Frequency and characteristics of immune-related thyroid adverse events in patients with resected stage III/IV melanoma treated with adjuvant PD-1 inhibitors: a national cohort study.

PURPOSE: Immune-related thyroid adverse events (irTAEs) occur frequently following immune checkpoint inhibitor (ICI) therapy. The purpose of this study is to provide knowledge about the incidence, clinical timeline characteristics, associated factors of irTAEs, and potential impact on treatment efficacy in patients with melanoma receiving adjuvant ICI therapy. METHODS: A national multicenter retrospective cohort study of patients with resected stage III/IV melanoma treated with adjuvant PD-1 inhibitors between November 2018 and December 2020. Data were extracted from the Danish Metastatic Melanoma Database. The irTAEs were defined as two consecutive abnormal TSH values and subdivided into transient or persistent. RESULTS: Of 454 patients, 99 developed an irTAE (21.8%), of these were 46 transient (46.5%) and 53 persistent (53.5%). Median time to transient and persistent irTAE was 55 and 44 days, respectively (p = 0.57). A hyperthyroid phase followed by hypothyroidism was seen in 73.6% of persistent irTAEs, whereas 87% of transient irTAEs developed an isolated hypo- or hyperthyroid phase. Multiple variable analysis demonstrated an association between irTAE and female sex (HR 2.45; 95% CI 1.63-3.70; p < 0.001), but no association with recurrence-free survival (HR 0.86; 95% CI 0.50-1.48; p = 0.587) or overall survival (HR 1.05; 95% CI 0.52-2.12, p = 0.891). CONCLUSIONS: IrTAE is a common side effect to PD-1 inhibitors primarily occurring within the first 3 months, with a high risk of persistency. Female sex is a strong predictive factor. IrTAE was not associated with improved clinical outcome.

IMPROVE: a feature model to predict neoepitope immunogenicity through broad-scale validation of T-cell recognition.

Background: Mutation-derived neoantigens are critical targets for tumor rejection in cancer immunotherapy, and better tools for neoepitope identification and prediction are needed to improve neoepitope targeting strategies. Computational tools have enabled the identification of patient-specific neoantigen candidates from sequencing data, but limited data availability has hindered their capacity to predict which of the many neoepitopes will most likely give rise to T cell recognition. Method: To address this, we make use of experimentally validated T cell recognition towards 17,500 neoepitope candidates, with 467 being T cell recognized, across 70 cancer patients undergoing immunotherapy. Results: We evaluated 27 neoepitope characteristics, and created a random forest model, IMPROVE, to predict neoepitope immunogenicity. The presence of hydrophobic and aromatic residues in the peptide binding core were the most important features for predicting neoepitope immunogenicity. Conclusion: Overall, IMPROVE was found to significantly advance the identification of neoepitopes compared to other current methods.

State-Of-The-Art Advancements on Cancer Vaccines and Biomarkers.

The origins of cancer vaccines date back to the 1800s. Since then, there have been significant efforts to generate vaccines against solid and hematologic malignancies using a variety of platforms. To date, these efforts have generally been met with minimal success. However, in the era of improved methods and technological advancements, supported by compelling preclinical and clinical data, a wave of renewed interest in the field offers the promise of discovering field-changing paradigms in the management of established and resected disease using cancer vaccines. These include novel approaches to personalized neoantigen vaccine development, as well as innovative immune-modulatory vaccines (IMVs) that facilitate activation of antiregulatory T cells to limit immunosuppression caused by regulatory immune cells. This article will introduce some of the limitations that have affected cancer vaccine development over the past several decades, followed by an introduction to the latest advancements in neoantigen vaccine and IMV therapy, and then conclude with a discussion of some of the newest technologies and progress that are occurring across the cancer vaccine space. Cancer vaccines are among the most promising frontiers for breakthrough innovations and strategies poised to make a measurable impact in the ongoing fight against cancer.

Molecular patterns of resistance to immune checkpoint blockade in melanoma.

Immune checkpoint blockade (ICB) has improved outcome for patients with metastatic melanoma but not all benefit from treatment. Several immune- and tumor intrinsic features are associated with clinical response at baseline. However, we need to further understand the molecular changes occurring during development of ICB resistance. Here, we collect biopsies from a cohort of 44 patients with melanoma after progression on anti-CTLA4 or anti-PD1 monotherapy. Genetic alterations of antigen presentation and interferon gamma signaling pathways are observed in approximately 25% of ICB resistant cases. Anti-CTLA4 resistant lesions have a sustained immune response, including immune-regulatory features, as suggested by multiplex spatial and T cell receptor (TCR) clonality analyses. One anti-PD1 resistant lesion harbors a distinct immune cell niche, however, anti-PD1 resistant tumors are generally immune poor with non-expanded TCR clones. Such immune poor microenvironments are associated with melanoma cells having a de-differentiated phenotype lacking expression of MHC-I molecules. In addition, anti-PD1 resistant tumors have reduced fractions of PD1+ CD8+ T cells as compared to ICB naïve metastases. Collectively, these data show the complexity of ICB resistance and highlight differences between anti-CTLA4 and anti-PD1 resistance that may underlie differential clinical outcomes of therapy sequence and combination.

Phase 1, first-in-human study of TYRP1-TCB (RO7293583), a novel TYRP1-targeting CD3 T-cell engager, in metastatic melanoma: active drug monitoring to assess the impact of immune response on drug exposure.

Introduction: Although checkpoint inhibitors (CPIs) have improved outcomes for patients with metastatic melanoma, those progressing on CPIs have limited therapeutic options. To address this unmet need and overcome CPI resistance mechanisms, novel immunotherapies, such as T-cell engaging agents, are being developed. The use of these agents has sometimes been limited by the immune response mounted against them in the form of anti-drug antibodies (ADAs), which is challenging to predict preclinically and can lead to neutralization of the drug and loss of efficacy. Methods: TYRP1-TCB (RO7293583; RG6232) is a T-cell engaging bispecific (TCB) antibody that targets tyrosinase-related protein 1 (TYRP1), which is expressed in many melanomas, thereby directing T cells to kill TYRP1-expressing tumor cells. Preclinical studies show TYRP1-TCB to have potent anti-tumor activity. This first-in-human (FIH) phase 1 dose-escalation study characterized the safety, tolerability, maximum tolerated dose/optimal biological dose, and pharmacokinetics (PK) of TYRP1-TCB in patients with metastatic melanoma (NCT04551352). Results: Twenty participants with cutaneous, uveal, or mucosal TYRP1-positive melanoma received TYRP1-TCB in escalating doses (0.045 to 0.4 mg). All participants experienced ≥1 treatment-related adverse event (TRAE); two participants experienced grade 3 TRAEs. The most common toxicities were grade 1-2 cytokine release syndrome (CRS) and rash. Fractionated dosing mitigated CRS and was associated with lower levels of interleukin-6 and tumor necrosis factor-alpha. Measurement of active drug (dual TYPR1- and CD3-binding) PK rapidly identified loss of active drug exposure in all participants treated with 0.4 mg in a flat dosing schedule for ≥3 cycles. Loss of exposure was associated with development of ADAs towards both the TYRP1 and CD3 domains. A total drug PK assay, measuring free and ADA-bound forms, demonstrated that TYRP1-TCB-ADA immune complexes were present in participant samples, but showed no drug activity in vitro. Discussion: This study provides important insights into how the use of active drug PK assays, coupled with mechanistic follow-up, can inform and enable ongoing benefit/risk assessment for individuals participating in FIH dose-escalation trials. Translational studies that lead to a better understanding of the underlying biology of cognate T- and B-cell interactions, ultimately resulting in ADA development to novel biotherapeutics, are needed.

Outcome of adjuvant immunotherapy in a real-world nation-wide cohort of patients with melanoma.

BACKGROUND: Clinical trials have demonstrated promising outcomes for adjuvant immunotherapy in patients with resected melanoma. Real-life data provide valuable insights to support patient guidance and treatment decisions. METHODS: Observational population-based study examining a national cohort of patients with resected stage III-IV melanoma referred for adjuvant therapy. Data were extracted from the Danish Metastatic Melanoma Database (DAMMED). RESULTS: Between November 2018 and January 2022, 785 patients received adjuvant anti-PD-1. The majority had stage III resected melanoma (87%), normal LDH levels (80%), and performance score 0 (87%). Patients were followed for a median of 25.6 months (95%CI 24-28). The median recurrence-free survival (RFS) and melanoma-specific survival (MSS) were not reached. The RFS was 78% (95%CI 75-81), 66% (63-70), and 59% (55-63); MSS was 97% (95-98), 93% (91-95), and 87% (84-90) at 1-, 2-, and 3-year; respectively. Less than half (42%) of the patients finalized planned therapy, 32% discontinued due to toxicity, and 19% due to melanoma recurrence. Patients discontinuing adjuvant treatment prematurely, without recurrence, had similar outcomes as patients finalizing therapy. In a multivariable analysis, ipilimumab plus nivolumab did not improve outcomes compared to ipilimumab monotherapy as a first-line metastatic treatment after adjuvant anti-PD-1. CONCLUSION: Survival outcomes in real-world patients with melanoma treated with adjuvant anti-PD-1 align with results from the randomized controlled trials. Patients discontinuing therapy prematurely, for other reasons than recurrence, had similar outcomes as patients finalizing planned treatment. First-line metastatic treatment with ipilimumab and nivolumab post-adjuvant anti-PD-1 did not show improved outcomes compared to ipilimumab/anti-PD-1 monotherapy.

Prospective Assessment of Fluorine-18-Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography (FDG-PET/CT) for Early Identification of Checkpoint-Inhibitor-Induced Pseudoprogression.

The activity of immune checkpoint inhibitors (ICIs) in patients with metastatic melanoma is often monitored using fluorine-18-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) scans. However, distinguishing disease progression (PD) from pseudoprogression (PsPD), where increased FDG uptake might reflect immune cell activity rather than tumor growth, remains a challenge. This prospective study compared the efficacy of dual-time point (DTP) FDG-PET/CT with modified response criteria (PERCIMT) in differentiating PsPD from PD. From July 2017-January 2021, 41 patients suspected to have PsPD on an evaluation scan were prospectively included (29 evaluable). A subsequent DTP FDG-PET/CT scan was conducted within 14 days, followed by a confirmatory FDG-PET/CT scan. Additionally, PERCIMT were applied. DTP FDG-PET/CT identified 24% with PsPD and 76% with PD. Applying PERCIMT criteria, 69% showed PsPD, while 31% had PD. On follow-up, 10 patients (34%) demonstrated confirmed PsPD, while 19 (66%) exhibited PD. The sensitivity and specificity of DTP FDG-PET/CT were 20% and 74%, respectively, and for PERCIMT this was 80% and 37%, respectively. Our findings suggest limited efficacy of DTP FDG-PET/CT in distinguishing PsPD from PD in ICI-treated patients with metastatic melanoma. The use of PERCIMT could complement clinical assessment and be incorporated in multidisciplinary team conferences for enhanced decision-making.

New expert advice on cancer in pregnancy.

Cancer in pregnancy is rare, and most physicians lack knowledge in handling pregnant cancer patients. This review summarises the present knowledge on this condition. In the Netherlands, an Advisory Board on Cancer in Pregnancy was established in 2012. The board supports Dutch physicians' decisions in the management of pregnant patients with cancer. In 2021 the International Advisory Board on Cancer in Pregnancy was established, and in continuation, the Danish Advisory Board on Cancer in Pregnancy (DABCIP) has now been founded. DABCIP consists of 22 members from 13 different medical disciplines.

Improving shared decision-making about cancer treatment through design-based data-driven decision-support tools and redesigning care paths: an overview of the 4D PICTURE project.

Background: Patients with cancer often have to make complex decisions about treatment, with the options varying in risk profiles and effects on survival and quality of life. Moreover, inefficient care paths make it hard for patients to participate in shared decision-making. Data-driven decision-support tools have the potential to empower patients, support personalized care, improve health outcomes and promote health equity. However, decision-support tools currently seldom consider quality of life or individual preferences, and their use in clinical practice remains limited, partly because they are not well integrated in patients' care paths. Aim and objectives: The central aim of the 4D PICTURE project is to redesign patients' care paths and develop and integrate evidence-based decision-support tools to improve decision-making processes in cancer care delivery. This article presents an overview of this international, interdisciplinary project. Design methods and analysis: In co-creation with patients and other stakeholders, we will develop data-driven decision-support tools for patients with breast cancer, prostate cancer and melanoma. We will support treatment decisions by using large, high-quality datasets with state-of-the-art prognostic algorithms. We will further develop a conversation tool, the Metaphor Menu, using text mining combined with citizen science techniques and linguistics, incorporating large datasets of patient experiences, values and preferences. We will further develop a promising methodology, MetroMapping, to redesign care paths. We will evaluate MetroMapping and these integrated decision-support tools, and ensure their sustainability using the Nonadoption, Abandonment, Scale-Up, Spread, and Sustainability (NASSS) framework. We will explore the generalizability of MetroMapping and the decision-support tools for other types of cancer and across other EU member states. Ethics: Through an embedded ethics approach, we will address social and ethical issues. Discussion: Improved care paths integrating comprehensive decision-support tools have the potential to empower patients, their significant others and healthcare providers in decision-making and improve outcomes. This project will strengthen health care at the system level by improving its resilience and efficiency.

Improving the cancer patient journey and respecting personal preferences: an overview of the 4D PICTURE project The 4D PICTURE project aims to help cancer patients, their families and healthcare providers better undertstand their options. It supports their treatment and care choices, at each stage of disease, by drawing on large amounts of evidence from different types of European data. The project involves experts from many different specialist areas who are based in nine European countries. The overall aim is to improve the cancer patient journey and ensure personal preferences are respected.

PD-L1 is a biomarker of real-world clinical outcomes for anti-CTLA-4 plus anti-PD-1 or anti-PD-1 monotherapy in metastatic melanoma.

BACKGROUND: Metastatic melanoma (MM) is commonly treated with a combination of nivolumab and ipilimumab, regardless of tumor PD-L1 expression. METHODS: We conducted a population-based study including all patients with MM (except ocular melanoma) treated in Denmark with first-line combination therapy or anti-PD-1 monotherapy since January 2017. Baseline data including known prognostic characteristics were used in multivariable and propensity-matched score (PMS) analyses to assess progression-free survival (PFS), melanoma-specific survival (MSS), and overall survival (OS) according to PD-L1 expression. RESULTS: We identified 1341 eligible patients, with known PD-L1 status for 1081 patients (43% PD-L1 ≥ 1%, 57% PD-L1 < 1%). PD-L1 ≥ 1% was an independent positive prognostic biomarker for survival in the overall cohort (MSS: HR 0.66, CI 0.52-0.83, p < 0.001). In the PMS PD-L1 ≥ 1% cohort, combination therapy showed similar clinical outcomes to monotherapy (PFS: HR 1.41, CI 0.94-2.11, p = 0.101; MSS: HR 1.21, CI 0.70-2.11, p = 0.49; OS: HR 1.17, CI 0.68-2.00, p = 0.567). In contrast, in the PMS PD-L1 < 1% and in the PMS PD-L1 < 1% BRAF WT cohorts, combination therapy improved PFS (respectively with HR 0.70, CI 0.53-0.93, p = 0.013; and HR 0.54, CI 0.37-0.78, p = 0.001), but did not reach statistically significant improvements of MSS (HR 0.72, CI 0.50-1.02, p = 0.065; and HR 0.79, CI 0.51-1.21, p = 0.278) or OS (HR 0.78, CI 0.56-1.08, p = 0.135; and HR 0.81, CI 0.54-1.21, p = 0.305) compared to monotherapy. CONCLUSION: Our findings support previous exploratory analyses of Checkmate-067, highlighting that improved clinical outcomes with combination therapy are not established in unselected patients with high (≥1%) tumor PD-L1 expression.

LTX-315 and adoptive cell therapy using tumor-infiltrating lymphocytes generate tumor specific T cells in patients with metastatic soft tissue sarcoma.

LTX-315 is an oncolytic peptide that elicits both local and systemic immune responses upon intratumoral injection. In the present pilot trial, we treated patients with metastatic soft tissue sarcoma with the combination of LTX-315 and adoptive T-cell therapy using in vitro expanded tumor-infiltrating lymphocytes. Six heavily pretreated patients were included in the trial and treated with LTX-315 of which four patients proceeded to adoptive T-cell therapy. Overall, the treatment was considered safe with only expected and manageable toxicity. The best overall clinical response was stable disease for 208 days, and in this patient, we detected tumor-reactive T cells in the blood that lasted until disease progression. In three patients T-cell reactivity against in silico predicted neoantigens was demonstrated. Additionally, de novo T-cell clones were generated and expanded in the blood following LTX-315 injections. In conclusion, this pilot study provides proof that it is feasible to combine LTX-315 and adoptive T-cell therapy, and that this treatment can induce systemic immune responses that resulted in stabilization of the disease in sarcoma patients with otherwise progressive disease. Further optimization of the treatment protocol is warranted to increase clinical activity. ClinicalTrials.gov Identifier: NCT03725605.

Sustained improved survival of patients with metastatic melanoma after the introduction of anti-PD-1-based therapies.

BACKGROUND: The introduction of modern therapies improved the median survival of patients with metastatic melanoma (MM). Here, we determined the real-world impact of modern treatments on the long-term survival of MM. METHODS: In a population-based study, we extracted all cases of MM diagnosed in four non-consecutive years marked by major changes in available 1st line treatments (2012, 2014, 2016, and 2018) from the Danish MM Database. Patients were grouped into "trial-like" and "trial-excluded" based on common trial eligibility criteria. RESULTS: We observed a sustained improved survival of "trial-like" patients diagnosed in 2016 or in 2018, compared to 2012 or 2014, but no major differences in 2018 versus 2016. In contrast, while survival of "trial-excluded" patients in 2016 was better compared to 2014 and 2012, survival in 2018 was improved over all previous years. We then developed a prognostic model based on multivariable stratified Cox regression, to predict the survival of newly diagnosed MM patients. Internal validation showed excellent discrimination and calibration, with a time-area-under-the-curve above 0.79 at multiple time horizons, for up to four years after diagnosis. CONCLUSIONS: The introduction of modern treatments such as anti-PD-1 has led to a sustained, improved survival of real-world patients with MM, regardless of their eligibility for clinical trials. We provide an updateable prognostic model that can be used to improve patient information. Overall, these data highlight a positive population-based impact of modern treatments and can help health technology assessment agencies worldwide to evaluate the appropriateness of drug pricing based on known cost-benefit data.

Health care and socioeconomic costs for long-term survivors after implementation of checkpoint-inhibitors and targeted agents for metastatic melanoma.

BACKGROUND: Real-life data on health care costs and loss of productivity after implementing new agents for metastatic melanoma are important to supplement model-based economic data. MATERIALS AND METHODS: All patients registered in the Danish Metastatic Melanoma Database (DAMMED) and the National Patient Registry in 2007-2011 were compared to 2012-2016 after the implementation of checkpoint inhibitors and targeted therapy. Health care costs, social transfer income (STI), and loss of productivity were calculated with a 2-step one model generalised linear regression (GLM) model. Medicine costs were calculated separately. RESULTS: In 2007-2011, 70 (15%) out of 464 patients were long-term survivors compared to 347 (32%) out of 1089 patients in 2012-2016. Total health care costs per patient year were significantly lower in the first treatment year (€41.457 versus €60.547, relative change (RC) 0.72, 95% confidence interval (CI) 0.56-0.94, p = 0.015) and without significant difference the second year in 2012-2016 compared to 2007-2011. Medicine costs per patient year increased the first (€85.464 versus €26.339, RC 3.39, 95% CI 2.61-4.41, p < 0.001) and the second (€26.464 versus €11.150, RC 2.59, 95% CI 1.98-3.40, p < 0.001) year in 2012-2016 compared to 2007-2011. Productivity increased for long-term survivors in 2012-2016 in contrast to 2007-2011. CONCLUSION: Implementation of targeted therapy and checkpoint-inhibitors has increased medicine costs more than three-fold for long-term survivors. Total health care costs excluding medicine costs were significantly lower for long-term survivors the first and without change the second treatment year in 2012-2016 compared to 2007-2011. However, the number of treated patients increased which leads to an increase in overall total health care costs. Importantly, productivity increased for long-term survivors in 2012-2016.

Stage-Specific Risk of Recurrence and Death From Melanoma in Denmark, 2008-2021: A National Observational Cohort Study of 25 720 Patients With Stage IA to IV Melanoma.

Importance: To ensure optimal treatment and surveillance of patients with melanoma, knowledge of the clinical stage-specific risk of recurrence, mortality, and recurrence patterns across the American Joint Committee on Cancer Eighth Edition (AJCC8) substages is needed. Objective: To estimate stage-specific recurrence and melanoma-specific mortality rates, assess absolute stage-specific risks of recurrence and mortality, and describe stage-specific recurrence patterns, including conditional rates. Design: Retrospective cohort study of prospectively collected nationwide population-based registry data. Setting: Nationwide, population-based cohort study. Participants: The 25 720 Danish patients, 18 years or older, diagnosed with first-time stage IA to IV cutaneous melanoma between January 1, 2008, and December 31, 2019, were included and followed up from time of primary treatment until December 31, 2021. Exposures: First diagnosis of stage IA to IV cutaneous melanoma. Main Outcomes: Stage-specific cumulative incidence of recurrence and melanoma-specific mortality, melanoma-specific recurrence-free survival, and assessed absolute stage-specific risks of recurrence and melanoma-specific mortality. Secondary outcomes were stage-specific recurrence patterns, including conditional rates, and melanoma-specific survival. Results: We followed up 25 720 patients for a median of 5.9 years (95% CI, 58.9-59.3 years). Mean age was 59.1 years (95% CI, 58.9-59.3 years). Patients with stage IIB to IIC melanoma were older, had more comorbidities at diagnosis, and had the lowest rate of pathologic staging by sentinel node biopsy (81.6%-87.4%). A total of 10.6% of patients developed recurrence; first recurrence included distant recurrence, alone or with synchronous locoregional recurrence, in 56.6% of patients. We found a comparable risk of recurrence in stages IIIA and IIB (29.7% vs 33.2%) and in stages IIIB and IIC (35.9% vs 36.8%), respectively. Melanoma-specific mortality was comparable between stages IIIA and IIA (13.0% vs 13.6%) and between stages IIIB and IIB (18.4% vs 22.0%), respectively. These risk patterns persisted in cause-specific hazards models. Conclusions and Relevance: This nationwide, population-based cohort study found that the increasing stages of the current AJCC8 staging system do not accurately reflect an increasing risk of recurrence and mortality in melanoma. The high proportion of distant recurrences suggests that hematogenous spread is a more common metastatic pathway than previously assumed, and surveillance with routine functional/cross-sectional imaging should be considered for stages IIB to IV. Future efforts should be put toward developing new tools for risk stratification and determining the survival effect of routine imaging in surveillance.

Targeting of multiple tumor-associated antigens by individual T cell receptors during successful cancer immunotherapy.

The T cells of the immune system can target tumors and clear solid cancers following tumor-infiltrating lymphocyte (TIL) therapy. We used combinatorial peptide libraries and a proteomic database to reveal the antigen specificities of persistent cancer-specific T cell receptors (TCRs) following successful TIL therapy for stage IV malignant melanoma. Remarkably, individual TCRs could target multiple different tumor types via the HLA A∗02:01-restricted epitopes EAAGIGILTV, LLLGIGILVL, and NLSALGIFST from Melan A, BST2, and IMP2, respectively. Atomic structures of a TCR bound to all three antigens revealed the importance of the shared x-x-x-A/G-I/L-G-I-x-x-x recognition motif. Multi-epitope targeting allows individual T cells to attack cancer in several ways simultaneously. Such "multipronged" T cells exhibited superior recognition of cancer cells compared with conventional T cell recognition of individual epitopes, making them attractive candidates for the development of future immunotherapies.

Restoring tumor immunogenicity with dendritic cell reprogramming.

Decreased antigen presentation contributes to the ability of cancer cells to evade the immune system. We used the minimal gene regulatory network of type 1 conventional dendritic cells (cDC1) to reprogram cancer cells into professional antigen-presenting cells (tumor-APCs). Enforced expression of the transcription factors PU.1, IRF8, and BATF3 (PIB) was sufficient to induce the cDC1 phenotype in 36 cell lines derived from human and mouse hematological and solid tumors. Within 9 days of reprogramming, tumor-APCs acquired transcriptional and epigenetic programs associated with cDC1 cells. Reprogramming restored the expression of antigen presentation complexes and costimulatory molecules on the surfaces of tumor cells, allowing the presentation of endogenous tumor antigens on MHC-I and facilitating targeted killing by CD8+ T cells. Functionally, tumor-APCs engulfed and processed proteins and dead cells, secreted inflammatory cytokines, and cross-presented antigens to naïve CD8+ T cells. Human primary tumor cells could also be reprogrammed to increase their capability to present antigen and to activate patient-specific tumor-infiltrating lymphocytes. In addition to acquiring improved antigen presentation, tumor-APCs had impaired tumorigenicity in vitro and in vivo. Injection of in vitro generated melanoma-derived tumor-APCs into subcutaneous melanoma tumors delayed tumor growth and increased survival in mice. Antitumor immunity elicited by tumor-APCs was synergistic with immune checkpoint inhibitors. Our approach serves as a platform for the development of immunotherapies that endow cancer cells with the capability to process and present endogenous tumor antigens.

Ex vivo modulation of intact tumor fragments with anti-PD-1 and anti-CTLA-4 influences the expansion and specificity of tumor-infiltrating lymphocytes.

Checkpoint inhibition (CPI) therapy and adoptive cell therapy with autologous tumor-infiltrating lymphocytes (TIL-based ACT) are the two most effective immunotherapies for the treatment of metastatic melanoma. While CPI has been the dominating therapy in the past decade, TIL-based ACT is beneficial for individuals even after progression on previous immunotherapies. Given that notable differences in response have been made when used as a subsequent treatment, we investigated how the qualities of TILs changed when the ex vivo microenvironment of intact tumor fragments were modulated with checkpoint inhibitors targeting programmed death receptor 1 (PD-1) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4). Initially, we show that unmodified TILs from CPI-resistant individuals can be produced, are overwhelmingly terminally differentiated, and are capable of responding to tumor. We then investigate these properties in ex vivo checkpoint modulated TILs finding that that they retain these qualities. Lastly, we confirmed the specificity of the TILs to the highest responding tumor antigens, and identified this reactivity resides largely in CD39+CD69+ terminally differentiated populations. Overall, we found that anti-PD-1 will alter the proliferative capacity while anti-CTLA4 will influence breadth of antigen specificity.

Uncoupling CD4+ TIL-Mediated Tumor Killing from JAK-Signaling in Melanoma.

PURPOSE: Impaired MHCI-presentation and insensitivity to immune effector molecules are common features of immune checkpoint blockade (ICB)-resistant tumors and can be, respectively, associated with loss of ß2 microglobulin (B2M) or impaired IFNγ signaling. Patients with ICB-resistant tumors can respond to alternative immunotherapies, such as infusion of autologous tumor-infiltrating lymphocytes (TIL). CD4+ T cells can exert cytotoxic functions against tumor cells; however, it is unclear whether CD4+ T-cell responses can be exploited to improve the clinical outcomes of patients affected by ICB-resistant tumors. EXPERIMENTAL DESIGN: Here, we exploited CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 gene editing to reproduce immune-resistant tumor phenotypes via gene knockout (KO). To determine the role of cytotoxic CD4+ TILs in ICB-resistant tumors, we investigated CD4+ TIL-mediated cytotoxicity in matched pairs of TILs and autologous melanoma cell lines, used as a model of patient-specific immune-tumor interaction. Around 40% of melanomas constitutively express MHC Class II molecules; hence, melanomas with or without natural constitutive MHC Class II expression (MHCIIconst+ or MHCIIconst-) were used. RESULTS: CD4+ TIL-mediated cytotoxicity was not affected by B2M loss but was dependent on the expression of CIITA. MHCIIconst+ melanomas were killed by tumor-specific CD4+ TILs even in the absence of IFNγ-mediated MHCII upregulation, whereas IFNγ was necessary for CD4+ TIL-mediated cytotoxicity against MHCIIconst- melanomas. Notably, although tumor-specific CD4+ TILs did not kill JAK1KO MHCIIconst- melanomas even after IFNγ stimulation, sensitivity to CD4+ TIL-mediated cytotoxicity was maintained by JAK1KO MHCIIconst+ melanomas. CONCLUSIONS: In conclusion, our data indicate that exploiting tumor-specific cytotoxic CD4+ TILs could help overcome resistance to ICB mediated by IFNγ-signaling loss in MHCIIconst+ melanomas. See related commentary by Betof Warner and Luke, p. 3829.

Neoepitope load, T cell signatures and PD-L2 as combined biomarker strategy for response to checkpoint inhibition immunotherapy.

Immune checkpoint inhibition for the treatment of cancer has provided a breakthrough in oncology, and several new checkpoint inhibition pathways are currently being investigated regarding their potential to provide additional clinical benefit. However, only a fraction of patients respond to such treatment modalities, and there is an urgent need to identify biomarkers to rationally select patients that will benefit from treatment. In this study, we explore different tumor associated characteristics for their association with favorable clinical outcome in a diverse cohort of cancer patients treated with checkpoint inhibitors. We studied 29 patients in a basket trial comprising 12 different tumor types, treated with 10 different checkpoint inhibition regimens. Our analysis revealed that even across this diverse cohort, patients achieving clinical benefit had significantly higher neoepitope load, higher expression of T cell signatures, and higher PD-L2 expression, which also correlated with improved progression-free and overall survival. Importantly, the combination of biomarkers serves as a better predictor than each of the biomarkers alone. Basket trials are frequently used in modern immunotherapy trial design, and here we identify a set of biomarkers of potential relevance across multiple cancer types, allowing for the selection of patients that most likely will benefit from immune checkpoint inhibition.