Phase 2 trial of a DNA vaccine (pTVG-HP) and nivolumab in patients with castration-sensitive non-metastatic (M0) prostate cancer

PURPOSE

We have previously reported that a plasmid DNA vaccine encoding prostatic acid phosphatase (pTVG-HP) had greater clinical activity when given in combination with pembrolizumab to patients with metastatic, castration-resistant prostate cancer. The current trial was conducted to evaluate vaccination with PD-1 blockade, using nivolumab, in patients with early, recurrent (M0) prostate cancer.

METHODS

Patients with M0 prostate cancer were treated with pTVG-HP (100 µg administered intradermally) and nivolumab (240 mg intravenous infusion) every 2 weeks for 3 months, and then every 4 weeks for 1 year of total treatment. Patients were then followed for an additional year off treatment. The primary objectives were safety and complete prostate-specific antigen (PSA) response (PSA<0.2 ng/mL).

RESULTS

19 patients were enrolled. No patients met the primary endpoint of complete PSA response; however, 4/19 (21%) patients had a PSA decline >50%. Median PSA doubling times were 5.9 months pretreatment, 25.6 months on-treatment (p=0.001), and 9.0 months in the subsequent year off-treatment. The overall median radiographic progression-free survival was not reached. Grade 3 or 4 events included adrenal insufficiency, fatigue, lymphopenia, and increased amylase/lipase. 9/19 (47%) patients developed immune-related adverse effects (irAE). The development of irAE and increased CXCL9 were associated with increased PSA doubling time. Quantitative NaF PET/CT imaging showed the resolution of subclinical lesions along with the development of new lesions at each time point.

CONCLUSIONS

In this population, combining nivolumab with pTVG-HP vaccination was safe, and immunologically active, prolonged the time to disease progression, but did not eradicate disease. Quantitative imaging suggested that additional treatments targeting mechanisms of resistance may be required to eliminate tumors.

TRIAL REGISTRATION NUMBER

NCT03600350.

Outcomes of Consolidative Nephrectomy following Primary Immunotherapy in Advanced Renal Cell Carcinoma: A Multicenter Analysis

BACKGROUND

To evaluate effect and outcomes of combination primary immunotherapy (IO) and nephrectomy for advanced renal cell carcinoma (RCC).

METHODS

We conducted a multicenter, retrospective analysis of patients with advanced/metastatic RCC who received IO followed by nephrectomy. Primary outcome was Bifecta (negative surgical margins and no 30-day surgical complications). Secondary outcomes included progression-free survival (PFS) following surgery, reduction in tumor/thrombus size, RENAL score, and clinical/pathologic downstaging. Cox regression multivariable analysis was conducted for predictors of Bifecta and PFS. Kaplan-Meier analysis assessed PFS, comparing Bifecta and non-Bifecta groups.

RESULTS

A total of 56 patients were analyzed (median age 63 years; median follow-up 22.5 months). A total of 40 (71.4%) patients were intermediate IMDC risk. Patients were treated with immunotherapy for median duration of 8.1 months. Immunotherapy resulted in reductions in tumor size (P < .001), thrombus size (P = .02), and RENAL score (P < .001); 38 (67.9%) patients were clinically downstaged on imaging (P < .001) and 25 (44.6%) patients were pathologically downstaged following surgery (P < .001). Bifecta was achieved in 38 (67.9%) patients. Predictors for bifecta achievement included decreasing tumor size (HR 1.08, P = .043) and pathological downstaging (HR 2.13, P = .047). Bifecta (HR 5.65, P = .009), pathologic downstaging (HR 5.15, P = .02), and increasing reduction in tumor size (HR 1.2, P = .007) were associated with improved PFS. Bifecta patients demonstrated improved 2-year PFS (84% vs. 71%, P = .019).

CONCLUSIONS

Primary immunotherapy reduced tumor/thrombus size and complexity. Pathologically downstaged patients were more likely to achieve bifecta, and these patients displayed improved 2-year PFS. Our study supports further inquiry in the use of CRN following primary immunotherapy for advanced renal cancer.

Neutrophil-to-eosinophil ratio as a biomarker for clinical outcomes in advanced stage melanoma patients treated with anti-PD-1 therapy

Neutrophil-to-lymphocyte ratios (NLR) and eosinophil counts are associated with improved survival in melanoma patients treated with immune checkpoint inhibitors, but no study has investigated neutrophil-to-eosinophil ratios (NER) as a predictive indicator in this population. In this retrospective study evaluating anti-PD-1 treated patients with advanced melanoma, progression-free survival (PFS), overall survival (OS), objective response rates (ORR), and risk of high-grade (grade ≥3) immune-related adverse events (irAEs) were compared between groups defined by median pretreatment NLR and NER as well as median NLR and NER at 1-month post-treatment. Lower baseline NLR and NER were associated with improved OS [HR: 0.504, 95% CI: 0.328-0.773, p = .002 and HR: 0.442, 95% CI: 0.288-0.681, p < .001, respectively] on univariate testing. After accounting for multiple covariates, our multivariate analysis found that lower pretreatment NER was associated with better ORR (by irRECIST) (OR: 2.199, 95% CI: 1.071-4.582, p = .033) and improved OS (HR: 0.480, 95% CI: 0.296-0.777, p = .003). Baseline NLR, 1-month NLR, and 1-month NER were not associated with ORR, PFS, or OS outcomes; but 1-month NER correlated with lower risk of grade ≥3 irAEs (OR: 0.392, 95% CI: 0.165-0.895, p = .029). Our findings suggest baseline NER merits additional investigation as a novel prognostic marker for advanced melanoma patients receiving anti-PD-1-based regimens.

Fragmentomic analysis of circulating tumor DNA-targeted cancer panels

BACKGROUND

The isolation of cell-free DNA (cfDNA) from the bloodstream can be used to detect and analyze somatic alterations in circulating tumor DNA (ctDNA), and multiple cfDNA-targeted sequencing panels are now commercially available for Food and Drug Administration (FDA)-approved biomarker indications to guide treatment. More recently, cfDNA fragmentation patterns have emerged as a tool to infer epigenomic and transcriptomic information. However, most of these analyses used whole-genome sequencing, which is insufficient to identify FDA-approved biomarker indications in a cost-effective manner.

PATIENTS AND METHODS

We used machine learning models of fragmentation patterns at the first coding exon in standard targeted cancer gene cfDNA sequencing panels to distinguish between cancer and non-cancer patients, as well as the specific tumor type and subtype. We assessed this approach in two independent cohorts: a published cohort from GRAIL (breast, lung, and prostate cancers, non-cancer, n = 198) and an institutional cohort from the University of Wisconsin (UW; breast, lung, prostate, bladder cancers, n = 320). Each cohort was split 70%/30% into training and validation sets.

RESULTS

In the UW cohort, training cross-validated accuracy was 82.1%, and accuracy in the independent validation cohort was 86.6% despite a median ctDNA fraction of only 0.06. In the GRAIL cohort, to assess how this approach performs in very low ctDNA fractions, training and independent validation were split based on ctDNA fraction. Training cross-validated accuracy was 80.6%, and accuracy in the independent validation cohort was 76.3%. In the validation cohort where the ctDNA fractions were all <0.05 and as low as 0.0003, the cancer versus non-cancer area under the curve was 0.99.

CONCLUSIONS

To our knowledge, this is the first study to demonstrate that sequencing from targeted cfDNA panels can be utilized to analyze fragmentation patterns to classify cancer types, dramatically expanding the potential capabilities of existing clinically used panels at minimal additional cost.

Getting ready for real-world use of electronic patient-reported outcomes (ePROs) for patients with cancer: A National Comprehensive Cancer Network ePRO Workgroup paper

Electronic patient‐reported outcome (ePRO) programs may offer advantages for patients with cancer, clinicians, health care systems, payors, and society in general; but developing and maintaining an ePRO program will require cancer centers to navigate defining meaningful problems, collecting ePROs, implementing action when those ePROs require intervention without over‐burdening clinicians, and monitoring the successes and failures of their ePRO programs. Physician informaticists from the National Comprehensive Cancer Network Electronic Health Record Advisory Group offer 10 guiding principles to consider when contemplating, building, or refining an ePRO program for patients with cancer.

Pathological Outcomes of Patients With Advanced Renal Cell Carcinoma Who Receive Nephrectomy Following Immunotherapy

BACKGROUND

Even though cytoreductive nephrectomy (CN) was once the standard of care for patients with advanced renal cell carcinoma (RCC), its role in treatment has not been well analyzed or defined in the era of immunotherapy (IO).

MATERIALS AND METHODS

This study analyzed pathological outcomes in patients with advanced or metastatic RCC who received IO prior to CN. This was a multi-institutional, retrospective study of patients with advanced or metastatic RCC. Patients were required to receive IO monotherapy or combination therapy prior to radical or partial CN. The primary endpoint assessed surgical pathologic outcomes, including American Joint Committee on Cancer (AJCC) staging and frequency of downstaging, at the time of surgery. Pathologic outcomes were correlated to clinical variables using a Wald-chi squared test from Cox regression in a multi-variable analysis. Secondary outcomes included objective response rate (ORR) defined by response evaluation criteria in solid tumors (RECIST) version 1.1 and progression-free survival (PFS), which were estimated using the Kaplan-Meier method with reported 95% CIs.

RESULTS

Fifty-two patients from 9 sites were included. Most patients were male (65%), 81% had clear cell histology, 11% had sarcomatoid differentiation. Overall, 44% of patients experienced pathologic downstaging, and 13% had a complete pathologic response. The ORR immediately prior to nephrectomy was stable disease in 29% of patients, partial response in 63%, progressive disease in 4%, and 4% unknown. Median follow-up for the entire cohort was 25.3 months and median PFS was 3.5 years (95% CI, 2.1-4.9).

CONCLUSIONS

IO-based interventions prior to CN in patients with advanced or metastatic RCC demonstrates efficacy, with a small fraction of patients showing a complete response. Additional prospective studies are warranted to investigate the role of CN in the modern IO-era.

Understanding the Tumor Immune Microenvironment in Renal Cell Carcinoma

Scientific understanding of how the immune microenvironment interacts with renal cell carcinoma (RCC) has substantially increased over the last decade as a result of research investigations and applying immunotherapies, which modulate how the immune system targets and eliminates RCC tumor cells. Clinically, immune checkpoint inhibitor therapy (ICI) has revolutionized the treatment of advanced clear cell RCC because of improved outcomes compared to targeted molecular therapies. From an immunologic perspective, RCC is particularly interesting because tumors are known to be highly inflamed, but the mechanisms underlying the inflammation of the tumor immune microenvironment are atypical and not well described. While technological advances in gene sequencing and cellular imaging have enabled precise characterization of RCC immune cell phenotypes, multiple theories have been suggested regarding the functional significance of immune infiltration in RCC progression. The purpose of this review is to describe the general concepts of the anti-tumor immune response and to provide a detailed summary of the current understanding of the immune response to RCC tumor development and progression. This article describes immune cell phenotypes that have been reported in the RCC microenvironment and discusses the application of RCC immunophenotyping to predict response to ICI therapy and patient survival.

Prognostic value of integrated liquid biopsies in patients (pts) with metastatic urothelial cancer (mUC)

547

Background: Despite recent therapeutic advancements for patients with mUC, including checkpoint inhibitors (CPIs), anti-FGFR and antibody-drug conjugates (ADCs), biomarker data to predict therapeutic response and identify mechanisms of resistance remain limited. Ongoing randomized clinical trials evaluating the combination of CPIs and ADCs in these pts underscore the need to develop biomarkers to better understand who might best respond to these therapies. Here, we employ a liquid biopsy approach to molecularly characterize circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA), including those isolated with Trop-2, the target of the novel drug Sacituzumab Govitecan and Datopotamab Deruxtecan. Methods: 104 blood samples serially collected from pts being treated for mUC were used for CTC collection using anti-EpCAM and Trop-2 antibodies in parallel. CTCs were isolated and stained for immune markers PD-L1 and HLA I using the VERSA (Versatile Exclusion-based Rare Sample Analysis) platform. Plasma was isolated for paired analysis of CTC and ctDNA content. CTCs were analyzed for enumeration and single-cell protein analysis. Overall survival (OS) was defined from time of sample collection, and survival analyses were performed using the Kaplan-Meier method. Results: We observed significantly shorter OS in pts with higher CTC burden (≥ 20 CTCs/7.5 mL blood) in samples captured with either EpCAM (median 34.1 vs 3.1 mo, P < 0.01) or Trop-2 (median 34.1 vs 6.2 months, P < 0.01). Furthermore, EpCAM and Trop-2 CTC burdens were higher at progression timepoints relative to responding or stable timepoints, when stratified according to treatment modality (table). Inter and intra-patient heterogeneous PD-L1 and HLA I expression and co-expression was observed on CTCs although no significant differences were seen globally between EpCAM and Trop-2 CTCs. In a cohort of pts treated with CPIs, we observed dynamic phenotypic changes in the ratio of HLA:PD-L1 that differed between EpCAM and Trop-2 CTCs. ctDNA analysis identified concordant increases in tumor fraction and acquired genomic mutations. When examined longitudinally across individual pts, these findings in tandem with changes in enumeration, suggest the emergence of different CTC subpopulations that may serve as biomarkers of resistance. Conclusions: We identify the prognostic significance of CTC enumeration with parallel EpCAM and Trop-2 CTC isolation and demonstrate the utility of a liquid biopsy assay that can detect pharmacodynamic changes in CTC burden and immune marker expression throughout the course of treatment. [Table: see text]

Biomarkers of response to enfortumab vedotin (EV) in patients (pts) with advanced urothelial carcinoma (aUC): Analysis of the UNITE study

450

Background: EV, an antibody-drug conjugate (ADC) targeting Nectin-4, is used widely in treatment-refractory aUC, but limited data are available on biomarkers predictive of EV outcomes. We investigated potential biomarkers of response to EV in a pt cohort in the UNITE dataset. Methods: We included the retrospective UNITE study pts from 16 sites, with available next generation sequencing using institutional or commercial platforms, treated with EV alone outside clinical trials. Observed response (ORR) was determined by investigators for evaluable pts with scans after ≥1 dose of EV. Assessed molecular biomarkers included tumor mutation burden (TMB), PD-L1 status, somatic alterations (alts) in ≥ 10% of pts ( TERTp, TP53, ARID1A, CDKN2A, CDKN2B, FGFR3, ERBB2, CCND1, KDM6A, MTAP, PIK3CA, RB1, TSC1) and presence of ≥1 DNA damage response mutations ( ATM, BARD1, BRCA1, BRCA2, CDK12, CHEK2, PALB2, PPP2R2A, or RAD51B). ORRs were compared using Chi-squared test, while median progression-free and overall survival (mPFS, mOS) from EV start were compared with log-rank test and Cox proportional hazards in pts with and without biomarker presence. Results: A total of 170 pts had outcomes and NGS data available. Median age was 70, 133 (78%) were men, 144 (85%) Caucasian, 110 (65%) with pure urothelial histology, 118 (69%) with primary bladder tumor, and 116 (68%) had ≥ 2 lines of therapy before EV. For all pts, ORR 47%, mPFS 6 mos, mOS 12 mos. ORRs were higher in pts with ERBB2 (67% vs 44%; p = 0.05) and TSC1 (68% vs 25%; p=0.04) alts vs wild-type. Shorter mPFS was noted in pts with CDKN2A, CDKN2B, and MTAP alts, and longer mOS in pts with high TMB (table). Conclusions: This large, multi-site, retrospective cohort of pts with aUC identified several potential biomarkers associated with differential outcomes to EV. These findings, upon external validation, may help inform clinical decision making and potential therapy sequencing with available ADCs. Limitations include retrospective nature, pt selection, and confounding biases. [Table: see text]

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]

Multi-center, retrospective study of first-line systemic therapy ± immune checkpoint inhibition for metastatic neuroendocrine carcinoma of the urinary tract

467

Background: Neuroendocrine, small cell, or large cell carcinoma originating from the urothelium (uro-NE/SCC/LCC) is rare. Outcomes for metastatic disease are dismal. Treatment is extrapolated from small cell lung cancer, for which immune checkpoint inhibitors (ICIs) have modest activity. Preliminary activity has been reported with ICI for uro-NE. We aimed to compare real-world progression-free survival (PFS) and overall survival (OS) between ICI-containing and non-ICI-containing regimens in the first line (1L) metastatic setting for uro-NE/SCC/LCC. Methods: We performed a retrospective study at 11 cancer centers. Patients (pts) who received systemic therapy (2011-2021) for biopsy confirmed metastatic uro-NE/SCC/LCC were included. Pts with metastasis within 6 months of (neo)adjuvant chemotherapy (CT) (n=16) were excluded from 1L analyses. Results: 102 pts with metastatic uro-NE/SCC/LCC were evaluable. 17 (16.7%) had NE histology, 81 (79.4%) SCC, and 4 (3.9%) LCC. NE/SCC/LCC was mixed with urothelial histology in 19 (18.6%). Primary tumors were most often in the bladder (84.3%, n=86), less frequently upper tract (11.8%, n=12) or urethra (3.9%, n=4). 42 pts (41.2%) were previously treated for localized disease, the rest were de novo metastatic (n=60, 58.8%). Pts who received an ICI in any line (n=61) had significantly longer OS (p=0.038) than pts that never received an ICI (n=41). As shown in the table, in the 1L, ICI-containing regimens (n=33) resulted in significantly longer PFS, but not OS or ORR compared to non-ICI regimens (n=53). Subdividing 1L regimens into ICI without CT (n=14), CT without ICI (n=53), or ICI + CT (n=19), both PFS and OS were significantly different with similar ORR. ICI w/o CT had the longest median PFS and OS with an ORR 57.1% comparable to CT regimens. Of 61 pts that received ICI in any line, 14 (23.0%) had an immune-related adverse event of any grade; 11 (18.0%) received steroids. Conclusions: This is the largest ever report of ICI for metastatic uro-NE/SCC/LCC. ICIs were associated with improved outcomes with expected added toxicity. Further prospective investigation of ICI regimens is warranted. [Table: see text]

Association of emergent neuroendocrine prostate cancer detected by liquid biopsies with survival and treatment resistance

247

Background: The mainstay of therapy in metastatic prostate cancer is androgen receptor (AR) signaling inhibition. However, the emergence of early castration resistance or neuroendocrine transformation is associated with poor prognosis. Reliable biomarkers are needed to identify these patients and guide selection of clinical therapy. Methods: mRNA was isolated from EpCAM-positive circulating tumor cells (CTCs) isolated from patients with CSPC, CRPC, or NEPC to measure expression of KLK2, KLK3 (PSA), TMPRSS2, FOLH1 (PSMA), synaptophysin ( SYP), and chromogranin ( CHGA). Post-hoc retrospective analysis of an institutional review board–approved prospective cohort (N = 98) was performed to identify patterns of gene expression. Samples were considered AR+ if 3 of 4 AR pathway genes ( TMPRSS2, KLK2, KLK3, and FOLH1) were positive, and were considered NE+ if either or both SYP or CHGA were positive. Blood samples from two prospective clinical trials of men with mCRPC treated with abiraterone and enzalutamide, respectively, were analyzed to confirm results. Longitudinal samples were collected from 17 patients (6 NEPC and 11 Adenocarcinoma) and cell free DNA was isolated and sequenced using a novel targeted exon panel. Results: AR and/or NE positive patients were found to have a median overall survival (OS) of 8.58 months as compared to a median OS of 29.6 months in the AR and NE negative population (p<0.0001; HR=2.75 [1.60-4.56]). In the subset of castrate resistant prostate cancer (CRPC) patients, AR+ and/or NE+ patients (n=31) were found to have a median OS of 6.74 months vs 18.79 months in the AR- and NE- group (n=39) (p= 0.0009; HR 2.38 [1.36-4.18]). We also tested samples from a phase II ARSI trials with abiraterone and enzalutamide, respectively. None of the baseline samples from these two trials met the above criteria for NEPC (AR- NE+) on their CTCs or histologically. Three of 48 total patients were identified with expression in their baseline blood samples without loss of AR target gene expression (AR+/NE+). Preliminary analysis of this small patient cohort in comparison to patients who were NE- shows that NE+ patients had worse OS (HR= 5.5906 [1.143-27.36), as would be expected by patients with emerging neuroendocrine differentiation. Integrated ctDNA sequencing identified mutations in genes associated with NEPC. Conclusions: The expression of NE genes in liquid biopsies while retaining AR target gene expression is associated with worse OS and may indicate the transition to neuroendocrine differentiation, with clinical characteristics consistent with this phenotype. Early identification of these patients may improve therapeutic decisions and improved patient outcomes. Pairing genomic alteration with changes in gene expression may additionally offer the basis for a new mechanism to assess efficacy of novel therapeutics in future clinical trials.

Concurrent durvalumab and radiation therapy (DUART) followed by adjuvant durvalumab in patients with localized urothelial cancer of bladder: results from phase II study, BTCRC-GU15-023

BACKGROUND

Patients with bladder cancer (BC) who are cisplatin ineligible or have unresectable disease have limited treatment options. Previously, we showed targeting programmed death-ligand 1 (PD-L1) with durvalumab (durva) and radiation therapy (RT) combination was safe in BC. We now report results from a phase II study evaluating the toxicity and efficacy of durva and RT in localized BC.

METHODS

This is a single-arm, multi-institutional phase II study; N=26. Enrolled patients had pure or mixed urothelial BC (T2-4 N0-2 M0) with unresectable tumors and were unfit for surgery or cisplatin ineligible. Patients received durva concurrently with RT ×7 weeks, followed by adjuvant durva × 1 year.

PRIMARY ENDPOINTS

(A) progression-free survival (PFS) at 1 year and (B) disease control rate (DCR) post adjuvant durva. Key secondary endpoints: (A) complete response (CR) post durvaRT (8 weeks), (B) overall survival (OS), (C) PFS and (D) toxicity. Correlative studies included evaluation of baseline tumor and blood (baseline, post durvaRT) for biomarkers.

RESULTS

Median follow-up was 27 months. Evaluable patients: 24/26 post durvaRT, 22/26 for DCR post adjuvant durva, all patients for PFS and OS. Post adjuvant durva, DCR was seen in 72.7%, CR of 54.5%. 1-year PFS was 71.5%, median PFS was 21.8 months. 1-year OS was 83.8%, median OS was 30.8 months. CR at 8 weeks post durvaRT was 62.5%. Node positive (N+) patients had similar median PFS and OS. DurvaRT was well tolerated. Grade ≥3 treatment-related adverse events: anemia, high lipase/amylase, immune-nephritis, transaminitis, dyspnea (grade 4-COPD/immune), fatigue, rash, diarrhea and scleritis. No difference in outcome was observed with PD-L1 status of baseline tumor. Patients with CR/PR or SD had an increase in naïve CD4 T cells, a decrease in PD-1+CD4 T cells at baseline and an increase in cytokine-producing CD8 T cells, including interferon gamma (IFNγ) producing cells, in the peripheral blood.

CONCLUSION

Durva with RT followed by adjuvant durva was safe with promising efficacy in localized BC patients with comorbidities, including N+ patients. Larger randomized studies, like S1806 and EA8185, are needed to evaluate the efficacy of combining immunotherapy and RT in BC.

TRIAL REGISTRATION NUMBER

NCT02891161.

Patterns of Health Portal Use by Regular Portal Users Among Patients With Cancer: Results From the UWCCC Survivorship Program

PURPOSE

We sought to evaluate the patterns of portal usage among patients with cancer who regularly log in to the portal. These data will inform approaches to facilitate portal use among patients with cancer.

PATIENTS AND METHODS

We conducted a retrospective analysis of patient portal usage by patients with cancer at the University of Wisconsin Carbone Cancer Center. Our analysis focuses on patterns of portal use by regular users (≥ 2 portal logins/year, > 3 months) receiving ongoing oncology care between January 1, 2017, and December 31, 2019. Demographics, cancer characteristics, number of oncology visits per month, and portal usage data were extracted. Regular portal users were grouped and compared on the basis of their frequency of use. A linear mixed-effects model was used to determine if the frequency of oncology visits influenced the number of logins.

RESULTS

We identified 2076 regular portal users. The median number of portal logins/year was 72 for the entire cohort. Age and race were associated with frequency of portal logins. There was no difference in frequency of portal login on the basis of cancer type or stage. Each additional oncology office visit in a month increased the frequency of portal logins by 3.05 ± 0.11 (SE) within the same month. Messages and test result functionalities were used by 98.7% and 98.9% of the regular users, respectively. Regular users who logged in to portal more frequently used all five studied portal functionalities.

CONCLUSION

Patients with cancer who use portals regularly use it more in proximity to an oncology office visit and use multiple available portal functionalities. These findings can direct strategic planning to facilitate portal utilization among those not engaged with this tool.

PARP inhibitors in metastatic prostate cancer

Poly-ADP ribose polymerase inhibitors (PARPi) are an emerging therapeutic option for the treatment of prostate cancer. Their primary mechanism of action is via induction of synthetic lethality in cells with underlying deficiencies in homologous recombination repair (HRR). In men with metastatic castrate-resistant prostate cancer (mCRPC) and select HRR pathway alterations, PARPi treatment has been shown to induce objective tumor responses as well as improve progression free and overall survival. Presently, there are two PARPi, olaparib and rucaparib, that are FDA approved in the treatment of mCRPC. Ongoing research is focused on identifying which HRR alterations are best suited to predict response to PARPi so that these therapies can be most effectively utilized in the clinic. While resistance to PARPi remains a concern, combination therapies may represent a mechanism to overcome or delay resistance.

Longitudinal Molecular Profiling of Circulating Tumor Cells in Metastatic Renal Cell Carcinoma

PURPOSE

Liquid biopsies in metastatic renal cell carcinoma (mRCC) provide a unique approach to understand the molecular basis of treatment response and resistance. This is particularly important in the context of immunotherapies, which target key immune-tumor interactions. Unlike metastatic tissue biopsies, serial real-time profiling of mRCC is feasible with our noninvasive circulating tumor cell (CTC) approach.

METHODS

We collected 457 longitudinal liquid biopsies from 104 patients with mRCC enrolled in one of two studies, either a prospective cohort or a phase II multicenter adaptive immunotherapy trial. Using a novel CTC capture and automated microscopy platform, we profiled CTC enumeration and expression of HLA I and programmed cell death-ligand 1 (PD-L1). Given their diametric immunological roles, we focused on the HLA I to PD-L1 ratio (HP ratio).

RESULTS

Patients with radiographic responses showed significantly lower CTC abundances throughout treatment. Furthermore, patients whose CTC enumeration trajectory was in the highest quartile (> 0.12 CTCs/mL annually) had shorter overall survival (median 17.0 months v 21.1 months, P < .001). Throughout treatment, the HP ratio decreased in patients receiving immunotherapy but not in patients receiving tyrosine kinase inhibitors. Patients with an HP ratio trajectory in the highest quartile (≥ 0.0012 annually) displayed significantly shorter overall survival (median 18.4 months v 21.2 months, P = .003).

CONCLUSION

In the first large longitudinal CTC study in mRCC to date to our knowledge, we identified the prognostic importance of CTC enumeration and the change over time of both CTC enumeration and the HP ratio. These insights into changes in both tumor burden and the molecular profile of tumor cells in response to different treatments provide potential biomarkers to predict and monitor response to immunotherapy in mRCC.

A clinical-grade liquid biomarker detects neuroendocrine differentiation in prostate cancer

BackgroundNeuroendocrine prostate cancer (NEPC) is an aggressive subtype, the presence of which changes the prognosis and management of metastatic prostate cancer.MethodsWe performed analytical validation of a Circulating Tumor Cell (CTC) multiplex RNA qPCR assay to identify the limit of quantification (LOQ) in cell lines, synthetic cDNA, and patient samples. We next profiled 116 longitudinal samples from a prospectively collected institutional cohort of 17 patients with metastatic prostate cancer (7 NEPC, 10 adenocarcinoma) as well as 265 samples from 139 patients enrolled in 3 adenocarcinoma phase II trials of androgen receptor signaling inhibitors (ARSIs). We assessed a NEPC liquid biomarker via the presence of neuroendocrine markers and the absence of androgen receptor (AR) target genes.ResultsUsing the analytical validation LOQ, liquid biomarker NEPC detection in the longitudinal cohort had a per-sample sensitivity of 51.35% and a specificity of 91.14%. However, when we incorporated the serial information from multiple liquid biopsies per patient, a unique aspect of this study, the per-patient predictions were 100% accurate, with a receiver-operating-curve (ROC) AUC of 1. In the adenocarcinoma ARSI trials, the presence of neuroendocrine markers, even while AR target gene expression was retained, was a strong negative prognostic factor.ConclusionOur analytically validated CTC biomarker can detect NEPC with high diagnostic accuracy when leveraging serial samples that are only feasible using liquid biopsies. Patients with expression of NE genes while retaining AR-target gene expression may indicate the transition to neuroendocrine differentiation, with clinical characteristics consistent with this phenotype.FundingNIH (DP2 OD030734, 1UH2CA260389, R01CA247479, and P30 CA014520), Department of Defense (PC190039 and PC200334), and Prostate Cancer Foundation (Movember Foundation - PCF Challenge Award).

Telaglenastat plus Everolimus in Advanced Renal Cell Carcinoma: A Randomized, Double-Blinded, Placebo-Controlled, Phase II ENTRATA Trial

PURPOSE

Glutaminase is a key enzyme, which supports elevated dependency of tumors on glutamine-dependent biosynthesis of metabolic intermediates. Dual targeting of glucose and glutamine metabolism by the mTOR inhibitor everolimus plus the oral glutaminase inhibitor telaglenastat showed preclinical synergistic anticancer effects, which translated to encouraging safety and efficacy findings in a phase I trial of 2L+ renal cell carcinoma (RCC). This study evaluated telaglenastat plus everolimus (TelaE) versus placebo plus everolimus (PboE) in patients with advanced/metastatic RCC (mRCC) in the 3L+ setting (NCT03163667).

PATIENTS AND METHODS

Eligible patients with mRCC, previously treated with at least two prior lines of therapy [including ≥1 VEGFR-targeted tyrosine kinase inhibitor (TKI)] were randomized 2:1 to receive E, plus Tela or Pbo, until disease progression or unacceptable toxicity. Primary endpoint was investigator-assessed progression-free survival (PFS; one-sided α <0.2).

RESULTS

Sixty-nine patients were randomized (46 TelaE, 23 PboE). Patients had a median three prior lines of therapy, including TKIs (100%) and checkpoint inhibitors (88%). At median follow-up of 7.5 months, median PFS was 3.8 months for TelaE versus 1.9 months for PboE [HR, 0.64; 95% confidence interval (CI), 0.34-1.20; one-sided P = 0.079]. One TelaE patient had a partial response and 26 had stable disease (SD). Eleven patients on PboE had SD. Treatment-emergent adverse events included fatigue, anemia, cough, dyspnea, elevated serum creatinine, and diarrhea; grade 3 to 4 events occurred in 74% TelaE patients versus 61% PboE.

CONCLUSIONS

TelaE was well tolerated and improved PFS versus PboE in patients with mRCC previously treated with TKIs and checkpoint inhibitors.

Management of Metastatic Clear Cell Renal Cell Carcinoma: ASCO Guideline

PURPOSE

To provide recommendations for the management of patients with metastatic clear cell renal cell carcinoma (ccRCC).

METHODS

An Expert Panel conducted a systematic literature review to obtain evidence to guide treatment recommendations.

RESULTS

The panel considered peer-reviewed reports published in English.

RECOMMENDATIONS

The diagnosis of metastatic ccRCC should be made using tissue biopsy of the primary tumor or a metastatic site with the inclusion of markers and/or stains to support the diagnosis. The International Metastatic RCC Database Consortium risk criteria should be used to inform treatment. Cytoreductive nephrectomy may be offered to select patients with kidney-in-place and favorable- or intermediate-risk disease. For those who have already had a nephrectomy, an initial period of active surveillance may be offered if they are asymptomatic with a low burden of disease. Patients with favorable-risk disease who need systemic therapy may be offered an immune checkpoint inhibitor (ICI) in combination with a vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitor (TKI); patients with intermediate or poor risk should be offered a doublet regimen (no recommendation was provided between ICIs or an ICI in combination with a VEGFR TKI). For select patients, monotherapy with either an ICI or a VEGFR TKI may be offered on the basis of comorbidities. Interleukin-2 remains an option, although selection criteria could not be identified. Recommendations are also provided for second- and subsequent-line therapy as well as the treatment of bone metastases, brain metastases, or the presence of sarcomatoid features. Participation in clinical trials is highly encouraged for patients with metastatic ccRCC.Additional information is available at www.asco.org/genitourinary-cancer-guidelines.

Abstract 5122: Identification of PD-L1 expression on circulating tumor cells as a prognostic indicator in prospective clinical trial, OMNIVORE

Despite recent therapeutic advances for patients with renal cell carcinoma (RCC) with immunotherapies, alone or in combination with VEGF tyrosine kinase inhibitors, there are no available biomarkers to predict patient benefit or evaluate mechanisms of resistance. The known heterogeneity of RCC may explain the limited utility of biomarker testing on single-site biopsies. This has led to great interest in liquid biopsy as an accessible source of tumor cells to evaluate mechanisms of response and resistance. Given the growing use of immunotherapy (IO) in patients with RCC, and the promise of their companion diagnostics in other disease settings, we evaluated the ability of liquid biopsy quantification of PD-L1 to predict patient response to IO in the OMNIVORE clinical trial, NCT03203473. Patients on trial were given nivolumab monotherapy, followed by radiographic scans at C3D1, with follow-up scans confirming CR/PR defined as “response.” Responding patients were placed on observation, while non-responders were transitioned to the dual therapy with nivolumab and ipilimumab arm. PD-L1 and HLA I expression was quantified on circulating tumor cells (CTCs) using Exclusion-Based Sample Preparation (ESP). Single-cell protein analysis of PD-L1 and HLA I on CTCs facilitated the generation of summary statistics including average expression of all CTCs, number of CTCs categorized as PD-L1 or HLA I positive, and frequency of CTCs with either positive or negative expression. ROC curves were used to compare diagnostic sensitivity and specificity of different CTC summary statistics for 30 patients with evaluable matched baseline and arm assignment data. Kaplan-Meier curve evaluation was performed on the summary statistic identified as that with the greatest clinical value. ROC curve analysis identified the metric “number of PD-L1+ CTCs” at arm assignment as having the greatest clinical value (AUC 0.8) compared to all other CTC summary statistics evaluated, with a diagnostic sensitivity/specificity of 88/60% at a cutoff of 2.5 PD-L1+ CTCs/7.5 mL. Survival analysis showed that patients with fewer PD-L1+ CTCs had a longer durable response (68 weeks vs. 16 weeks, HR 2.9) to single agent nivolumab. These results suggest that the number of PD-L1+ CTCs is a potential biomarker of treatment response that may have utility for treatment stratification and investigation of novel combination strategies for patients with poor prognostic features. This biomarker is now being tested in multiple prospective clinical trials to further study clinical utility.

Citation Format: Rory M. Bade, Jennifer L. Schehr, Matthew C. Mannino, Matthew L. Bootsma, Hamid Emamekhoo, Shuang G. Zhao, Toni K. Choueiri, Sabina Signoretti, Rana R. McKay, Joshua M. Lang. Identification of PD-L1 expression on circulating tumor cells as a prognostic indicator in prospective clinical trial, OMNIVORE [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5122.

A phase I trial of elimusertib in combination with cisplatin or with cisplatin plus gemcitabine in advanced solid tumors with an emphasis on urothelial carcinoma

TPS3174

Background: Cisplatin, a well-established backbone of combination therapy of various advanced solid tumors, inhibits DNA synthesis by forming DNA cross-links and adducts. Despite the activity of cisplatin, tumor cells can either be refractory or develop resistance to treatment. Cisplatin has been demonstrated to cause cell cycle G2/M arrest, which may allow for DNA damage response (DDR) and repair. Ataxia telangiectasia mutated (ATM) and ataxia telangiectasia and Rad 3-related (ATR) protein kinases are key regulators of DDR, and contribute to maintaining genomic integrity in response to various exogenous and endogenous genotoxic insults like cytotoxic chemotherapy. In fact, cisplatin has been shown to transiently increase ATR expression. Inhibitors of ATR have been studied in combination with cisplatin both in vitro and in vivo, demonstrating enhanced activity. The oral small molecule ATR inhibitor elimusertib, which has been studied as a single agent in a Phase I study, has also demonstrated enhanced activity with cisplatin in vitro in lung cancer and bladder cancer cell lines. We sought to conduct a Phase I study evaluating the combination of elimusertib with cisplatin or with cisplatin and gemcitabine. Methods: In the first cohort, patients with histologically confirmed advanced solid tumors for which cisplatin-based therapy would be considered appropriate, who exhibit adequate organ function, and have received < 300 mg/m2 of cisplatin previously are treated with cisplatin on Day (D) 1 and with elimusertib on D2 & 9 of each 21-day cycle. The study follows a phase I queue (IQ) 3+3 dose escalation design, following standard practices for dose-limiting toxicity (DLT) impact on escalation, and when the maximum tolerated dose (MTD) is established with cisplatin alone, this will inform the first dose level of the next cohort, in which patients will be treated with cisplatin on D1, gemcitabine on D1 & 8, and elimusertib on D2 & 9 of each 21-day cycle. An expansion cohort will enroll urothelial carcinoma patients when the second MTD is established. The primary objective of the study is to evaluate the safety and MTD of elimusertib in combination with cisplatin, as well as in combination with cisplatin and gemcitabine. Secondary study objectives include evaluation of pharmacokinetics of elimusertib in these combinations, preliminary efficacy, and evaluating the association between ATM expression and responses to therapy. Currently, 6 patients have been enrolled to the first cohort of the study. Clinical trial information: NCT04491942.

Supporting Structured Data Capture for Patients With Cancer: An Initiative of the University of Wisconsin Carbone Cancer Center Survivorship Program to Improve Capture of Malignant Diagnosis and Cancer Staging Data

PURPOSE

Structured data elements within electronic health records are health-related information that can be entered, stored, and extracted in an organized manner at later time points. Tracking outcomes for cancer survivors is also enabled by structured data. We sought to increase structured data capture within oncology practices at multiple sites sharing the same electronic health records.

METHODS

Applying engineering approaches and the Plan-Do-Study-Act cycle, we launched dual quality improvement initiatives to ensure that a malignant diagnosis and stage were captured as structured data. Intervention: Close Visit Validation (CVV) requires providers to satisfy certain criteria before closing ambulatory encounters. CVV may be used to track open clinical encounters and chart delinquencies to encourage optimal clinical workflows. We added two cancer-specific required criteria at the time of closing encounters in oncology clinics: (1) the presence of at least one malignant diagnosis on the Problem List and (2) staging all the malignant diagnoses on the Problem List when appropriate.

RESULTS

Six months before the CVV implementation, the percentage of encounters with a malignant diagnosis on the Problem List at the time of the encounter was 65%, whereas the percentage of encounters with a staged diagnosis was 32%. Three months after cancer-specific CVV implementation, the percentages were 85% and 75%, respectively. Rates had increased to 90% and 88% more than 2 years after implementation.

CONCLUSION

Oncologist performance improved after the implementation of cancer-specific CVV criteria, with persistently high percentages of relevant malignant diagnoses and cancer stage structured data capture 2 years after the intervention.

Outcomes with novel combinations in nonclear cell renal cell carcinoma (nccRCC): ORACLE study

4545

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

Quantitative imaging biomarkers of immune-related adverse events in immune-checkpoint blockade-treated metastatic melanoma patients: a pilot study

PURPOSE

To develop quantitative molecular imaging biomarkers of immune-related adverse event (irAE) development in malignant melanoma (MM) patients receiving immune-checkpoint inhibitors (ICI) imaged with 18F-FDG PET/CT.

METHODS

18F-FDG PET/CT images of 58 MM patients treated with anti-PD-1 or anti-CTLA-4 ICI were retrospectively analyzed for indication of irAE. Three target organs, most commonly affected by irAE, were considered: bowel, lung, and thyroid. Patient charts were reviewed to identify which patients experienced irAE, irAE grade, and time to irAE diagnosis. Target organs were segmented using a convolutional neural network (CNN), and novel quantitative imaging biomarkers - SUV percentiles (SUVX%) of 18F-FDG uptake within the target organs - were correlated with the clinical irAE status. Area under the receiver-operating characteristic curve (AUROC) was used to quantify irAE detection performance. Patients who did not experience irAE were used to establish normal ranges for target organ 18F-FDG uptake.

RESULTS

A total of 31% (18/58) patients experienced irAE in the three target organs: bowel (n=6), lung (n=5), and thyroid (n=9). Optimal percentiles for identifying irAE were bowel (SUV95%, AUROC=0.79), lung (SUV95%, AUROC=0.98), and thyroid (SUV75%, AUROC=0.88). Optimal cut-offs for irAE detection were bowel (SUV95%>2.7 g/mL), lung (SUV95%>1.7 g/mL), and thyroid (SUV75%>2.1 g/mL). Normal ranges (95% confidence interval) for the SUV percentiles in patients without irAE were bowel [1.74, 2.86 g/mL], lung [0.73, 1.46 g/mL], and thyroid [0.86, 1.99 g/mL].

CONCLUSIONS

Increased 18F-FDG uptake within irAE-affected organs provides predictive information about the development of irAE in MM patients receiving ICI and represents a potential quantitative imaging biomarker for irAE. Some irAE can be detected on 18F-FDG PET/CT well before clinical symptoms appear.

Phase 2 trial of T-cell activation using MVI-816 and pembrolizumab in patients with metastatic, castration-resistant prostate cancer (mCRPC)

Background

We previously reported a trial using a DNA vaccine encoding prostatic acid phosphatase (MVI-816, pTVG-HP), given over 12 weeks concurrently or sequentially with pembrolizumab, in patients with mCRPC. We report the final analysis of this trial following two additional treatment arms in which patients with mCRPC continued concurrent treatment until progression.

Materials and methods

Patients with mCRPC were treated with MVI-816 and pembrolizumab every 3 weeks (arm 3, n=20) or MVI-816 every 2 weeks and pembrolizumab every 4 weeks (arm 4, n=20). The primary objectives were safety, 6-month progression-free survival (PFS), median time to radiographic progression, and objective response rates. Secondary objectives included immunological evaluations.

Results

In 25 patients with measurable disease, there were no complete response and one confirmed partial response in a patient who subsequently found to have an MSI^hi tumor. 4/40 patients (10%) had a prostate-specific antigen decline >50%. The estimated overall radiographic PFS rate at 6 months was 47.2% (44.4% arm 3, 61.5% arm 4). Accounting for all off-study events, overall median time on treatment was 5.6 months (95% CI: 5.4 to 10.8 months), 5.6 months for arm 3 and 8.1 months for arm 4 (p=0.64). Thirty-two per cent of patients remained on trial beyond 6 months without progression. Median overall survival was 22.9 (95% CI: 16.2 to 25.6) months. One grade 4 event (hyperglycemia) was observed. Immune-related adverse events (irAEs) >grade 1 were observed in 42% of patients overall. Interferon-γ and/or granzyme B immune response to prostatic acid phosphatase was detected in 2/20 patients in arm 3 and 6/20 patients in arm 4. Plasma cytokines associated with immune activation and CD8+ T-cell recruitment were augmented at weeks 6 and 12. The development of irAE was significantly associated with a prolonged time on treatment (HR=0.42, p=0.003). Baseline DNA homologous recombination repair mutations were not associated with longer time to progression.

Conclusions

Findings here demonstrate that combining programmed cell death 1 blockade with MVI-816 is safe, can augment tumor-specific T cells, and can result in a favorable 6-month disease control rate. Correlative studies suggest T-cell activation by vaccination is critical to the mechanism of action of this combination. Future randomized clinical trials are needed to validate these findings.

Trial registration number

NCT02499835.

Single cell phenotyping of PDL1 and HLA1 on circulating tumor cells (CTC) in clear cell renal cell carcinoma (ccRCC) on systemic treatment with immunotherapy (IO) and vascular endothelial growth factor receptor tyrosine kinase inhibitors (TKI)

381

Background: Single agent or combination regimens using different IO and TKI agents have dramatically improved survival of patients (pt) with advanced ccRCC. Nevertheless, selecting optimal combination and sequencing of treatments remains challenging given the current absence of predictive biomarkers. Considering substantial disease heterogeneity and tumor clonal evolution, CTCs could provide a more comprehensive and longitudinal assessment of disease and response to treatment when compared to single site biopsy. In this study we explore changes in CTC characteristics in correlation with pt’s response (Resp) to treatment and progression (PD). Methods: 152 blood sample time points from 44 ccRCC pts (mean=3.5 sample/pt, range= 1-9) were included. An automated microfluidic platform using exclusion-based sample technology was employed for high sensitivity enrichment of RCC CTCs using EpCAM and CAIX antibodies. High-specificity CTC identification was achieved with positive staining for pCK or CAXII, and negative staining for CD45, CD34 and CD66b. Single cell phenotyping of PDL1 and HLA1 expression on each CTC was quantified with automated image analysis algorithms followed by manual visual QA of the putative CTCs. Cellular-level expression of PDL1 and HLA1 were compared within treatment-response groupings, using Wilcoxon rank-sum tests (Table). Results: Pts were 70% male, 93% Caucasian, 51% de novo metastatic, 98% received systemic treatment. CTC samples were collected at baseline (12) or while on treatment with IO (71), TKI (55), or IO/TKI (14). Across treatments, the number of CTCs increased from Resp to PD but this trend was not statistically significant. PDL1 expression was higher at PD compared to Resp on IO and IO/TKI but not significantly different on TKI. HLA1 expression was higher at PD compared to Resp on IO and TKI but not significantly different on IO/TKI. Average CTC PD-L1 expression was higher at Resp to IO compared to baseline. Conclusions: Single cell phenotyping of PDL1 and HLA1 were done at Resp compared to PD time points on IO and/or TKI to identify potential mechanisms of resistance. Further evaluation of these preliminary results in prospective trials is ongoing to advance new predictive biomarkers for ccRCC.[Table: see text]

Pathologic outcomes at cytoreductive nephrectomy (CN) following immunotherapy (IO) for patients with advanced renal cell carcinoma (RCC)

334

Background: IO, either as combination therapy in the frontline or monotherapy in the second line, has improved outcomes for patients with advanced RCC. With the movement away from upfront CN, limited data are available on the outcomes of patients who receive IO with delayed CN. In this study, we characterized the pathologic and survival outcomes for patients who received IO followed by CN. Methods: We conducted a multi-center, retrospective analysis of patients with advanced/metastatic RCC having received IO combination or monotherapy followed by CN. An IRB-approved and HIPAA-compliant registry was used to collect data from the electronic medical record. Our primary endpoint was the degree of pathologic downstaging comparing baseline clinical T stage to pathologic T stage following IO. Secondary endpoints included investigator assessed response using RECIST principals, progression-free survival (PFS), and overall survival (OS). Results: We identified53 patients with advanced RCC across 9 institutions who were eligible for the study. The median age was 63 years, 72% were white, and 60% were male. 81% of patients had clear cell histology, 11% had sarcomatoid differentiation, and 75% presented with de novo metastatic disease. Baseline IMDC risk is as follows: 4% favorable, 55% intermediate, and 26% poor risk with 15% unknown. 23% had bone metastases and 23% had liver metastases at baseline. Lines of therapy prior to CN was 1 line in 74% of patients, 2 lines in 25%, and 3 lines in 2%. For the line of IO therapy immediately preceding CN, 49% received nivolumab+ipilimumab, 30% received IO monotherapy, and 21% received combination IO/VEGF therapy. The median duration of therapy prior to surgery was 11.3 months (range 0.38-47.8). 28% of patients discontinued treatment after CN for observation. Best overall response prior to CN was stable disease in 25% of patients, partial response in 60%, and progressive disease in 4% with 11% unknown. Following receipt of IO-based treatment, 38% of patients exhibited downstaging from the baseline clinical T stage to the CN pathological T stage (Table). 11% of patients had no residual disease at CN. For pathologic outcomes, 85% of patients had negative margins, 75% had necrosis present, and the median tumor size at CN was 6.5 cm. The median PFS was 11.3 months and median OS was 25.7 months for the overall cohort. Conclusions: IO-based strategies demonstrate efficacy in the renal primary in patients with advanced RCC. T stage downstaging was demonstrated in 38% of patients with 11% having a complete pathologic response in the renal primary following IO administration. Biomarker studies on baseline and CN tissue will further elucidate molecular predictors of response and resistance to IO therapy.[Table: see text]

Impact of neoadjuvant immune checkpoint inhibitor therapy on primary tumor size and complexity: Correlation with surgical quality and short term oncological outcomes

390

Background:The concept of primary systemic therapy has gained increasing traction in the management of metastatic and locally advanced Renal Cell Carcinoma (RCC). Most series have evaluated the use of tyrosine-kinase inhibitors, however, with the emergence of immune checkpoint inhibitor therapy as first line agents in advanced RCC, further assessment of efficacy is warranted. We examined the effects of immunotherapy (IO) combinations on the primary tumor and consequent surgical quality and short-term oncological outcomes. Methods: We conducted a multi-center, retrospective analysis of patients with advanced/metastatic RCC having received IO followed by Radical (RN) or partial nephrectomy (PN). Primary outcome was achievement of Bifecta (composite outcome of complete resection and no 30-day post-operative complications). Predictors for achievement of Bifecta were assessed with logistic regression multivariable analysis. Secondary outcomes were change in maximal tumor dimension, RENAL nephrometry score and disease progression. Kaplan-Meier analysis was used to assess progression-free survival (PFS) for Bifecta and non-Bifecta patients. Results: We identified 52 patients with advanced RCC across 9 institutions who were eligible. The median age was 63 years and 60.4% were males. Median tumor size at diagnosis was 9.3 cm. 19.6% had T4 disease and 75% had AJCC Stage IV disease. IO treatment resulted in significant reductions in median tumor size (-25.4%; 9.7 cm vs. 7.3cm p = 0.0129) and RENAL nephrometry score (9 to 8, p = 0.032). 43 (83%) of patients underwent RN and (9) 17% had PN. Median tumor size was smaller for PN (8 vs. 4.1 cm, p < 0.001), and 30 day complication rates were higher (p = 0.024). Bifecta was achieved in 39 patients [33/42 (78.6%) RN and 6/9 (67%) PN, p = 0.264). Predictors for achievement of Bifecta were younger age (OR 1.06, p = 0.01), increasing reduction in tumor size (OR 1.187, p < 0.001), and shorter time between therapy and surgery (OR 1.07, p < 0.001). Kaplan-Meier analysis demonstrated longer median time to progression in the Bifecta-positive group compared to patients who failed to achieve Bifecta (75 vs. 30 months, p = 0.04). Conclusions: Pre-surgical therapy resulted in tumor size and complexity reduction. Tumor size reduction was predictive for achievement of Bifecta, which was associated with improved short term oncological outcomes. To our knowledge, this is the first series evaluating the effect of neoadjuvant systemic therapy on the primary tumor prior to surgical intervention.

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.

Safety and efficacy of nivolumab plus ipilimumab in patients with advanced renal cell carcinoma with brain metastases: CheckMate 920

Background

Nivolumab plus ipilimumab (NIVO + IPI) has demonstrated long‐term efficacy and safety in patients with previously untreated, advanced renal cell carcinoma (aRCC). Although most phase 3 clinical trials exclude patients with brain metastases, the ongoing, multicohort phase 3b/4 CheckMate 920 trial (ClincalTrials.gov identifier NCT02982954) evaluated the safety and efficacy of NIVO + IPI in a cohort that included patients with aRCC and brain metastases, as reported here.

Methods

Patients with previously untreated aRCC and asymptomatic brain metastases received NIVO 3 mg/kg plus IPI 1 mg/kg every 3 weeks × 4 followed by NIVO 480 mg every 4 weeks. The primary end point was the incidence of grade ≥3 immune‐mediated adverse events (imAEs) within 100 days of the last dose of study drug. Key secondary end points were progression‐free survival and the objective response rate according to Response Evaluation Criteria in Solid Tumors, version 1.1 (both determined by the investigator). Exploratory end points included overall survival, among others.

Results

After a minimum follow‐up of 24.5 months (N = 28), no grade 5 imAEs occurred. The most common grade 3 and 4 imAEs were diarrhea/colitis (n = 2; 7%) and hypophysitis, rash, hepatitis, and diabetes mellitus (n = 1 each; 4%). The objective response rate was 32% (95% CI, 14.9%‐53.5%) with a median duration of response of 24.0 months; 4 of 8 responders remained without reported progression. Seven patients (25%) had intracranial progression. The median progression‐free survival was 9.0 months (95% CI, 2.9‐12.0 months), and the median overall survival was not reached (95% CI, 14.1 months to not estimable).

Conclusions

In patients who had previously untreated aRCC and brain metastases—a population with a high unmet medical need that often is underrepresented in clinical trials—the approved regimen of NIVO + IPI followed by NIVO showed encouraging antitumor activity and no new safety signals.

CheckMate 920 is the first prospective, multicohort study of nivolumab plus ipilimumab as first‐line therapy for advanced renal cell carcinoma in patients who have a poor prognosis and a high unmet medical need. In cohort 3 (advanced renal cell carcinoma and brain metastases), nivolumab plus ipilimumab has a safety profile consistent with previous reports of this dosing regimen with encouraging antitumor activity.

294 Evaluation of radiographic response in the intact renal mass (intact-Rmass) to immune checkpoint inhibitor (ICI) combination regimens in patients with metastatic renal cell carcinoma (mRCC)

Background

As most of the patients previously enrolled in trials had nephrectomy before starting systemic treatment (syst-Rx), the response of the intact-Rmass to novel ICI and tyrosine kinase inhibitor (TKI) combination regimens is not well described.

Methods

A retrospective review of 227 patients with mRCC who were treated with ICI (single agent or combinations) in the 1st- or 2nd-line was conducted. Following the appropriate regulatory process, collaborators from 6 US sites collected clinical, pathological, and outcome data via chart review. Overall response was investigator-assessed for all patients with at least one post-treatment scan or evidence of clinical progression after treatment initiation. Overall radiographic response (ORR) represents any radiographic response in the metastatic disease per investigator’s assessment. To accurately assess response in intact-Rmass, 3-dimensional measurement of the intact-Rmass was performed and Rmass volume was calculated at baseline and at the time of best overall response for 1st- and 2nd-line therapy. Radiographic response in intact-Rmass is defined as >30% decrease in the Rmass volume.

Results

Median age at diagnosis was 62 years, 69% were male, 82% had clear cell histology. 15% and 12% had sarcomatoid and rhabdoid features, respectively. Overall, 82 patients (36%) had a measurable intact-Rmass while receiving syst-Rx. 63 (28%) patients never had a nephrectomy, and 10 (4%) patients had delayed nephrectomy after a good overall response to syst-Rx. 108 (48%) received ICI in 1st-line (88/108 received ipilimumab/nivolumab combination). 91 (40%), and 18 (8%) patients received TKI, or ICI+TKI in 1st-line. 161 (71%) and 86 (38%) of the patients received 2nd-line and 3rd-line therapy, respectively. 104 (46%) received ICI in 2nd-line (75/104 treated with single-agent ICI). 48 (21%), and 4 (2%) patients received TKI, or ICI+TKI in 2nd-line. Radiographic response in intact-Rmass for evaluable patients is summarized in table 1. The highest response rates in intact-Rmass were seen with ICI+TKI combinations. Higher rates of radiographic response in intact-Rmass were seen in patients treated with ICI in 1st-line compared to 2nd-line, possibly related to higher usage of ICI combinations (ipilimumab/nivolumab) in 1st-line. Overall metastatic disease response to different regimens in the 1st-line or 2nd-line was not different based on the history of nephrectomy prior to syst-Rx (table 2).

Abstract 294 Table 1

Radiographic response (≥30% decrease in volume) in the intact renal mass

Abstract 294 Table 2

Overall radiographic response (ORR) per investigator assessment

Conclusions

Higher radiographic response rates in the intact-Rmass were seen in patients treated with ICI+TKI and ICI in the 1st-line. There was no significant difference in overall metastatic disease response to 1st- or 2nd-line treatment based on the history of nephrectomy prior to syst-Rx.

Ethics Approval

Each of the 6 participating centers had their IRB approved protocol for retrospective study and data collection. Data Use Agreements were obtained for each center to share limited data set data with University of Wisconsin - Madison (IRB protocol UW17148 # 2018–0213). Final analysis was performed at University of Wisconsin.

Consent not applicable to retrospective studies.

506 IGNYTE: an open-label, multicenter, phase 1/2 (Ph 1/2) clinical trial of RP1 ± nivolumab in patients with advanced solid tumors

Background

RP1 is an enhanced potency oncolytic HSV-1 which expresses a fusogenic glycoprotein (GALV-GP R-) and granulocyte macrophage colony stimulating factor (GM-CSF).1 In pre-clinical studies, RP1 demonstrated potent GALV-GP R-enhanced anti-tumor activity and immunogenic cell death. This Phase 1/2 (Ph 1/2) study was designed to evaluate the safety and efficacy of RP1 ± nivolumab (nivo) in patients (pts) with advanced solid tumors, including pts whose disease failed prior anti-PD-1/PD-L1 therapy and has reported promising interim data in a number of tumor types including cutaneous squamous cell carcinoma (CSCC) and anti-PD1 failed melanoma to date.2

Methods

This is a multi-center, first-in-human, open label, multi-cohort, non-randomized Ph1 study of RP1 alone and combined with nivo followed by Ph2 in combination with nivo in pts with recurrent advanced solid tumors including those that progressed after prior anti-PD-1/PD-L1 therapy. The Ph 1 monotherapy dose escalation (n=14) and RP-1 combination expansion (n=22) cohorts are fully enrolled. Approximately 260 pts are expected to be enrolled in the ongoing Ph 2 portion across five cohorts; melanoma (n=30, enrollment complete), non-melanoma skin cancer (n=45, to include 15 pts with anti-PD-1/PD-L1 failed disease), anti-PD-1 failed MSI-H/dMMR tumors (n=30), anti-PD-1/PD-L1-failed non-small-cell lung cancer (n=30) and a registration-directed cohort in anti-PD-1 failed cutaneous melanoma (n=125). Pts in the Ph 2 portion receive up to 10 mL of RP1 intratumorally into one or more superficial or deep seated/visceral lesions at the recommended Ph 2 dose (1x10^6 PFU/mL × 1 followed by 1x10^7 PFU/mL × 7, Q2W). Following the first dose of RP1, nivo (240 mg IV Q2W for 4 months then 480 mg IV Q4W for up to 2 years) is subsequently administered in combination. Pts may receive up to 8 additional doses of RP1 if they meet protocol-specified criteria. Tumor assessments are performed Q8W. The primary objectives of the Ph 2 part of the study are to assess the safety, tolerability, and overall response rate (ORR) of RP1 in combination with nivo, by independent review for the anti-PD1 failed melanoma cohort. Secondary objectives include duration of response, complete response rate, disease control rate, PFS, 1-year and 2-year survival rates. Exploratory objectives include biodistribution and shedding analysis of RP1 and biomarker studies, including analyses of tumor biopsies and blood samples. Enrollment is currently ongoing in the UK and US, with additional sites in the EU (including France and Spain) are expected to open in 2021.

Trial Registration

NCT03767348

References

Thomas S, Kuncheria L, Roulstone V, Kyula JN, Mansfield D, Bommareddy PK, Smith H, Kaufman HL, Harrington KJ, Coffin RS. Development of a new fusion-enhanced oncolytic immunotherapy platform based on herpes simplex virus type 1. J Immunother Cancer 2019;7(1):214.

Coffin R, Astley-Sparke P, and Middleton M (2021, June 3rd). Retrieved from https://ir.replimune.com/static-files/f4fe3349-e082-4d41-94a1-106ce7e78a23

Ethics Approval

The study was approved by institutional review board or the local ethics committee at each site. Informed consent was obtained from patients prior to enrollment.

350 Phase 2 trial of a DNA vaccine with pembrolizumab in patients with metastatic, castration-resistant prostate cancer (mCRPC)

Background

We previously reported a pilot clinical trial using a DNA vaccine encoding prostatic acid phosphatase (pTVG-HP), given over 12 weeks either concurrently or in sequence with pembrolizumab, in patients with mCRPC. We report here the final analysis of this trial following two additional treatment arms in which patients with mCRPC were treated beyond 12 weeks until progression.

Methods

Patients with mCRPC were treated with pTVG-HP and pembrolizumab every 3 weeks (Arm 3, n=20), or pTVG-HP every 2 weeks and pembrolizumab every 4 weeks (Arm 4, n=20). The primary objectives were safety, 6-month PFS, median time to radiographic progression, and objective response rates. Secondary objectives included immunological evaluations.

Results

Treatment was without unexpected toxicity, and only 1 grade 4 event (hyperglycemia) was observed. Immune related adverse events (irAE) > grade 1 included adrenal insufficiency, hepatitis, colitis, thyroid dysfunction, pancreatitis, pneumonitis, and rash, occurring in 42% of patients overall. 10/25 patients with measurable disease experienced any decrease in tumor volume from baseline, with 1 confirmed PR and no CR. 23/66 (35%) experienced any PSA decline from baseline. Overall median TTP was 5.4 months (95% CI; 5.3–8.1 months); median TTP for Arm 3 was 5.3 months compared to 8.0 months for Arm 4. Overall, 41.7% of patients had no radiographic progression at 6 months (29.9% Arm 3, 57.9% Arm 4). Median overall survival was 22.9 months. IFNγ and/or granzyme B immune response to PAP was detected in 2/20 patients in Arm 3 and 6/20 patients in Arm 4. Cytokines associated with immune activation and CD8+ T cell recruitment were augmented in the plasma of patients at weeks 6 and 12. Increased IFNγ in the sera at week 6 trended with prolonged TTP (p=0.010) and overall survival (p=0.025). The development of irAE was associated with a prolonged TTP (HR=0.25, p=0.003).

Conclusions

PD-1 pathway inhibitors have demonstrated little clinical activity to date as monotherapies for mCRPC. Our findings demonstrate that combining PD-1 blockade with tumor-targeted T-cell activation using pTVG-HP is safe, can augment tumor-specific T cells, and result in objective changes with longer time to progression than what has been observed in previous trials. The association of progression or survival with increased IFNγ, irAE, and vaccine schedule suggests T cell activation by vaccination is critical to the mechanism of action of this combination. This study suggests this approach should be further evaluated in randomized clinical trials for patients with advanced mCRPC.

Acknowledgements

Funding for this trial was from a 2014 Movember Prostate Cancer Foundation Challenge Award and Madison Vaccines, Inc.

Trial Registration

NCT02499835

Ethics Approval

This trial was reviewed and approved by the University of Wisconsin Human Subjects’ Review Committee (IRB), protocol 2015–0453. All participants provided IRB-approved written informed consent before taking part.

Effect of Cisplatin and Gemcitabine With or Without Berzosertib in Patients With Advanced Urothelial Carcinoma: A Phase 2 Randomized Clinical Trial

IMPORTANCE

Preclinical studies suggest that inhibition of single-stranded DNA repair by ataxia telangiectasia and Rad3 (ATR) may enhance the cytotoxicity of cisplatin, gemcitabine, and other chemotherapeutic agents. Cisplatin with gemcitabine remains the standard up-front therapy for treatment in patients with metastatic urothelial cancer.

OBJECTIVE

To determine whether the use of the selective ATR inhibitor, berzosertib, could augment the activity of cisplatin with gemcitabine.

DESIGN, SETTING, AND PARTICIPANTS

In a phase 2 randomized clinical trial, 87 patients across 23 centers in the National Cancer Institute Experimental Therapeutics Clinical Trials Network were randomized to receive either cisplatin with gemcitabine alone (control arm) or cisplatin with gemcitabine plus berzosertib (experimental arm). Key eligibility criteria included confirmed metastatic urothelial cancer, no prior cytotoxic therapy for metastatic disease, 12 months or more since perioperative therapy, and eligibility for cisplatin receipt based on standard criteria. The study was conducted from January 27, 2017, to December 15, 2020.

INTERVENTIONS

In the control arm, cisplatin, 70 mg/m2, was given on day 1 and gemcitabine, 1000 mg/m2, was given on days 1 and 8 of a 21-day cycle. In the experimental arm, cisplatin, 60 mg/m2, was given on day 1; gemcitabine, 875 mg/m2, on days 1 and 8; and berzosertib, 90 mg/m2, on days 2 and 9 of a 21-day cycle.

MAIN OUTCOMES AND MEASURES

The primary end point of the study was progression-free survival. The analysis was on all patients who started therapy.

RESULTS

Of the total of 87 patients randomized, 41 patients received cisplatin with gemcitabine alone and 46 received cisplatin with gemcitabine plus berzosertib. Median age was 67 (range, 32-84) years, and 68 patients (78%) were men. Median progression-free survival was 8.0 months for both arms (Bajorin risk-adjusted hazard ratio, 1.22; 95% CI, 0.72-2.08). Median overall survival was shorter with cisplatin with gemcitabine plus berzosertib compared with cisplatin with gemcitabine alone (14.4 vs 19.8 months; Bajorin risk-adjusted hazard ratio, 1.42; 95% CI, 0.76-2.68). Higher rates of grade 3 vs grade 4 thrombocytopenia (59% vs 39%) and neutropenia (37% vs 27%) were observed with cisplatin with gemcitabine and berzosertib compared with cisplatin with gemcitabine alone; consequently, more dose reductions were needed in the experimental arm. Patients in the experimental arm received a median cisplatin dose of 250 mg/m2, which was significantly lower than the median dose of 370 mg/m2 in the control arm (P < .001).

CONCLUSIONS AND RELEVANCE

The addition of berzosertib to cisplatin with gemcitabine did not prolong progression-free survival relative to cisplatin with gemcitabine alone in patients with metastatic urothelial cancer, and a trend toward inferior survival was observed with this combination. Berzosertib plus cisplatin with gemcitabine was associated with significantly higher hematologic toxicities despite attenuated dosing of cisplatin with gemcitabine.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02567409.

Image intensity histograms as imaging biomarkers: application to immune-related colitis

Purpose.To investigate image intensity histograms as a potential source of useful imaging biomarkers in both a clinical example of detecting immune-related colitis (irColitis) in¹⁸F-FDG PET/CT images of immunotherapy patients and an idealized case of classifying digital reference objects (DRO).Methods.Retrospective analysis of bowel¹⁸F-FDG uptake in N = 40 patients receiving immune checkpoint inhibitors was conducted. A CNN trained to segment the bowel was used to generate the histogram of bowel¹⁸F-FDG uptake, and percentiles of the histogram were considered as potential metrics for detecting inflammation associated with irColitis. A model of the colon was also considered using cylindrical DRO. Classification of DRO with different intensity distributions was undertaken under varying geometry and noise settings.Results.The most predictive biomarker of irColitis was the 95th percentile of the bowel SUV histogram (SUV_95%). Patients later diagnosed with irColitis had a significantly higher increase in SUV_95%from baseline to first on-treatment PET than patients who did not experience irColitis (p = 0.02). An increase in SUV_95%> + 40% separated pre-irColitis change from normal variability with a sensitivity of 75% and specificity of 88%. Furthermore, histogram percentiles were ideal metrics for classifying 'hot center' and 'cold center' DRO, and were robust to varying DRO geometry and noise, and to the presence of spoiler volumes unrelated to the detection task.Conclusions.The 95th percentile of the bowel SUV histogram was the optimal metric for detecting irColitis on¹⁸F-FDG PET/CT. Image intensity histograms are a promising source of imaging biomarkers for clinical tasks.

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

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

Patterns and predictors of cancer-specific patient health portal usage among patients with cancer: results from the UWCCC Survivorship Program

Background

Portals can assist patients in managing their healthcare. Understanding how patients with cancer use portals can facilitate improvements in patient engagement in cancer care. This study sought to determine if patients with cancer used portals differently for cancer versus noncancer purposes. The effects of geographic residence (rural vs. urban residence) and cancer stage on portal usage were also investigated.

Methods

We conducted a retrospective analysis of portal usage by patients seen at an NCI‐designated cancer center between 2015 and 2019. Demographics, cancer characteristics, and portal usage (number of successful logins, messages sent, and results viewed) were extracted. Messages sent and results viewed in the portal were deemed oncologist‐specific and cancer specific if sent to or ordered in medical oncology departments, respectively.

Results

The analysis included a total of 5950 patients with cancer. Patients were less likely to send and view oncologist‐specific messages compared to non‐oncologist‐specific messages. They were also less likely to view cancer results compared to noncancer results. Compared to urban counterparts, patients residing in rural areas had lower odds of having any logins and logged in less frequently during the year of diagnosis. Compared to patients with non‐metastatic disease, individuals with metastatic disease were more likely to become frequent portal users.

Conclusions

Patients may use portals differently for cancer versus noncancer purposes; urban residence and metastatic cancer were associated with more frequent usage. Further investigation can inform interventions to increase accessibility for groups at a disadvantage related to the use of this technology and to help patients better leverage portals to manage their cancer.

Prospective Evaluation of Clinical Outcomes Using a Multiplex Liquid Biopsy Targeting Diverse Resistance Mechanisms in Metastatic Prostate Cancer

Nearly all men with prostate cancer treated with androgen receptor (AR) signaling inhibitors (ARSIs) develop resistance via diverse mechanisms including constitutive activation of the AR pathway, driven by AR genomic structural alterations, expression of AR splice variants (AR-Vs), or loss of AR dependence and lineage plasticity termed neuroendocrine prostate cancer. Understanding these de novo acquired ARSI resistance mechanisms is critical for optimizing therapy.

Safety and efficacy outcomes with nivolumab plus ipilimumab in patients with advanced renal cell carcinoma and brain metastases: results from the CheckMate 920 trial

4515

Background: Combination therapy with nivolumab plus ipilimumab (NIVO+IPI) has demonstrated long-term efficacy and tolerability in patients with previously untreated advanced renal cell carcinoma (aRCC). Previous phase 3 clinical trials of patients with advanced or metastatic cancers have mostly excluded patients with brain metastases. CheckMate 920 is an ongoing, phase 3b/4 clinical trial of NIVO+IPI treatment in patients with aRCC with a high unmet medical need. We present updated safety and efficacy results for the cohort of patients with aRCC of any histology and brain metastases from CheckMate 920 (NCT02982954). Methods: Patients with previously untreated advanced/metastatic aRCC of any histology, with asymptomatic brain metastases (not currently receiving corticosteroids or radiation), and Karnofsky performance status ≥ 70% were assigned to treatment with NIVO 3 mg/kg + IPI 1 mg/kg every 3 weeks × 4 doses followed by NIVO 480 mg every 4 weeks for ≤ 2 years or until disease progression/unacceptable toxicity. The primary endpoint was incidence of grade ≥ 3 immune-mediated adverse events (imAEs) within 100 days of last dose of study drug. Key secondary endpoints included progression-free survival (PFS) and objective response rate (ORR) by RECIST v1.1 (both per investigator). Exploratory endpoints included overall survival (OS). Results: Of 28 treated patients with brain metastases, 85.7% were men; median (range) age was 60 (38–87) years, and 14.3% had sarcomatoid features. With 24.5 months minimum follow-up of the 28 patients enrolled, median duration of therapy (range) was 3.4 (0.0–23.3) months for NIVO and 2.1 (0.0–3.3) months for IPI. No grade 5 imAEs occurred. Grade 3–4 imAEs by category were diarrhea/colitis (7.1%), hypophysitis (3.6%), rash (3.6%), hepatitis (3.6%), and diabetes mellitus (3.6%). Of the 25 patients who were evaluable for ORR, the ORR was 32.0% (95% CI, 14.9–53.5). No patients achieved complete response, 8 achieved partial response, and 10 patients had stable disease. Median time to response (range) was 2.8 (2.4–3.0) months. Median duration (range) of response was 24.0 (3.9–not estimable [NE]) months; 4 of 8 responders remain without reported progression. Of 28 patients, 7 (25%) had intracranial progression. Median PFS (n = 28) was 9.0 (95% CI, 2.9–12.0) months. Median OS (n = 28) was still not reached (95% CI, 14.1 months–NE). Conclusions: In patients with previously untreated aRCC and brain metastases, a population with high unmet medical need that is often underrepresented in clinical trials, the approved treatment regimen of NIVO+IPI followed by NIVO for aRCC showed no new safety signals and continues to show encouraging antitumor activity with longer follow-up. Clinical trial information: NCT02982954.

Outcomes with novel combinations in non-clear cell renal cell carcinoma(nccRCC): ORACLE study

4580

Background: Despite advances in the treatment of clear cell RCC, there is a paucity of data to guide management of nccRCC due to the heterogeneity and rarity of these tumors. The clinical activity of new combination therapies (including immunotherapy (IO), anti-vascular endothelial growth factor inhibitors (VEGF), and mammalian target of rapamycin (mTOR) inhibitors) in metastatic nccRCC is not known. Methods: In this multicenter retrospective analysis, we explored the efficacy of combination systemic therapies in patients with nccRCC. Baseline and follow-up demographic, clinical, treatment, and radiographic data were collected. The primary endpoint was objective response rate (ORR) assessed by investigator review. Secondary endpoints include progression- free survival (PFS), disease control rate (DCR), median duration of response (DOR), overall survival (OS), and biomarker correlates. Results: Among 66 included patients, median age was 59 yr; 60% were male and 62% white. Histologies included papillary (38%), chromophobe (17%), unclassified (24%), translocation (12%), and other (9 %). Sarcomatoid and/or rhabdoid differentiation was present in 18%, 70% had prior nephrectomy, 86% were IMDC intermediate/poor risk, 29% and 32% had liver and bone metastasis respectively. 67% received combination treatment in the first line. Comparison of outcomes based on treatment regimen is shown in the table. Conclusions: Antitumor activity was observed with novel combinations in nccRCC which warrants further prospective studies. Response rates and survival with combination therapy in this dataset remain inferior to rates seen in clear cell RCC.[Table: see text]

A randomized phase II study comparing cisplatin and gemcitabine with or without berzosertib in patients with advanced urothelial carcinoma

4507

Background: Cisplatin with gemcitabine (CG) remains the standard upfront chemotherapy regimen for metastatic urothelial cancer (mUC). Preclinical synergy was noted between cisplatin and berzosertib, a selective ATR inhibitor. The current study sought to determine if the combination of berzosertib and CG could improve clinical outcomes in mUC. Methods: An open-label, randomized study was conducted across 23 centers in the United States through the Experimental Therapeutics Clinical Trials Network of the National Cancer Institute. Key eligibility criteria included confirmed mUC, no prior cytotoxic therapy for metastatic disease, ≥ 12 months since perioperative therapy and eligibility for cisplatin based on standard criteria. Patients (pts) were randomized to receive either CG alone (control arm) or CG plus berzosertib (experimental arm). In the control arm, 70 mg/m2 of cisplatin was given on day 1 and gemcitabine at 1000 mg/m2 on days 1 and 8 of a 21-day cycle. In the experimental arm, 60 mg/m2 of cisplatin was given on day 1, gemcitabine at 875 mg/m2 on days 1 and 8 and berzosertib at 90 mg/m2 on days 2 and 9 of a 21-day cycle. The primary endpoint of the study was progression-free survival (PFS), with secondary endpoints including response rate (RR), overall survival (OS) and toxicity. Results: A total of 87 pts (median age 67; M:F 68:19) were randomized; 41 pts received CG alone while 46 received CG with berzosertib. Visceral metastases were present in 49% of pts and 52%, 45% and 3% of pts were Bajorin risk 0, 1 and 2, respectively. Median PFS was 8.0 months for both arms (Bajorin risk adjusted hazard ratio [HR] 1.22, 95% confidence interval [CI] 0.72-2.08). RR was 54%(4 CR, 21 PR) in the CG with berzosertib arm and 63% (4 CR, 22 PR) in CG alone arm (P = 0.66). Median OS was shorter with CG with berzosertib as compared to CG alone (14.4 versus 19.8 months; Bajorin risk adjusted HR 1.42, 95%CI 0.76-2.68). Notably higher rates of grade 3/4 thrombocytopenia (59% vs 39%) and neutropenia (37% vs 27%) were observed with CG plus berzosertib compared to CG alone. Higher rates of toxicity-related discontinuation were seen in the experimental arm (24% vs 15%), and the median cumulative cisplatin dose in the experimental arm was 250 mg/m2, as compared to 370 mg/m2 in the control arm (P < 0.001). Conclusions: No improvement in PFS was observed with the addition of berzosertib to CG, and a trend towards inferior survival was observed. These results suggest caution in reducing the starting dose of cytotoxic therapy to accommodate addition of a myelosuppressive agent, as in the experimental arm of this study. Clinical trial information: NCT02567409.

A case of metastatic renal cell carcinoma with concomitant Castleman's disease treated with immunotherapy

Castleman's disease (CD) is an uncommon lymphoproliferative process that can present concurrent to other solid organ malignancy, especially in selected populations. Concomitant CD and renal cell carcinoma (RCC) are challenging in terms of diagnosis and treatment. Assessment of CD involvement is a crucial step in selecting the optimal treatment strategy. Here we report a case of metastatic RCC and concurrent CD treated with surgery and immunotherapy.

Diagnostic utility of (18)f-fluciclovine positron emission tomography (FACBC) in biochemically recurrent (BCR) prostate cancer (PCa) based on prior primary treatment modality for localized disease and the impact of FACBC findings on treatment selection

34

Background: Management of BCR PCa requires accurate assessment of location and extent of recurrent disease. FACBC has been shown to be a sensitive modality for detection and localization of recurrent disease but treatment guidelines are based on the findings of conventional (conv) imaging, including computed tomography, magnetic resonance imaging, or bone scintigraphy, and little is known about how prior treatment impacts FACBC findings and concordance with conv scans. Methods: This single-center retrospective study included 137 patients (pts) who had FACBC for BCR at the University of Wisconsin-Madison from 10/2017-10/2019. Clinical, pathological, imaging, and treatment data were collected by chart review. Pts were classified by type of primary treatment for localized PCa, either radical prostatectomy (RP) or radiation therapy (RT). Findings of conv scans performed within 4 weeks prior or any time after FACBC were collected. Results: 105 pts had RP and 32 pts had RT as their primary PCa treatment. Gleason score and PSA at diagnosis were similar between groups. Median PSA at time of FACBC was higher in the RT compared to RP group (3.3 vs 0.7 ng/dL) and median time from initial diagnosis to FACBC was longer (70 vs 55 months). Frequency of (+) FACBC findings was higher in the RT group (66% vs 47%); only 3% of pts in the RT group had a (-) FACBC compared to 29% in the RP group. The rate of (+) lesions in the prostate/prostate bed was higher in the RT group (41% vs 22%), while the rate of (+) lesions in pelvic nodes and distant sites was similar between groups. Of 69 pts who also had conv imaging, 61% had concordant conv imaging findings. In the RT group, conv and FACBC findings were similar in 47% of pts and not similar in 28%. In the RP group, conv and FACBC findings were similar in 26% of pts and not similar in 17%. Management after FACBC is listed in table. Median time from FACBC to first (+) conv scans was 6 (range: 0-18) and 5 (range: 0-17) months for RT and RP groups, respectively. Conclusions: In this large retrospective cohort, pts treated with initial RT had a longer median time from diagnosis to FACBC and higher median PSA at the time of FACBC compared to the RP group. RT patients had a higher rate of (+) FACBC findings but were more likely to continue on observation. The median time from FACBC to first (+) conv scan was 5-6 months, supporting the role of FACBC in earlier detection of recurrent disease in both groups of patients. Further analysis of concordance between FACBC and conv imaging is in process. [Table: see text]

18F-DCFPyL PSMA PET imaging compared to conventional imaging in the detection of pelvic nodal metastases in patients with locally advanced or oligometastatic prostate cancer

36

Background: Interest has arisen in the use of prostate specific membrane antigen (PSMA) PET/CT imaging to detect prostate cancer at metastatic sites using different tracers. Here, we examined the ability of 18F-DCFPyL (DCFPyL) PSMA-based PET imaging to detect nodal disease in comparison to conventional imaging in a cohort of men with locally advanced or oligometastatic prostate cancer (PC). Methods: UW17009 is an IRB-approved open-label, single-arm trial that enrolled 26 patients with newly diagnosed advanced PC. Patients received androgen deprivation therapy and docetaxel for 3 months followed by radical prostatectomy (RP) and pelvic lymph node dissection (PLND). Exploratory interventions include PSMA PET/CT and MRI imaging as a method for determining treatment response and heterogeneity in primary PC and metastatic lesions performed before and after chemohormonal therapy. Prior to randomization, patients received DCFPyL PET/CT and PET/MR imaging as well as CTs and Bone Scans. A mean dose of 7.86 mCi DCFPyL was administered. Whole-body PET/CT images were acquired starting at approximately 60 minutes after radiotracer injection followed by dedicated pelvic PET/MR and whole-body PET/MR. PET imaging findings were compared to conventional dedicated CT imaging and were correlated to the results of final pathologic examination of each pelvic nodal dissection. Results: 26 patients underwent conventional and exploratory imaging with subsequent neoadjuvant treatment, RP and PLND. The mean diagnostic PSA was 32.1 ng/dl and 88.5% had Gleason 9 PCa. Using conventional imaging, pelvic nodal disease was identified in 6/26 patients. Pelvic lymph node uptake was identified in 12/26 patients using DCFPyL-based PSMA PET. Initial correlation of the pathologic specimens with pretreatment PSMA PET imaging revealed pelvic nodal metastatic PC in 10/12(83%) patients. On a per-lymph node packet basis (6 per patient), there were 156 evaluable regions, including 65 from patients with positive nodes. PSMA detected 14 packets that were positive for PC and 102 packets that were negative on imaging and final pathology. PC was missed in 5 packets. The mean tumor size in the missed nodes was 2.3 mm(range 1-4 mm). Calculated sensitivity was 73.7%(95% CI [48.8, 90.8]), 85.7 % specificity(95% CI[78.1, 91.4]), and 95.3 % negative predictive value(95% CI[90.5, 97.7]). Conclusions: In comparison to conventional imaging, in this cohort, DCFPyL PSMA-based PET imaging identified nodal positive disease at twice the rate and when evaluating on a per-packet basis, there was high negative predictive value. Ongoing analysis of post-chemohormonal therapy PET imaging may provide more information regarding tumor response in this cohort.