Faculty Bibliography

BACKGROUND:Recent evidence suggests that immunotherapy efficacy in melanoma is modulated by gut microbiota. Few studies have examined this phenomenon in humans, and none have incorporated metatranscriptomics, important for determining expression of metagenomic functions in the microbial community. METHODS:In melanoma patients undergoing immunotherapy, gut microbiome was characterized in pre-treatment stool using 16S rRNA gene and shotgun metagenome sequencing (n = 27). Transcriptional expression of metagenomic pathways was confirmed with metatranscriptome sequencing in a subset of 17. We examined associations of taxa and metagenomic pathways with progression-free survival (PFS) using 500 × 10-fold cross-validated elastic-net penalized Cox regression. RESULTS:Higher microbial community richness was associated with longer PFS in 16S and shotgun data (p < 0.05). Clustering based on overall microbiome composition divided patients into three groups with differing PFS; the low-risk group had 99% lower risk of progression than the high-risk group at any time during follow-up (p = 0.002). Among the species selected in regression, abundance of Bacteroides ovatus, Bacteroides dorei, Bacteroides massiliensis, Ruminococcus gnavus, and Blautia producta were related to shorter PFS, and Faecalibacterium prausnitzii, Coprococcus eutactus, Prevotella stercorea, Streptococcus sanguinis, Streptococcus anginosus, and Lachnospiraceae bacterium 3 1 46FAA to longer PFS. Metagenomic functions related to PFS that had correlated metatranscriptomic expression included risk-associated pathways of L-rhamnose degradation, guanosine nucleotide biosynthesis, and B vitamin biosynthesis. CONCLUSIONS:This work adds to the growing evidence that gut microbiota are related to immunotherapy outcomes, and identifies, for the first time, transcriptionally expressed metagenomic pathways related to PFS. Further research is warranted on microbial therapeutic targets to improve immunotherapy outcomes.

Despite major improvements in combatting metastatic melanoma since the advent of immunotherapy, the overall survival for patients with advanced disease remains low. Recently, there is a growing number of reports supporting an "obesity paradox," in which patients who are overweight or mildly obese may exhibit a survival benefit in patients who received immune checkpoint inhibitors. We studied the relationship between body mass index and progression-free survival and overall survival in a cohort of 423 metastatic melanoma patients receiving immunotherapy, enrolled and prospectively followed up in the NYU Interdisciplinary Melanoma Cooperative Group database. We analyzed this association stratified by first vs. second or greater-line of treatment and treatment type adjusting for age, gender, stage, lactate dehydrogenase, Eastern Cooperative Oncology Group performance status, number of metastatic sites, and body mass index classification changes. In our cohort, the patients who were overweight or obese did not have different progression-free survival than patients with normal body mass index. Stratifying this cohort by first vs. non-first line immunotherapy revealed a moderate but insignificant association between being overweight or obese and better progression-free survival in patients who received first line. Conversely, an association with worse progression-free survival was observed in patients who received non-first line immune checkpoint inhibitors. Specifically, overweight and obese patients receiving combination immunotherapy had a statistically significant survival benefit, whereas patients receiving the other treatment types showed heterogeneous trends. We caution the scientific community to consider several important points prior to drawing conclusions that could potentially influence patient care, including preclinical data associating obesity with aggressive tumor biology, the lack of congruence amongst several investigations, and the limited reproduced comprehensiveness of these studies.

Background: Banking of human biospecimens linked to prospective, well-annotated clinical information is critical for advancing biomedical research. However, the establishment of an efficient biobank encompasses many issues including adherence to federal regulations, institutional policies and governance of the relationship between the biobank, investigators and funding agents. Here we report on the efforts of the Center for Biospecimen Research and Development (CBRD) at NYULH to establish a state-of-the-art biobank. Method(s): In 2015, we identified the need to establish a centralized infrastructure to facilitate research collaborations and support clinical trial studies. The four main considerations were: 1) creating a centralized mechanism to consent, collect and bank human biospecimens 2) Organizing, de-identifying, and annotating subjects' samples linked to their clinical data 3) Establishing multidisciplinary involvement of pathology departments 4) Enhancing quality control measures to achieve CAP and NYS DOH accreditation. To address these considerations, we created a Universal Consent (UC) form; developed a Laboratory Information Management System that assists in specimen organization and links subject samples to clinical data in their electronic medical record and fostered a partnership between the pathology department, individual researchers and the CBRD to develop best practices in biobanking. Result(s): Since June 2016, using the UC, 18,906 of 27,355 (70%) subjects agreed to use their specimens and data for research. 9,054 patients had specimens collected using the UC and additional specific consent if needed. We collected 4,178 unique samples (tissue, blood and fluids)-13,969 aliquots by the UC method and 7,713 samples from fresh and archival collections for specific research studies or clinical trials. The CBRD supported 93 research projects and 251 clinical trials. Conclusion(s): Establishment of the CBRD permitted the increase in absolute number of patients approached for research; enhancement of specimen quality and organization and introduction of the electronic crosslink to minimize the time and overhead needed for clinical data retrieval. Building on this success, we are upgrading our IT infrastructure to expand upon the data collected, digitalizing tissue slides to improve quality control and building an automated molecular genotyping database using existing NGS data to increase the number of trans-lational research projects

Multiple primary melanoma (MPM) has been associated with a higher 10-year mortality risk compared to patients with single primary melanoma (SPM). Given that 3-8% of patients with SPM develop additional primary melanomas, new markers predictive of MPM risk are needed. Based on the evidence that the immune system may regulate melanoma progression, we explored whether germline genetic variants controlling the expression of 41 immunomodulatory genes modulate the risk of MPM compared to patients with SPM or healthy controls. By genotyping these 41 variants in 977 melanoma patients, we found that rs2071304, linked to the expression of SPI1, was strongly associated with MPM risk reduction (OR = 0.60; 95% CI = 0.45-0.81; p = 0.0007) when compared to patients with SPM. Furthermore, we showed that rs6695772, a variant affecting expression of BATF3, is also associated with MPM-specific survival (HR = 3.42; 95% CI = 1.57-7.42; p = 0.0019). These findings provide evidence that the genetic variation in immunomodulatory pathways may contribute to the development of secondary primary melanomas and also associates with MPM survival. The study suggests that inherited host immunity may play an important role in MPM development.

Patients diagnosed with metastatic melanoma have varied clinical courses, even in patients with similar disease characteristics. We examine the impact of initial stage of melanoma diagnosis, BRAF status of primary melanoma, and receiving adjuvant therapy on postmetastatic overall survival (pmOS). We studied melanoma patients presenting to Perlmutter Cancer Center at New York University and prospectively enrolled in New York University melanoma biospecimen database and followed up on protocol-driven schedule. Patients were stratified by stage at initial melanoma diagnosis as per AJCC 7th ed. guidelines. pmOS was determined using the Kaplan-Meier method and Cox's proportional hazards models were used to assess hazard ratios (HRs). Three hundred and four out of 3204 patients developed metastatic disease over the time of follow-up (median follow-up 2.2 years, range: 0.08-35.2 years). Patients diagnosed with stage I (n=96) melanoma had longer pmOS (29.5 months) than those diagnosed with stage II (n=99, pmOS 14.9 months) or stage III (n=109, pmOS 15.1 months) melanoma (P=0.036). Initial stage of diagnosis remained significant in multivariate analysis when controlling for lactate dehydrogenase and site of metastases [primary diagnosis stage II (HR 1.44, P=0.046), stage III (HR 1.5, P=0.019)]. Adjuvant treatment was associated with better survival but BRAF mutation status did not show an association. Our data challenge the general assumption that primary melanomas converge upon diagnosis of metastatic disease and behave uniformly. Primary stage of melanoma at the time of diagnosis may be prognostic of outcome, similar to lactate dehydrogenase and metastatic disease sites.

Immune-checkpoint inhibition (ICI) treatments improve outcomes for metastatic melanoma; however, > 60% of treated patients do not respond to ICI. Current biomarkers do not reliably explain ICI resistance. Given the link between ICI and autoimmunity, we investigated if genetic susceptibility to autoimmunity modulates ICI efficacy. In 436 patients with metastatic melanoma receiving single line ICI or combination treatment, we tested 25 SNPs, associated with > 2 autoimmune diseases in recent genome-wide association studies, for modulation of ICI efficacy. We found that rs17388568-a risk variant for allergy, colitis and type 1 diabetes-was associated with increased anti-PD-1 response, with significance surpassing multiple testing adjustments (OR 0.26; 95% CI 0.12-0.53; p = 0.0002). This variant maps to a locus of established immune-related genes: IL2 and IL21. Our study provides first evidence that autoimmune genetic susceptibility may modulate ICI efficacy, suggesting that systematic testing of autoimmune risk loci could reveal personalized biomarkers of ICI response.

Although much clinical progress has been made in harnessing the immune system to recognize and target cancer, there is still a significant lack of an understanding of how tumors evade immune recognition and the mechanisms that drive tumor resistance to both T-cell and checkpoint blockade immunotherapy. Our objective is to understand how tumor-mediated signaling through inhibitory receptors, including PD-1, combines to affect the process of T-cell recognition of tumor antigen and activation signaling. This has the goal of understanding the basis of resistance to PD-1 blockade and potentially identifying new molecular targets to enable T-cells to overcome dysfunction mediated by multiple inhibitory receptors. Biomembrane Force Probe (BFP) measurements show that that the activities of TCR-proximal signaling components affect T-cell mechanosensing and sensitivity at the earliest stages of antigen recognition and are influenced by PD-1 and other inhibitory receptors via Shp-1/2 by targeting CD28 and Lck to directly suppress TCR-pMHC-CD8 binding. Phospho-proteomics and flow cytometry-based analysis of patient-derived T-cells from PD-1 responders and nonresponders identified additional mediators, signaling components and pathways associated with PD-1 checkpoint blockade resistance. Targeting these interactions and understanding the basis of resistance to PD-1 blockade would potentially allow identification of novel biomarkers of resistance or new molecular targets to enable T-cells to overcome dysfunction during PD-1 checkpoint blockade

Detecting mutations in the plasma of patients with solid tumors is becoming a valuable method of diagnosing and monitoring cancer. The TERT promoter is mutated at high frequencies in multiple cancer types, most commonly at positions -124 and -146 (designated C228T and C250T, respectively). Detection of these mutations has been challenging because of the high GC content of this region (approximately 80%). We describe development of novel probe-based droplet digital PCR assays that specifically detect and quantify these two mutations, along with the less common 242-243 CC>TT mutation, and demonstrate their application using human tumor and plasma samples from melanoma patients. Assay designs and running conditions were optimized using cancer cell line genomic DNAs with the C228T or C250T mutations. The limits of detection were 0.062% and 0.051% mutant allele fraction for the C228T and C250T assays, respectively. Concordance of 100% was observed between droplet digital PCR and sequencing-based orthogonal methods in the detection of TERT mutant DNA in 32 formalin-fixed, paraffin-embedded melanoma tumors. TERT^mutant DNA was also identified in 21 of 27 plasma samples (78%) from patients with TERT^mutant tumors, with plasma mutant allele fractions ranging from 0.06% to 15.3%. There were no false positives in plasma. These data demonstrate the potential of these assays to specifically detect and quantify TERT^mutant DNA in tumors and plasma of cancer patients.