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.

Noninvasive Detection of Neuroendocrine Prostate Cancer through Targeted Cell-free DNA Methylation

Castration-resistant prostate cancer (CRPC) is a heterogeneous disease associated with phenotypic subtypes that drive therapy response and outcome differences. Histologic transformation to castration-resistant neuroendocrine prostate cancer (CRPC-NE) is associated with distinct epigenetic alterations, including changes in DNA methylation. The current diagnosis of CRPC-NE is challenging and relies on metastatic biopsy. We developed a targeted DNA methylation assay to detect CRPC-NE using plasma cell-free DNA (cfDNA). The assay quantifies tumor content and provides a phenotype evidence score that captures diverse CRPC phenotypes, leveraging regions to inform transcriptional state. We tested the design in independent clinical cohorts (n = 222 plasma samples) and qualified it achieving an AUC > 0.93 for detecting pathology-confirmed CRPC-NE (n = 136). Methylation-defined cfDNA tumor content was associated with clinical outcomes in two prospective phase II clinical trials geared towards aggressive variant CRPC and CRPC-NE. These data support the application of targeted DNA methylation for CRPC-NE detection and patient stratification.

SIGNIFICANCE

Neuroendocrine prostate cancer is an aggressive subtype of treatment-resistant prostate cancer. Early detection is important, but the diagnosis currently relies on metastatic biopsy. We describe the development and validation of a plasma cell-free DNA targeted methylation panel that can quantify tumor fraction and identify patients with neuroendocrine prostate cancer noninvasively. This article is featured in Selected Articles from This Issue, p. 384.

Comprehensive multiplexed autoantibody profiling of patients with advanced urothelial cancer

BACKGROUND

Comprehensive profiling of autoantibodies (AAbs) in metastatic urothelial cancer (mUC) has not been performed to date. This may aid in diagnosis of UC, uncover novel therapeutic targets in this disease as well as identify associations between AAbs and response and toxicity to systemic therapies.

METHODS

We used serum from patients with mUC collected prior to and after systemic therapy (immune checkpoint inhibitor (ICI) or platinum-based chemotherapy (PBC)) at Dana-Farber Cancer Institute. 38 age-matched and sex-matched healthy controls (HCs) from healthy blood donors were also evaluated. The SeroTag immuno-oncology discovery array (Oncimmune) was used, with quantification of the AAb reactivity toward 1132 antigens. Bound AAbs were detected using an anti-immunoglobulin G-specific detection antibody conjugated to the fluorescent reporter dye phycoerythrin. The AAb reactivity was reported as the median fluorescence intensity for each color and sample using a Luminex FlexMAP3D analyzer. Clinical outcomes of interest included radiographic response and development of immune-related adverse events (irAEs). Significance analysis of microarray was used to compare mUC versus HC and radiographic response. Associations with irAE were evaluated using a logistic regression model. P<0.05 was considered statistically significant.

RESULTS

66 patients were included with a median age of 68 years; 54 patients (82%) received ICI and 12 patients (18%) received PBC. Compared with HCs, AAbs against the cancer/testis antigens (CTAG1B, CTAG2, MAGEB18), HSPA1A, TP53, KRAS, and FGFR3 were significantly elevated in patients with mUC. AAbs against BRCA2, TP53, and CTNBB1 were associated with response, and those against BICD2 and UACA were associated with resistance to ICI therapy. AAbs against MITF, CDH3, and KDM4A were associated with development of irAEs in patient who received an ICI. A higher variance in pre-to-post treatment fold change in AAb levels was seen in patients treated with ICI versus PBC and was associated with response to ICI.

CONCLUSIONS

This is the first report of comprehensive AAb profiling of patients with mUC and identified key AAbs that were elevated in patients with mUC versus HCs as well as AAbs associated with therapeutic response to ICI. These findings are hypothesis generating and further mechanistic studies evaluating humoral immunity in UC are required.

Safety and efficacy of immune checkpoint inhibitors in advanced penile cancer: report from the Global Society of Rare Genitourinary Tumors

BACKGROUND

Treatment options for penile squamous cell carcinoma are limited. We sought to investigate clinical outcomes and safety profiles of patients with penile squamous cell carcinoma receiving immune checkpoint inhibitors.

METHODS

This retrospective study included patients with locally advanced or metastatic penile squamous cell carcinoma receiving immune checkpoint inhibitors between 2015 and 2022 across 24 centers in the United States, Europe, and Asia. Overall survival and progression-free survival were estimated using the Kaplan-Meier method. Objective response rates were determined per Response Evaluation Criteria in Solid Tumours 1.1 criteria. Treatment-related adverse events were graded per the Common Terminology Criteria for Adverse Events, version 5.0. Two-sided statistical tests were used for comparisons.

RESULTS

Among 92 patients, 8 (8.7%) were Asian, 6 (6.5%) were Black, and 24 (29%) were Hispanic and/or Latinx. Median (interquartile range) age was 62 (53-70) years. In all, 83 (90%) had metastatic penile squamous cell carcinoma, and 74 (80%) had received at least second-line treatment. Most patients received pembrolizumab monotherapy (n = 26 [28%]), combination nivolumab-ipilimumab with or without multitargeted tyrosine kinase inhibitors (n = 23 [25%]), or nivolumab (n = 16 [17%]) or cemiplimab (n = 15 [16%]) monotherapies. Median overall and progression-free survival were 9.8 months (95% confidence interval = 7.7 to 12.8 months) and 3.2 months (95% confidence interval = 2.5 to 4.2 months), respectively. The objective response rate was 13% (n = 11/85) in the overall cohort and 35% (n = 7/20) in patients with lymph node-only metastases. Visceral metastases, Eastern Cooperative Oncology Group (ECOG) performance status of 1 or higher, and a higher neutrophil/lymphocyte ratio were associated with worse overall survival. Treatment-related adverse events occurred in 27 (29%) patients, and 9.8% (n = 9) of the events were grade 3 or higher.

CONCLUSIONS

Immune checkpoint inhibitors are active in a subset of patients with penile squamous cell carcinoma. Future translational studies are warranted to identify patients more likely to derive clinical benefit from immune checkpoint inhibitors.

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.

A genetic basis for cancer sex differences revealed in Xp11 translocation renal cell carcinoma

Xp11 translocation renal cell carcinoma (tRCC) is a female-predominant kidney cancer driven by translocations between the TFE3 gene on chromosome Xp11.2 and partner genes located on either chrX or on autosomes. The rearrangement processes that underlie TFE3 fusions, and whether they are linked to the female sex bias of this cancer, are largely unexplored. Moreover, whether oncogenic TFE3 fusions arise from both the active and inactive X chromosomes in females remains unknown. Here we address these questions by haplotype-specific analyses of whole-genome sequences of 29 tRCC samples from 15 patients and by re-analysis of 145 published tRCC whole-exome sequences. We show that TFE3 fusions universally arise as reciprocal translocations with minimal DNA loss or insertion at paired break ends. Strikingly, we observe a near exact 2:1 female:male ratio in TFE3 fusions arising via X:autosomal translocation (but not via X inversion), which accounts for the female predominance of tRCC. This 2:1 ratio is at least partially attributable to oncogenic fusions involving the inactive X chromosome and is accompanied by partial re-activation of silenced chrX genes on the rearranged chromosome. Our results highlight how somatic alterations involving the X chromosome place unique constraints on tumor initiation and exemplify how genetic rearrangements of the sex chromosomes can underlie cancer sex differences.

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.

Enfortumab vedotin (EV) outcomes with and without immediate prior immune checkpoint inhibitor (ICI) in patients (pts) with advanced urothelial carcinoma (aUC)

514

Background: EV is FDA-approved in pts with aUC and ≥1 prior therapy line. Data from EV-103 trial indicate robust response to first-line EV/pembrolizumab, suggesting potentially at least additive treatment effect with EV/ICI combination. Given the long half-life of ICIs, pts who start EV treatment immediately after ICI may potentially derive benefit from that therapy sequence. We hypothesized that the last systemic therapy prior to EV would impact outcomes, as pts treated with ICI immediately prior to EV would have superior outcomes relative to pts treated with chemotherapy (chemo). Methods: UNITE is a retrospective study of pts treated with EV at 16 US sites. Pt characteristics and outcomes were abstracted from EMR review at each site. Observed response was determined by investigators for evaluable pts with scans following ≥1 EV dose. Pts treated with EV monotherapy were divided into two groups based on whether they received chemo or ICI as the line of therapy immediately prior to EV, regardless of other therapy received. Chi-squared test was used to assess differences in pt characteristics and ORR while log-rank tests were used for OS and PFS measured from EV start. Results: Among 325 pts treated with EV monotherapy, 247 had chemo or ICI as immediate prior treatment, with 186 pts receiving ICI (Group A) and 61 pts receiving platinum-based chemo (Group B). In 247-pt cohort, ORR to EV was 52% and mPFS and mOS were 6 and 13 mos. Group B pts were younger, had more bone mets and higher Bellmunt risk factors, but were otherwise similar to Group A (Table). Most pts had both prior chemo and ICI in both group A (58%) and group B (84%). Group A pts had shorter time from last treatment (median 1.2 vs 3.2 mo, p<0.01), lower ORR to immediate prior treatment (16% vs 37%, p<0.01) and fewer prior therapy lines (mean 1.9 vs 2.6, p<0.01). Group A had superior ORR (58% vs 37%, p=0.02), mPFS (6.9 vs 4.8 mo, p=0.02) and mOS (15.2 vs 8.8 mo, p=0.01) from EV start vs Group B. Conclusions: Pts with aUC treated with EV had superior outcomes if they received ICI instead of chemo as immediate prior treatment, suggesting the hypothesis that this may represent an optimal therapy sequence or combination. These data need external validation as limitations include retrospective design, lack of randomization, and selection and confounding biases. [Table: see text]

Association of peripheral blood neutrophil-lymphocyte ratio (NLR) and red cell distribution width (RDW) with immune checkpoint inhibitors (ICIs) for metastatic urothelial carcinoma (mUC)

540

Background: Determining a benefit from ICIs radiographically may take months and may be confounded by pseudoprogression. The NLR & RDW are readily accessible inflammatory markers from routine peripheral blood analysis and have been associated with outcomes in malignancies. We evaluated the association of early changes in NLR and RDW within 4 weeks after initiating ICI with any regression of tumor (ART) and overall survival (OS) in mUC. Methods: This study included de-identified data from Dana-Farber Cancer Institute in pts with mUC who were treated with ICIs from 2015 to 2020. Age, gender, setting (untreated vs. post-platinum), sites of metastasis (mets), performance status (PS), platelet count, RDW, and NLR at baseline and 3-4 weeks after initiating the ICI were collected. The primary objective was to assess the association of early increase in NLR by ≥1.0 from baseline or RDW at 3-4 weeks (as a continuous variable) post-ICI therapy with ART and OS. ART was assessed via subsequent imaging at any time point while on ICI. A multivariable logistic regression model and Cox proportional-hazards model were employed to identify the association of NLR changes with ART and OS, respectively, using backward selection. Results: A total of 330 pts were evaluable. The median age was 70 years, 72.1% (n = 298) were male and 69.4% (n= 227) received post-platinum ICI (remaining were platinum naïve). 46.5% (n = 146) experienced ART and the median OS was 13 months (11.14-16.14). An increase in NLR ≥ 1 in 3-4 weeks was associated with a lower rate of ART (OR: 0.41, 95% CI 0.24-0.70; p: 0.001) and worse OS (hazard ratio [HR]: 1.84, 95% CI 1.37-2.46; p < 0.0001) on multivariable analysis (Table). Higher RDW values at 3-4 weeks were associated with worse OS (HR: 1.08, 95% CI 1.03-1.14; p: 0.0004) but were not associated with ART. Conclusions: In pts with mUC initiating ICI, an early increase in NLR ≥ 1 and higher RDW in 3-4 weeks were associated with poor outcomes. Early changes in these readily available variables may enable early modification or intensification of therapy to improve outcomes. External validation of these findings is warranted. [Table: see text]

Incidence of Germline Variants in Familial Bladder Cancer and Among Patients With Cancer Predisposition Syndromes

BACKGROUND

The familial aggregation of bladder cancers has been observed, but the incidence and association of familial bladder cancer with germline pathogenic and likely pathogenic (P/LP) variants is unknown.

PATIENTS AND METHODS

A retrospective analysis was conducted of patients with bladder cancer treated at the Dana-Farber Cancer Institute to identify those with a first-degree relative with bladder cancer. A second cohort of patients referred to DFCI for suspicion of a cancer predisposition syndrome was analyzed for candidate P/LP germline variants. Descriptive statistics were generated.

RESULTS

Among 885 patients with bladder cancer, 38 patients (4.3%) had a family history of bladder cancer in a first-degree relative. No significant association of age of diagnosis was observed between patients with and without a first-degree family history of bladder cancer (P = .3). In the second cohort, 27 of 80 (34%) patients with bladder cancer evaluated for cancer predisposition syndromes harbored a P/LP germline variant. P/LP variants were identified most commonly in the following genes: BRCA1 (n = 5), MSH2 (n = 5), MLH1 (n = 4), ATM (n = 3), and CHEK2 (n = 2). Of the 27 patients with identified germline P/LP variants, 20 (74%) had a family history of a tumor component syndrome in a first- or second-degree relative and 3 were subsequently diagnosed with another genetically-linked associated cancer.

CONCLUSION

Familial bladder cancer defined as bladder cancer in the proband and a first-degree relative, was present in 4.3% of patients with bladder cancer and was not associated with age of diagnosis. Additionally, among patients suspected to have a familial cancer syndrome, one-third harbored a germline P/LP variant. Further study of germline variants in patients with familial bladder cancer including somatic testing for loss of heterozygosity may provide insights regarding disease pathogenesis and inform therapy.

Single cell transcriptomic characterization of natural killer (NK) cell populations in clear cell renal cell carcinoma and association with clinical outcomes

e16521

Background: Natural killer (NK) cells are thought to play a key role in the immune response against cancer, including clear cell renal cell carcinoma (ccRCC). However, the transcriptomic landscape of NK cells in ccRCC and the mechanisms of NK cell evasion by ccRCC are poorly understood. Methods: We analyzed scRNA-sequencing (10x Genomics) data from tumor specimens and adjacent non-tumor tissue from ccRCC at various clinical stages. Clustering analysis and NK cell lineage markers were used to identify distinct NK cell populations. Differential gene expression analysis was used to characterize each cluster compared to the total population of NK cells. Results were correlated with clinical stage. Gene signatures, derived from NK cell subclusters of interest, were then used to interrogate bulk transcriptomic datasets and associate expression with clinical outcomes. Results: Single-cell RNA-sequencing data was analyzed from 13 patients, corresponding to > 23,000 individual NK cells. Clustering analysis revealed 11 distinct NK cell subsets, including two “resident” NK cell clusters that were enriched among patients with metastatic disease. These clusters expressed CD9, ITGA1/CD49a, and ITGAE/CD103. Further examination of these clusters showed a common panel of differentially expressed genes, including decreased expression of cytotoxicity markers and upregulation of inhibitor checkpoints such as KLRC1/NKG2a. A gene expression signature representing this resident NK cell phenotype was associated with worse overall survival in two large, independent patient cohorts (TCGA and CheckMate-025). Conclusions: Among patients with ccRCC, a retrospective single cell transcriptomic analysis revealed heterogeneous NK cell populations. A seemingly dysfunctional, “resident” NK cell phenotype is enriched among patients with metastatic disease and is associated with worse survival in patients with advanced ccRCC, including those treated with immune checkpoint inhibitors. Restoration of NK cell function could be a future therapeutic opportunity among patients with ccRCC.

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.

Longitudinal Evaluation of Circulating Tumor DNA Using Sensitive Amplicon-Based Next-Generation Sequencing to Identify Resistance Mechanisms to Immune Checkpoint Inhibitors for Advanced Urothelial Carcinoma

Serial evaluation of circulating tumor DNA may allow noninvasive assessment of drivers of resistance to immune checkpoint inhibitors (ICIs) in advanced urothelial cancer (aUC). We used a novel, amplicon-based next-generation sequencing assay to identify genomic alterations (GAs) pre- and post-therapy in 39 patients with aUC receiving ICI and 6 receiving platinum-based chemotherapy (PBC). One or more GA was seen in 95% and 100% of pre- and post-ICI samples, respectively, commonly in TP53 (54% and 54%), TERT (49% and 59%), and BRCA1/BRCA2 (33% and 33%). Clearance of ≥1 GA was seen in 7 of 9 patients responding to ICI, commonly in TP53 (n = 4), PIK3CA (n = 2), and BRCA1/BRCA2 (n = 2). A new GA was seen in 17 of 20 patients progressing on ICI, frequently in BRCA1/BRCA2 (n = 6), PIK3CA (n = 3), and TP53 (n = 3), which seldom emerged in patients receiving PBC. These findings highlight the potential for longitudinal circulating tumor DNA evaluation in tracking response and resistance to therapy.

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.

Efficacy of enfortumab vedotin in advanced urothelial cancer: Analysis from the Urothelial Cancer Network to Investigate Therapeutic Experiences (UNITE) study

BACKGROUND

Enfortumab vedotin (EV) is a novel antibody-drug conjugate approved for advanced urothelial cancer (aUC) refractory to prior therapy. In the Urothelial Cancer Network to Investigate Therapeutic Experiences (UNITE) study, the authors looked at the experience with EV in patient subsets of interest for which activity had not been well defined in clinical trials.

METHODS

UNITE was a retrospective study of patients with aUC treated with recently approved agents. This initial analysis focused on patients treated with EV. Patient data were abstracted from chart reviews by investigators at each site. The observed response rate (ORR) was investigator-assessed for patients with at least 1 post-baseline scan or clear evidence of clinical progression. ORRs were compared across subsets of interest for patients treated with EV monotherapy.

RESULTS

The initial UNITE analysis included 304 patients from 16 institutions; 260 of these patients were treated with EV monotherapy and included in the analyses. In the monotherapy cohort, the ORR was 52%, and it was >40% in all reported subsets of interest, including patients with comorbidities previously excluded from clinical trials (baseline renal impairment, diabetes, and neuropathy) and patients with fibroblast growth factor receptor 3 (FGFR3) alterations. Progression-free survival and overall survival were 6.8 and 14.4 months, respectively. Patients with a pure urothelial histology had a higher ORR than patients with a variant histology component (58% vs 42%; P = .06).

CONCLUSIONS

In a large retrospective cohort, responses to EV monotherapy were consistent with data previously reported in clinical trials and were also observed in various patient subsets, including patients with variant histology, patients with FGFR3 alterations, and patients previously excluded from clinical trials with an estimated glomerular filtration rate < 30 mL/min and significant comorbidities.

LAY SUMMARY

Enfortumab vedotin, approved by the Food and Drug Administration in 2019, is an important new drug for the treatment of patients with advanced bladder cancer. This study looks at the effectiveness of enfortumab vedotin as it has been used at multiple centers since approval, and focuses on important patient populations previously excluded from clinical trials. These populations include patients with decreased kidney function, diabetes, and important mutations. Enfortumab vedotin is effective for treating these patients. Previously reported clinical trial data have been replicated in this real-world setting, and support the use of this drug in broader patient populations.

Efficacy of anti-PD(L)1 therapy for patients (Pts) with advanced urothelial carcinoma (aUC) with primary resistance to platinum-based chemotherapy (PC)

e16515

Background: PC remains standard first-line (1L) therapy for aUC. Approximately 15% of pts exhibit primary resistance (P-R) to PC and ∼25% progress by 4 months. PD(L)1 inhibitors yield objective response rates (ORR) of ∼20% in pts with progression after PC; however, it is unclear if this benefit extends to pts with P-R to PC. We examined the efficacy of anti-PD(L)1 in pts with aUC who experienced P-R to 1L PC. Methods: We conducted a multi-institutional retrospective study of pts with aUC who experienced P-R to PC and were subsequently treated with single-agent anti-PD(L)1 therapy. Eligibility included pts with unresectable or metastatic disease diagnosed after January 1, 2017. P-R to PC was defined as radiographic progression by RECISTv1.1 within 12 weeks from initiation of PC. Pts who developed metastatic disease while receiving (neo)adjuvant PC were eligible. Clinicopathologic variables were collected. ORR to anti-PD(L)1 was the primary endpoint. Secondary endpoints included time to treatment failure (TTF, defined as time from start of anti-PD(L)1 therapy to next line of therapy, hospice or death) and overall survival (OS) were estimated using Kaplan-Meier method. Multivariate (MV) analysis using Cox regression evaluating factors associated with OS was performed. Results: Overall, 42 pts were included: 74% male, median age 65 (28-90); 79% ever smokers; 21% mixed histology; 31% received definitive locoregional therapy. Metastatic sites at diagnosis of aUC included: lymph node only (19%), liver (29%), bone (38%) and lung (33%). At diagnosis of aUC, ECOG PS was 0 in 26%, 1 in 52% and unknown in 21%. 1L PC included cisplatin (76%) and carboplatin (24%) based regimens. Anti-PD(L)1 was received either 2L (98%) or 3L (2%). Overall, ORR to anti-PD(L)1 was 17%: CR (2%), PR (14%), SD (14%), PD (57%) and unknown (12%). Of the 24 pts with PD as best response to anti-PD(L)1, only 9 (38%) received subsequent therapy. Overall, median TTF was 4.2 mo (95% CI 2.8-6.7 mo) and median OS was 7.4 mo (95% CI 4.2-11.1 mo). ORR in patients with a PDL1 combined positive score ≥ 10% (n=6) was 0%: 1 SD and 5 PD. MV analysis for OS from start of anti-PD(L)1 is shown (Table). Conclusions: P-R to PC portends a poor prognosis in pts with aUC. While a subset of patients may respond to anti-PD(L)1 therapy, the majority of pts do not derive benefit. Alternative agents, e.g. antibody drug conjugates and FGFR inhibitors, and combination-therapy should be investigated for this high risk population.[Table: see text]

Angiotensin Blockade Modulates the Activity of PD1/L1 Inhibitors in Metastatic Urothelial Carcinoma

BACKGROUND

The renin-angiotensin system is involved in the regulation of angiogenesis and cell proliferation. Angiotensin inhibition may improve drug delivery by enhancing tumor perfusion partly by downregulating transforming growth factor (TGF)-β. Because TGF-β is associated with resistance in patients with metastatic urothelial carcinoma (mUC) receiving programmed cell death protein 1/programmed cell death ligand 1 (PD1/L1) inhibitors, we hypothesized that angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) may enhance the outcomes of patients with mUC who receive PD1/L1 inhibitors.

PATIENTS AND METHODS

Data from patients with mUC who received PD1/L1 inhibitors as monotherapy were obtained; patients from the Dana-Farber Cancer Institute constituted the discovery dataset, and data from Moffitt Cancer Center served as the validation dataset. A logistic regression investigated the impact of concurrent ACEI/ARB primarily on any regression of tumor (ART) after controlling for prognostic factors.

RESULTS

Data were available for 178 patients from the discovery dataset, of whom 153 (86%) had received prior platinum and 33 (18.5%) concurrent ACEIs/ARBs. Multivariable logistic regression analysis revealed that ACEIs/ARBs were associated with greater probability of ART (odds ratio [OR] = 2.69; 95% confidence interval [CI], 1.15-6.30; P = .022). In the validation dataset, 101 patients were available, of whom 59 (58.4%) had received prior platinum and 22 (21.8%) concurrent ACEIs/ARBs. ACEI/ARB demonstrated a trend for association with ART (OR = 3.28; 95% CI, 0.98-10.99; P = .054) on multivariable analysis of the validation dataset.

CONCLUSIONS

Concurrent angiotensin blockade was associated with a higher rate of tumor regression in patients with mUC receiving PD1/L1 inhibitors. Validation is warranted in a prospective trial, especially given the cost efficacy of ACEIs/ARBs.

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.

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

432

Background: The renin-angiotensin system (RAS) is involved in regulation of angiogenesis, cell proliferation, desmoplasia and immunosuppression. Angiotensin converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARB) may have antitumor effects partly by inhibiting transforming growth factor (TGF)-β, a major resistance mechanism in bladder cancer. Methods: Patients (pts) with muscle invasive bladder cancer (MIBC) treated or not treated with ACEi/ARB while receiving preceding radical cystectomy (RC) were assessed for pathologic complete response (pCR) defined as pT0N0 and overall survival (OS). Pathologic features, performance status, clinical stage, type and number of cycles of NAC, and presence of grade ≥3 toxicities were collected retrospectively. The Kaplan-Meier method was used to estimate overall survival (OS). Logistic and Cox regression was used to explore factors potentially prognostic for pCR and OS respectively. Results: 187 patients received NAC followed by RC. The mean age at the time of NAC was 65. 71% were male and 29% were female. Of the 187 patients, 61% received Cisplatin/Gemcitabine and 28.3% received dose dense MVAC. Of patients receiving NAC, 53 (28%) had a pCR. The 5-year OS was 64%. There were 41 (21.9%) patients taking an ACEi and 24 (12.8%) patients taking an ARB at the start of NAC. Of the 41 patients who took an ACEi, 17 (41.5%) had a pCR; of the 146 patients who did not take an ACEi, 36 (24.7%) had a pCR. ACEi intake during NAC was the only factor associated with pCR on multivariable analysis (odds ratio of 2.17 [95% CI 1.05-4.48] p = 0.037). pCR was the only factor shown to be associated with significantly improved OS (Hazard Ratio 0.18 [95% CI 0.07-0.45] p = < 0.001). After adjusting for pCR, ACEi was not significantly prognostic of OS (HR = 1.12, 95% CI = 0.60 to 2.09, p = 0.72). ARB intake while receiving NAC was not associated with pCR or OS. Conclusions: ACEi intake was associated with significantly increased pCR in patients with MIBC receiving NAC, and pCR was the only significant factor associated with OS. We hypothesize that ACEi may augment the activity of NAC and increase pCR, which translates to improved OS. ACEi intake was not associated with improvement in OS potentially due to competing causes of mortality in patients requiring ACEi. Our data requires validation.

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

354

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.

Genomic landscape of variant urinary tumor histologies

467

Background: The genetics of urothelial carcinoma (UC), the most common histology of urinary tract (UT) tumors, is well characterized; much less is known about the genomic features of rare histologic variants of UT tumors. We aim to compare the genomic alterations (GA) of UT tumors with adenocarcinoma (AD), small cell (SC), squamous cell (SQ), or plasmacytoid (PC) histologies, to UC tumors. Methods: We identified patients with pure variant (AD, SC, SQ, PC) or UC histology with genetic characterization through the GENIE registry. Patient tumor genomic data were captured by Memorial Sloan Kettering Cancer Center (MSK)-IMPACT and Dana-Farber Cancer Institute (DFCI)-Oncopanel NGS initiatives. Tumors with mixed histology were excluded. We limited our analysis to genes tested >1000 times (N=211). Mutation frequencies and copy number variants (CNVs), collectively called GAs, were determined for AD, SC, SQ, PC, and UC, and were compared using the Fisher’s Exact test and Kruskall Wallis test. Nominal p values were obtained, and FDR correction was employed (q < 0.1). Results: We identified 1199 patients with available genomic data who met the inclusion criteria. Histologic distribution was: 32 AD, 13 SC, 15 SQ, 11 PC, and 1128 UC tumors. The median age was 68 years and 77% of patients were male. Statistically significant differences in genetic alterations by subtype are shown in the table below. ARID1A and KDM6A GAs were higher in UC; PC and SC; CDH1 GAs higher in PC; RB1 and TP53 GAs higher in SC; SMAD4 GAs higher in AD; and NFE2L2 GAs higher in SQ. Conclusions: Variant UT histologies exhibit a distinct pattern of alterations compared to UC, consistent with their divergent clinical behavior. This suggests different biological origins for these variant histologies and possibly different therapeutic vulnerabilities. Exploring the GAs of these UT tumors in larger datasets is warranted. [Table: see text]

Efficacy of enfortumab vedotin in advanced urothelial cancer: Retrospective analysis of the Urothelial Cancer Network to Investigate Therapeutic Experiences (UNITE) Study

443

Background: Enfortumab vedotin (EV) is an antibody-drug conjugate targeting Nectin-4, which is FDA approved for patients (pts) with treatment-refractory advanced urothelial cancer (aUC). The activity of EV in pt subsets of interest such as those with distinct histological variants has not been well defined. Methods: A retrospective study of pts with aUC treated with ≥1 dose of EV as standard of care (SOC) or on a clinical trial (if trial results already reported) at 12 US sites was undertaken. Objective response rate (ORR) was investigator-assessed for pts with at least one post-baseline scan or clear evidence of clinical progression. ORR was compared across subsets of interest using proportion test. Results: A total of 184 patients with aUC were included; median age at diagnosis 70, 20% women and 60% with definitive surgery. Most common primary sites included bladder (70%) and upper tract (28%). Majority of pts (72%) had pure urothelial histology (UH) per local review, but 26% had at least a component of variant histology (VH), most commonly squamous (14%), micropapillary (8%) or plasmacytoid (3%). EV was given as monotherapy in 84% and as SOC in 58%; and 81% had ≥ 1 prior treatment in the metastatic (met) setting. ECOG PS was ≥2 in 15%; 37% had baseline neuropathy, 15% diabetes and 9% had GFR≤30. At median follow-up of 37.0 (IQR: 20.5-60.2) months from initial diagnosis, median time from met diagnosis to EV start was 11.7 (IQR: 4.3 – 20.5) months. Median duration of EV was 5.5 (IQR: 1.4 – 6.7) months, and 84% of pts were evaluable for response. ORR for evaluable pts was 53% (8% CR, 45% PR); 25% had SD and 21% PD. Median PFS and OS were not yet reached. At data cutoff in 9/2020, 55% had stopped EV (36% due to PD, 19% intolerance) and 65% were alive. Comparison of ORR in subgroups of interest for 127 evaluable pts treated with EV monotherapy is shown in the table below. Notably, among 31 pts with FGFR3 alterations, 26 were evaluable and ORR was 46%. Conclusions: In a large, retrospective, multi-institutional cohort, responses to EV were observed across a broad range of aUC pts, including pts with variant histology component, FGFR3 alterations and also in populations previously excluded from clinical trials such as pts with GFR<30 and significant baseline comorbidities. No significant differences in ORR were demonstrated for patient subsets of interest. [Table: see text]

Nitrogen oxidation consortia dynamics influence the performance of full-scale rotating biological contactors

Ammonia oxidising microorganisms (AOM) play an important role in ammonia removal in wastewater treatment works (WWTW) including rotating biological contactors (RBCs). Environmental factors within RBCs are known to impact the performance of key AOM, such that only some operational RBCs have shown ability for elevated ammonia removal. In this work, long-term treatment performance of seven full-scale RBC systems along with the structure and abundance of the ammonia oxidising bacteria (AOB) and archaea (AOA) communities within microbial biofilms were examined. Long term data showed the dominance of AOB in most RBCs, although two RBCs had demonstrable shift toward an AOA dominated AOM community. Next Generation Sequencing of the 16S rRNA gene revealed diverse evolutionary ancestry of AOB from RBC biofilms while nitrite-oxidising bacteria (NOBs) were similar to reference databases. AOA were more abundant in the biofilms subject to lower organic loading and higher oxygen concentration found at the distal end of RBC systems. Modelling revealed a distinct nitrogen cycling community present within high performing RBCs, linked to efficient control of RBC process variables (retention time, organic loading and oxygen concentration). We present a novel template for enhancing the resilience of RBC systems through microbial community analysis which can guide future strategies for more effective ammonia removal. To best of the author's knowledge, this is the first comparative study reporting the use of next generation sequencing data on microbial biofilms from RBCs to inform effluent quality of small WWTW.

Links between psychotic and neurotic symptoms in the general population: an analysis of longitudinal British National Survey data using Directed Acyclic Graphs

BACKGROUND

Non-psychotic affective symptoms are important components of psychotic syndromes. They are frequent and are now thought to influence the emergence of paranoia and hallucinations. Evidence supporting this model of psychosis comes from recent cross-fertilising epidemiological and intervention studies. Epidemiological studies identify plausible targets for intervention but must be interpreted cautiously. Nevertheless, causal inference can be strengthened substantially using modern statistical methods.

METHODS

Directed Acyclic Graphs were used in a dynamic Bayesian network approach to learn the overall dependence structure of chosen variables. DAG-based inference identifies the most likely directional links between multiple variables, thereby locating them in a putative causal cascade. We used initial and 18-month follow-up data from the 2000 British National Psychiatric Morbidity survey (N = 8580 and N = 2406).

RESULTS

We analysed persecutory ideation, hallucinations, a range of affective symptoms and the effects of cannabis and problematic alcohol use. Worry was central to the links between symptoms, with plausible direct effects on insomnia, depressed mood and generalised anxiety, and recent cannabis use. Worry linked the other affective phenomena with paranoia. Hallucinations were connected only to worry and persecutory ideation. General anxiety, worry, sleep problems, and persecutory ideation were strongly self-predicting. Worry and persecutory ideation were connected over the 18-month interval in an apparent feedback loop.

CONCLUSIONS

These results have implications for understanding dynamic processes in psychosis and for targeting psychological interventions. The reciprocal influence of worry and paranoia implies that treating either symptom is likely to ameliorate the other.

Sleep duration and psychotic experiences in patients at risk of psychosis: A secondary analysis of the EDIE-2 trial

Sleep disturbance is common among individuals at risk of psychosis, yet few studies have investigated the relationship between sleep disturbance and clinical trajectory. The Early Detection and Intervention Evaluation (EDIE-2) trial provides longitudinal data on sleep duration and individual psychotic experiences from a cohort of individuals at risk of psychosis, which this study utilises in an opportunistic secondary analysis. Shorter and more variable sleep was hypothesised to be associated with more severe psychotic experiences and lower psychological wellbeing. Mixed effect models were used to test sleep duration and range as predictors of individual psychotic experiences and psychological wellbeing over the 12-24 months (with assessments every 3 months) in 160 participants. Shorter sleep duration was associated with more severe delusional ideas and hallucinations cross-sectionally and longitudinally. The longitudinal relationships did not remain significant after conservative controls were added for the previous severity of psychotic experiences. No significant relationships were found between the sleep variables and other psychotic experiences (e.g. cognitive disorganisation), or psychological wellbeing. The results support a relationship between shorter sleep duration and delusional ideas and hallucinations. Future studies should focus on improving sleep disturbance measurement, and test whether treating sleep improves clinical trajectory in the at-risk group.

Virtual reality in the assessment, understanding, and treatment of mental health disorders

Mental health problems are inseparable from the environment. With virtual reality (VR), computer-generated interactive environments, individuals can repeatedly experience their problematic situations and be taught, via evidence-based psychological treatments, how to overcome difficulties. VR is moving out of specialist laboratories. Our central aim was to describe the potential of VR in mental health, including a consideration of the first 20 years of applications. A systematic review of empirical studies was conducted. In all, 285 studies were identified, with 86 concerning assessment, 45 theory development, and 154 treatment. The main disorders researched were anxiety (n = 192), schizophrenia (n = 44), substance-related disorders (n = 22) and eating disorders (n = 18). There are pioneering early studies, but the methodological quality of studies was generally low. The gaps in meaningful applications to mental health are extensive. The most established finding is that VR exposure-based treatments can reduce anxiety disorders, but there are numerous research and treatment avenues of promise. VR was found to be a much-misused term, often applied to non-interactive and non-immersive technologies. We conclude that VR has the potential to transform the assessment, understanding and treatment of mental health problems. The treatment possibilities will only be realized if - with the user experience at the heart of design - the best immersive VR technology is combined with targeted translational interventions. The capability of VR to simulate reality could greatly increase access to psychological therapies, while treatment outcomes could be enhanced by the technology's ability to create new realities. VR may merit the level of attention given to neuroimaging.

Anatomical variations in epididymal-testicular fusion in stallions and their possible clinical significance

REASONS FOR PERFORMING STUDY

Fusion anomalies of the epididymis with the testis may be clinically relevant in horses. However, anatomical variations in epididymal-testicular fusion have not been classified, and their clinical significance is unknown.

OBJECTIVES

To describe anatomical variations and clinical significance of epididymal-testicular fusion in stallions.

STUDY DESIGN

Anatomical study of testes from castrations, and description of 2 clinical cases with atypical epididymal-testicular fusion.

METHODS

A total of 104 testes were obtained from equine castrations. Eight patterns of epididymal-testicular fusion were identified. Two clinical cases with epididymal dislocation were also described.

RESULTS

Close attachment of the entire epididymis to the testis was the most common pattern of fusion (40%). Ninety-five per cent of cryptorchid testes and 34% of scrotal testes in the studied sample had elongated proper ligaments of the testes. Dislocation of the epididymal tail was observed in 2 stallions that had atypically long proper ligaments inserted on the dorsal aspect of the testes.

CONCLUSIONS

Patterns of epididymal-testicular fusion can vary in stallions. Elongated proper ligaments of the testes occur mostly in cryptorchid testes but are also found in stallions with scrotal testes. Epididymal dislocation may develop in stallions with long proper ligaments that are inserted dorsally on the testes.

Delusional belief flexibility and informal caregiving relationships in psychosis: a potential cognitive route for the protective effect of social support

Aims. For people with psychosis, contact with informal caregivers is an important source of social support, associated with recovery, and with better outcomes following individual cognitive therapy (CBTp). In this study, we tested whether increased flexibility in delusional thinking, an established predictor of positive outcome following CBTp, was a possible mechanism underlying this effect. Methods. 219 participants with delusions (mean age 38 years; 71% male; 75% White) were grouped according to the presence of a caregiver (37% with a caregiver) and caregiver level of expressed emotion (High/Low EE, 64% Low). Delusional belief flexibility was compared between groups, controlling for interpersonal functioning, severity of psychotic symptoms, and other hypothesised outcome predictors. Results. Participants with caregivers were nearly three times more likely than those without to show flexibility (OR = 2.7, 95% CI 1.5 to 5.0, p = 0.001), and five times more likely if the caregiving relationship was Low EE (OR = 5.0, 95% CI 2.0-13.0, p = 0.001). ORs remained consistent irrespective of controlling for interpersonal functioning and other predictors of outcome. Conclusions. This is the first evidence that having supportive caregiving relationships is associated with a specific cognitive attribute in people with psychosis, suggesting a potential cognitive mechanism by which outcomes following CBTp, and perhaps more generally, are improved by social support.

Understanding jumping to conclusions in patients with persecutory delusions: working memory and intolerance of uncertainty

BACKGROUND

Persecutory delusions are a key psychotic experience. A reasoning style known as 'jumping to conclusions' (JTC) - limited information gathering before reaching certainty in decision making - has been identified as a contributory factor in the occurrence of delusions. The cognitive processes that underpin JTC need to be determined in order to develop effective interventions for delusions. In the current study two alternative perspectives were tested: that JTC partially results from impairment in information-processing capabilities and that JTC is a motivated strategy to avoid uncertainty.

METHOD

A group of 123 patients with persistent persecutory delusions completed assessments of JTC (the 60:40 beads task), IQ, working memory, intolerance of uncertainty, and psychiatric symptoms. Patients showing JTC were compared with patients not showing JTC.

RESULTS

A total of 30 (24%) patients with delusions showed JTC. There were no differences between patients who did and did not jump to conclusions in overall psychopathology. Patients who jumped to conclusions had poorer working memory performance, lower IQ, lower intolerance of uncertainty and lower levels of worry. Working memory and worry independently predicted the presence of JTC.

CONCLUSIONS

Hasty decision making in patients with delusions may partly arise from difficulties in keeping information in mind. Interventions for JTC are likely to benefit from addressing working memory performance, while in vivo techniques for patients with delusions will benefit from limiting the demands on working memory. The study provides little evidence for a contribution to JTC from top-down motivational beliefs about uncertainty.

Prevalence and spectrum of in utero structural brain abnormalities in fetuses with complex congenital heart disease

BACKGROUND AND PURPOSE

Brain injury is a major complication in neonates with complex congenital heart disease. Preliminary evidence suggests that fetuses with congenital heart disease are at greater risk for brain abnormalities. However, the nature and frequency of these brain abnormalities detected by conventional fetal MR imaging has not been examined prospectively. Our primary objective was to determine the prevalence and spectrum of brain abnormalities detected on conventional clinical MR imaging in fetuses with complex congenital heart disease and, second, to compare the congenital heart disease cohort with a control group of fetuses from healthy pregnancies.

MATERIALS AND METHODS

We prospectively recruited pregnant women with a confirmed fetal congenital heart disease diagnosis and healthy volunteers with normal fetal echocardiogram findings who underwent a fetal MR imaging between 18 and 39 weeks gestational age.

RESULTS

A total of 338 fetuses (194 controls; 144 with congenital heart disease) were studied at a mean gestational age of 30.61 ± 4.67 weeks. Brain abnormalities were present in 23% of the congenital heart disease group compared with 1.5% in the control group (P < .001). The most common abnormalities in the congenital heart disease group were mild unilateral ventriculomegaly in 12/33 (36.4%) and increased extra-axial spaces in 10/33 (30.3%). Subgroup analyses comparing the type and frequency of brain abnormalities based on cardiac physiology did not reveal significant associations, suggesting that the brain abnormalities were not limited to those with the most severe congenital heart disease.

CONCLUSIONS

This is the first large prospective study reporting conventional MR imaging findings in fetuses with congenital heart disease. Our results suggest that brain abnormalities are prevalent but relatively mild antenatally in fetuses with congenital heart disease. The long-term predictive value of these findings awaits further study.