Patient engagement in designing and publishing research in prostate cancer: a scoping review.

Patients with cancer have the unique ability of being able to offer valuable insights into how cancer therapeutics may impact the overall patient experience and improve clinical outcomes. Patient engagement could therefore contribute to tailoring treatment strategies and research design according to patient needs. This study evaluated patient engagement in prostate cancer research by identifying patient input in the prostate cancer literature. We performed a keyword cluster analysis of articles from multiple databases and congresses in which patients provided input on disease management or were involved in study design, manuscript authorship or presentation of results (patient voice). In total, 112 studies were included. Patients were involved in the design of 11 studies and were credited as authors in four studies. This review suggests a lack of meaningful patient involvement in prostate cancer research and publications.

Patients with cancer have first-hand knowledge of what does and does not work for their care. Therefore, their voice is valuable to help improve treatment and guide research. Our goal was to find prostate cancer articles with patient input. We searched databases using keywords related to patient voice. We looked for articles involving patients in designing, writing or presenting the study. Only four out of the 112 articles we identified were published in journals focused on involving patients. Eleven articles involved patients in designing the study. Four articles involved patients in writing the published work. Overall, we did not find many articles where patients had a meaningful role in the study. Prostate cancer treatment and research will likely benefit from more patient input.

Repeat Next-Generation Sequencing Testing on Progression in Men With Metastatic Prostate Cancer Can Identify New Actionable Alterations.

PURPOSE: There are limited data available on the real-world patterns of molecular testing in men with advanced prostate cancer. We thus sought to evaluate next-generation sequencing (NGS) testing in the United States, focused on single versus serial NGS testing, the different disease states of testing (hormone-sensitive v castration-resistant, metastatic vs nonmetastatic), tissue versus plasma circulating tumor DNA (ctDNA) assays, and how often actionable data were found on each NGS test. METHODS: The Prostate Cancer Precision Medicine Multi-Institutional Collaborative Effort clinical-genomic database was used for this retrospective analysis, including 1,597 patients across 15 institutions. Actionable NGS data were defined as including somatic alterations in homologous recombination repair genes, mismatch repair deficiency, microsatellite instability (MSI-high), or a high tumor mutational burden ≥10 mut/MB. RESULTS: Serial NGS testing (two or more NGS tests with specimens collected more than 60 days apart) was performed in 9% (n = 144) of patients with a median of 182 days in between test results. For the second NGS test and beyond, 82.1% (225 of 274) of tests were from ctDNA assays and 76.1% (217 of 285) were collected in the metastatic castration-resistant setting. New actionable data were found on 11.1% (16 of 144) of second NGS tests, with 3.5% (5 of 144) of tests detecting a new BRCA2 alteration or MSI-high. A targeted therapy (poly (ADP-ribose) polymerase inhibitor or immunotherapy) was given after an actionable result on the second NGS test in 31.3% (5 of 16) of patients. CONCLUSION: Repeat somatic NGS testing in men with prostate cancer is infrequently performed in practice and can identify new actionable alterations not present with initial testing, suggesting the utility of repeat molecular profiling with tissue or blood of men with metastatic castration-resistant prostate cancer to guide therapy choices.

Clinical implications of AR alterations in advanced prostate cancer: a multi-institutional collaboration.

BACKGROUND: AR gene alterations can develop in response to pressure of testosterone suppression and androgen receptor targeting agents (ARTA). Despite this, the relevance of these gene alterations in the context of ARTA treatment and clinical outcomes remains unclear. METHODS: Patients with castration-resistant prostate cancer (CRPC) who had undergone genomic testing and received ARTA treatment were identified in the Prostate Cancer Precision Medicine Multi-Institutional Collaborative Effort (PROMISE) database. Patients were stratified according to the timing of genomic testing relative to the first ARTA treatment (pre-/post-ARTA). Clinical outcomes such as time to progression, PSA response, and overall survival were compared based on alteration types. RESULTS: In total, 540 CRPC patients who received ARTA and had tissue-based (n = 321) and/or blood-based (n = 244) genomic sequencing were identified. Median age was 62 years (range 39-90) at the time of the diagnosis. Majority were White (72.2%) and had metastatic disease (92.6%) at the time of the first ARTA treatment. Pre-ARTA genomic testing was available in 24.8% of the patients, and AR mutations and amplifications were observed in 8.2% and 13.1% of the patients, respectively. Further, time to progression was longer in patients with AR amplifications (25.7 months) compared to those without an AR alteration (9.6 months; p = 0.03). In the post-ARTA group (n = 406), AR mutations and AR amplifications were observed in 18.5% and 35.7% of the patients, respectively. The most common mutation in post-ARTA group was L702H (9.9%). CONCLUSION: In this real-world clinicogenomics database-driven study we explored the development of AR alterations and their association with ARTA treatment outcomes. Our study showed that AR amplifications are associated with longer time to progression on first ARTA treatment. Further prospective studies are needed to optimize therapeutic strategies for patients with AR alterations.

Biomarker-Directed Therapy in Black and White Men With Metastatic Castration-Resistant Prostate Cancer.

Importance: Black men have higher incidence and mortality from prostate cancer. Whether precision oncology disparities affect Black men with metastatic castration-resistant prostate cancer (mCRPC) is unknown. Objective: To compare precision medicine data and outcomes between Black and White men with mCRPC. Design, Setting, and Participants: This retrospective cohort study used data collected by the Prostate Cancer Precision Medicine Multi-Institutional Collaborative Effort (PROMISE) consortium, a multi-institutional registry with linked clinicogenomic data, from April 2020 to December 2021. Participants included Black and White patients with mCRPC with molecular data. Data were analyzed from December 2021 to May 2023. Exposures: Database-reported race and ethnicity. Main Outcomes and Measures: The primary outcome was the frequency of actionable molecular data, defined as the presence of mismatch repair deficiency (MMRD) or high microsatellite instability (MSI-H), homologous recombination repair deficiency, or tumor mutational burden of 10 mutations per megabase or greater. Secondary outcomes included the frequency of other alterations, the type and timing of genomic testing performed, and use of targeted therapy. Efficacy outcomes were prostate-specific antigen response rate, site-reported radiographic response, and overall survival. Results: A total of 962 eligible patients with mCRPC were identified, including 204 Black patients (21.2%; median [IQR] age at diagnosis, 61 [55-67] years; 131 patients [64.2%] with Gleason scores 8-10; 92 patients [45.1%] with de novo metastatic disease) and 758 White patients (78.8%; median [IQR] age, 63 [57-69] years; 445 patients [58.7%] with Gleason scores 8-10; 310 patients [40.9%] with de novo metastatic disease). Median (IQR) follow-up from mCRPC was 26.6 (14.2-44.7) months. Blood-based molecular testing was more common in Black men (111 men [48.7%]) than White men (317 men [36.4%]; P < .001). Rates of actionable alterations were similar between groups (65 Black men [32.8%]; 215 White men [29.1%]; P = .35), but MMRD or MSI-H was more common in Black men (18 men [9.1]) than White men (36 men [4.9%]; P = .04). PTEN alterations were less frequent in Black men than White men (31 men [15.7%] vs 194 men [26.3%]; P = .003), as were TMPRSS alterations (14 men [7.1%] vs 155 men [21.0%]; P < .001). No other differences were seen in the 15 most frequently altered genes, including TP53, AR, CDK12, RB1, and PIK3CA. Matched targeted therapy was given less frequently in Black men than White men (22 men [33.5%] vs 115 men [53.5%]; P = .008). There were no differences in response to targeted therapy or survival between the two cohorts. Conclusions and Relevance: This cohort study of men with mCRPC found higher frequency of MMRD or MSI-H and lower frequency of PTEN and TMPRSS alterations in Black men compared with White men. Although Black men received targeted therapy less frequently than White men, no differences were observed in clinical outcomes.

Clinical implications of AR alterations in advanced prostate cancer: A multi-institutional collaboration.

Background: AR gene alterations can develop in response to pressure of testosterone suppression and androgen receptor targeting agents (ARTA). Despite this, the relevance of these gene alterations in the context of ARTA treatment and clinical outcomes remains unclear. Methods: Patients with castration-resistant prostate cancer (CRPC) who had undergone genomic testing and received ARTA treatment were identified in the Prostate Cancer Precision Medicine Multi-Institutional Collaborative Effort (PROMISE) database. Patients were stratified according to the timing of genomic testing relative to the first ARTA treatment (pre-/post-ARTA). Clinical outcomes such as time to progression, PSA response, and overall survival were compared based on alteration types. Results: In total, 540 CRPC patients who received ARTA and had tissue-based (n=321) and/or blood-based (n=244) genomic sequencing were identified. Median age was 62 years (range 39-90) at the time of the diagnosis. Majority were White (72.2%) and had metastatic disease (92.6%) at the time of the first ARTA treatment. Pre-ARTA genomic testing was available in 24.8% of the patients, and AR mutations and amplifications were observed in 8.2% and 13.1% of the patients, respectively. Further, time to progression was longer in patients with AR amplifications (25.7 months) compared to those without an AR alteration (9.6 months; p=0.03). In the post-ARTA group (n=406), AR mutations and AR amplifications were observed in 18.5% and 35.7% of the patients, respectively. The most common mutation in post-ARTA group was L702H (9.9%). Conclusion: To our knowledge, this is the largest real-world clinicogenomics database-driven study exploring the development of ARalterations and their association with ARTA treatment outcomes. Our study showed that AR amplifications are associated with longer time to progression on first ARTA treatment. Further prospective studies are needed to optimize therapeutic strategies for patients with AR alterations.

Considerations for Designing and Implementing a Multi-institution Undergraduate Medical Education Experience.

Cancer Care Experience (CCE) is a unique elective educational program to further explore the subspecialty of oncology beyond the scope of the traditional undergraduate medical education curriculum. During the COVID-19 pandemic, CCE moved from an in-person to a virtual learning platform. This transition allowed program leaders to offer CCE as a multi-institutional program, with students participating from both Duke University School of Medicine and Penn State College of Medicine. Our study aimed to investigate the effectiveness of virtual learning, student perspectives on multi-institutional collaboration, and the program's impact on the student's understanding of oncology care and clerkship preparedness. Overall, students indicated CCE was an impactful program for them to learn more about oncology and that virtual learning was an effective learning platform. Furthermore, our results suggest students found the multi-institutional aspect valuable and that a multi-institution, hybrid (in-person and virtual) platform was preferred. Our study highlights the success of CCE as a multi-institution program and an effective elective program to expose students to the field of oncology further.

Response to bipolar androgen therapy and PD-1 inhibition in a patient with metastatic castration-resistant prostate cancer and a germline CHEK2 mutation.

We present the case of a patient with germline CHEK2-mutated metastatic castration-resistant prostate cancer (mCRPC) who responded to bipolar androgen therapy (BAT) combined with pembrolizumab after progressing through multiple lines of therapy. The patient was diagnosed in his 40s following an elevated screening prostate-specific antigen and biopsy. Over the course of 20 years, he progressed through nearly all standard therapies including androgen deprivation, combined androgen blockade, traditional chemotherapy, targeted therapies and experimental agents. He was ultimately treated with BAT, whereby the patient's cycle was between low (castrate) and high (supraphysiological) testosterone levels. This counterintuitive approach resulted in a marked response to BAT plus pembrolizumab consolidation lasting 13 months. His underlying germline mutation in CHEK2, an important mediator of DNA repair, may have sensitised the cancer cells to the DNA damage caused by BAT. Single case report outcomes should not be used as evidence of efficacy for treatment regimes. Our case supports further investigation into BAT plus immunotherapy for patients with DNA repair-deficient mCRPC.

Foreign accent syndrome as a heralding manifestation of transformation to small cell neuroendocrine prostate cancer.

A man in his 50s with metastatic hormone-sensitive prostate cancer, receiving androgen deprivation therapy and abiraterone acetate/prednisone, presented with an uncontrollable 'Irish brogue' accent despite no Irish background, consistent with foreign accent syndrome (FAS). He had no neurological examination abnormalities, psychiatric history or MRI of the brain abnormalities at symptom onset. Imaging revealed progression of his prostate cancer, despite undetectable prostate-specific antigen levels. Biopsy confirmed transformation to small cell neuroendocrine prostate cancer (NEPC). Despite chemotherapy, his NEPC progressed resulting in multifocal brain metastases and a likely paraneoplastic ascending paralysis leading to his death. We report FAS as the presenting manifestation of transformation to small cell NEPC, a previously undescribed phenomenon. His presentation was most consistent with an underlying paraneoplastic neurological disorder (PND), despite a negative serum paraneoplastic panel. This report enhances the minimal existing literature on FAS and PNDs associated with transformed NEPC.

Remission of progressive metastatic castration-resistant prostate cancer during abiraterone therapy following unilateral adrenalectomy for a functioning adrenal adenoma.

Despite advances and introduction of new therapies in the last decade, metastatic castration-resistant prostate cancer (mCRPC) has a poor prognosis. The development of androgen axis-targeted therapies such as abiraterone acetate, enzalutamide and darolutamide can prolong survival in mCPRC; however, resistance remains a barrier to prolonged response, necessitating exploration into resistance mechanisms and locoregional therapies. Here, we describe a patient with mCRPC that was progressing on abiraterone acetate. He was also found to have primary hyperaldosteronism from a functional adrenal adenoma, and thus he had a partial adrenalectomy to remove this tumour. Pathology confirmed an aldosterone-producing adrenal adenoma. After his adrenalectomy, he had a sharp decline in both his PSA (prostate specific antigen) and testosterone levels, and he enjoyed a year-long period of remission after his adrenalectomy. We propose several explanations for his response, the most likely being that his adenoma was producing both aldosterone and androgens. This is a unique case of mCRPC responding to partial adrenalectomy from a functional adrenal adenoma, and it raises insights that warrant further investigation into underlying mechanisms of resistance to androgen-targeted therapies.

Evaluation of tumor microenvironment and biomarkers of immune checkpoint inhibitor response in metastatic renal cell carcinoma.

BACKGROUND: Immunotherapy combinations including ipilimumab and nivolumab are now the standard of care for untreated metastatic renal cell carcinoma (mRCC). Biomarkers of response are lacking to predict patients who will have a favorable or unfavorable response to immunotherapy. This study aimed to use the OmniSeq transcriptome-based platform to develop biomarkers of response to immunotherapy. METHODS: Two cohorts of patients were retrospectively collected. These included an investigational cohort of patients with mRCC treated with immune checkpoint inhibitor therapy from five institutions, and a subsequent validation cohort of patients with mRCC treated with combination ipilimumab and nivolumab from two institutions (Duke Cancer Institute and Cleveland Clinic Taussig Cancer Center). Tissue-based RNA sequencing was performed using the OmniSeq Immune Report Card on banked specimens to identify gene signatures and immune checkpoints associated with differential clinical outcomes. A 5-gene expression panel was developed based on the investigational cohort and was subsequently evaluated in the validation cohort. Clinical outcomes including progression-free survival (PFS) and overall survival (OS) were extracted by retrospective chart review. Objective response rate (ORR) was assessed by Response Evaluation Criteria in Solid Tumors (RECIST) V.1.1. RESULTS: The initial investigation cohort identified 86 patients with mRCC who received nivolumab (80%, 69/86), ipilimumab/nivolumab (14%, 12/86), or pembrolizumab (6%, 5/86). A gene expression score was created using the top five genes found in responders versus non-responders (FOXP3, CCR4, KLRK1, ITK, TIGIT). The ORR in patients with high gene expression (GEhigh) on the 5-gene panel was 29% (14/48), compared with low gene expression (GElow) 3% (1/38, χ2 p=0.001). The validation cohort was comprised of 62 patients who received ipilimumab/nivolumab. There was no difference between GEhigh and GElow in terms of ORR (44% vs 38.5%), PFS (HR 1.5, 95% CI 0.58 to 3.89), or OS (HR 0.96, 95% CI 0.51 to 1.83). Similarly, no differences in ORR, PFS or OS were observed when patients were stratified by tumor mutational burden (high=top 20%), PD-L1 (programmed death-ligand 1) expression by immunohistochemistry or RNA expression, or CTLA-4 (cytotoxic T-lymphocytes-associated protein 4) RNA expression. The International Metastatic RCC Database Consortium (IMDC) risk score was prognostic for OS but not PFS. CONCLUSION: A 5-gene panel that was associated with improved ORR in a predominantly nivolumab monotherapy population of patients with mRCC was not predictive for radiographic response, PFS, or OS among patients with mRCC treated with ipilimumab and nivolumab.

Making National Cancer Institute-Designated Comprehensive Cancer Center Knowledge Accessible to Community Oncologists via an Online Tumor Board: Longitudinal Observational Study.

BACKGROUND: Expert knowledge is often shared among multidisciplinary academic teams at tumor boards (TBs) across the country, but these conversations exist in silos and do not reach the wider oncology community. OBJECTIVE: Using an oncologist-only question and answer (Q&A) website, we sought to document expert insights from TBs at National Cancer Institute-designated Comprehensive Cancer Centers (NCI-CCCs) to provide educational benefits to the oncology community. METHODS: We designed a process with the NCI-CCCs to document and share discussions from the TBs focused on areas of practice variation on theMednet, an interactive Q&A website of over 13,000 US oncologists. The faculty translated the TB discussions into concise, non-case-based Q&As on theMednet. Answers were peer reviewed and disseminated in email newsletters to registered oncologists. Reach and engagement were measured. Following each Q&A, a survey question asked how the TB Q&As impacted the readers' practice. RESULTS: A total of 23 breast, thoracic, gastrointestinal, and genitourinary programs from 16 NCI-CCC sites participated. Between December 2016 and July 2021, the faculty highlighted 368 questions from their TBs. Q&As were viewed 147,661 times by 7381 oncologists at 3515 institutions from all 50 states. A total of 277 (75%) Q&As were viewed every month. Of the 1063 responses to a survey question on how the Q&A affected clinicians' practices, 646 (61%) reported that it confirmed their current practice, 163 (20%) indicated that a Q&A would change their future practice, and 214 (15%) reported learning something new. CONCLUSIONS: Through an online Q&A platform, academics at the NCI-CCCs share knowledge outside the walls of academia with oncologists across the United States. Access to up-to-date expert knowledge can reassure clinicians' practices, significantly impact patient care in community practices, and be a source of new knowledge and education.

PROMISE: a real-world clinical-genomic database to address knowledge gaps in prostate cancer.

PURPOSE: Prostate cancer is a heterogeneous disease with variable clinical outcomes. Despite numerous recent approvals of novel therapies, castration-resistant prostate cancer remains lethal. A "real-world" clinical-genomic database is urgently needed to enhance our characterization of advanced prostate cancer and further enable precision oncology. METHODS: The Prostate Cancer Precision Medicine Multi-Institutional Collaborative Effort (PROMISE) is a consortium whose aims are to establish a repository of de-identified clinical and genomic patient data that are linked to patient outcomes. The consortium structure includes a (1) bio-informatics committee to standardize genomic data and provide quality control, (2) biostatistics committee to independently perform statistical analyses, (3) executive committee to review and select proposals of relevant questions for the consortium to address, (4) diversity/inclusion committee to address important clinical questions pertaining to racial disparities, and (5) patient advocacy committee to understand patient perspectives to improve patients' quality of care. RESULTS: The PROMISE consortium was formed by 16 academic institutions in early 2020 and a secure RedCap database was created. The first patient record was entered into the database in April 2020 and over 1000 records have been entered as of early 2021. Data entry is proceeding as planned with the goal to have over 2500 patient records by the end of 2021. CONCLUSIONS: The PROMISE consortium provides a powerful clinical-genomic platform to interrogate and address data gaps that have arisen with increased genomic testing in the clinical management of prostate cancer. The dataset incorporates data from patient populations that are often underrepresented in clinical trials, generates new hypotheses to direct further research, and addresses important clinical questions that are otherwise difficult to investigate in prospective studies.

Differences in Toxicity and Outcomes in Clinical Trial Participants From Minority Populations.

Black men have a higher prevalence of and mortality rate from prostate cancer compared with White men and have been shown to present with more aggressive and later-stage disease. How prostate cancer treatment affects these racial disparities is still unclear. Several studies have shown that Black men who receive treatment have a more pronounced decrease in prostate cancer-specific death; however, there remains a large disparity in all-cause mortality. This disparity may be in part related to a higher risk of death resulting from comorbidities, given the higher rates of cardiovascular disease and diabetes in Black men, both of which are complicated by the use of androgen-deprivation therapy. To further understand these disparities, it is important that we analyze the racial differences in adverse event rates and severity. Increasing the percentage of Black men in clinical trials will improve the understanding of the biologic drivers of racial disparities in prostate cancer. To evaluate the potential differences in adverse event reporting and demonstrate the feasibility of enrolling equal numbers of Black and White men in trials, we performed a prospective, multicenter study of abiraterone plus prednisone with androgen-deprivation therapy in men with metastatic castration-resistant prostate cancer, stratified by race. Racial differences in prostate-specific antigen kinetics and toxicity profile were demonstrated. Higher rates and severity of adverse events related to adrenal hormone suppression, including hypertension, hypokalemia, and hypomagnesemia, were seen in the Black cohort, not previously reported. Increased enrollment of Black men in prostate cancer clinical trials is imperative to further understand the impact of race on clinical outcomes and treatment tolerability.

LRP1B mutations are associated with favorable outcomes to immune checkpoint inhibitors across multiple cancer types.

BACKGROUND: Low-density lipoprotein receptor-related protein 1b (encoded by LRP1B) is a putative tumor suppressor, and preliminary evidence suggests LRP1B-mutated cancers may have improved outcomes with immune checkpoint inhibitors (ICI). METHODS: We conducted a multicenter, retrospective pan-cancer analysis of patients with LRP1B alterations treated with ICI at Duke University, Johns Hopkins University (JHU) and University of Michigan (UM). The primary objective was to assess the association between overall response rate (ORR) to ICI and pathogenic or likely pathogenic (P/LP) LRP1B alterations compared with LRP1B variants of unknown significance (VUS). Secondary outcomes were the associations with progression-free survival (PFS) and overall survival (OS) by LRP1B status. RESULTS: We identified 101 patients (44 Duke, 35 JHU, 22 UM) with LRP1B alterations who were treated with ICI. The most common tumor types by alteration (P/LP vs VUS%) were lung (36% vs 49%), prostate (9% vs 7%), sarcoma (5% vs 7%), melanoma (9% vs 0%) and breast cancer (3% vs 7%). The ORR for patients with LRP1B P/LP versus VUS alterations was 54% and 13%, respectively (OR 7.5, 95% CI 2.9 to 22.3, p=0.0009). P/LP LRP1B alterations were associated with longer PFS (HR 0.42, 95% CI 0.26 to 0.68, p=0.0003) and OS (HR 0.62, 95% CI 0.39 to 1.01, p=0.053). These results remained consistent when excluding patients harboring microsatellite instability (MSI) and controlling for tumor mutational burden (TMB). CONCLUSIONS: This multicenter study shows significantly better outcomes with ICI therapy in patients harboring P/LP versus VUS LRP1B alterations, independently of TMB/MSI status. Further mechanistic and prospective validation studies are warranted.

Management of men with metastatic castration-resistant prostate cancer following potent androgen receptor inhibition: a review of novel investigational therapies.

BACKGROUND: Androgen-targeted therapy and chemotherapy are currently the mainstay of treatment in metastatic castration resistant prostate cancer (mCRPC). When progression occurs despite these therapeutic strategies, additional FDA-approved treatment options are lacking. However, there is a vast amount of emerging data surrounding novel investigational therapies in this space. METHODS: We reviewed and summarized the body of literature surrounding the current treatment options for mCRPC. Medline and Pubmed as well as abstracts from international congresses were utilized to gather relevant literature surrounding investigational treatment of mCRPC. We highlight the results of recent trials investigating the use of novel strategies to treat mCRPC. RESULTS: Androgen-targeted therapy and chemotherapy will remain foundational in the treatment of mCRPC. However, heavily pretreated patients who have developed resistance may benefit from novel therapeutic strategies. The use of poly(adenosine diphosphate [ADP]-ribose) polymerase inhibitors (PARPi) has now gained FDA approval for patients with homologous recombination repair (HRR) gene mutations. Novel androgen receptor (AR) degraders and the use of radioligand therapy (RLT) with Lu-PSMA-617 (Lu-PSMA) are under investigation. Immune-directed therapies, including programmed death (PD-1) inhibition, bi-specific T-cell engager (BiTE) technology, and chimeric antigen receptor (CAR) T-cell therapy, have shown promise in early phase trials. Further understanding of resistance mechanisms has led to additional therapeutic targets, including targeting the PI3K-Akt-mTOR pathway and enhancer of zester homolog 2 (EZH2). CONCLUSIONS: Based on our review of the literature, exciting new therapeutic strategies exist for the treatment of mCRPC. In particular, PARPi, AR degraders, PSMA-targeted therapies, immune-directed therapies, and agents targeting resistance mechanisms as monotherapy or in combination could improve patient outcomes. Additional data from randomized trials are necessary to understand the efficacy and tolerability of these treatment strategies.

Proliferative potential and response to nivolumab in clear cell renal cell carcinoma patients.

Background: Biomarkers predicting immunotherapy response in metastatic renal cell cancer (mRCC) are lacking. PD-L1 immunohistochemistry is a complementary diagnostic for immune checkpoint inhibitors (ICIs) in mRCC, but has shown minimal clinical utility and is not used in routine clinical practice. Methods: Tumor specimens from 56 patients with mRCC who received nivolumab were evaluated for PD-L1, cell proliferation (targeted RNA-seq), and outcome. Results: For 56 patients treated with nivolumab as a standard of care, there were 2 complete responses and 8 partial responses for a response rate of 17.9%. Dividing cell proliferation into tertiles, derived from the mean expression of 10 proliferation-associated genes in a reference set of tumors, poorly proliferative tumors (62.5%) were more common than moderately (30.4%) or highly proliferative (8.9%) counterparts. Moderately proliferative tumors were enriched for PD-L1 positive (41.2%), compared to poorly proliferative counterparts (11.4%). Objective response for moderately proliferative (29.4%) tumors was higher than that of poorly (11.4%) proliferative counterparts, but not statistically significant (p = .11). When cell proliferation and negative PD-L1 tumor proportion scores were combined statistically significant results were achieved (p = .048), showing that patients with poorly proliferative and PD-L1 negative tumors have a very low response rate (6.5%) compared to moderately proliferative PD-L1 negative tumors (30%). Conclusions: Cell proliferation has value in predicting response to nivolumab in clear cell mRCC patients, especially when combined with PD-L1 expression. Further studies which include the addition of progression-free survival (PFS) along with sufficiently powered subgroups are required to further support these findings.

PD-L1 Assay Concordance in Metastatic Renal Cell Carcinoma and Metastatic Urothelial Carcinoma.

BACKGROUND: Immune checkpoint inhibitors are now standard of care for many patients with metastatic renal cell carcinoma (mRCC) and metastatic urothelial carcinoma (mUC). Given real-world limitations in programmed death-ligand 1 (PD-L1) testing, concordance studies between PD-L1 assays are needed. We undertook comparisons of Dako 28-8 and Ventana SP142 assays in mRCC and Dako 22C3 and Ventana SP263 assays in mUC. PATIENTS AND METHODS: Thirty-two patients with mRCC and 18 patients with mUC who had received immune checkpoint inhibitor therapy were identified. Formalin-fixed paraffin-embedded tumor samples for patients with mRCC were evaluated with Dako 28-8 and Ventana SP142 PD-L1 immunohistochemistry assays. For patients with mUC, formalin-fixed paraffin-embedded tumor samples were evaluated with Dako 22C3 and Ventana SP263 PD-L1 immunohistochemistry assays. RESULTS: The majority (29/32; 91%) of mRCC cases were concordant between assays. The majority (17/18; 94%) of mUC cases were also concordant between assays. CONCLUSIONS: There was strong concordance between PD-L1 assays chosen for comparison in both mRCC and mUC, with similar performance characteristics. One limitation is the small number of cases in this study; larger comparison studies are needed for this biomarker in mRCC and mUC.

Characterization of tumor mutation burden, PD-L1 and DNA repair genes to assess relationship to immune checkpoint inhibitors response in metastatic renal cell carcinoma.

BACKGROUND: Immune checkpoint inhibitors (ICIs) have expanded treatment options for metastatic renal cell carcinoma (mRCC); however, there are limited predictive biomarkers for response to ICIs in this indication, with programmed death-ligand 1 (PD-L1) status demonstrating little predictive utility in mRCC. While predictive of ICI response in other tumor types, the utility of tumor mutation burden (TMB) in mRCC is unclear. Here, we assess TMB, loss of antigen presentation genes and PD-L1 status correlated with outcomes to ICI treatment in mRCC. METHODS: Tumor samples from 34 patients with mRCC treated with ICI therapy at Duke Cancer Institute were retrospectively evaluated using Personal Genome Diagnostics elio tissue complete (RUO version), a tumor genomic profiling assay for somatic variants, TMB, microsatellite status and genomic status of antigen presentation genes. Tumor samples were also analyzed with the Dako 28-8 PD-L1 immunohistochemistry assay. Deidentified clinical information was extracted from the medical record, and tumor response was evaluated based on the Response Evaluation Criteria In Solid Tumors (RECIST) V.1.1 criteria. RESULTS: Patients were stratified by overall response following ICI therapy and designated as progressive disease (PD; n=18) or disease control groups (DC; n=16). TMB scores ranged from 0.36 to 12.24 mutations/Mb (mean 2.83 mutations/Mb) with no significant difference between the PD and DC groups (3.01 vs 2.63 mutations/Mb, respectively; p=0.7682). Interestingly, 33% of PD patients displayed loss of heterozygosity of major histocompatibility complex class I genes (LOH-MHC) vs 6% of DC patients. Nine of 34 samples were PD-L1-positive (4 in the PD group; 5 in the DC group), suggesting no correlation between PD-L1 expression and response to ICI therapy. Notably, the DC group displayed an enrichment of mutations in DNA repair genes (p=0.04), with 68.8% exhibiting at least one mutated homologous recombination repair (HRR)-related gene compared with only 38.9% of the PD group (p=0.03). CONCLUSIONS: Overall, neither TMB nor PD-L1 correlated with ICI response and TMB was not significantly associated with PD-L1 expression. The higher incidence of LOH-MHC in PD group suggests that loss of antigen presentation may restrict response to ICIs. Separately, enrichment of HRR gene mutations in the DC group suggests potential utility in predicting ICI response and a potential therapeutic target, warranting future studies.