Project description:Purpose: Utility of immunological treatment in cancer has increased; however, many patients do not respond to treatment. Identification of robust predictive biomarkers is required to correctly stratify patients. Although clinical trials based on adoptive T cell therapy (ACT) have yielded high response rates and many durable responses in melanoma, 50-60% of the patients have no clinical benefit. Herein, we searched for predictive biomarkers to ACT in melanoma. Methods: Whole exome- and transcriptome sequencing, neoantigen prediction and immune cell signature analysis were applied to pre-treatment melanoma samples from 27 patients recruited to a clinical phase I/II trial of ACT in stage IV melanoma. All patients had previously been treated with other immunotherapies. Results: We found that clinical benefit was associated with significantly higher neoantigen load (P=0.025). High mutation and neoantigen load were significantly associated with improved progression-free and overall survival (P=8x10^-4 and P=0.001, respectively). Further, gene-expression analysis of pre-treatment biopsies showed that clinical benefit was associated with strong immune activation signatures including a high MHC-I antigen processing and presentation score. Conclusions: These results improve our understanding of clinical benefit of ACT in melanoma, which can lead to clinically useful predictive biomarkers to be used for selecting patients that benefit from these highly intensive treatment regimens.
Project description:<p>Immune checkpoint inhibitors are effective cancer treatments, but molecular determinants of clinical benefit are unknown. Ipilimumab and tremelimumab are antibodies against cytotoxic T-lymphocyte antigen 4 (CTLA-4). Anti-CTLA-4 treatment prolongs overall survival in patients with melanoma. CTLA-4 blockade activates T cells and enables them to destroy tumor cells.</p> <p>We obtained tumor tissue from patients with melanoma who were treated with ipilimumab or tremelimumab. Whole-exome sequencing was performed on tumors and matched blood samples. Somatic mutations and candidate neoantigens generated from these mutations were characterized. Neoantigen peptides were tested for the ability to activate lymphocytes from ipilimumab-treated patients.</p> <p>Malignant melanoma exomes from 64 patients treated with CTLA-4 blockade were characterized with the use of massively parallel sequencing. A discovery set consisted of 11 patients who derived a long-term clinical benefit and 14 patients who derived a minimal benefit or no benefit. Mutational load was associated with the degree of clinical benefit (P = 0.01) but alone was not sufficient to predict benefit. Using genomewide somatic neoepitope analysis and patient-specific HLA typing, we identified candidate tumor neoantigens for each patient. We elucidated a neo-antigen landscape that is specifically present in tumors with a strong response to CTLA-4 blockade. We validated this signature in a second set of 39 patients with melanoma who were treated with anti-CTLA-4 antibodies. Predicted neoantigens activated T cells from the patients treated with ipilimumab.</p>
Project description:<p>Desmoplastic melanoma (DM) is a rare subtype of melanoma characterized by dense fibrous stroma, resistance to chemotherapy and a lack of actionable driver mutations, but is highly associated with ultraviolet light DNA damage. We analysed 60 patients with advanced DM treated with programmed cell death 1 (PD-1) or PD-1 ligand (PD-L1) blocking antibody therapy. Objective tumor responses were observed in 42 of the 60 patients (70%, 95% confidence interval 57-81%), including 19 patients (32% overall) with a complete response. Whole-exome sequencing revealed a high mutational load and frequent NF-1 mutations (14 out of 17 cases). Immunohistochemistry (IHC) analysis from 19 DM and 13 non-DM revealed a higher percentage of PD-L1 positive cells in the tumor parenchyma in DM (p = 0.04), highly associated with increased CD8 density and PD-L1 expression in the tumor invasive margin. Therefore, patients with advanced DM derive significant clinical benefit from PD-1/PD-L1 immune checkpoint blockade therapy despite being a cancer defined by its dense desmoplastic fibrous stroma. The benefit is likely derived from the high mutational burden and a frequent pre-existing adaptive immune response limited by PD-L1 expression.</p>
Project description:The optimal T cell attributes for the adoptive immunotherapy of cancer and viral diseases are currently unclear. Recent adoptive transfer clinical trials using ex vivo expanded tumor infiltrating lymphocytes has provided evidence that differentiated effector T cells can mediate durable responses in selected cancer patients. The capacity of these transferred cells to persist in the host was found to strongly correlate with their clinical activity. Thus, there is significant interest in identifying intrinsic markers that define antigen specific effector T cells that can develop into long-lived memory cells rather than undergoing apoptosis after infusion in humans. We recently reported the long term persistence of ex vivo expanded tumor specific CD8+ T effector clones in refractory metastatic melanoma patients after adoptive T cell transfer. By utilizing these highly homogeneous clone populations, we sought to define the pre-infusion cellular and molecular attributes associated with their effector to memory transition. Comparative transcriptional profiling found the pre-infusion clone mRNA expression levels of the IL-7 receptor (IL-7Ra) and the proto-oncogene, c-myc, directly correlated with the level of clonal persistence after adoptive transfer in humans. The predictive value of these markers was further established by utilizing IL-7R protein, induced pSTAT5, and c-myc mRNA expression to prospectively identify human tumor specific effector clones that could engraft after controlled adoptive transfer into highly immunodeficient mice. These findings support that IL-7R and c-myc expression are valuable cell intrinsic markers that can predict the fate of effector CD8+ T cells after adoptive transfer. We used microarrays to compare the pre-infusion gene expression profile of melanoma-specific CD8+ T cell clones that would eventually either persist or not after adoptive transfer in humans. We derived ten melanoma-specific CD8+ T cell clones and determined their degree of persistence after adoptive therapy into patients. We performed microarray on the pre-infusion samples of six persisting and four non-persisting clones to obtain a comparative gene signature profile.
Project description:In this manuscript, the authors had hypothesized a multi-dimensional approach modeling of both tumor and immune-related molecular mechanisms would better predict immune checkpoint blockade (ICB) response than simpler mutation-focused biomarkers, such as tumor mutational burden (TMB). The authors showed that the predictive power increases with deeper modeling of neoantigens and immune-related resistance mechanisms of ICB. The neoantigen burden score (NBS) and composite neoantigen presentation score (NEOPS) mentioned in the transcript was fully reproduced. Internally they used XGBoost algorithm to generate the results and the same is provided as dataset file. That is, the dataset provided here demonstrates that their integrative approach outperformed single-analyte biomarkers such as those found in cohort of patients with late-stage melanoma. This model is now addresses the issues in reproducing itself which was caused by version changes and deprecation of some R packages. It uses checkpoint package, which acts as a time machine for CRAN packages thereby promoting FAIReR sharing of ML models.
Project description:PD-1 immune checkpoint blockade provides significant clinical benefits for cancer patients. However, factors influencing innate sensitivity remain incompletely catalogued. We analyzed the somatic mutanomes and transcriptomes of pretreatment melanoma biopsies. Mutations in cell adhesion genes and the DNA repair gene BRCA2 were enriched in responding tumors, and a high mutational load associated with improved survival. Innately resistant tumors displayed frequent transcriptomic up-expression of genes that enriched for mesenchymal transition, cell adhesion, ECM organization, wound-healing and angiogenesis. The transcriptomes of innate resistance also enriched for signatures indicating up-regulation of these processes. Notably, MAPK-targeted therapy (MAPKi) induced similar signatures in melanoma, suggesting that a form of MAPKi resistance mediates cross-resistance to anti-PD-1 therapy. Co-enrichment of IPRIM (Innate anti-PD-1 Resistance Induced by MAPKi) signatures defined a transcriptomic subset across advanced cancers, suggesting that attenuating processes underlying these signatures may augment anti-PD1 responses. Thus, multi-factorial determinants influence anti-PD-1 patterns in melanoma.
Project description:Adoptive cell transfer (ACT) using neoantigen-specific T cells is an effective immunotherapeutic strategy. However, the difficulty in identifying and screening neoantigen-specific T cells limits its widespread application. Here, we prepared neoantigen-reactive T cells (NRTs) after immunization with a tumor lysate-loaded dendritic cell (DC) vaccine (OCDC) for ACT. Our results demonstrated that the OCDC vaccine could induce a neoantigen-specific immune response, and it was feasible to prepare NRTs by loading immunogenic neoantigens onto DCs and coculturing them with spleen lymphocytes from mice immunized with the OCDC vaccine. We then transferred these NRTs back to the LL/2 tumor-bearing mice after OCDC vaccine immunization and found that OCDC vaccine and NRTs adoptive transfer combination treatment could induce a stronger antitumor response. Furthermore, we found that infused NRTs could migrate into the tumor microenvironment to exert antitumor effects. Our research provides a new and convenient method of preparing NRTs for ACT. The clinical translation of this approach has the potential to increase ACT efficacy.
Project description:Adoptive cell transfer (ACT) using neoantigen-specific T cells is an effective immunotherapeutic strategy. However, the difficulty in identifying and screening neoantigen-specific T cells limits its widespread application. Here, we prepared neoantigen-reactive T cells (NRTs) after immunization with a tumor lysate-loaded dendritic cell (DC) vaccine (OCDC) for ACT. Our results demonstrated that the OCDC vaccine could induce a neoantigen-specific immune response, and it was feasible to prepare NRTs by loading immunogenic neoantigens onto DCs and coculturing them with spleen lymphocytes from mice immunized with the OCDC vaccine. We then transferred these NRTs back to the LL/2 tumor-bearing mice after OCDC vaccine immunization and found that OCDC vaccine and NRTs adoptive transfer combination treatment could induce a stronger antitumor response. Furthermore, we found that infused NRTs could migrate into the tumor microenvironment to exert antitumor effects. Our research provides a new and convenient method of preparing NRTs for ACT. The clinical translation of this approach has the potential to increase ACT efficacy.
Project description:Adoptive cell therapy (ACT) using ex vivo–expanded tumor-infiltrating lymphocytes (TILs) can eliminate or shrink metastatic melanoma, but its long-term efficacy remains limited to a fraction of patients. Using longitudinal samples from 13 patients with metastatic melanoma treated with TIL-ACT in a phase 1 clinical study, we interrogated cellular states within the tumor microenvironment (TME) and their interactions. We performed bulk and single-cell RNA sequencing, whole-exome sequencing, and spatial proteomic analyses in pre- and post-ACT tumor tissues, finding that ACT responders exhibited higher basal tumor cell–intrinsic immunogenicity and mutational burden. Compared with nonresponders, CD8+ TILs exhibited increased cytotoxicity, exhaustion, and costimulation, whereas myeloid cells had increased type I interferon signaling in responders. Cell-cell interaction prediction analyses corroborated by spatial neighborhood analyses revealed that responders had rich baseline intratumoral and stromal tumor–reactive T cell networks with activated myeloid populations. Successful TIL-ACT therapy further reprogrammed the myeloid compartment and increased TIL-myeloid networks. Our systematic target discovery study identifies potential T-myeloid cell network–based biomarkers that could improve patient selection and guide the design of ACT clinical trials.
Project description:Adoptive cell therapy (ACT) using ex vivo–expanded tumor-infiltrating lymphocytes (TILs) can eliminate or shrink metastatic melanoma, but its long-term efficacy remains limited to a fraction of patients. Using longitudinal samples from 13 patients with metastatic melanoma treated with TIL-ACT in a phase 1 clinical study, we interrogated cellular states within the tumor microenvironment (TME) and their interactions. We performed bulk and single-cell RNA sequencing, whole-exome sequencing, and spatial proteomic analyses in pre- and post-ACT tumor tissues, finding that ACT responders exhibited higher basal tumor cell–intrinsic immunogenicity and mutational burden. Compared with nonresponders, CD8+ TILs exhibited increased cytotoxicity, exhaustion, and costimulation, whereas myeloid cells had increased type I interferon signaling in responders. Cell-cell interaction prediction analyses corroborated by spatial neighborhood analyses revealed that responders had rich baseline intratumoral and stromal tumor–reactive T cell networks with activated myeloid populations. Successful TIL-ACT therapy further reprogrammed the myeloid compartment and increased TIL-myeloid networks. Our systematic target discovery study identifies potential T-myeloid cell network–based biomarkers that could improve patient selection and guide the design of ACT clinical trials.