively. Grade ≥3 trAEs occurred in 4 (22%) patients with PNS and 7 (18%) patients without PNS.

CONCLUSIONS

Exacerbations of pre-existing PNS occurred in 29% of patients treated with ICIs and both exacerbations and de novo PNS occur early in the ICI course. TrAE from ICIs were similar between patients with and without PNS. Our data suggest that pre-existing PNS should not preclude consideration of ICI therapy although patients may not derive the same clinical benefit compared with patients without PNS.

Influence of TP53 Comutation on the Tumor Immune Microenvironment and Clinical Outcomes With Immune Checkpoint Inhibitors in STK11-Mutant Non-Small-Cell Lung Cancer

PURPOSE

Non-small-cell lung cancer (NSCLC) with STK11mut has inferior outcomes to immune checkpoint inhibitors (ICIs). Using multiomics, we evaluated whether a subtype of STK11mut NSCLC with a uniquely inflamed tumor immune microenvironment (TIME) harboring TP53 comutations could have favorable outcomes to ICIs.

PATIENTS AND METHODS

NSCLC tumors (N = 16,896) were analyzed by next-generation sequencing (DNA-Seq/592 genes). A subset (n = 5,034) underwent gene expression profiling (RNA-Seq/whole transcriptome). Exome-level neoantigen load for STK11mut NSCLC was obtained from published pan-immune analysis. Tumor immune cell content was obtained from transcriptome profiles using the microenvironment cell population (MCP) counter. ICI data from POPLAR/OAK (n = 34) and the study by Rizvi et al (n = 49) were used to model progression-free survival (PFS), and a separate ICI-treated cohort (n = 53) from Dana-Farber Cancer Institute (DFCI) was used to assess time to treatment failure (TTF) and tumor RECIST response for STK11mutTP53mut versus STK11mutTP53wt NSCLC.

RESULTS

Overall, 12.6% of NSCLC tumors had a STK11mut with the proportions of tumor mutational burden (TMB)-high (≥10 mut/Mb), PD-L1 ≥50%, and microsatellite instability-high being 38.3%, 11.8%, and 0.72%, respectively. Unsupervised hierarchical clustering of STK11mut (n = 463) for stimulator of interferon-gamma (STING) pathway genes identified a STING-high cluster, which was significantly enriched in TP53mut NSCLC (P < .01). Compared with STK11mutTP53wt, tumors with STK11mutTP53mut had higher CD8+T cells and natural killer cells (P < .01), higher TMB (P < .001) and neoantigen load (P < .001), and increased expression of MYC and HIF-1A (P < .01), along with higher expression (P < .01) of glycolysis/glutamine metabolism genes. Meta-analysis of data from OAK/POPLAR and the study by Rizvi et al showed a trend toward improved PFS in patients with STK11mutTP53mut. In the DFCI cohort, compared with the STK11mut TP53wt cohort, the STK11mutTP53mut tumors had higher objective response rates (42.9% v 16.7%; P = .04) and also had longer TTF (14.5 v 4.5 months, P adj = .054) with ICI.

CONCLUSION

STK11mut NSCLC with TP53 comutation is a distinct subgroup with an immunologically active TIME and metabolic reprogramming. These properties should be exploited to guide patient selection for novel ICI-based combination approaches.

Association of Baseline Tumor-Specific Neoantigens and CD8+ T-Cell Infiltration With Immune-Related Adverse Events Secondary to Immune Checkpoint Inhibitors

PURPOSE

Recent evidence has shown that higher tumor mutational burden strongly correlates with an increased risk of immune-related adverse events (irAEs). By using an integrated multiomics approach, we further studied the association between relevant tumor immune microenvironment (TIME) features and irAEs.

METHODS

Leveraging the US Food and Drug Administration Adverse Event Reporting System, we extracted cases of suspected irAEs to calculate the reporting odds ratios (RORs) of irAEs for cancers treated with immune checkpoint inhibitors (ICIs). TIME features for 32 cancer types were calculated on the basis of the cancer genomic atlas cohorts and indirectly correlated with each cancer's ROR for irAEs. A separate ICI-treated cohort of non-small-cell lung cancer (NSCLC) was used to evaluate the correlation between tissue-based immune markers (CD8+, PD-1/L1+, FOXP3+, tumor-infiltrating lymphocytes [TILs]) and irAE occurrence.

RESULTS

The analysis of 32 cancers and 33 TIME features demonstrated a significant association between irAE RORs and the median number of base insertions and deletions (INDEL), neoantigens (r = 0.72), single-nucleotide variant neoantigens (r = 0.67), and CD8+ T-cell fraction (r = 0.51). A bivariate model using the median number of INDEL neoantigens and CD8 T-cell fraction had the highest accuracy in predicting RORs (adjusted r2 = 0.52, P = .002). Immunoprofile assessment of 156 patients with NSCLC revealed a strong trend for higher baseline median CD8+ T cells within patients' tumors who experienced any grade irAEs. Using machine learning, an expanded ICI-treated NSCLC cohort (n = 378) further showed a treatment duration-independent association of an increased proportion of high TIL (>median) in patients with irAEs (59.7% v 44%, P = .005). This was confirmed by using the Fine-Gray competing risk approach, demonstrating higher baseline TIL density (>median) associated with a higher cumulative incidence of irAEs (P = .028).

CONCLUSION

Our findings highlight a potential role for TIME features, specifically INDEL neoantigens and baseline-immune infiltration, in enabling optimal irAE risk stratification of patients.

Comparison of outcomes for Hispanic and non-Hispanic patients with advanced renal cell carcinoma in the International Metastatic Renal Cell Carcinoma Database

BACKGROUND

Existing data on the impact of Hispanic ethnicity on outcomes for patients with renal cell carcinoma (RCC) is mixed. The authors investigated outcomes of Hispanic and non-Hispanic White (NHW) patients with advanced RCC receiving systemic therapy at large academic cancer centers using the International Metastatic Renal Cell Carcinoma Database (IMDC).

METHODS

Eligible patients included non-Black Hispanic and NHW patients with locally advanced or metastatic RCC initiating systemic therapy. Overall survival (OS) and time to first-line treatment failure (TTF) were calculated using the Kaplan-Meier method. The effect of ethnicity on OS and TTF were estimated by Cox regression hazard ratios (HRs).

RESULTS

A total of 1563 patients (181 Hispanic and 1382 NHW) (mostly males [73.8%] with clear cell RCC [81.5%] treated with tyrosine kinase inhibitor [TKI] monotherapy [69.9%]) were included. IMDC risk groups were similar between groups. Hispanic patients were younger at initial diagnosis (median 57 vs. 59 years, p = .015) and less likely to have greater than one metastatic site (60.8% vs. 76.8%, p < .001) or bone metastases (23.8% vs. 33.4%, p = .009). Median OS and TTF was 38.0 months (95% confidence interval [CI], 28.1-59.2) versus 35.7 months (95% CI, 31.9-39.2) and 7.8 months (95% CI, 6.2-9.0) versus 7.5 months (95% CI, 6.9-8.1), respectively, in Hispanic versus NHW patients. In multivariable Cox regression analysis, no statistically significant differences were observed in OS (adjusted hazard ratio [HR], 1.07; 95% CI, 0.86-1.31, p = .56) or TTF (adjusted HR, 1.06; 95% CI, 0.89-1.26, p = .50).

CONCLUSIONS

The authors did not observe statistically significant differences in OS or TTF between Hispanic and NHW patients with advanced RCC. Receiving treatment at tertiary cancer centers may mitigate observed disparities in cancer outcomes.

Consolidation Osimertinib Versus Durvalumab Versus Observation After Concurrent Chemoradiation in Unresectable EGFR-Mutant NSCLC: A Multicenter Retrospective Cohort Study

INTRODUCTION

Durvalumab improves survival when used as consolidation therapy after chemoradiation (CRT) in patients with stage III NSCLC. The optimal consolidation therapy for patients with EGFR-mutant (EGFRmut) stage III NSCLC remains unknown.

METHODS

In this multi-institutional, international retrospective analysis across 24 institutions, we evaluated outcomes in patients with stage III EGFRmut NSCLC treated with concurrent CRT followed by consolidation therapy with osimertinib, durvalumab, or observation between 2015 and 2022. Kaplan-Meier method was used to estimate real-world progression-free survival (rwPFS, primary end point) and overall survival (secondary end point). Treatment-related adverse events (trAEs) during consolidation treatment were defined using Common Terminology Criteria for Adverse Events version 5.0. Multivariable Cox regression analysis was used.

RESULTS

Of 136 patients with stage III EGFRmut NSCLC treated with definitive concurrent CRT, 56 received consolidation durvalumab, 33 received consolidation osimertinib, and 47 was on observation alone. Baseline characteristics were similar across the three cohorts. With a median follow-up of 46 months for the entire cohort, the median duration of treatment was not reached (NR) for osimertinib (interquartile range: NR-NR) and was 5.5 (interquartile range: 2.4-10.8) months with durvalumab. After adjusting for nodal status, stage III A/B/C, and age, patients treated with consolidation osimertinib had significantly longer 24-month rwPFS compared to those treated with durvalumab or in the observation cohorts (osimertinib: 86%, durvalumab: 30%, observation: 27%, p < 0.001 for both comparisons). There was no difference in rwPFS between the durvalumab and the observation cohorts. No significant difference in overall survival across the three cohorts was detected, likely due to the limited follow-up. Any-grade trAE occurred in 52% (2 [6.1%] grade ≥3) and 48% (10 [18%] grade ≥3) of patients treated with osimertinib and durvalumab, respectively. Of 45 patients who progressed on consolidation durvalumab, 37 (82%) subsequently received EGFR tyrosine kinase inhibitors. Of these, 14 (38%) patients developed trAEs including five patients with pneumonitis (14%; 2 [5.4%] grade ≥3) and five patients with diarrhea (14%; 1 [2.7%] grade ≥3).

CONCLUSIONS

This study suggests that among patients with stage III unresectable NSCLC with a sensitizing EGFR mutation, consolidation osimertinib was associated with a significantly longer rwPFS compared to durvalumab or observation. No unanticipated safety signals were observed with consolidation osimertinib.

Benchmarking mismatch repair testing for patients with cancer receiving immunotherapy

Immunohistochemistry (IHC) is currently the first-line test for mismatch repair deficiency (MMR-D). Bou Farhat et al. show that mismatch repair (MMR) mutation signature by next-generation sequencing is a highly sensitive assay capable of detecting MMR-D cases that are missed in 1% and 5% of patients with MMR-D colorectal cancer (CRC) and endometrial cancer (EC), respectively. Patients with MMR-D tumors missed by IHC have similar clinical outcomes to patients with MMR-D by both IHC and mutation signature.

Treatment-related adverse events, including fatal toxicities, in patients with solid tumours receiving neoadjuvant and adjuvant immune checkpoint blockade: a systematic review and meta-analysis of randomised controlled trials

BACKGROUND

Incorporating immune checkpoint blockade into perioperative cancer therapy has improved clinical outcomes. However, the safety of immune checkpoint blockade needs better evaluation, given the chances of more prolonged disease-free survival. We aimed to assess how adding immune checkpoint blockade to perioperative therapy affects treatment-related adverse events.

METHODS

For this systematic review and meta-analysis, we searched PubMed/MEDLINE, Embase, Web of Science, and the Cochrane Library from database inception until Aug 8, 2023, for randomised controlled trials that assessed the addition of immune checkpoint blockade to neoadjuvant or adjuvant therapy for cancer, reported treatment-related deaths, and had a design in which the experimental group assessed immune checkpoint blockade in combination with the therapy used in the control group. Meta-analysis was done to pool odds ratios (ORs) of treatment-related deaths, any grade and grade 3-4 treatment-related adverse events, serious adverse events, and adverse events leading to treatment discontinuation. The protocol is registered with PROSPERO, CRD42022343741.

FINDINGS

28 randomised controlled trials with 16 976 patients were included. The addition of immune checkpoint blockade was not significantly associated with increased treatment-related deaths (OR 1·76, 95% CI 0·95-3·25; p=0·073), consistent across immune checkpoint blockade subtype (I2=0%). 40 fatal toxicities were identified across 9864 patients treated with immune checkpoint blockade, with pneumonitis being the most common (six [15·0%]); 13 fatal toxicities occurred among 7112 patients who were not treated with immune checkpoint blockade. The addition of immune checkpoint blockade increased the incidence of grade 3-4 treatment-related adverse events (OR 2·73, 95% CI 1·98-3·76; p<0·0001), adverse events leading to treatment discontinuation (3·67, 2·45-5·51; p<0·0001), and treatment-related adverse events of any grade (2·60 [1·88-3·61], p<0·0001). The immune checkpoint blockade versus placebo design primarily used as adjuvant therapy was associated with increased incidence of treatment-related deaths (4·02, 1·04-15·63; p=0·044) and grade 3-4 adverse events (5·31, 3·08-9·15; p<0·0001), whereas the addition of immune checkpoint blockade in the neoadjuvant setting was not associated with increased incidence of treatment-related death (1·11, 95% CI 0·38-3·29; p=0·84) or grade 3-4 adverse events (1·17, 0·90-1·51; p=0·23).

INTERPRETATION

The addition of immune checkpoint blockade to perioperative therapy was associated with an increase in grade 3-4 treatment-related adverse events and adverse events leading to treatment discontinuation. These findings provide safety insights for further clinical trials assessing neoadjuvant or adjuvant immune checkpoint blockade therapy. Clinicians should closely monitor patients for treatment-related adverse events to prevent treatment discontinuations and morbidity from these therapies in earlier-stage settings.

FUNDING

None.

ATM deficiency confers specific therapeutic vulnerabilities in bladder cancer

Ataxia-telangiectasia mutated (ATM) plays a central role in the cellular response to DNA damage and ATM alterations are common in several tumor types including bladder cancer. However, the specific impact of ATM alterations on therapy response in bladder cancer is uncertain. Here, we combine preclinical modeling and clinical analyses to comprehensively define the impact of ATM alterations on bladder cancer. We show that ATM loss is sufficient to increase sensitivity to DNA-damaging agents including cisplatin and radiation. Furthermore, ATM loss drives sensitivity to DNA repair-targeted agents including poly(ADP-ribose) polymerase (PARP) and Ataxia telangiectasia and Rad3 related (ATR) inhibitors. ATM loss alters the immune microenvironment and improves anti-PD1 response in preclinical bladder models but is not associated with improved anti-PD1/PD-L1 response in clinical cohorts. Last, we show that ATM expression by immunohistochemistry is strongly correlated with response to chemoradiotherapy. Together, these data define a potential role for ATM as a predictive biomarker in bladder cancer.

Enzyme-mediated depletion of methylthioadenosine restores T cell function in MTAP-deficient tumors and reverses immunotherapy resistance

Chromosomal region 9p21 containing tumor suppressors CDKN2A/B and methylthioadenosine phosphorylase (MTAP) is one of the most frequent genetic deletions in cancer. 9p21 loss is correlated with reduced tumor-infiltrating lymphocytes (TILs) and resistance to immune checkpoint inhibitor (ICI) therapy. Previously thought to be caused by CDKN2A/B loss, we now show that it is loss of MTAP that leads to poor outcomes on ICI therapy and reduced TIL density. MTAP loss causes accumulation of methylthioadenosine (MTA) both intracellularly and extracellularly and profoundly impairs T cell function via the inhibition of protein arginine methyltransferase 5 (PRMT5) and by adenosine receptor agonism. Administration of MTA-depleting enzymes reverses this immunosuppressive effect, increasing TILs and drastically impairing tumor growth and importantly, synergizes well with ICI therapy. As several studies have shown ICI resistance in 9p21/MTAP null/low patients, we propose that MTA degrading therapeutics may have substantial therapeutic benefit in these patients by enhancing ICI effectiveness.

Safety and Activity of Immune Checkpoint Inhibitors in People Living With HIV and Cancer: A Real-World Report From the Cancer Therapy Using Checkpoint Inhibitors in People Living With HIV-International (CATCH-IT) Consortium

PURPOSE

Compared with people living without HIV (PWOH), people living with HIV (PWH) and cancer have traditionally been excluded from immune checkpoint inhibitor (ICI) trials. Furthermore, there is a paucity of real-world data on the use of ICIs in PWH and cancer.

METHODS

This retrospective study included PWH treated with anti-PD-1- or anti-PD-L1-based therapies for advanced cancers. Kaplan-Meier method was used to estimate overall survival (OS) and progression-free survival (PFS). Objective response rates (ORRs) were measured per RECIST 1.1 or other tumor-specific criteria, whenever feasible. Restricted mean survival time (RMST) was used to compare OS and PFS between matched PWH and PWOH with metastatic NSCLC (mNSCLC).

RESULTS

Among 390 PWH, median age was 58 years, 85% (n = 331) were males, 36% (n = 138) were Black; 70% (n = 274) received anti-PD-1/anti-PD-L1 monotherapy. Most common cancers were NSCLC (28%, n = 111), hepatocellular carcinoma ([HCC]; 11%, n = 44), and head and neck squamous cell carcinoma (HNSCC; 10%, n = 39). Seventy percent (152/216) had CD4+ T cell counts ≥200 cells/µL, and 94% (179/190) had HIV viral load <400 copies/mL. Twenty percent (79/390) had any grade immune-related adverse events (irAEs) and 7.7% (30/390) had grade ≥3 irAEs. ORRs were 69% (nonmelanoma skin cancer), 31% (NSCLC), 16% (HCC), and 11% (HNSCC). In the matched mNSCLC cohort (61 PWH v 110 PWOH), 20% (12/61) PWH and 22% (24/110) PWOH had irAEs. Adjusted 42-month RMST difference was -0.06 months (95% CI, -5.49 to 5.37; P = .98) for PFS and 2.23 months (95% CI, -4.02 to 8.48; P = .48) for OS.

CONCLUSION

Among PWH, ICIs demonstrated differential activity across cancer types with no excess toxicity. Safety and activity of ICIs were similar between matched cohorts of PWH and PWOH with mNSCLC.

Machine learning-based immune phenotypes correlate with STK11/KEAP1 co-mutations and prognosis in resectable NSCLC: a sub-study of the TNM-I trial

BACKGROUND

We aim to implement an immune cell score model in routine clinical practice for resected non-small-cell lung cancer (NSCLC) patients (NCT03299478). Molecular and genomic features associated with immune phenotypes in NSCLC have not been explored in detail.

PATIENTS AND METHODS

We developed a machine learning (ML)-based model to classify tumors into one of three categories: inflamed, altered, and desert, based on the spatial distribution of CD8+ T cells in two prospective (n = 453; TNM-I trial) and retrospective (n = 481) stage I-IIIA NSCLC surgical cohorts. NanoString assays and targeted gene panel sequencing were used to evaluate the association of gene expression and mutations with immune phenotypes.

RESULTS

Among the total of 934 patients, 24.4% of tumors were classified as inflamed, 51.3% as altered, and 24.3% as desert. There were significant associations between ML-derived immune phenotypes and adaptive immunity gene expression signatures. We identified a strong association of the nuclear factor-κB pathway and CD8+ T-cell exclusion through a positive enrichment in the desert phenotype. KEAP1 [odds ratio (OR) 0.27, Q = 0.02] and STK11 (OR 0.39, Q = 0.04) were significantly co-mutated in non-inflamed lung adenocarcinoma (LUAD) compared to the inflamed phenotype. In the retrospective cohort, the inflamed phenotype was an independent prognostic factor for prolonged disease-specific survival and time to recurrence (hazard ratio 0.61, P = 0.01 and 0.65, P = 0.02, respectively).

CONCLUSIONS

ML-based immune phenotyping by spatial distribution of T cells in resected NSCLC is able to identify patients at greater risk of disease recurrence after surgical resection. LUADs with concurrent KEAP1 and STK11 mutations are enriched for altered and desert immune phenotypes.

Epigenomic charting and functional annotation of risk loci in renal cell carcinoma

While the mutational and transcriptional landscapes of renal cell carcinoma (RCC) are well-known, the epigenome is poorly understood. We characterize the epigenome of clear cell (ccRCC), papillary (pRCC), and chromophobe RCC (chRCC) by using ChIP-seq, ATAC-Seq, RNA-seq, and SNP arrays. We integrate 153 individual data sets from 42 patients and nominate 50 histology-specific master transcription factors (MTF) to define RCC histologic subtypes, including EPAS1 and ETS-1 in ccRCC, HNF1B in pRCC, and FOXI1 in chRCC. We confirm histology-specific MTFs via immunohistochemistry including a ccRCC-specific TF, BHLHE41. FOXI1 overexpression with knock-down of EPAS1 in the 786-O ccRCC cell line induces transcriptional upregulation of chRCC-specific genes, TFCP2L1, ATP6V0D2, KIT, and INSRR, implicating FOXI1 as a MTF for chRCC. Integrating RCC GWAS risk SNPs with H3K27ac ChIP-seq and ATAC-seq data reveals that risk-variants are significantly enriched in allelically-imbalanced peaks. This epigenomic atlas in primary human samples provides a resource for future investigation.

Association of Machine Learning-Based Assessment of Tumor-Infiltrating Lymphocytes on Standard Histologic Images With Outcomes of Immunotherapy in Patients With NSCLC

Importance

Currently, predictive biomarkers for response to immune checkpoint inhibitor (ICI) therapy in lung cancer are limited. Identifying such biomarkers would be useful to refine patient selection and guide precision therapy.

Objective

To develop a machine-learning (ML)-based tumor-infiltrating lymphocytes (TILs) scoring approach, and to evaluate TIL association with clinical outcomes in patients with advanced non-small cell lung cancer (NSCLC).

Design, Setting, and Participants

This multicenter retrospective discovery-validation cohort study included 685 ICI-treated patients with NSCLC with median follow-up of 38.1 and 43.3 months for the discovery (n = 446) and validation (n = 239) cohorts, respectively. Patients were treated between February 2014 and September 2021. We developed an ML automated method to count tumor, stroma, and TIL cells in whole-slide hematoxylin-eosin-stained images of NSCLC tumors. Tumor mutational burden (TMB) and programmed death ligand-1 (PD-L1) expression were assessed separately, and clinical response to ICI therapy was determined by medical record review. Data analysis was performed from June 2021 to April 2022.

Exposures

All patients received anti-PD-(L)1 monotherapy.

Main Outcomes and Measures

Objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) were determined by blinded medical record review. The area under curve (AUC) of TIL levels, TMB, and PD-L1 in predicting ICI response were calculated using ORR.

Results

Overall, there were 248 (56%) women in the discovery cohort and 97 (41%) in the validation cohort. In a multivariable analysis, high TIL level (≥250 cells/mm2) was independently associated with ICI response in both the discovery (PFS: HR, 0.71; P = .006; OS: HR, 0.74; P = .03) and validation (PFS: HR = 0.80; P = .01; OS: HR = 0.75; P = .001) cohorts. Survival benefit was seen in both first- and subsequent-line ICI treatments in patients with NSCLC. In the discovery cohort, the combined models of TILs/PD-L1 or TMB/PD-L1 had additional specificity in differentiating ICI responders compared with PD-L1 alone. In the PD-L1 negative (<1%) subgroup, TIL levels had superior classification accuracy for ICI response (AUC = 0.77) compared with TMB (AUC = 0.65).

Conclusions and Relevance

In these cohorts, TIL levels were robustly and independently associated with response to ICI treatment. Patient TIL assessment is relatively easily incorporated into the workflow of pathology laboratories at minimal additional cost, and may enhance precision therapy.

Germline variants associated with toxicity to immune checkpoint blockade

Immune checkpoint inhibitors (ICIs) have yielded remarkable responses but often lead to immune-related adverse events (irAEs). Although germline causes for irAEs have been hypothesized, no individual variant associated with developing irAEs has been identified. We carried out a genome-wide association study of 1,751 patients on ICIs across 12 cancer types. We investigated two irAE phenotypes: (1) high-grade (3-5) and (2) all-grade events. We identified 3 genome-wide significant associations (P < 5 × 10-8) in the discovery cohort associated with all-grade irAEs: rs16906115 near IL7 (combined P = 3.6 × 10-11; hazard ratio (HR) = 2.1); rs75824728 near IL22RA1 (combined P = 3.5 × 10-8; HR = 1.8); and rs113861051 on 4p15 (combined P = 1.2 × 10-8, HR = 2.0); rs16906115 was replicated in 3 independent studies. The association near IL7 colocalized with the gain of a new cryptic exon for IL7, a critical regulator of lymphocyte homeostasis. Patients carrying the IL7 germline variant exhibited significantly increased lymphocyte stability after ICI initiation, which was itself predictive of downstream irAEs and improved survival.

Ancestry-driven recalibration of tumor mutational burden and disparate clinical outcomes in response to immune checkpoint inhibitors

The immune checkpoint inhibitor (ICI) pembrolizumab is US FDA approved for treatment of solid tumors with high tumor mutational burden (TMB-high; ≥10 variants/Mb). However, the extent to which TMB-high generalizes as an accurate biomarker in diverse patient populations is largely unknown. Using two clinical cohorts, we investigated the interplay between genetic ancestry, TMB, and tumor-only versus tumor-normal paired sequencing in solid tumors. TMB estimates from tumor-only panels substantially overclassified individuals into the clinically important TMB-high group due to germline contamination, and this bias was particularly pronounced in patients with Asian/African ancestry. Among patients with non-small cell lung cancer treated with ICIs, those misclassified as TMB-high from tumor-only panels did not associate with improved outcomes. TMB-high was significantly associated with improved outcomes only in European ancestries and merits validation in non-European ancestry populations. Ancestry-aware tumor-only TMB calibration and ancestry-diverse biomarker studies are critical to ensure that existing disparities are not exacerbated in precision medicine.

The Prostate Cancer Androgen Receptor Cistrome in African American Men Associates with Upregulation of Lipid Metabolism and Immune Response

African-American (AA) men are more likely to be diagnosed with and die from prostate cancer than European American (EA) men. Despite the central role of the androgen receptor (AR) transcription factor in prostate cancer, little is known about the contribution of epigenetics to observed racial disparities. We performed AR chromatin immunoprecipitation sequencing on primary prostate tumors from AA and EA men, finding that sites with greater AR binding intensity in AA relative to EA prostate cancer are enriched for lipid metabolism and immune response genes. Integration with transcriptomic and metabolomic data demonstrated coinciding upregulation of lipid metabolism gene expression and increased lipid levels in AA prostate cancer. In a metastatic prostate cancer cohort, upregulated lipid metabolism associated with poor prognosis. These findings offer the first insights into ancestry-specific differences in the prostate cancer AR cistrome. The data suggest a model whereby increased androgen signaling may contribute to higher levels of lipid metabolism, immune response, and cytokine signaling in AA prostate tumors. Given the association of upregulated lipogenesis with prostate cancer progression, our study provides a plausible biological explanation for the higher incidence and aggressiveness of prostate cancer observed in AA men.

SIGNIFICANCE

With immunotherapies and inhibitors of metabolic enzymes in clinical development, the altered lipid metabolism and immune response in African-American men provides potential therapeutic opportunities to attenuate racial disparities in prostate cancer.

Pan-cancer (ca) analysis of the safety and efficacy of immune checkpoint inhibitors (ICI) in patients (pts) living with HIV (PLWH): Results from the international CATCH-IT consortium

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Background: PLWH and ca are inadequately represented in clinical trials evaluating ICI especially in the setting of low CD4 counts (ct) and elevated HIV viral loads (VL). We assembled an international cohort of PLWH and ca treated with ICI to evaluate toxicity profiles and clinical outcomes. Methods: We retrospectively collected data on 204 PLWH and ca receiving ≥ 1 cycle of ICI between 2015-2021 at 14 academic medical centers in the US and Europe. Immune-related adverse events (irAEs) were graded per the Common Terminology Criteria for Adverse Events (CTCAE) V5.0. Baseline CD4 ct, CD8 ct and HIV VL were collected within 3 months (mo) of ICI initiation when available. Fisher’s exact test was performed to compare categorical variables. Median (med) Overall Survival (OS) and Objective Response Rate (ORR) were calculated for 186 pts treated in the metastatic (met) setting. Results: Among 204 PLWH treated with ICI, 174 (85%) were cis-gender males. 61 (31%) were Black and 34 (18%) were Hispanic/Latinx. Pts were treated with pembrolizumab (n=93), nivolumab (n=71), atezolizumab (n= 20), nivolumab and ipilimumab (n=13), durvalumab (n=6), or avelumab (n=1). Med number of prior lines of systemic therapy was 1 (range: 0-5). Among pts with available baseline data, 36/133 (27%) had CD4 ct <200 cells/µL while 12/136 (9%) had VL ≥400 copies/mL. irAEs of any grade occurred in 43 (21%) pts and 13 (7%) were grade ≥3 while 19 (9%) required steroids. Pts with CD4 ct <200 cells/µL experienced fewer irAEs than pts with CD4 ct ≥200 cells/µL (2/36 vs 26/97; p<0.01). The incidence of any grade irAEs was similar between pts with CD4/CD8 ratio <0.4 vs ≥0.4 (8/54 vs 18/72; p=0.16) and between pts with HIV VL ≥400 vs <400 copies/mL (1/12 vs 28/124; p=0.46). Clinical outcomes are shown in the table below. Among 29 pts with met non-small cell lung ca (NSCLC) with available CD4 ct, the ORR of pts with CD4 ct <200 cells/µL was 13% (95% CI:0-53) vs 38% (95% CI:18-62) in pts with CD4 ct ≥ 200 cells/µL (1/8 vs 8/21; p=0.38). Conclusions: In the largest dataset to our knowledge, we demonstrate tolerability and activity of ICI among PLWH regardless of CD4 ct and HIV VL levels. CD4 ct <200 cells/µL may be associated with a lower incidence of irAEs. An analysis of a larger cohort is underway. [Table: see text]

Comparison of outcomes for Hispanic and non-Hispanic patients with advanced renal cell carcinoma in the International Metastatic Renal Cell Carcinoma Database

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Background: Epidemiologic studies suggest that Hispanic patients with renal cell carcinoma (RCC) have worse outcomes than non-Hispanic White patients (NHW). It is unclear if this disparity is related to inherent biological differences or patients’ social determinants of health (SDOH). Utilizing the International Metastatic Renal Cell Carcinoma Database (IMDC) of patients with RCC primarily receiving care at academic medical centers, we investigated outcomes of Hispanic and NHW patients with advanced RCC. Methods: Eligible patients included patients who self-reported being non-Black Hispanic or NHW with locally advanced or metastatic RCC initiating systemic therapy. The primary endpoint was overall survival (OS) and secondary endpoint was time to treatment failure (TTF) for the first-line therapy. Kaplan Meier curves were constructed for OS and TTF. Cox regression was used to estimate hazard ratios (HR) adjusted for confounding variables. Results: The cohort included 1,563 patients, of which 181 (11.6%) were Hispanic. Most patients were male (74%) with clear cell histology (82%). IMDC risk groups were 18%, 58%, 24% for favorable, intermediate, and poor risk, respectively, and were similar by ethnic groups. Compared to NHW, Hispanic patients were younger at diagnosis (median 57 vs 59 years, p = 0.036), less likely to have > 1 metastatic site (61% vs 77%, p < 0.001) and bone metastases (24% vs 33%, p = 0.009). 1,178 patients (124 Hispanic vs. 1,054 NWH) received treatment before 2018, 385 patients (57 Hispanic vs. 328 NWH) received treatment during or after 2018. With regards to first line therapy, the majority received tyrosine kinase inhibitor (TKI) monotherapy (70%), 10% received immunotherapy (IO) + IO, 9% received TKI + IO, 4% received IO monotherapy, and 8% received other treatments. Median TTF was 7.8 months (95% Confidence Interval (CI): 6.2-9.0) in Hispanic patients and 7.5 months (95% CI: 6.9-8.1) in NHW patients. On multivariable analysis, there was no significant difference in TTF between Hispanic and NHW patients (HR 1.05, 95% CI: 0.89-1.25, p = 0.558). Significant predictors of TTF were presence of unfavorable site of metastases, histology, IMDC risk group, and therapy type. Median OS was 38.0 months (95% CI: 28.1-59.2) in Hispanic patients and 35.7 months (95% CI: 31.9-39.2) in NHW patients. On multivariable analysis, there was no significant difference in OS between Hispanic and NHW patients (HR 1.07, 95% CI: 0.87-1.32, p = 0.544). Significant predictors of OS were number of metastatic sites, presence of unfavorable metastasis, histology, IMDC risk group, and therapy type. Conclusions: In this analysis, we did not detect a difference in OS or TTF for Hispanic patients with RCC. Our data suggest that access to care (as available in a tertiary cancer hospital) can mitigate the historic difference in outcomes in Hispanic versus NWH patients.

Germline variants across self-reported racial populations with urothelial carcinoma (UC)

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Background: Prior studies of the UC germline landscape centered around White patients with minimal representation of other racial populations. Herein, we examine the frequency of germline pathogenic and likely pathogenic (P/LP) variants in 2,582 patients with UC from various racial populations. Methods: 2,582 patients with UC underwent germline testing of 1 to 126 genes using massively parallel sequencing with customized capture bait-sets to analyze exonic regions, flanking intronic regions, and copy number alterations (CNAs). P/LP variants including single nucleotide variants, indels and CNAs were reported. Fisher’s Exact test and multivariable logistic regression were used after accounting for the number of genes tested, age at diagnosis, site of disease (upper versus lower tract), gender, family history of UC, and personal history of any cancer. Results: Among the 2,582 patients with UC, median age at diagnosis was 63 years (range, 4-90) and 1158 (44.8%) were female. There were 58 Asians (2.2%), 110 Blacks (4.3%), and 2,414 Whites (93.5%). Overall, 1,639/2,582 (63.5%) patients had a personal history of another cancer and 284/2,393 (11.9%) had history of UC in a family member. 465 P/LP variants were identified in 18% of patients, among whom 286 (11.1%) harbored ≥1 clinically actionable variants. P/LP in cancer-associated genes were most frequently reported in MSH2 (72/2,512, 2.9%), monoallelic MUTYH (45/2,136, 2.1%), BRCA2 (44/2,299, 1.9%) and MSH6 (47/2,511, 1.9%). Patients with upper tract UC had significantly more P/LP (72/247, 29.1%) compared to lower tract UC (332/2,076, 16%, p= 1.3x10-5). Age at diagnosis, gender, personal history of other primary cancers, or family history of UC were not significantly associated with the prevalence of P/LP variants. There were no significant differences ( p= 0.33) in P/LP variants across Asians (11/58, 19.0%), Blacks (14/110, 12.7%), and Whites (440/2,414, 18.2%) although a trend towards lower P/LP in Blacks is notable. Compared to Whites, Blacks and Asians harbored significantly more variants of unknown significance (VUS, Whites vs Blacks: 241/2414 vs 25/110, p= 0.0015; Whites vs Asians: 241/2414 vs 17/58, p= 4e-7). Asians with UC harbored significantly more P/LP variants in ATM (2/50, 4%) compared to Whites (30/2122, 1.4%, OR = 1.1 [95% CI, 1.0-1.2]) and Asian controls from the gnomAD Database. There were no significant differences across racial populations for other highly altered genes ( BRCA1/2, CHEK2, FH, MSH2/6, MUTYH) or for actionable variants. Conclusions: Germline P/LP variants were identified in 18% of patients with UC and were enriched in upper tract tumors. Although no significant differences in P/LP prevalence were noted among patients of different racial populations, a trend towards lower P/LP in Blacks and a higher rate of VUS in Asians and Blacks suggest that ongoing analysis by genetic ancestry may provide richer admixture data and insights.

Dual CDKN2A/MTAP loss compared to CDKN2A loss alone and response to immune-checkpoint inhibitors (ICI) in advanced solid tumors

2622

Background: We previously showed that CDKN2A genomic alterations (GAs) are associated with resistance to ICI (Adib E, Clinical Cancer Research, 2021). The majority of such GAs are homozygous deletions, which commonly (̃50-80%) include MTAP, located 100kb telomeric of CDKN2A. MTAP loss leads to 5′-deoxy-5′-methylthioadenosine (MTA) accumulation and immunosuppressive effects in tumors. We examined combined CDKN2A/MTAP deletion vs. CDKN2A deletion/mutation alone as predictors of poor ICI response. Methods: We curated clinical data for cancer patients (pts) treated with ICI at Dana-Farber Cancer Institute through 6/2021, who had targeted panel sequencing. Inclusion criteria were: ICI in metastatic setting, ≥2 cycles, no concurrent systemic therapy, cancer type with > 50 pts treated. CDKN2A/ MTAP GAs were defined as a deep deletion affecting both genes; CDKN2A only GAs included both homozygous deletions and truncating mutations. Hazard ratios (HR) for overall survival (OS) and time-to-treatment failure (TTF) were derived using multivariable Cox regression, adjusted for prior lines of therapy, treatment type (single vs. combination ICI), tumor mutational burden and ECOG PS. We also used a machine learning approach to quantify the density of tumor-infiltrating lymphocytes (TILs) in digital whole-slide H&E images of 144 melanoma pts with available genomic data. Results: 921 pts with 6 cancer types were studied: non-small cell lung cancer (NSCLC, n = 366), melanoma (mel, n = 228), urothelial carcinoma (UC, n = 120), esophagogastric carcinoma (EGC,n = 90), head and neck squamous cell carcinoma (HNSCC, n = 58), and renal cell carcinoma (RCC, n = 59). UC pts with MTAP/ CDKN2A GAs had shorter OS and TTF than pts without GA in either gene (OS HR = 1.9[1.1-3.4], p = 0.005; TTF HR = 1.8[1.0-3.1], p = 0.0016) after adjusting for covariates. Similar results were seen for melanoma (OS HR = 2.5[1.4-2.6],p = 0.00065; TTF HR = 1.9[1.1-3.2],p = 0.018). There was no significant difference between pts with CDKN2A GA only and those without GA in either gene for OS or TTF in either UC or melanoma. CDKN2A/MTAP status was not associated with significantly shorter survival for NSCLC and EGC; while the analysis was confounded by HPV events for HNSCC, and underpowered for RCC. ML-based analysis of digital slides for melanoma, showed that tumors with CDKN2A GAs only (n = 42) had similar median density of TILs compared to tumors without GAs in either gene (n = 84; 920 vs. 943 TILs/mm2; p = 0.42). In contrast, tumors with co-occurring CDKN2A/ MTAP GAs had lower TIL density (529 TIL/mm2, n = 17 vs. 925 TIL/mm2, n = 126 (pooled); p = 0.018, Wilcoxon rank sum). Conclusions: In this study, we showed that co-occurrence of MTAP/CDKN2A GAs, but not CDKN2A GA only, was associated with worse outcomes in pts with UC and melanoma treated with ICI. Lower TIL density was also seen in melanoma tissue samples with combined MTAP/CDKN2A GA.

Distinct oncogenic signatures in malignant PEComa and leiomyosarcoma identified by integrative RNA-seq and H3K27ac ChIP-seq analysis

11552

Background: Malignant perivascular epithelioid cell tumor (PEComa) and leiomyosarcoma (LMS) are two sarcomas with overlapping morphologic and immunophenotypic features which can make their diagnostic distinction challenging. We aimed to characterize the transcriptional and epigenetic landscape of PEComa and LMS to identify distinguishing features. Methods: We performed whole transcriptome RNA-sequencing on 19 PEComas and compared their gene expression profile to 259 sarcomas from The Cancer Genome Atlas (TCGA) including 104 LMS. ChIP-sequencing for H3K27ac, a histone modification associated with activation of nearby genes/open chromatin, was conducted on 9 malignant PEComas and 12 LMS and were compared with publicly available data from 4 other sarcoma subtypes (chordoma; osteosarcoma; undifferentiated pleomorphic sarcoma; rhabdomyosarcoma; n = 29 tumors). Results: Genome-wide epigenetic and transcriptional analyses revealed overlapping patterns between PEComa and LMS, which were distinct from other sarcomas. However, we also identified a set of highly expressed and epigenetically distinct transcripts which may represent diagnostic?biomarkers: e.g., DAPL1, MLANA, SULT1C2, GPR143, and CHI3L1 for PEComa; and MYOCD, WDFC2, DES, MYH11, and CNN1 for LMS; each of which showed >17x fold higher expression for each tumor entity by DESeq2 (FDR<0.0001). Gene Set Enrichment Analyses (GSEA) demonstrated enrichment in the KEGG Lysosome pathway for PEComa (FDR=0.11), whereas myogenesis and smooth muscle contraction pathways were enriched in LMS (FDR=0.09). Integrative transcriptomic and epigenetic analyses revealed a unique set of master core transcription factors for each tumor type including among others MYOCD for LMS; MITF for PEComa, which require further functional investigation. Twelve selected genes including new as well as known and standard diagnostic markers (e.g., DAPL1, MLANA, GPR143, PNL2, CHI3L1, DES, MYH11, ER, CD68, PU.1, pS6 and CNN1) were validated by immunohistochemistry (IHC) in multiple sections from PEComa and LMS (n = 26). The combination of three melanocytic markers (HMB45, MLANA, PNL2) and pS6 can distinguish LMS from PEComas (**** p<0.0001). IHC for CD68 and PU.1 macrophage markers did not show any difference regarding the degree of immune infiltration in PEComa vs. LMS. Conclusions: Our studies revealed novel epigenetic signatures translating into lysosomal and melanocytic proteins for PEComa and myogenic proteins for LMS, which may serve as useful diagnostic biomarkers in the distinction of these two sarcoma subtypes.

TSC1-mutant bladder cancer expression signature in relation to nuclear localization of TFE3 and potential for targetable dependency

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Background: Mutation and inactivation of the tumor suppressor gene TSC1 is a recurrent (6-10%) event in bladder cancer, but whether it functions as a driver event for tumor development has been uncertain. Methods: We performed differential gene expression and pathway analyses using RNA-seq data from the curated TCGA TSC1 mutant BLCA (n = 26) and TSC1 wild-type BLCA (n = 382) cohort and compared to an internal cohort of putative TSC1/TSC2-driven tumors (n = 63). Mechanistic studies, as well as RNA-seq and H3K27ac ChIP-seq analyses, were conducted in 2 TSC1 mutant/WT BLCA cell lines. Results: Comparison of The Cancer Genome Atlas (TCGA) TSC1-mutant bladder cancers ( TSC1mBLCA) with TCGA TSC1 wildtype tumors ( TSC1WTBLCA) identified a conserved TSC-associated expression signature, similar to ones seen in syndromic TSC tumors. GSEA and DESeq2 analyses implicated both mTORC1 hyperactivation, as well as activation of lysosomal pathways in TSC1mBLCA. We validated our findings by IHC analysis of a separate cohort of TSC1mBLCA (n = 5), compared to TSC1WTBLCA (n = 5). In addition, we found that TFE3, a transcriptional regulator of lysosomal gene expression, was relatively highly expressed in BLCA (compared to other MiT-TFE genes) and was localized to the nucleus in TSC1mBLCA but not in TSC1WTBLCA. Mechanistic studies of two TSC1mBLCA cell lines and their respective TSC1 addback derivatives, recapitulated the phenotype found in human tumors and demonstrated that TFE3 was both post-translationally modified and predominantly nuclear in TSC1-null cell lines compared to TSC1 addbacks. RNA-seq and H3K27ac ChIP-Seq analyses showed that TSC1mBLCA cell lines retained elements of the TSC-associated expression signature that was seen in TSC1mBLCA tumors, confirming differential activation of TFE3 in response to TSC1 loss. Nuclear localization of TFE3 in TSC1mBLCA cell lines was only partially reversed by rapamycin treatment and was unaffected by treatment of Torin1. SiRNA mediated knockdown of TFE3 significantly decreased cell growth and viability in TSC1mBLCA cell lines and did not result in compensatory upregulation of TFEB and MITF. Conclusions: Our findings indicate that TSC1 mutant bladder tumors retain elements of a conserved transcriptional signature that is characterized by nuclear localization and activation of TFE3. Aberrant TFE3 activation likely contributes to TSC1mBLCA development and may therefore be amenable to targeted therapy.

Risk and predictors of ipilimumab-associated cardiac adverse events among patients treated for melanoma: A national cohort analysis

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Background: Ipilimumab is a CTLA-4 inhibitor widely used to treat advanced melanoma. While ipilimumab-induced cardiac immune-related adverse events (irAE) have been reported, there is a paucity of data from large cohorts. We investigated the risk and predictors of ipilimumab-associated cardiac irAE in a national cohort of patients with cutaneous melanoma. Methods: Using SEER-Medicare linked data, we compared the risk of cardiac irAE between patients treated with ipilimumab with or without concomitant treatment for cutaneous melanoma and controls not treated with ipilimumab following a primary diagnosis of cutaneous melanoma. We excluded patients ≤65 years and patients with cardiac comorbidities diagnosed within one year prior to the initiation of melanoma treatment. The primary endpoint was the incidence of at least one cardiac irAE after ipilimumab initiation including acute pericarditis, myocarditis, cardiomyopathy, conduction disorders, cardiac dysthymias, acute heart failure, and takotsubo syndrome. To estimate the risk of cardiac irAE, we conducted a multivariable competing-risk analysis adjusting for death of any cause within one year of treatment as a competing event. Then, we constructed a stepwise logistic regression to assess the predictors of having at least one cardiac irAE within one year of ipilimumab initiation. Subgroup analysis was conducted among patients who received ipilimumab only. The models were adjusted for patient demographics, disease stage, Charlson comorbidity index (CCI), history of hypertension, autoimmune disease, end stage renal disease (ESRD), chronic anticoagulant, and steroid use. Results: The cohort included 715 patients treated with ipilimumab and 22,070 controls. In the ipilimumab arm, 23.4% had metastatic disease, 9.5% had a history of autoimmune disease, and 2.2% had CCI≥2. The incidence rates of cardiac irAE among patients who received ipilimumab and among the control group were 23.3 and 13.6 per 1,000 person-years, respectively. We found that patients who received ipilimumab had a higher risk of cardiac irAE compared to controls (adjusted hazard ratio 1.87; 95%CI 1.50-2.32; p < 0.001). In addition to ipilimumab treatment, other predictors of cardiac irAE included male gender, older age, patients with metastatic disease, history of autoimmune disease, hypertension, ESRD, anticoagulant use, and CCI≥2. The predictors of cardiac irAE were also consistent in the subgroup analysis of patients who received ipilimumab only. Conclusions: Patients who received ipilimumab with or without concomitant treatment for cutaneous melanoma had a higher risk for cardiac irAE. Predictors of cardiac irAE help tailor therapy according to patients’ risk profiles.

Artificial intelligence in digital pathology approach identifies the predictive impact of tertiary lymphoid structures with immune-checkpoints therapy in NSCLC

9065

Background: The presence of Tertiary Lymphoid Structures (TLS) in multiple cancer types has been recognized as a potential predictive biomarker for response to immune-checkpoint blockade. However, there is no standardized method to quantify their presence. In this context, Artificial Intelligence (AI)-based assessment of histology images may well contribute to improve reproducibility, accuracy and speed of TLS quantification. Methods: We developed an automated workflow for quantification of TLS on digitized H&E slides through A) pixel-level classification of tissue using supervised artificial neural networks model, B) object-level cell classification of candidate TLS regions, C) merging the two approaches for curation and validation of TLS versus non-TLS regions. 433 advanced stage non-small cell lung cancer (NSCLC) patients treated with first or subsequent line of anti-PD-(L)1 single agent at DFCI were included in this study. Results: TLS were detected in 37% (n = 161) of the patients H&E slides, with the highest score of 4.7 TLS per mm2 (interquartile range: Q1 = 0, Q2 = 0, Q3 = 0.03 TLS/mm2). TLS density (per mm2) was significantly higher in surgically resected (n = 246; TLSPOS= 49%) compared to bioptic samples (n = 187; TLSPOS= 21%). No association was observed between TLS and tumor mutational burden (TMB) or PD-L1 protein expression as continuous variables. Among clinically actionable mutations, EGFR (all subtypes) mutated patients (n = 38) had a significantly lower number of TLS compared to patients without EGFR mutations. Patients with ≥ 0.01 TLS/mm2 had a significantly higher objective response rate (32% vs 22%, p = 0.03), a significantly longer median progression-free survival (PFS, 4.8 vs 2.7 months, HR: 0.73, 95% CI: 0.59-0.90, p = 0.004), and a significantly improved median overall survival (OS, 16.5 vs 12.5 months, HR: 0.72, 95% CI: 0.57-0.92, p = 0.008). In multivariable analysis, after adjusting for PD-L1 (≥ vs < 50%), TMB (≥ vs < 10 mu/Mb), sex, age, ECOG score, smoking and line of treatment, TLS/mm2 (≥ vs < 0.01) levels were found to be an independent positive predictive factor for both PFS (HR:0.69, 95% CI: 0.54-0.88, p = 0.003) and OS (HR: 0.70, 95% CI: 0.52-0.93, p = 0.01). Conclusions: These findings suggest that TLS status is an independent predictor of immunotherapy effectiveness in NSCLC, with predictive value similar to that of PD-L1 expression and TMB. This novel AI system has potential for automated identification and quantification of the TLS on digital histopathological slides, and could be utilized in a standard pathology workflow with relative ease. These findings are currently being validated in other solid tumors and cohorts.

Digital quantification of lymphocytic infiltration on routine H&E images and immunotherapy response in non–small cell lung cancer

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Background: Current biomarker(s) for immuno-oncology (IO) therapy response prediction in lung cancer are limited. Additional predictive biomarkers are useful to help refine patient selection and guide precision therapy. Methods: Biopsy and surgical specimens stained with hematoxylin-eosin (H&E) were subjected to whole-slide scanning for 446 advanced stage non-small cell lung cancer (NSCLC) treated with single agent immune check point inhibitors (ICI). A machine learning model was trained on H&E images for classification of tumor infiltrating lymphocytes (TILs), tumor cells, and stromal cells in specific tissue types. Results: TIL levels were found to be highly variable, with a range of 12 to 4270 cells/mm2, and median of 319 (Q1 = 159, Q3 = 681). TIL levels were assessed on tissue samples from multiple organs which had shown primary or metastatic NSCLC, and were similar across all specimen sites except the liver, for which median TIL levels were significantly lower, at 90 cells/mm2. There was no correlation between tumor mutational burden (TMB) and TIL levels, while high TIL levels were correlated with high PD-L1 (≥ 50%) expression. Patients who experienced a partial/complete response to ICI therapy had a trend to higher median TILs compared to those who had progressive/stable disease (350 versus 310 cells/mm2, P = 0.09). In a multivariable analysis after controlling for covariates (incl. sex, age, cigarette smoking, ECOG, PD-L1, TMB & treatment line), a higher TIL level (≥ 250 cells/mm2) was an independent predictor of IO response for both progression-free survival (PFS; HRadj 0.70; 95% CI, 0.55 - 0.89; P = 0.003) and overall survival (HRadj 0.73; 95% CI, 0.56 - 0.95; P = 0.02). In a ROC analysis considering single biomarkers, PD-L1 had the highest AUC (0.68, P < 0.001), while TIL (AUC = 0.53, P = 0.08) and TMB (AUC = 0.55, P = 0.05) had similar AUC values for classifying responders from non-responders based on objective response rate. Using weighted linear regression approach to combine the biomarkers, paired PD-L1/TMB had the greatest AUC (0.70, P < 0.001) compared to PD-L1 single assay. In the PD-L1 negative (< 1%, N = 50) subgroup, TIL levels had superior predictive performance for classification of IO responders (AUC = 0.77, P = 0.02) compared to TMB (AUC = 0.57, P = 0.3), such that patients with a high TIL level (≥ 250 cells/mm2) had an improved PFS (median PFS: 2.7 vs 2.2 months; HR = 0.48; 95% CI, 0.26 - 0.87; P = 0.02). Conclusions: Digital TIL quantification with use of machine learning is feasible. TIL levels appear to be a robust and independent biomarker of likelihood of response to IO treatment in NSCLC, especially in the PD-L1 negative subgroup. The findings of this study are under validation in additional lung cancer cohorts.

Variation in targetable genomic alterations in non-small cell lung cancer by genetic ancestry, sex, smoking history, and histology

Background

Genomic alterations in 8 genes are now the targets of FDA-approved therapeutics in non-small cell lung cancer (NSCLC), but their distribution according to genetic ancestry, sex, histology, and smoking is not well established.

Methods

Using multi-institutional genetic testing data from GENIE, we characterize the distribution of targetable genomic alterations in 8 genes among 8675 patients with NSCLC (discovery cohort: DFCI, N = 3115; validation cohort: Duke, Memorial Sloan Kettering Cancer Center, Vanderbilt, N = 5560). For the discovery cohort, we impute genetic ancestry from tumor-only sequencing and identify differences in the frequency of targetable alterations across ancestral groups, smoking pack-years, and histologic subtypes.

Results

We identified variation in the prevalence of KRAS^G12C, sensitizing EGFR mutations, MET alterations, ALK, and ROS1 fusions according to the number of smoking pack-years. A novel method for computing continental (African, Asian, European) and Ashkenazi Jewish ancestries from panel sequencing enables quantitative analysis of the correlation between ancestry and mutation rates. This analysis identifies a correlation between Asian ancestry and EGFR mutations and an anti-correlation between Asian ancestry and KRAS^G12C mutation. It uncovers 2.7-fold enrichment for MET exon 14 skipping mutations and amplifications in patients of Ashkenazi Jewish ancestry. Among never/light smokers, targetable alterations in LUAD are significantly enriched in those with Asian (80%) versus African (49%) and European (55%) ancestry. Finally, we show that 5% of patients with squamous cell carcinoma (LUSC) and 17% of patients with large cell carcinoma (LCLC) harbor targetable alterations.

Conclusions

Among patients with NSCLC, there was significant variability in the prevalence of targetable genomic alterations according to genetic ancestry, histology, and smoking. Patients with LUSC and LCLC have 5% rates of targetable alterations supporting consideration for sequencing in those subtypes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13073-022-01041-x.

Prevalence of pathogenic germline cancer risk variants in testicular cancer patients: Identifying high risk groups

BACKGROUND

Germline studies in testicular cancer have focused on unselected populations but so far have not led to recommendations for testicular cancer screening.

OBJECTIVE

Herein, we hypothesized that men with testicular cancer and an additional risk factor for hereditary cancer predisposition carry a higher rate of pathogenic variants than men with testicular cancer without another risk factor.

METHODS AND RESULTS

187 patients with a personal history of testicular cancer underwent germline testing via Invitae. Patients were divided into low-risk and high-risk patients. Low-risk patients (n=83) had testicular cancer as their only primary malignancy without a family history of testicular cancer. High-risk patients (n=104) had additional primary malignancies and/or a family history of testicular cancer. 23.1% of patients harbored pathogenic germline variants with 19.6% carrying actionable variants. Among low-risk patients, 13.5% carried pathogenic variants versus 29.9% in the high-risk cohort. Of patients with a family history of non-testicular cancers and a personal history of additional primary malignancies, 32% harbored pathogenic variants.

CONCLUSION

High-risk patients are twice as likely to harbor pathogenic variants compared to low-risk patients. Importantly, patients with a family history of cancer and other primary malignancies represent a subset of patients that may benefit from genetic evaluation.

Comprehensive metabolomic profiling of plasma from patients (pts) with metastatic urothelial carcinoma (mUC) receiving immune checkpoint inhibitors (ICI) or platinum-based chemotherapy (PBC)

565

Background: Metabolomic profiling of plasma from mUC pts has not been comprehensively examined. Plasma metabolomics may capture the effects of interactions between the malignancy, host and therapy. We hypothesized that Identifying metabolites in plasma from patients with mUC receiving an ICI or PBC may shed valuable insights regarding tumor biology and mechanisms of resistance. Methods: We obtained 0.2 ml plasma before and after starting therapy from pts with mUC receiving an ICI or PBC at the Dana-Farber Cancer Institute. Plasma metabolomic profiling was conducted at the Broad Institute using 3 complementary liquid chromatography tandem mass spectrometry (LC-MS)-based metabolomics platforms. We measured 648 metabolites at baseline prior to starting ICI/PBC and at a second time point in each subject following initiation of ICI/PBC. Metabolite levels were assumed to be normally distributed with log transformation to transform distributions to be approximately symmetric. We performed Wilcoxon-rank sum test to compare the levels of metabolites before and after initiation of the ICI or PBC (significance at p < 0.05). Results: Plasma was available at baseline and during therapy in 53 mUC pts (ICI: n = 43; PBC: n = 10). The median age was 68 (range: 39-86) years and 42 (82.3%) were male. The median time from baseline to the second time point was 4.7 months (range: 0.7-90.2). The ICIs administered were atezolizumab (n = 20), pembrolizumab (n = 16), nivolumab (n = 5), and durvalumab + tremelimumab (n = 1). We identified 20 metabolites that were significantly increased in post-PBC plasma samples (vs. pre-PBC) and 19 metabolites increased in post-ICI (vs. pre-ICI) samples (p < 0.05). All altered metabolites except one (Uracil) were exclusive for each treatment group. The most significant metabolites that increased following initiation of the ICI and PBC are shown in the Table. Evaluation of the association of plasma metabolomics with clinical outcomes and toxicities is ongoing. Conclusions: This is the first report, to our knowledge, of comprehensive metabolomic plasma profiling of pre- and post-ICI and PBC pts with mUC. The metabolomic changes after ICI appear distinct from those seen after PBC. Furthermore, our study sheds insights on potential mechanisms of resistance and new therapeutic targets in pts with mUC.[Table: see text]

Early changes in peripheral blood neutrophil-lymphocyte ratio (NLR) to predict outcomes with immune checkpoint inhibitors (ICIs) for metastatic urothelial carcinoma (mUC)

449

Background: ICIs have provided advances in the therapy of mUC. However, the objective determination of benefit from ICIs determined by radiographic imaging may take months and may be confounded by pseudoprogression. Peripheral blood cells appear to reflect tumor microenvironment immune infiltrating cells. Given the known prognostic impact of baseline peripheral blood NLR, we aimed to investigate dynamic early changes in NLR as a biomarker of benefit in patients (pts) with mUC. Methods: Deidentified data from mUC pts who were treated with ICIs at Dana Farber Cancer Institute from 2015 to 2020 were reviewed retrospectively. Demographic data (age, gender), setting (untreated vs. post-platinum), sites of metastasis, performance status (PS), platelet count, and NLR at baseline and 3-4 weeks after initiating the ICI were collected. We assessed the association of NLR at baseline and 3-4 weeks after starting the ICI with any regression of tumor (ART) and overall survival (OS). A multivariable logistic regression model and Cox proportional-hazards model was employed to identify the association of NLR changes with ART and OS, respectively, using backward selection. Results: A total of 144 pts were included. The median age was 76 years and 100 (69.3%) were male. Overall, 54.8% (n=79) had ART and the median OS was 15.2 (12.2-23.5) months. 37.5% (n=54) were platinum naive and the remaining received post-platinum ICI therapy. In the multivariable models (Table), an increase in NLR, defined as an increase in NLR by ≥1.0 from baseline at 3-4 weeks was significantly associated with lower odds of ART (Odds Ratio (OR)= 0.80; 95% CI = 0.70-0.90; p = 0.0004) and worse OS (HR = 1.08; 95% CI = 1.05-1.11; p < 0.0001). The presence of liver metastasis was associated with lower odds of ART (OR = 0.30; 95% CI = 0.13-0.70; p = 0.006) and OS (HR 2.73; 95% CI 1.71 - 4.36; p<0.0001). Conclusions: Change in NLR in the first 4 weeks after initiating ICI for mUC was associated with tumor regression and survival in pts with mUC. Change in NLR may assist in early identification of benefit as well as identification of pts who may have progression of disease. Further validation is warranted to facilitate the early discrimination of benefit from ICIs in pts with mUC.[Table: see text]

Association of changes in albumin levels with survival and toxicities in patients (pts) with metastatic urothelial carcinoma (mUC) receiving enfortumab vedotin (EV)

481

Background: EV is an anti-Nectin-4 antibody-drug conjugate that has been approved by the US FDA for mUC progressing on platinum and PD1/L1 inhibitor therapy and in cisplatin-ineligible pts following prior therapy. However, prognostic and predictive biomarkers in the setting of EV therapy are unclear. We aimed to investigate baseline and early changes in commonly available clinical and laboratory tests that could help predict survival and toxicities in patients with mUC treated with EV. Methods: Data from patients with mUC who were treated with EV at Dana Farber Cancer Institute between 2017 and 2021 were reviewed retrospectively. We assessed the association of demographic (age, sex), clinical (ECOG-performance status [PS], sites of metastasis) and laboratory variables (hemoglobin, RDW, neutrophil count, lymphocyte count, neutrophil-to-lymphocyte ratio, platelet count and serum albumin) at baseline as well as after 4-7 weeks of treatment with Overall Survival (OS) by constructing univariate and multivariable Cox proportional-hazards models. Any variables significantly associated with OS at the univariate level (using an alpha-level of 0.1 to determine statistical significance) were then entered into the multivariable model. Predictors were eliminated from the final multivariable models by a backward selection process, retaining only those with a p-value of ≤ 0.05. Results: A total of 49 patients who received EV were included in the analysis. The median age was 72 years (range 48-88) and 36 (73.5%) were male. The median OS was 13.3 months (range: 2.7-38.7) and grade 3-4 toxicities were seen in 11 pts (22.4%). In the final multivariable models, lower serum albumin at 4-7 weeks (HR = 0.18; 95% CI = 0.05-0.71; p = 0.015), and baseline ECOG-PS of 1 vs. 0 (HR = 2.56; 95% CI = 1.05-6.21; p = 0.038) were significantly associated with worse OS (Table). Patients with higher serum albumin levels at 4-7 weeks also had significantly lower odds of experiencing grade 3-4 adverse events on EV (OR = 0.05; 95% CI = 0.002-0.52; p = 0.02). Conclusions: Lower serum albumin appeared to predict worse survival and severe toxicities in mUC pts receiving EV. This information may guide therapy and assist in the prevention of toxicities. Additionally, ECOG-PS was prognostic while the location of metastatic disease was not prognostic in the setting of EV.[Table: see text]

Impact of angiotensin-converting enzyme inhibitors (ACEi) on pathologic complete response with neoadjuvant chemotherapy (NAC) for muscle-invasive bladder cancer (MIBC)

485

Background: The renin-angiotensin system (RAS) has been demonstrated to modulate cell proliferation, desmoplasia, angiogenesis and immunosuppression. Angiotensin pathway inhibitors are postulated to favorably reprogram the stroma in part by inhibition of transforming growth factor-β, a major mechanism of resistance, and have been previously reported to be associated with improved outcomes in the setting of immune checkpoint inhibitors (ICIs) for metastatic urothelial carcinoma (Jain R, Clin Genitourin Cancer 2021). In this analysis, we examined the association of angiotensin inhibitors in the setting of NAC for MIBC preceding radical cystectomy (RC). Methods: Pts with MIBC who received NAC preceding radical cystectomy were assembled from 3 institutions: Dana-Farber Cancer Institute (DFCI), Moffitt Cancer Center (MCC) and McGill University Health Center (MUHC). Pts were retrospectively assessed for the association of concurrent ACEi/angiotensin receptor blockers (ARB) use at initiation of NAC on pathologic complete response (pCR), defined as pT0N0, and overall survival (OS). Pathologic features, performance status (PS), clinical stage, type/number of cycles of NAC, and toxicities were collected. The Kaplan-Meier method was used to estimate OS. Logistic and Cox regression were used to explore factors potentially prognostic for pCR and OS respectively. Results: 302 MIBC pts who received NAC preceding RC were available from 3 institutions: DFCI (n = 187), MCC (n = 50) and MUHC (n = 65). Overall, 141 pts (46.7%) received Cisplatin/Gemcitabine, 130 (43.1%) received dose dense MVAC and the remaining received other regimens. The overall pCR rate was 26.2%. The 5-year OS was 62%. 63 (20.9%) pts were receiving an ACEi and 41 (13.6%) were receiving an ARB. ACEi prior to NAC approached significance for association with pCR (odds ratio = 1.71 (95% CI = 0.94-3.11) p = 0.077). Pts with cT3/4N0-N1 disease receiving ACEi had higher pCR rates (30.8% (8/26) vs 17.7% (14/98), p = 0.056) than those not on ACEi; no difference was observed for pts with cT2N0 tumors (31.1% vs 31.3%, p = 0.99). pCR, ECOG-PS and clinical stage were significantly associated with improved OS. ARB intake was not associated with pCR or OS. Conclusions: ACEi intake appeared potentially associated with increased pCR in pts with MIBC receiving NAC, which was more pronounced in those with higher clinical stages cT3/4N0-1. Given the association of pCR with OS, our data suggest the potential relevance of angiotensin as a therapeutic target in aggressive MIBC. Future prospective validation is warranted to repurpose angiotensin inhibitors in this setting, given their excellent toxicity profile and low costs.

Multiplexed autoantibody (AA) profiling of patients (pts) with metastatic urothelial carcinoma (mUC) receiving immune checkpoint inhibitors or platinum-based chemotherapy

558

Background: The AA profile may be altered in malignancies and provide insights into tumor biology and the immune state. We hypothesized that the longitudinal AA profiling of mUC pts receiving an immune checkpoint inhibitor (ICI) may provide insights into the immune response, which may be associated with immune events and help discover new therapeutic targets. Methods: We utilized serum from mUC pts receiving an ICI or platinum-based chemotherapy (PBC) at the Dana-Farber Cancer Institute. Age and sex matched healthy controls were also studied. The SeroTag immuno-oncology discovery array (Oncimmune) was utilized, with quantification of the AA reactivity towards 1150 antigens. Bound autoantibodies were detected using an anti-IgG-specific detection antibody conjugated to the fluorescent reporter dye phycoerythrin. The AA reactivity was reported as the median fluorescence intensity (MFI) for each color and sample using a Luminex FlexMAP3D analyzer. A significance analysis of microarrays was performed to identify AAs with elevated levels in bladder cancer compared to matched healthy controls (HCs). AAs with > 1.5 increase between pre- and post-treatment were reported. Scatter and box-whisker plots were reported for all pts and antigens, respectively. Results: Pre- (n = 66) and post treatment (n = 65) serum samples were available from mUC pts receiving pembrolizumab (n = 25), atezolizumab (n = 21), nivolumab (n = 5), avelumab (n = 1), durvalumab + tremelimumab (n = 1), nivolumab plus vaccine (n = 1), and 12 pts who received PBC (cisplatin n = 8, carboplatin n = 4). The median duration between the pre- and post-therapy samples was 6 months, median age was 67.7 years (range 40-91) with 51 men (77.3%). Overall, significant heterogeneity of AAs between pts was observed with 37 AAs showing higher reactivity in pre-treatment mUC pts vs. 47 HCs, notably anti-CTAG1 (NY-ESO-1), CTAG2 (NY-ESO-2), MAGE B-18, KRAS, GRB2, RARRES2, HSP72 and FGFR3 (all p < 0.05). Pre- and post-therapy AA profiles were similar with unique changes seen in each patient. Notably, 3 pts receiving an ICI developed AAs to NY-ESO-1. Pts receiving PBC less frequently developed new AAs, although pts treated with cisplatin appeared to develop AAs more frequently compared to carboplatin-treated pts. Conclusions: This is the first report of a comprehensive AA profile using a novel platform in mUC pts. The study identified multiple elevated AAs in mUC pts vs. HCs, most notably NY-ESO-1, which also developed in some pts following ICIs. Pts treated with PBC did not develop new AAs frequently, although there appeared to be a difference between cisplatin and carboplatin-based chemotherapy. Further development of this platform is warranted to provide data that is orthogonal to genomic/transcriptomic profiling and shed insights on potential therapeutically actionable antigens.

FOXP3+ T-cell infiltration is associated with improved outcomes in metastatic urothelial carcinoma (mUC) treated with immune-checkpoint inhibitors (ICI)

549

Background: Given that ICIs benefit a minority of mUC patients and are associated with significant costs, biomarkers are necessary to optimally utilize them in the clinic. Although FOXP3+ T-cells have been associated with an immune-cold environment in many cancers, studies in urothelial carcinoma have shown an opposite trend. Methods: Formalin-fixed paraffin-embedded slides from tumor specimens were collected for patients with mUC treated with ICI at Dana-Farber Cancer Institute. A novel multiplex immunofluorescence (mIF) panel, ImmunoProfile, was performed for PD-L1, PD-1, FOXP3, CD8 and DAPI, then scanned by a Vectra Polaris platform. Regions of interest were defined and used for quantitative analysis using PerkinElmer/Akoya. Intratumoral (IT) and tumor-stroma interface (TSI) density (cells/mm2) of each cell type was calculated. Clinical data was collected through chart review, and associations between cell density and response were assessed. Wilcoxon Rank-Sum test between responders (CR/PR) and non-responders (SD/PD) was used to generate p-values, followed by Benjamini-Hochberg correction. Receiver-operating curve (ROC) and area-under-curve (AUC) calculations were performed to determine the optimal cutoff (OC) differentiating responders from non-responders. Cox proportional hazards models were used to estimate OS and PFS, accounting for type of therapy (single vs. combination ICI), baseline neutrophil-to-lymphocyte ratio (NLR), PD-L1 CPS, prior therapy, non-urothelial component, ECOG-PS and liver metastases (mets). Results: Of 35 patients assessed by ImmunoProfile, 32 were evaluable for response. Most patients (88%) were male and the median age at ICI start was 73 years. Median number of prior lines of therapy was 1 (range 0 – 3), and the majority (72%) was treated with single-agent ICI. Eight patients (25%) had CR/PR, eight had SD and 16 had PD as best response. Of all IF stains assessed, IT-TSI FOXP3 was the strongest predictor of objective response (q-value = 0.006), followed by IT-CD8 (q = 0.014). ROC analysis yielded an AUC of 0.812 (0.656 – 0.969) and the optimal cutpoint was set at 75 IT-TSI-FOXP3 cells/mm2. ORR was 46% in FOXP3-high ( > 75/mm2) vs 14% in FOXP3-low mUCs. A combined model using IT-TSI-FOXP3 and clinical covariates (NLR, ECOG-PS, line of therapy, histology, and liver mets) had an AUC of 0.929. PFS was significantly longer in the FOXP3-high group (7.9 [5.7 – NR] months) compared to the FOXP3-low group (2.3 [2.1 – 6.1] months) on multivariable analysis (p = 0.007). OS also showed the same trend (p = 0.1). Conclusions: In this pilot study of ImmunoProfile, a novel mIF panel, higher FOXP3+ infiltration in tumors was associated with better outcomes and a composite clinico-IHC panel exhibited robust prognostic impact in mUC pts treated with ICI. Further study of this mIF panel is warranted to implement it in routine practice.

Biomarker-Based Phase II Study of Sapanisertib (TAK-228): An mTORC1/2 Inhibitor in Patients With Refractory Metastatic Renal Cell Carcinoma

PURPOSE

Sapanisertib is a kinase inhibitor that inhibits both mammalian target of rapamycin complex 1 (mTORC1) and mTORC2. In this multicenter, single-arm phase II trial, we evaluated the efficacy of sapanisertib in patients with treatment-refractory metastatic renal cell carcinoma (mRCC; NCT03097328).

METHODS

Patients with mRCC of any histology progressing through standard therapy (including prior mTOR inhibitors) had baseline biopsy and received sapanisertib 30 mg by mouth once weekly until unacceptable toxicity or disease progression. The primary end point was objective response rate by RECIST 1.1. Tissue biomarkers of mTOR pathway activation were explored.

RESULTS

We enrolled 38 patients with mRCC (clear cell = 28; variant histology = 10) between August 2017 and November 2019. Twenty-four (63%) had received ≥ 3 prior lines of therapy; 17 (45%) had received prior rapalog therapy. The median follow-up was 10.4 (range 1-27.4) months. Objective response rate was two of 38 (5.3%; 90% CI, 1 to 15.6); the median progression-free survival (PFS) was 2.5 months (95% CI, 1.8 to 3.7). Twelve patients (32%) developed treatment-related grade 3 adverse events, with no grade 4 or 5 toxicities. Alterations in the mTOR pathway genes were seen in 5 of 29 evaluable patients (MTOR n = 1, PTEN n = 3, and TSC1 n = 1) with no association with response or PFS. Diminished or loss of PTEN expression by immunohistochemistry was seen in 8 of 21 patients and trended toward shorter PFS compared with intact PTEN (median 1.9 v 3.7 months; hazard ratio 2.5; 95% CI, 0.9 to 6.7; P = .055).

CONCLUSION

Sapanisertib had minimal activity in treatment-refractory mRCC independent of mTOR pathway alterations. Additional therapeutic strategies are needed for patients with refractory mRCC.

Synergistic antitumor activity of pan-PI3K inhibition and immune checkpoint blockade in bladder cancer

Background

Immune checkpoint blockade (ICB) induces durable response in approximately 20% of patients with advanced bladder urothelial cancer (aUC). Over 50% of aUCs harbor genomic alterations along the phosphoinositide 3-kinase (PI3K) pathway. The goal of this project was to determine the synergistic effects and mechanisms of action of PI3K inhibition and ICB combination in aUC.

Methods

Alterations affecting the PI3K pathway were examined in The Cancer Genome Atlas (TCGA) and the Cancer Dependency Map databases. Human and mouse cells with Pten deletion were used for in vitro studies. C57BL/6 mice carrying syngeneic tumors were used to determine in vivo activity, mechanisms of action and secondary resistance of pan-PI3K inhibition, ICB and combination.

Results

Alterations along the PI3K pathway occurred in 57% of aUCs in TCGA. CRISPR (clustered regularly interspaced short palindromic repeats) knockout of PIK3CA induced pronounced inhibition of cell proliferation (p=0.0046). PI3K inhibition suppressed cancer cell growth, migration and colony formation in vitro. Pan-PI3K inhibition, antiprogrammed death 1 (aPD1) therapy and combination improved the overall survival (OS) of syngeneic mice with PTEN-deleted tumors from 27 days of the control to 48, 37, and 65 days, respectively. In mice with tumors not containing a PI3K pathway alteration, OS was prolonged by the combination but not single treatments. Pan-PI3K inhibition significantly upregulated CD80, CD86, MHC-I, and MHC-II in dendritic cells, and downregulated the transforming growth factor beta pathway with a false discovery rate-adjusted q value of 0.001. Interferon alpha response was significantly upregulated with aPD1 therapy (q value: <0.001) and combination (q value: 0.027). Compared with the control, combination treatment increased CD8⁺ T-cell infiltration (p=0.005), decreased T_reg-cell infiltration (p=0.036), and upregulated the expression of multiple immunostimulatory cytokines and granzyme B (p<0.01). Secondary resistance was associated with upregulation of the mammalian target of rapamycin (mTOR) pathway and multiple Sprr family genes.

Conclusions

The combination Pan-PI3K inhibition and ICB has significant antitumor effects in aUC with or without activated PI3K pathway and warrants further clinical investigation. This combination creates an immunostimulatory tumor milieu. Secondary resistance is associated with upregulation of the mTOR pathway and Sprr family genes.

Gene Expression Signature Correlates with Outcomes in Metastatic Renal Cell Carcinoma Patients Treated with Everolimus Alone or with a Vascular Disrupting Agent

Everolimus monotherapy use for metastatic renal cell carcinoma (mRCC) has diminished due to recent approvals of immune checkpoint and VEGF inhibitors. We hypothesized that gene expression associated with everolimus benefit may provide rationale to select appropriate patients. To address this hypothesis, tumors from a phase I/II trial that compared everolimus alone or with BNC105P, a vascular disrupting agent, were profiled using Nanostring as a discovery cohort. A phase III trial (CheckMate 025) was used for validation. Clinical benefit (CB) was defined as response or stable disease for ≥6 months. A propensity score covariate adjustment was used, and model discrimination performance was assessed using the area under the ROC curve (AUC). In a discovery cohort of 82 patients, 35 (43%) were treated with everolimus alone and 47 (57%) received everolimus + BNC105P. Median PFS (mPFS) was 4.9 (95% CI, 2.8-6.2) months. A four-gene signature (ASXL1, DUSP6, ERCC2, and HSPA6) correlated with CB with everolimus ± BNC105P [AUC, 86.9% (95% CI, 79.2-94.7)]. This was validated in 130 patients from CheckMate 025 treated with everolimus [AUC, 60.2% (95% CI, 49.7-70.7)]. Among 43 patients (52.4%) with low expression of an 18-gene signature, everolimus + BNC105P was associated with significantly longer mPFS compared with everolimus alone (10.4 vs. 6.9 months; HR, 0.49; 95% CI, 0.24-1.002; P = 0.047). These signatures warrant further validation to select patients who may benefit from everolimus alone or with a vascular disrupting agent.

CDKN2A Alterations and Response to Immunotherapy in Solid Tumors

PURPOSE

Immune checkpoint inhibitors (ICI) have shown clinical benefit in many types of metastatic cancers with only a few predictive biomarkers identified so far. CDKN2A is commonly altered in human cancers, but prior studies have provided conflicting evidence regarding the association between CDKN2A genomic alterations (GA) and response to ICIs. Herein, we examined the impact of loss-of-function CDKN2A alterations on response and survival in patients treated with ICIs.

EXPERIMENTAL DESIGN

We studied the association between loss-of-function CDKN2A alterations and the response to ICIs in two independent cohorts of six different cancer types. Seven hundred and eighty-nine patients treated at Dana-Farber Cancer Institute (DFCI; Boston, MA) and 1,250 patients treated at Memorial Sloan Kettering Cancer Center (MSKCC; New York, NY) were included in the final analysis. Patients' tumors were sequenced using Oncopanel or MSK-IMPACT. RNA sequencing data from The Cancer Genome Atlas and IMvigor210 were used to investigate differences in the tumor microenvironment.

RESULTS

In the DFCI cohort, CDKN2A GAs were associated with poor response and survival in patients with urothelial carcinoma treated with ICIs, but not those treated with platinum-based therapy. Similarly, CDKN2A GAs were associated with worse outcomes in the MSKCC urothelial carcinoma cohort treated with ICIs. There was no association of CDKN2A status with ICI treatment outcome in five other cancers: esophagogastric, head and neck, non-small cell lung, renal cell carcinoma, and melanoma. Immuno-inflammatory pathways were significantly reduced in expression in CDKN2A-altered tumors.

CONCLUSIONS

Our data show that CDKN2A GAs were associated with reduced benefit from ICI therapy in urothelial carcinoma as well as changes in the tumor-immune microenvironment.

The impact of antibiotic (Ab) exposure on clinical outcomes in patients with metastatic renal cell carcinoma (mRCC) treated with immune checkpoint inhibitors (ICI) or VEGF targeted therapy (VEGF-TT)

4552

Background: Retrospective studies have shown an association between Ab exposure and inferior clinical outcomes in patients receiving ICI across various tumor types, including mRCC. However, it is unclear whether Ab exposure has a unique interaction with ICI or is an independent prognostic marker, regardless of treatment. We sought to examine Ab exposure and its association with clinical outcomes in patients with mRCC treated with ICI compared to VEGF-TT. Methods: We identified patients treated with ICI (anti-PD-L1 alone or in combination with VEGF or CTLA4 inhibitor) or VEGF-TT alone in first to fourth line settings from 2009-2020 across 3 academic centers in North America. Ab exposure was defined as administration of Ab within 60 days prior to initiation of systemic therapy. Outcomes of interest were response rate (RR), time to treatment failure (TTF) and overall survival (OS). Multivariable Cox regression was performed to control for imbalances in International mRCC Database Consortium (IMDC) risk factors, histology, and treatment line. Results: We identified 748 patients. Among the ICI (n=427) and VEGF-TT (n=321) cohorts, 13% vs 15% (p=0.47) had Ab exposure and 57% vs 48% (p=0.046) were treated in the first line setting. The proportion of favorable, intermediate, and poor risk disease by IMDC criteria differed between Ab exposed and unexposed patients in the ICI (14% vs 18%, 47% vs 62%, 39% vs 21% p=0.03) and VEGF-TT (7% vs 13%, 43% vs 60%, 50% vs 27%, p=0.01) cohorts. RR, TTF and OS results are displayed in Table 1. Multivariable analysis did not show a significant independent association between Ab exposure and OS in both the ICI (HR 1.13, p=0.62) and VEGF-TT (HR 1.32, p=0.16) cohorts. Treatment modality (ICI vs VEGF-TT) did not modify the effect of Ab exposure on OS (p=0.84). Conclusions: Ab exposure was associated with higher IMDC risk scores in both the ICI and VEGF-TT cohorts as well as inferior OS on univariable analysis. After adjusting for IMDC risk factors, histology and treatment line, we were unable to find an independent association between Ab exposure and OS in multivariable analysis for either cohort.[Table: see text]

Genetic ancestry and clinical outcomes to immune checkpoint inhibitors among seven common cancers

10536

Background: Prior studies and clinical trials report associations between self-reported race and clinical outcomes to Immune Checkpoint Inhibitors (ICIs). However, comprehensive studies of ancestry-associated differences in clinical outcomes have not been performed. We derived genetic ancestry scores and assessed clinical outcomes in 1341 patients with cancer treated with ICIs. Methods: Patients at the Dana-Farber Cancer Institute treated with ICIs only and with relevant cancer types and targeted exome sequencing data (Oncopanel) were included. Relevant cancer types included colorectal adenocarcinoma (CRC), esophagogastric adenocarcinoma (EGC), head and neck squamous cell carcinoma (HNSCC), melanoma, non-small cell lung cancer (NSCLC), renal cell carcinoma (RCC), and urothelial carcinoma (UC). We developed a bioinformatics pipeline to infer fine-scale genetic ancestry for each patient (n=1341) directly from tumor sequencing data by leveraging off and on-target sequenced reads and external ancestry reference panels. Three ancestry scores were determined (African, East Asian, European). Overall survival (OS) and time-to-treatment failure (TTF) were compared by Cox logistic regression between ancestral populations. Hazard ratio (HR) was derived using multivariable analysis, adjusted for single versus combination therapy, prior lines of therapy, and tumor mutational burden (TMB, as percentiles). Results: Median follow-up was 37.8 months (m; interquartile range: 35.7-39.5m). Common cancer types included CRC (n=52), EGC (n=114), HNSCC (n=88), melanoma (n=274), NSCLC (n=571), RCC (n=99), and UC (n=143). A higher East Asian ancestry (EAS) was significantly associated with worse OS ( p=0.03) and TTF ( p=0.002) in patients with RCC, independent of the histologic subtype (Table). There was no significant association between any of the three ancestral populations and clinical outcomes in the other 6 cancer types. Conclusions: We described clinical outcomes to ICIs across three global populations in 7 cancers. As the medical field re-evaluates the use of self-reported race in clinical decision-making, we utilize a novel ancestry pipeline that can be readily applied to tumor-only sequencing panels and better characterize non-white populations. We find no ancestry differences in clinical outcomes except in patients with RCC treated with ICIs which will require future validation. We plan to analyze genomic correlates of response by ancestry in each of the cancer types to better understand these diverge clinical behaviors.[Table: see text]

Genomic landscape of malignnant mesothelioma by site and histology

8559

Background: Malignnant mesothelioma (MM) is a highly lethal tumor that can develop in the pleura, the peritoneum, the pericardium or the testes. While the genomic features of pleural MM have been well-described overall, less is known about the distribution of genetic alterations (GAs) according to histology. In addition, few reports comparing genetic features according to disease site are available. Methods: We identified patients with pleural or peritoneal mesothelioma with mutational analysis through the GENIE registry. Patient tumor genetic data were provided by Memorial Sloan-Kettering Cancer Center (MSK)-IMPACT and Dana-Farber Cancer Institute (DFCI)-Oncopanel NGS initiatives. Patients with more than one sequenced sample were excluded. We limited our analysis to genes common to all versions of both panels and that were significantly mutated in the TCGA mesothelioma cohort. Mutation and copy number variant (CNV), collectively called GAs, were determined, and were compared using the Fisher’s Exact test and Kruskal-Wallis Test. Comparisons were made both by disease site (pleural vs. peritoneal) and histology for the pleural samples (epithelioid vs. biphasic vs. sarcomatoid). Nominal p-values were obtained, and FDR correction was employed (q<0.1). Results: We identified 439 patients with MM in the GENIE registry who fit the inclusion criteria. The median age was 70.5 years for pleural MM and 60 years for peritoneal MM (Wilcoxon-rank sum test p-value = 3e-9). 72% of patients were male. CDKN2A/CDKN2B GAs (97% and 100% being deletions in CDKN2A and CDKN2B respectively), a described prognostic marker in MM, were more common in pleural than in peritoneal MM. Among pleural MMs, tumors of epithelioid histology had less NF2 GAs than biphasic or sarcomatoid tumors, whereas sarcomatoid tumors had the lowest frequency of BAP1 GAs (Table). Conclusions: Malignnant mesotheliomas of different disease sites and/or histologies display distinct patterns of GAs. These findings may contribute in part to differences in response to treatment and survival among these subsets of MM.[Table: see text]

Improving tumor mutational burden calibration in non-European patients

1559

Background: Tumor mutational burden (TMB), has been recently granted FDA approval as a biomarker for ICI treatment in tumors with a high mutation load (≥ 10/MB). To leverage this biomarker in the clinical setting, it is necessary to evaluate its application in diverse patient populations. In particular, tumor-only sequencing may overestimate TMB in non-EUR populations for which reference panels are small or unavailable, and thus have poorer predictive performance. Herein, we investigate the effect of TMB overestimation in non-EURs on patient diagnosis and clinical outcomes in a real world patient cohort. Methods: TMB was computed using a tumor-only NGS platform (Oncopanel) for 8349 cancer patients (pts) of 7 cancer types (Table). Genetic ancestry was inferred directly from tumor sequencing data and confirmed for a subset of pts using germline SNP arrays. TMB was compared using Wilcoxon rank-sum test between European (EUR) and non-EUR pts. TMB percentile rank by ancestral group (East Asian, African, European) and tumor histology was computed. In non-EUR pts, TMB was calibrated by reassigning its value to the corresponding percentile rank in EUR pts having the same cancer (AH-TMB). Tumors with raw TMB ≥ 10/MB were assigned as TMB-high (TMBH; with the rest referred to as TMBL for TMB-low) and those with calibrated AH-TMB ≥ 10/MB as AH-TMBH. A subset of pts treated with ICIs at DFCI and of EUR ancestry were analyzed. TMB was intentionally mis-calibrated in EURs (MC-TMB), to mimic the TMB overestimation observed in non-EURs. Associations between TMBH status and overall survival (OS) was assessed using Cox regression. Results: Uncalibrated TMB was significantly higher in tumors from non-EUR pts overall (p <0.0001, Table) as anticipated, whereas this difference was not observed in tumors with matched germline filtering. We reassigned non-EUR pts into low/high groups using calibrated AH-TMB, which changed the assignment of 67/670 non-EURs, most of which (65/67) were downgraded from TMBH to AH-TMBL. In the ICI-treated cohort, there was a strong association between TMBH status and OS (p = 2e-11, HR = 0.6) whereas MC-TMBH (mimicking the miscalibration in non-EUR samples) had a weaker association with OS (p = 0.0013, HR = 0.8). Importantly, pts assigned to TMB-H due to miscalibration (90 TMB-L/MC-TMBH pts) had shorter OS compared to the true TMBH group (p = 3e-6, HR = 1.9). Conclusions: In this analysis, we showed that tumor-only sequencing platforms can overestimate TMB in non-EUR pts, impacting treatment decisions and outcomes. Replacing raw TMB counts with an ancestry-adjusted measure could optimize TMB application in the clinical setting when germline sequencing is not available. Accurate ancestry inference can be performed using tumor-only sequencing.[Table: see text]

Phase II Clinical Trial of Everolimus in a Pan-Cancer Cohort of Patients with mTOR Pathway Alterations

PURPOSE

This was a multicenter, histology-agnostic, single-arm prospective phase II trial of therapeutic activity of everolimus, an oral mTORC1 inhibitor, in patients with advanced solid tumors that harbored TSC1/TSC2 or MTOR mutations.

PATIENTS AND METHODS

Patients with tumors with inactivating TSC1/TSC2 or activating MTOR mutations identified in any Clinical Laboratory Improvement Amendments (CLIA)-certified laboratory were eligible. Patients were treated with everolimus 10 mg once daily until disease progression or unacceptable toxicity. The primary endpoint was objective response rate (ORR). Whole-exome sequencing was performed to identify co-occurring genomic alterations.

RESULTS

Between November 2015 and October 2018, 30 patients were enrolled at Dana-Farber Cancer Institute and Memorial Sloan Kettering Cancer Center. Tumors harbored TSC1 (13/30), TSC2 (15/30), concurrent TSC1 and TSC2 (1/30), or MTOR (1/30) mutations. The most common treatment-related adverse event of any grade was mucositis (8/30, 27%); 1 patient had fatal pneumonitis. Partial responses were seen in 2 patients [7%; 95% confidence interval (CI), 1%-22%]. Median progression-free survival was 2.3 months (95% CI, 1.8-3.7 months) and median overall survival (OS) was 7.3 months (95% CI, 4.5-12.7 months). There was no clear association between other genomic alterations and response. Of the 2 patients with objective response, 1 had upper tract urothelial carcinoma with biallelic inactivation of TSC1 and high tumor mutation burden, and the other had uterine carcinoma with biallelic TSC2-inactivating mutations and PEComa-like pathologic features.

CONCLUSIONS

Everolimus therapy had a disappointing ORR (7%) in this pan-cancer, mutation-selected, basket study.See related commentary by Kato and Cohen, p. 3807.

Trans-ethnic variation in germline variants of patients with renal cell carcinoma

Prior studies of the renal cell carcinoma (RCC) germline landscape investigated predominantly patients of European ancestry. We examine the frequency of germline pathogenic and likely pathogenic (P/LP) variants in 1,829 patients with RCC from various ancestries. Overall, P/LP variants are found in 17% of patients, among whom 10.3% harbor one or more clinically actionable variants with potential preventive or therapeutic utility. Patients of African ancestry with RCC harbor significantly more P/LP variants in FH compared to patients of non-African ancestry with RCC and African controls from the Genome Aggregation Database (gnomAD). Patients of non-African ancestry have significantly more P/LP variants in CHEK2 compared to patients of African ancestry with RCC and non-Finnish Europeans controls. Non-Africans with RCC have more actionable variants compared to Africans with RCC. This work helps understand the underlying biological differences in RCC between Africans and non-Africans and paves the way to more comprehensive genomic characterization of underrepresented populations.

Impact of FGFR2/3 activating genomic alterations on response to enfortumab vedotin in metastatic urothelial carcinoma (mUC)

472

Background: Enfortumab Vedotin (EV), an antibody-drug conjugate that targets nectin-4, is approved for metastatic urothelial carcinoma (mUC) progressing post-platinum and PD1/L1 inhibitor therapy. Erdafitinib is approved in patients for post-platinum mUC with activating genomic alterations in FGFR2/3, but the activity of EV in this subset is unclear. We investigated the activity of EV in patients (pts) with mUC based on FGFR2/3 genotype to inform management. Methods: In this multi-center, retrospective analysis, we assessed the objective response rate (ORR) to EV in mUC pts with and without FGFR2/3 genomic alterations detected by targeted panel next-generation sequencing. Activating gene fusions and known hotspots mutations in the two genes were considered. Descriptive analysis of ORR and patient characteristics was performed. Fisher’s exact test and binomial test with two-tailed p-value were used. Results: 40 pts were available from 4 institutions. Most pts were male (31/40, 78%) and the median age at start of EV was 74.1 (range 49 – 90) years. Ten patients (25%) had upper tract urothelial carcinoma (UTUC), and 33 (82%) had baseline ECOG performance status of 0-1. 31 of 39 patients had received both platinum-based chemotherapy and PD1/L1 inhibitors. Seven patients had confirmed activating hotspot FGFR3 mutations (p.S249C or p.Y373C). One pt had FGFR2 high-level amplification (HA), and one had FGFR3 HA. Of 36 patients evaluable for ORR, 18 had partial response (PR), 12 had stable disease (SD) and 6 had progressive disease (PD). Patients with FGFR2/3 activating mutations exhibited an ORR that was not statistically different compared to patients without no mutations: 2/7 (29%; 90% CI: 5 – 66%) vs. 16/29 (55%; 90% CI: 38 – 71%) respectively ( p-value = 0.4). 3/7 patients with FGFR3 hotspot mutations received an FGFR2/3 inhibitor and none responded; one of them had a sequential response to EV. Conclusions: In this multi-center retrospective cohort, FGFR2/3 activating genomic alterations did not appear to compromise response to EV in mUC. Larger studies are required to confirm our findings and optimal sequencing of EV and erdafitinib in mUC pts with FGFR2/3 genomic alterations requires further assessment.

Biomarker-based phase II study of sapanisertib (TAK-228), an mTORC1/2 inhibitor in patients with refractory metastatic renal cell carcinoma (mRCC)

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Background: Approved rapalogs inhibit mTORC1 and have limited activity in mRCC, possibly due to compensatory feedback loops. Sapanisertib addresses the incomplete inhibition of the mTOR pathway through targeting of both mTORC1 and mTORC2 with antitumour activity demonstrated in patients with mRCC. In this multicenter, single arm phase II trial, we evaluated the efficacy of sapanisertib in patients with mRCC progressing on standard therapies (NCT03097328). Methods: Eligible mRCC patients had an ECOG performance status of 0-2 and had progressed on standard therapies. Prior therapy with rapalogs (everolimus, temsirolimus) and variant RCC histologies were permitted. Patients had a baseline biopsy and received treatment with sapanisertib 30 mg by mouth weekly until unacceptable toxicity or disease progression. The primary endpoint was overall response rate (ORR) by RECIST 1.1. Tissue biomarkers of mTOR pathway activation were explored. Results: We enrolled 38 mRCC patients (clear cell = 28; variant histology = 10) between August 2017 and November 2019. The majority had intermediate (76%) or poor risk (11%) by IMDC criteria. Twenty (53%) had received ≥ 3 lines of therapy; 13 (34%) patients received prior rapalogs. Median follow-up was 10.4 months (range 1-27.4) and median duration of therapy was 1.6 (range 0.3-13.8) months. ORR by central review was 2 of 38 (5.3% 90%CI: 1%-15.6%). 31.6% of all patients and 30.7% of those with prior rapalog exposure had some tumor shrinkage during course of treatment. Median progression free survival (PFS) was 2.5 months (95% CI 1.8,3.7). Twelve patients (32%) developed treatment-related grade 3 adverse events (AEs) with no grade 4 or 5 toxicity reported; 6 patients (16%) required dose reduction and 4 (11%) discontinued therapy for AEs. Oncopanel tumor sequencing identified alterations in the mTOR pathway in 6 of 29 patients ( MTOR n = 2, PTEN n = 3, TSC1 n = 1.) Reduced PTEN expression by immunohistochemistry was seen in 7 of 19 patients. There was no association between mTOR pathway mutations or PTEN loss and response to sapanisertib. Conclusions: In this study we demonstrate minimal activity of sapanisertib in patients with treatment refractory mRCC with no clear benefit among patients with mTOR/PTEN pathway alterations. Additional treatment strategies are needed for patients with refractory mRCC.

Impact of concurrent ACE inhibitors and ARBs on outcomes with immune-checkpoint inhibitors (ICIs) for patients (pts) with metastatic renal cell carcinoma (mRCC)

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Background: The renin-angiotensin system (RAS) is involved in regulation of angiogenesis and cell proliferation and may improve drug delivery by enhancing tumor perfusion partly by downregulating transforming growth factor (TGF)-β. Since (TGF)-β appears to be associated with resistance in patients receiving immune checkpoint inhibitors (ICIs), we investigated whether angiotensin converting enzyme inhibitors (ACEI) and angiotensin receptor blockers (ARBs) may enhance the outcomes of mRCC pts receiving ICI. Methods: Data from mRCC pts who received ICIs at the Dana-Farber Cancer Institute (DFCI) was obtained. Data for ACEI and ARB administration was collected with concurrent administration defined as ongoing therapy from the time of starting ICI . The Kaplan-Meier method and Cox were used to evaluate the impact of concurrent ACEI/ARB on overall survival (OS). Results: Data was available for 134 pts. The mean age was 63 years (Range 37-85)). 94 (70%) pts were male. The therapies included Nivolumab+/-Other (104), Atezolizumab+/-Other (21), Pembrolizumab+/-Other (8) and Durvalumab +Tremelimumab (1). 35 (25%) pts received ICI as first line treatment, 52 (39%) received as second line treatment, and 48 (36%) received as third line or higher. Out of the 134 pts, 39 (29%) had been treated with an ACEI or ARB during ICI treatment. Out of the 39 pts who had ACEI or ARB, 2 (5%) had complete response (CR) as best response, 11 (28%) had partial response (PR), 17 (46%) had stable disease (SD) and 9 (23%) had progressive disease (PD). Out of the 95 pts who did not receive ACEI or ARB, 3 pts (3%) had CR as their best response to ICI, 19 (21%) had PR, 39 (43%) had SD, and 29 (32%) had PD, (5 patients’ best response were unevaluable). The median OS for those who had ACEI/ARBs and did not have ACEI/ARBs was 32 months and 20 months respectively. Univariable analysis revealed that patients who received ACEI/ARBs had improved OS (Logrank p-value = 0.002; HR = 2.5 [95%CI: 1.4 - 4.5]). Conclusions: In this hypothesis-generating study, concurrent ACEI/ARBs are associated with better outcomes for mRCC pts receiving ICIs. Given the availability of ACEI/ARBs, it is important to validate this result in a larger dataset and after controlling for known prognostic factors.