Clinical responses in a phase II study using adoptive transfer of short-term cultured tumor infiltration lymphocytes in metastatic melanoma patients

Non-viral delivery of RNA for therapeutic T cell engineering

Adoptive T cell transfer has shown great success in treating blood cancers, resulting in a growing number of FDA-approved therapies using chimeric antigen receptor (CAR)-engineered T cells. However, the effectiveness of this treatment for solid tumors is still not satisfactory, emphasizing the need for improved T cell engineering strategies and combination approaches. Currently, CAR T cells are mainly manufactured using gammaretroviral and lentiviral vectors due to their high transduction efficiency. However, there are concerns about their safety, the high cost of producing them in compliance with current Good Manufacturing Practices (cGMP), regulatory obstacles, and limited cargo capacity, which limit the broader use of engineered T cell therapies. To overcome these limitations, researchers have explored non-viral approaches, such as membrane permeabilization and carrier-mediated methods, as more versatile and sustainable alternatives for next-generation T cell engineering. Non-viral delivery methods can be designed to transport a wide range of molecules, including RNA, which allows for more controlled and safe modulation of T cell phenotype and function. In this review, we provide an overview of non-viral RNA delivery in adoptive T cell therapy. We first define the different types of RNA therapeutics, highlighting recent advancements in manufacturing for their therapeutic use. We then discuss the challenges associated with achieving effective RNA delivery in T cells. Next, we provide an overview of current and emerging technologies for delivering RNA into T cells. Finally, we discuss ongoing preclinical and clinical studies involving RNA-modified T cells.

Multimodal stimulation screens reveal unique and shared genes limiting T cell fitness

Genes limiting T cell antitumor activity may serve as therapeutic targets. It has not been systematically studied whether there are regulators that uniquely or broadly contribute to T cell fitness. We perform genome-scale CRISPR-Cas9 knockout screens in primary CD8 T cells to uncover genes negatively impacting fitness upon three modes of stimulation: (1) intense, triggering activation-induced cell death (AICD); (2) acute, triggering expansion; (3) chronic, causing dysfunction. Besides established regulators, we uncover genes controlling T cell fitness either specifically or commonly upon differential stimulation. Dap5 ablation, ranking highly in all three screens, increases translation while enhancing tumor killing. Loss of Icam1-mediated homotypic T cell clustering amplifies cell expansion and effector functions after both acute and intense stimulation. Lastly, Ctbp1 inactivation induces functional T cell persistence exclusively upon chronic stimulation. Our results functionally annotate fitness regulators based on their unique or shared contribution to traits limiting T cell antitumor activity.

Cost-effectiveness of treating advanced melanoma with tumor-infiltrating lymphocytes based on an international randomized phase 3 clinical trial

INTRODUCTION

In a multicenter, open-label randomized phase 3 clinical trial conducted in the Netherlands and Denmark, treatment with ex vivo-expanded tumor-infiltrating lymphocytes (TIL-NKI/CCIT) from autologous melanoma tumor compared with ipilimumab improved progression-free survival in patients with unresectable stage IIIC-IV melanoma after failure of first-line or second-line treatment. Based on this trial, we conducted a cost-utility analysis.

METHODS

A Markov decision model was constructed to estimate expected costs (expressed in 2021€) and outcomes (quality-adjusted life years (QALYs)) of TIL-NKI/CCIT versus ipilimumab in the Netherlands. The Danish setting was assessed in a scenario analysis. A modified societal perspective was applied over a lifetime horizon. TIL-NKI/CCIT production costs were estimated via activity-based costing. Through sensitivity analyses, uncertainties and their impact on the incremental cost-effectiveness ratio (ICER) were assessed.

RESULTS

Mean total undiscounted lifetime benefits were 4.47 life years (LYs) and 3.52 QALYs for TIL-NKI/CCIT and 3.33 LYs and 2.46 QALYs for ipilimumab. Total lifetime undiscounted costs in the Netherlands were €347,168 for TIL-NKI/CCIT (including €67,547 for production costs) compared with €433,634 for ipilimumab. Undiscounted lifetime cost in the Danish scenario were €337,309 and €436,135, respectively. This resulted in a dominant situation for TIL-NKI/CCIT compared with ipilimumab in both countries, meaning incremental QALYs were gained at lower costs. Survival probabilities, and utility in progressive disease affected the ICER most.

CONCLUSION

Based on the data of a randomized phase 3 trial, treatment with TIL-NKI/CCIT in patients with unresectable stage IIIC-IV melanoma is cost-effective and cost-saving, both in the current Dutch and Danish setting. These findings led to inclusion of TIL-NKI/CCIT as insured care and treatment guidelines. Publicly funded development of the TIL-NKI/CCIT cell therapy shows realistic promise to further explore development of effective personalized treatment while warranting economic sustainability of healthcare systems.

Adoptive T cell therapy for solid tumors: current landscape and future challenges

Adoptive cell therapy (ACT) comprises different strategies to enhance the activity of T lymphocytes and other effector cells that orchestrate the antitumor immune response, including chimeric antigen receptor (CAR) T-cell therapy, T-cell receptor (TCR) gene-modified T cells, and therapy with tumor-infiltrating lymphocytes (TILs). The outstanding results of CAR-T cells in some hematologic malignancies have launched the investigation of ACT in patients with refractory solid malignancies. However, certain characteristics of solid tumors, such as their antigenic heterogeneity and immunosuppressive microenvironment, hamper the efficacy of antigen-targeted treatments. Other ACT modalities, such as TIL therapy, have emerged as promising new strategies. TIL therapy has shown safety and promising activity in certain immunogenic cancers, mainly advanced melanoma, with an exciting rationale for its combination with immune checkpoint inhibitors. However, the implementation of TIL therapy in clinical practice is hindered by several biological, logistic, and economic challenges. In this review, we aim to summarize the current knowledge, available clinical results, and potential areas of future research regarding the use of T cell therapy in patients with solid tumors.

Biomarkers for response to TIL therapy: a comprehensive review

Adoptive cell therapy with tumor-infiltrating lymphocytes (TIL) has demonstrated durable clinical responses in patients with metastatic melanoma, substantiated by recent positive results of the first phase III trial on TIL therapy. Being a demanding and logistically complex treatment, extensive preclinical and clinical effort is required to optimize patient selection by identifying predictive biomarkers of response. This review aims to comprehensively summarize the current evidence regarding the potential impact of tumor-related factors (such as mutational burden, neoantigen load, immune infiltration, status of oncogenic driver genes, and epigenetic modifications), patient characteristics (including disease burden and location, baseline cytokines and lactate dehydrogenase serum levels, human leucocyte antigen haplotype, or prior exposure to immune checkpoint inhibitors and other anticancer therapies), phenotypic features of the transferred T cells (mainly the total cell count, CD8:CD4 ratio, ex vivo culture time, expression of exhaustion markers, costimulatory signals, antitumor reactivity, and scope of target tumor-associated antigens), and other treatment-related factors (such as lymphodepleting chemotherapy and postinfusion administration of interleukin-2).

Exercise sensitizes PD-1/PD-L1 immunotherapy as a hypoxia modulator in the tumor microenvironment of melanoma

Introduction

Hypoxia is associated with unfavorable prognoses in melanoma patients, and the limited response rates of patients to PD-1/PD-L1 blockade could be attributed to the immunosuppressive tumor microenvironment induced by hypoxia. Exercise offers numerous benefits in the anti-tumor process and has the potential to alleviate hypoxia; however, the precise mechanisms through which it exerts its anti-tumor effects remain unclear, and the presence of synergistic effects with PD-1/PD-L1 immunotherapy is yet to be definitively established.

Methods

We established a B16F10 homograft malignant melanoma model and implemented two distinct exercise treatments (low/moderate-intensity swim) based on the mice's exercise status. The specific function manner of exercise-induced anti-tumor effects was determined through RNA sequencing and analysis of changes in the tumor microenvironment. Furthermore, moderate-intensity swim that exhibited superior tumor suppression effects was combined with Anti-PD-1 treatment to evaluate its in vivo efficacy in mouse models.

Results

Exercise intervention yielded a considerable effect in impeding tumor growth and promoting apoptosis. Immunohistochemistry and RNA sequencing revealed improvements in tumor hypoxia and down-regulation of hypoxia-related pathways. Cellular immunofluorescence and ELISA analyses demonstrated a notable increase of cytotoxic T cell amount and a decrease of regulatory T cells, indicating an improvement of tumor immune microenvironment. In comparison to Anti-PD-1 monotherapy, tumor suppressive efficacy of exercise combination therapy was found to be enhanced with improvements in both the hypoxic tumor microenvironment and T cell infiltration.

Conclusion

Exercise has the potential to function as a hypoxia modulator improving the tumor immune microenvironment, resulting in the promotion of anti-tumor efficacy and the facilitation of biologically safe sensitization of PD-1/PD-L1 immunotherapy.

TIL Therapy: Facts and Hopes

After a positive phase III trial, it is evident that treatment with tumor-infiltrating lymphocytes (TIL) is a safe, feasible, and effective treatment modality for patients with metastatic melanoma. Further, the treatment is safe and feasible in diverse solid tumors, regardless of the histologic type. Still, TIL treatment has not obtained the regulatory approvals to be implemented on a larger scale. Therefore, its availability is currently restricted to a few centers worldwide. In this review, we present the current knowledge of TIL therapy and discuss the practical, logistic, and economic challenges associated with implementing TIL therapy on a larger scale. Finally, we suggest strategies to facilitate the widespread implementation of TIL therapy and approaches to develop the next generation of TILs.

"One more chance to survive": the experiences of patients with advanced melanoma and their partners with tumor-infiltrating lymphocyte therapy-a qualitative study and recommendations for future care

PURPOSE

Patients with advanced melanoma refractory to first-line treatment have a need for effective second-line treatment options. A recent phase 3 trial showed promising results for adoptive cell therapy with tumor-infiltrating lymphocytes (TILs) as second-line therapy in patients with advanced melanoma. However, it remains unknown how patients and their partners experience TIL therapy, which is key to evaluate and improve the quality of care.

METHODS

Semi-structured interviews about the experience of TIL therapy were conducted with patients with advanced melanoma and their partners 2-4 weeks post-treatment (short term) and >6 months after treatment (long term).

RESULTS

In total, 25 interviews were conducted with advanced melanoma patients treated with TIL (n=13) and their partners (n=12), with the majority being short-term interviews (n=17). Overall, patients and partners experienced TIL therapy as intense (uncertainty of successful TIL culture, multiple treatment-related toxicities, and extensive hospitalization). Patients and partners with young children or other caregiving responsibilities encountered the most challenges during TIL therapy. All patients, however, reported a recovery of all treatment-related toxicities within 2-4 weeks (except fatigue).

CONCLUSION

Clinical data justify the role of TIL therapy in the treatment of advanced melanoma. With the distinct nature of TIL therapy compared to the current standard of care, we have provided patient-centered recommendations that will further enhance the quality of TIL therapy.

IMPLICATIONS FOR CANCER SURVIVORS

As more patients with advanced melanoma are expected to receive TIL therapy in the future, our findings could be incorporated into survivorship care plans for this novel group of advanced melanoma survivors treated with TIL.

IL-7R licenses a population of epigenetically poised memory CD8+ T cells with superior antitumor efficacy that are critical for melanoma memory

Recurrence of advanced melanoma after therapy is a major risk factor for reduced survival, and treatment options are limited. Antitumor immune memory plays a critical role in preventing melanoma recurrence and memory T cells could be a potent cell-based therapy, but the identity, and functional properties of the required immune cells are incompletely understood. Here, we show that an IL-7Rhi tumor-specific CD8+ population is critical for antitumor memory and can be epigenetically augmented to drive powerful antitumor immune responses. Using a model of functional antimelanoma memory, we found that high IL-7R expression selectively marks a CD8+ population in lymphoid organs that plays critical roles in maintaining tumor remission after immunotherapy or surgical resection. This population has intrinsic cytotoxic activity, lacks markers of exhaustion and has superior antitumor efficacy. IL-7Rhi cells have a functionally poised epigenetic landscape regulated by DNA methylation, which can be augmented by hypomethylating agents to confer improved survival and complete melanoma clearance in naive mice. Importantly, greater than 95% of tumor-specific T cells in draining lymph nodes after therapy express high levels of IL-7R. This overlap between IL-7Rhi and antigen-specific T cells allows for enrichment of a potent functional CD8+ population without determining antigen-specificity, which we demonstrate in a melanoma model without a known antigen. We identify that IL-7R expression in human melanoma is an independent prognostic factor of improved survival. These findings advance our basic understanding of antitumor memory and suggest a cell-based therapy using high IL-7R expression to enrich for a lymph node population with superior antitumor activity that can be augmented by hypomethylating agents.

MYC Induces Immunotherapy and IFNγ Resistance Through Downregulation of JAK2

Immunotherapy has revolutionized the treatment of advanced melanoma. Because the pathways mediating resistance to immunotherapy are largely unknown, we conducted transcriptome profiling of preimmunotherapy tumor biopsies from patients with melanoma that received PD-1 blockade or adoptive cell therapy with tumor-infiltrating lymphocytes. We identified two melanoma-intrinsic, mutually exclusive gene programs, which were controlled by IFNγ and MYC, and the association with immunotherapy outcome. MYC-overexpressing melanoma cells exhibited lower IFNγ responsiveness, which was linked with JAK2 downregulation. Luciferase activity assays, under the control of JAK2 promoter, demonstrated reduced activity in MYC-overexpressing cells, which was partly reversible upon mutagenesis of a MYC E-box binding site in the JAK2 promoter. Moreover, silencing of MYC or its cofactor MAX with siRNA increased JAK2 expression and IFNγ responsiveness of melanomas, while concomitantly enhancing the effector functions of T cells coincubated with MYC-overexpressing cells. Thus, we propose that MYC plays a pivotal role in immunotherapy resistance through downregulation of JAK2.

Advances in adoptive T-cell therapy for metastatic melanoma

Adoptive T cell therapy (ACT) is a fast developing, niche area of immunotherapy (IO), which is revolutionising the therapeutic landscape of solid tumour oncology, especially metastatic melanoma (MM). Identifying tumour antigens (TAs) as potential targets, the ACT response is mediated by either Tumour Infiltrating Lymphocytes (TILs) or genetically modified T cells with specific receptors - T cell receptors (TCRs) or chimeric antigen receptors (CARs) or more prospectively, natural killer (NK) cells. Clinical trials involving ACT in MM from 2006 to present have shown promising results. Yet it is not without its drawbacks which include significant auto-immune toxicity and need for pre-conditioning lymphodepletion. Although immune-modulation is underway using various combination therapies in the hope of enhancing efficacy and reducing toxicity. Our review article explores the role of ACT in MM, including the various modalities - their safety, efficacy, risks and their development in the trial and the real world setting.

CAR T-Cell Therapy for Cancer: Latest Updates and Challenges, with a Focus on B-Lymphoid Malignancies and Selected Solid Tumours

Although exponential progress in treating advanced malignancy has been made in the modern era with immune checkpoint blockade, survival outcomes remain suboptimal. Cellular immunotherapy, such as chimeric antigen receptor T cells, has the potential to improve this. CAR T cells combine the antigen specificity of a monoclonal antibody with the cytotoxic 'power' of T-lymphocytes through expression of a transgene encoding the scFv domain, CD3 activation molecule, and co-stimulatory domains. Although, very rarely, fatal cytokine-release syndrome may occur, CAR T-cell therapy gives patients with refractory CD19-positive B-lymphoid malignancies an important further therapeutic option. However, low-level expression of epithelial tumour-associated-antigens on non-malignant cells makes the application of CAR T-cell technology to common solid cancers challenging, as does the potentially limited ability of CAR T cells to traffic outside the blood/lymphoid microenvironment into metastatic lesions. Despite this, in advanced neuroblastoma refractory to standard therapy, 60% long-term overall survival and an objective response in 63% was achieved with anti GD2-specific CAR T cells.

Safety and Clinical Response to Combined Immunotherapy with Autologous iNKT Cells and PD-1+CD8+ T Cells in Patients Failing First-line Chemotherapy in Stage IV Pancreatic Cancer

Purpose

A phase I clinical trial was conducted to assess the safety and feasibility of invariant natural killer T (iNKT) cells combined with PD-1⁺CD8⁺ T cells in patients with advanced pancreatic cancer and failing the first-line chemotherapy.

Patients and Methods

Fifteen eligible patients were enrolled, of whom 9 received at least three cycles of treatment each. In total, 59 courses were administered.

Results

Fever was the most common adverse event, peaking at about 2-4 hours after cell infusion and reverting within 24 hours without treatment in all patients. Influenza-like reactions such as headache, myalgia, and arthralgia were also observed in 4, 4, and 3 of the patients, respectively. In addition, vomiting and dizziness were prevalent, while abdominal pain, chest pain, rash, and stuffy nose were rare adverse events, each reported in 1 patient. Side effects above grade 2 were not observed. Two patients achieved partial regression, while 1 patient experienced disease progression assessed 4 weeks after the third course. Three patients are still alive at the time of writing and have progression-free survival longer than 12 months. The overall survival time has been extended to over 12 months in 6 of the 9 patients. No constant changes of CD4⁺ T, B, and NK cells were recorded except for elevated CD8⁺ T cells after the first course.

Conclusions

The combination of autologous iNKT cells and PD-1⁺CD8⁺ T cells was a safe therapeutic strategy against advanced pancreatic cancer. The patients exhibited a potentially promising prolonged survival time. Further study appears warranted to evaluate the efficacy of these combined cell infusions in pancreatic cancer.

Trial registration

This trial was included in the clinical trial which was registered in ClinicalTrials.gov (ID:NCT03093688) on March 15, 2017.

Significance

There is an unmet need for novel, more effective, and tolerable therapies for pancreatic cancer. Here we present a phase I clinical trial employing iNKT cells combined with PD-1⁺CD8⁺ T cells in 9 patients with advanced pancreatic cancer and failing the first-line chemotherapy. The combined immunotherapy was shown to be feasible in the enrolled patients with limited side effects and optimistic clinical responses, which could bring opportunity of therapeutic advancement.

Immunoscore Signatures in Surgical Specimens and Tumor-Infiltrating Lymphocytes in Pretreatment Biopsy Predict Treatment Efficacy and Survival in Esophageal Cancer

OBJECTIVES

Tumor-infiltrating lymphocytes (TILs) have long been recognized as playing an important role in tumor immune microenvironment. Lately, the Immunoscore (IS) has been proposed as a new method of quantifying the number of TILs in association with patient survival in several cancer types.

METHODS

In 300 preoperatively untreated esophageal cancer (EC) patients who underwent curative resection at two different institutes, immunohistochemical staining using CD3 and CD8 antibodies was performed to evaluate IS, as objectively scored by auto-counted TILs in the tumor core and invasive margin. In addition, in pre-neoadjuvant chemotherapy (pre-NAC) endoscopic biopsies of a different cohort of 146 EC patients who received NAC, CD3, and CD8 were immunostained to evaluate TIL density.

RESULTS

In all cases, the IS-high (score 3-4) group tended to have better survival [5-year overall survival (OS) of the IS-high vs low group: 77.6 vs 65.8%, P = 0.0722] than the IS-low (score 1-2) group. This trend was more remarkable in cStage II-IV patients (70.2 vs 54.5%, P = 0.0208) and multivariate analysis of OS further identified IS (hazard ratio 2.07, P = 0.0043) to be an independent prognostic variable. In preNAC biopsies, NAC-responders had higher densities than non-responders of both CD3 + ( P = 0.0106) and CD8 + cells ( P = 0.0729) and, particularly CD3 + cell density was found to be an independent prognostic factor (hazard ratio 1.75, P = 0.0169).

CONCLUSIONS

The IS signature in surgical specimens and TIL density in preNAC- biopsies could be predictive markers of clinical outcomes in EC patients.

Immunotherapy in Melanoma: Recent Advances and Future Directions

The use of immunotherapy in the treatment of advanced and high-risk melanoma has led to a striking improvement in outcomes. Although the incidence of melanoma has continued to rise, median survival has improved from approximately 6 months to nearly 6 years for patients with advanced inoperable stage IV disease. Recent understanding of the tumor microenvironment and its interplay with the immune system has led to the explosive development of novel immunotherapy treatments. Since the approval of the therapeutic cytokines interleukin-2 and interferon alfa-2 in the 1990s, the development of novel immune checkpoint inhibitors (ICIs), oncolytic virus therapy, and modulators of the tumor microenvironment have given way to a new era in melanoma treatment. Monoclonal antibodies directed at programmed cell death protein 1 receptor (PD-1) and its ligand (PDL-1), cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), and lymphocyte-activation gene 3 (LAG-3) have provided robust activation of the adaptive immune system, restoring immune surveillance leading to host tumor recognition and destruction. Multiple other immunomodulatory therapeutics are under investigation to overcome resistance to ICI therapy, including the toll-like receptor-9 (TLR-9) and 7/8 (TLR-7/8) agonists, stimulator of interferon genes (STING) agonists, and fecal microbiota transplantation. In this review, we focus on the recent advances in immunotherapy for the treatment of melanoma and provide an update on novel therapies currently under investigation.

Modulating the proliferative and cytotoxic properties of patient-derived TIL by a synthetic immune niche of immobilized CCL21 and ICAM1

A major challenge in developing an effective adoptive cancer immunotherapy is the ex-vivo generation of tumor-reactive cells in sufficient numbers and with enhanced cytotoxic potential. It was recently demonstrated that culturing of activated murine CD8+ T-cells on a "Synthetic Immune Niche" (SIN), consisting of immobilized CCL21 and ICAM-1, enhances T-cell expansion, increases their cytotoxicity against cultured cancer cells and suppresses tumor growth in vivo. In the study reported here, we have tested the effect of the CCL21+ICAM1 SIN, on the expansion and cytotoxic phenotype of Tumor Infiltrating Lymphocytes (TIL) from melanoma patients, following activation with immobilized anti-CD3/CD28 stimulation, or commercial activation beads. The majority of TIL tested, displayed higher expansion when cultured on the coated SIN compared to cells incubated on uncoated substrate and a lower frequency of TIM-3+CD8+ cells after stimulation with anti-CD3/CD28 beads. Comparable enhancement of TIL proliferation was obtained by the CCL21+ICAM1 SIN, in a clinical setting that included a 14-day rapid expansion procedure (REP). Co-incubation of post-REP TIL with matching target cancerous cells demonstrated increased IFNγ secretion beyond baseline in most of the TIL cultures, as well as a significant increase in granzyme B levels following activation on SIN. The SIN did not significantly alter the relative frequency of CD8/CD4 populations, as well as the expression of CD28, CD25, several exhaustion markers and the differentiation status of the expanded cells. These results demonstrate the potential capacity of the CCL21+ICAM1 SIN to reinforce TIL-based immunotherapy for cancer patients.

Tissue-resident memory T cells in gastrointestinal tumors: turning immune desert into immune oasis

Tissue-resident memory T cells (Trm) are a particular type of T cell subgroup, which stably reside in tissues and have been revealed to be the most abundant memory T cell population in various tissues. They can be activated in the local microenvironment by infection or tumor cells and rapidly clean them up to restore homeostasis of local immunity in gastrointestinal tissues. Emerging evidence has shown that tissue-resident memory T cells have great potential to be mucosal guardians against gastrointestinal tumors. Therefore, they are considered potential immune markers for immunotherapy of gastrointestinal tumors and potential extraction objects for cell therapy with essential prospects in clinical translational therapy. This paper systematically reviews the role of tissue-resident memory T cells in gastrointestinal tumors and looks to the future of their prospect in immunotherapy to provide a reference for clinical application.

Tumor-Infiltrating Lymphocyte Therapy or Ipilimumab in Advanced Melanoma

BACKGROUND

Immune checkpoint inhibitors and targeted therapies have dramatically improved outcomes in patients with advanced melanoma, but approximately half these patients will not have a durable benefit. Phase 1-2 trials of adoptive cell therapy with tumor-infiltrating lymphocytes (TILs) have shown promising responses, but data from phase 3 trials are lacking to determine the role of TILs in treating advanced melanoma.

METHODS

In this phase 3, multicenter, open-label trial, we randomly assigned patients with unresectable stage IIIC or IV melanoma in a 1:1 ratio to receive TIL or anti-cytotoxic T-lymphocyte antigen 4 therapy (ipilimumab at 3 mg per kilogram of body weight). Infusion of at least 5×10⁹ TILs was preceded by nonmyeloablative, lymphodepleting chemotherapy (cyclophosphamide plus fludarabine) and followed by high-dose interleukin-2. The primary end point was progression-free survival.

RESULTS

A total of 168 patients (86% with disease refractory to anti-programmed death 1 treatment) were assigned to receive TILs (84 patients) or ipilimumab (84 patients). In the intention-to-treat population, median progression-free survival was 7.2 months (95% confidence interval [CI], 4.2 to 13.1) in the TIL group and 3.1 months (95% CI, 3.0 to 4.3) in the ipilimumab group (hazard ratio for progression or death, 0.50; 95% CI, 0.35 to 0.72; P<0.001); 49% (95% CI, 38 to 60) and 21% (95% CI, 13 to 32) of the patients, respectively, had an objective response. Median overall survival was 25.8 months (95% CI, 18.2 to not reached) in the TIL group and 18.9 months (95% CI, 13.8 to 32.6) in the ipilimumab group. Treatment-related adverse events of grade 3 or higher occurred in all patients who received TILs and in 57% of those who received ipilimumab; in the TIL group, these events were mainly chemotherapy-related myelosuppression.

CONCLUSIONS

In patients with advanced melanoma, progression-free survival was significantly longer among those who received TIL therapy than among those who received ipilimumab. (Funded by the Dutch Cancer Society and others; ClinicalTrials.gov number, NCT02278887.).

Immunotherapy Options for Acral Melanoma, A fast-growing but Neglected Malignancy

Melanoma is the deadliest form of skin cancer. It is classified as cutaneous and non-cutaneous, with the former characterized by developing in sun-exposed areas of the skin, UV-light radiation being its most important risk factor and ordinarily affecting fair skin populations. In recent years, the incidence of melanoma has been increasing in populations with darker complexion, for example, Hispanics, in which acral melanoma is highly prevalent. The WHO estimates that the incidence and mortality of melanoma will increase by more than 60% by 2040, particularly in low/medium income countries. Acral melanoma appears in the palms, soles and nails, and because of these occult locations, it is often considered different from other cutaneous melanomas even though it also originates in the skin. Acral melanoma is very rare in Caucasian populations and is often not included from genetic analysis and clinical trials. In this review, we present the worldwide epidemiology of acral melanoma; we summarize its genetic characterization and point out important signaling pathways for targeted therapy. We also discuss how genetic analyses have shown that acral melanoma carries a sufficient mutational load and neoantigen formation to be targeted by the immune system, arguing for a potential benefit with novel immunotherapeutic strategies, alone or combined with targeted therapy. This is important because chemotherapy remains the first-line treatment in non-developed nations despite a disheartening response. In summary, the increased incidence and mortality of acral melanoma in low/medium income countries calls for increasing our knowledge about its nature and therapeutic options and leveling off the asymmetric research conducted primarily on Caucasian populations.

Novel IKZF3 transcriptomic signature correlates with positive outcomes of skin cutaneous melanoma: A pan-cancer analysis

To investigate the potential relationship between Ikaros family genes and skin cutaneous melanoma (SKCM), we undertook a pan-cancer analysis of the transcriptional signature and clinical data of melanoma through multiple databases. First, 10,327 transcriptomic samples from different cancers were included to determine the overall characteristics and clinical prognoses associated with Ikaros gene expression across cancer types. Second, differentially expressed genes analysis, prognostic evaluation, and gene set enrichment analysis were employed to investigate the role of Ikaros (IKZF) genes in SKCM. Third, we evaluated the relationship between Ikaros family genes and SKCM immune infiltrates and verified the findings using the GEO single-cell sequencing dataset. The results show that Ikaros genes were widely expressed among different cancer types with independently similar patterns as follows: 1. IKZF1 and IKZF3, and 2. IKZF2 and IKZF4–5. IKZF2 and IKZF5 were downregulated in the primary tumor, and IKZF1–3 expression decreased significantly as the T-stage or metastasis increased in SKCM. Moreover, high IKZF1–3 expression was associated with better overall survival, disease-specific survival, and progression-free interval. IKZF3 is an independent prognostic factor of SKCM. Among Ikaros genes, the expression of IKZF1 and IKZF3 positively correlated with the infiltration level of CD4⁺ T cells and CD8⁺ T cells, B cells, and Tregs in SKCM and negatively correlated with the infiltration level of M0 and M1 macrophages. Moreover, single-cell sequencing data analysis revealed that IKZF1 and IKZF3 were mainly expressed by immune cells. Correlation analysis shows the immune factors and drug responses associated with IKZF3 expression. In conclusion, the present study is the first, to our knowledge, to identify a pan-cancer genomic signature of the Ikaros gene family among different cancers. Expression of these family members, particularly high levels of IKZF3, indicate positive immunological status and beneficial clinical outcomes of SKCM. IKZF3 may therefore serve as potential targets for immunotherapy of melanoma.

The Next Generation of Cellular Immunotherapy: Chimeric Antigen Receptor-Natural Killer Cells

The advent of chimeric antigen receptor (CAR) engineering has led to the development of powerful cellular therapies for cancer. CAR T cell-based treatments have had notable clinical success, but logistical issues and associated toxicities are recognized limitations. There is emerging interest in using other immune effector cell types for CAR therapy. Natural killer (NK) cells are part of the innate immune system, and these lymphocytes play major roles in immunosurveillance and antitumor immune responses. Incorporating CARs into NK cells provides the opportunity to harness and enhance their innate cytotoxic potential toward malignancies. In this review, we discuss the production of CAR-engineered NK cells, highlight data on their preclinical and clinical efficacy, and examine the obstacles and strategies to overcome them.

Novel cellular therapies for hepatobiliary malignancies

BACKGROUND

The mortalities of hepatobiliary malignancies are high. With the failure of conventional chemotherapy and unsatisfactory outcome of molecular targeted drugs, immune-based therapy has become a new focus of research in hepatobiliary cancers treatment.

DATA SOURCES

We performed a PubMed search with relevant articles published up to May 2022 and the following keywords: cellular immunotherapy, hepatobiliary cancer, antigen receptor T cell therapy, and receptor-engineered T cell. Information of clinical trials was obtained from https://clinicaltrials.gov/.

RESULTS

Cell therapies for hepatobiliary malignancies are at early stage of development. The current review showed that cellular therapies are safe and feasible in patients. These findings provide an important platform for future lager scale clinical trials on immunotherapy in patients with hepatobiliary malignancies.

CONCLUSIONS

With the continuous advances of cellular immunotherapy, the combination of cellular immunotherapy with surgery, chemotherapy and radiotherapy will be new therapeutic strategies for patients with hepatobiliary cancer.

Membrane anchored IL-18 linked to constitutively active TLR4 and CD40 improves human T cell antitumor capacities for adoptive cell therapy

Background

Adoptive transfer of tumor-infiltrating lymphocytes (TILs) or blood T cells genetically redirected by an antitumor TCR or CAR induces a strong antitumor response in a proportion of patients with cancer; however, the therapeutic efficacy is often limited by rapid decline in T cell functions. Coadministering supportive cytokines frequently provokes systemic side effects preventing their broad clinical application. We recently showed that cytokines can be anchored to the cell membrane in a functional fashion and that cytokine receptor signaling can synergize with TLR4 and CD40 signaling. Here, we aimed at augmenting T cell activation by simultaneous signaling through the cytokine receptor, toll-like receptor and TNF-type receptor using IL-18, TLR4 and CD40 as prototypes.

Methods

Genes were expressed on electroporation of in vitro-transcribed mRNA in CD4+ and CD8+ T cells from healthy donors redirected against melanoma cells with an anti-melanotransferrin CAR and in TILs derived from melanoma patients. Functional assays included the activation of signaling pathways, expression of activation and differentiation markers, cytokine secretion and killing of melanoma target cells.

Results

To provide IL-18 costimulation to T cells in-cis while avoiding systemic effects, we genetically anchored IL-18 to the T cell membrane, either alone (memIL-18) or fused with constitutively active (ca)TLR4 and caCD40 signaling domains arranged in tandem, creating a synthetic ‘all-in-one’ memIL-18-TLR4-CD40 receptor. MemIL-18-TLR4-CD40, but not memIL-18, triggered strong NF-κB activation in cells lacking the IL-18 receptor, attesting to functionality of the TLR-CD40 moiety. While the membrane-anchored cytokine was found to act mainly in-cis, some T cell activation in-trans was also observed. The electroporated T cells exhibited spontaneous T-bet upregulation and IFN-γ and TNF-α secretion. Melanoma-induced activation of CAR-T cells and TILs as manifested by cytokine secretion and cytolytic activity was substantially augmented by both constructs, with memIL-18-TLR4-CD40 exerting stronger effects than memIL-18 alone.

Conclusions

Linking membrane anchored IL-18 with caTLR4 and caCD40 signaling in one hybrid transmembrane protein provides simultaneous activation of three T cell costimulatory pathways through one genetically engineered membrane molecule, strongly amplifying T cell functions for adoptive T cell therapy of cancer.

Tumor Infiltrating Lymphocyte (TIL) Therapy for Solid Tumor Treatment: Progressions and Challenges

Over the past decade, immunotherapy, especially cell-based immunotherapy, has provided new strategies for cancer therapy. Recent clinical studies demonstrated that adopting cell transfer of tumor-infiltrating lymphocytes (TILs) for advanced solid tumors showed good efficacy. TIL therapy is a type of cell-based immunotherapy using the patient’s own immune cells from the microenvironment of the solid tumor to kill tumor cells. In this review, we provide a comprehensive summary of the current strategies and challenges in TIL isolation and generation. Moreover, the current clinical experience of TIL therapy is summarized and discussed, with an emphasis on lymphodepletion regimen, the use of interleukin-2, and related toxicity. Furthermore, we highlight the clinical trials where TIL therapy is used independently and in combination with other types of therapy for solid cancers. Finally, the limitations, future potential, and directions of TIL therapy for solid tumor treatment are also discussed.

Adenosine-deaminase-acting-on-RNA-1 facilitates T-cell migration toward human melanoma cells

The effect of tumor/T-cell interactions on subsequent immune infiltration is undefined. Here we report that pre-exposure of melanoma cells to cognate T cells enhanced the chemotaxis of new T cells in vitro. The effect was HLA class I-restricted and IFNγ-dependent, as it was abolished by β2M-knockdown, MHC-blocking antibodies, JAK1 inhibitors, JAK1-silencing and IFNgR1-blocking antibodies. RNA-sequencing of 73 melanoma metastases showed a significant correlation between the interferon-inducible p150 isoform of adenosine-deaminase-acting-on-RNA-1 (ADAR1) enzyme and immune infiltration. Consistent with this, co-cultures of cognate melanoma/T-cell pairs led to IFNγ-dependent induction of ADAR1-p150 in the melanoma cells, as visualized in situ using dynamic cell blocks, in ovo using fertilized chick eggs, and in vitro with Western blots. ADAR1 staining and RNA-sequencing in patient-derived biopsies following immunotherapy showed a rise in ADAR1-p150 expression concurrently with CD8+ cell infiltration and clinical response. Silencing ADAR1-p150 abolished the IFNγ-driven enhanced T-cell migration, confirming its mechanistic role. Silencing and overexpression of the constitutive isoform of ADAR1, ADAR1-p110, decreased and increased T-cell migration, respectively. Chemokine arrays showed that ADAR1 controls the secretion of multiple chemokines from melanoma cells, probably through microRNA-mediated regulation. Chemokine receptor blockade eliminated the IFNγ-driven T-cell chemotaxis. We propose that the constitutive ADAR1 downregulation observed in melanoma contributes to immune exclusion, whereas antigen-specific T cells induce ADAR1-p150 by releasing IFNγ, which can drive T-cell infiltration.

Phase I study of adjuvant immunotherapy with autologous tumor-infiltrating lymphocytes in locally advanced cervical cancer

BACKGROUND

Adoptive cell therapy (ACT) with tumor-infiltrating lymphocytes (TILs) has achieved remarkable clinical efficacy in metastatic cancers such as melanoma and cervical cancer (CC). Here we explored the safety, feasibility and preliminary tumor response and performed translational investigations of adjuvant immunotherapy using infusion of autogenous (auto)-TILs following concurrent chemoradiotherapy (CCRT) in CC patients with locally advanced disease.

METHODS

Twenty-seven CC patients with stage III to IV disease were recruited in this single-center, phase I study. TILs were isolated from lesions in the uterine cervix and generated under good manufacturing practices (GMP) conditions and then infused after CCRT plus intramuscular interleukin (IL)-2 injections.

RESTULTS

From 27 patients, TILs were successfully expanded from 20 patients, with a feasibility of 74.1%. Twelve patients received TILs following CCRT. Adverse events (AEs) were primarily attributable to CCRT. Only 1 (8.3%) patient experienced severe toxicity with a grade 3 hypersensitivity reaction after TIL infusion. No autoimmune AEs, such as pneumonitis, hepatitis, or myocarditis, occurred, and there was no treatment-related mortality. Nine of 12 patients (75.0%) attained complete response, with a disease control duration of 9 to 22 months. Translational investigation showed that the transcriptomic characteristics of the infused TIL products and some immune biomarkers in the tumor microenvironment and serum of CC patients at baseline were correlated with the clinical response.

CONCULSION

TIL-based ACT following CCRT was safe in an academic center setting, with potential effective responses in locally advanced CC patients. 'Hot' inflammatory immune environments are beneficial to the clinical efficacy of TIL-based ACT as adjuvant therapy.

TRIAL REGISTRATION

CLINICALTRIALS

gov NCT04443296.

FUNDING

Natinoal Key R&D Program: Sci-Tech Key Program of the Guangzhou City Science Foundation; the Guangdong Provinve Sci-Tech International Key Program; the National Natural Science Foundation of China.

Integrated analysis reveals the pivotal interactions between immune cells in the melanoma tumor microenvironment

Melanoma is the most lethal type of skin cancer. Despite the breakthroughs in the clinical treatment of melanoma using tumor immunotherapy, many patients do not benefit from these immunotherapies because of multiple immunosuppressive mechanisms. Therefore, there is an urgent need to determine the mechanisms of tumor-immune system interactions and their molecular determinants to improve cancer immunotherapy. In this study, combined analysis of microarray data and single-cell RNA sequencing data revealed the key interactions between immune cells in the melanoma microenvironment. First, differentially expressed genes (DEGs) between normal and malignant tissues were obtained using GEO2R. The DEGs were then subjected to downstream analyses, including enrichment analysis and protein–protein interaction analysis, indicating that these genes were associated with the immune response of melanoma. Then, the GEPIA and TIMER databases were used to verify the differential expression and prognostic significance of hub genes, and the relationship between the hub genes and immune infiltration. In addition, we combined single cell analysis from GSE123139 to identify immune cell types, and validated the expression of the hub genes in these immune cells. Finally, cell-to-cell communication analysis of the proteins encoded by the hub genes and their interactions was performed using CellChat. We found that the CCL5-CCR1, SELPLG-SELL, CXCL10-CXCR3, and CXCL9-CXCR3 pathways might play important roles in the communication between the immune cells in tumor microenvironment. This discovery may reveal the communication basis of immune cells in the tumor microenvironment and provide a new idea for melanoma immunotherapy.

A Toolkit for Profiling the Immune Landscape of Pediatric Central Nervous System Malignancies

The prognosis of pediatric central nervous system (CNS) malignancies remains dismal due to limited treatment options, resulting in high mortality rates and long-term morbidities. Immunotherapies, including checkpoint inhibition, cancer vaccines, engineered T cell therapies, and oncolytic viruses, have promising results in some hematological and solid malignancies, and are being investigated in clinical trials for various high-grade CNS malignancies. However, the role of the tumor immune microenvironment (TIME) in CNS malignancies is mostly unknown for pediatric cases. In order to successfully implement immunotherapies and to eventually predict which patients would benefit from such treatments, in-depth characterization of the TIME at diagnosis and throughout treatment is essential. In this review, we provide an overview of techniques for immune profiling of CNS malignancies, and detail how they can be utilized for different tissue types and studies. These techniques include immunohistochemistry and flow cytometry for quantifying and phenotyping the infiltrating immune cells, bulk and single-cell transcriptomics for describing the implicated immunological pathways, as well as functional assays. Finally, we aim to describe the potential benefits of evaluating other compartments of the immune system implicated by cancer therapies, such as cerebrospinal fluid and blood, and how such liquid biopsies are informative when designing immune monitoring studies. Understanding and uniformly evaluating the TIME and immune landscape of pediatric CNS malignancies will be essential to eventually integrate immunotherapy into clinical practice.

Eradicating tumor in a recurrent cervical cancer patient with autologous tumor-infiltrating lymphocytes and a modified lymphodepleting regimen

Tumor-infiltrating lymphocyte (TIL) therapy has shown promising results against several cancers. However, traditional lymphodepleting regimens are severe and represent a major limitation for a more widespread use of TIL. The modified pretreatment strategies may alleviate side effects and demonstrate the persistence of tumor-reactive T cells in the blood. Here, we report a case who was diagnosed recurrent cervical cancer with bladder metastasis. Omitting high dose of IL-2, she received intravenous dose of cyclophosphamide (20 mg/kg) for 3 days, approximately 48 hours before receiving the intravenous infusion of TILs. Half dosage (100 mg) of PD1 antibody was administered with purpose of neutralizing PD1 expressed on T cells surface. She achieved complete response 10 weeks after one-time TILs infusion. Adverse reactions were negligible and safely manageable in a general ward without the need for intervention from intensive care units. Time-course peripheral blood counts and TCR repertoire sequencing demonstrated a robust expansion and long-term persistence of the infused TILs. These results illustrated the potential value of modified lymphodepletion, followed by TILs for the treatment of patients with cervical cancer with local recurrence. Trial registration number, NCT04766320.

Combined IL-2, agonistic CD3 and 4-1BB stimulation preserve clonotype hierarchy in propagated non-small cell lung cancer tumor-infiltrating lymphocytes

Background

Adoptive cell transfer (ACT) of tumor-infiltrating lymphocytes (TIL) yielded clinical benefit in patients with checkpoint blockade immunotherapy-refractory non-small cell lung cancer (NSCLC) prompting a renewed interest in TIL-ACT. This preclinical study explores the feasibility of producing a NSCLC TIL product with sufficient numbers and enhanced attributes using an improved culture method.

Methods

TIL from resected NSCLC tumors were initially cultured using (1) the traditional method using interleukin (IL)-2 alone in 24-well plates (TIL 1.0) or (2) IL-2 in combination with agonistic antibodies against CD3 and 4-1BB (Urelumab) in a G-Rex flask (TIL 3.0). TIL subsequently underwent a rapid expansion protocol (REP) with anti-CD3. Before and after the REP, expanded TIL were phenotyped and the complementarity-determining region 3 β variable region of the T-cell receptor (TCR) was sequenced to assess the T-cell repertoire.

Results

TIL 3.0 robustly expanded NSCLC TIL while enriching for CD8⁺ TIL in a shorter manufacturing time when compared with the traditional TIL 1.0 method, achieving a higher success rate and producing 5.3-fold more TIL per successful expansion. The higher proliferative capacity and CD8 content of TIL 3.0 was also observed after the REP. Both steps of expansion did not terminally differentiate/exhaust the TIL but a lesser differentiated population was observed after the first step. TIL initially expanded with the 3.0 method exhibited higher breadth of clonotypes than TIL 1.0 corresponding to a higher repertoire homology with the original tumor, including a higher proportion of the top 10 most prevalent clones from the tumor. TIL 3.0 also retained a higher proportion of putative tumor-specific TCR when compared with TIL 1.0. Numerical expansion of TIL in a REP was found to perturb the clonal hierarchy and lessen the proportion of putative tumor-specific TIL from the TIL 3.0 process.

Conclusions

We report the feasibility of robustly expanding a T-cell repertoire recapitulating the clonal hierarchy of the T cells in the NSCLC tumor, including a large number of putative tumor-specific TIL clones, using the TIL 3.0 methodology. If scaled up and employed as a sole expansion platform, the robustness and speed of TIL 3.0 may facilitate the testing of TIL-ACT approaches in NSCLC.

Adoptive T-cell Immunotherapy: Perfecting Self-Defenses

As an important part of the immune system, T lymphocytes exhibit undoubtedly an important role in targeting and eradicating cancer. However, despite these characteristics, their natural antitumor response may be insufficient. Numerous clinical trials in terminally ill cancer patients testing the design of novel and efficient immunotherapeutic approaches based on the adoptive transfer of autologous tumor-specific T lymphocytes have shown encouraging results. Moreover, this also led to the approval of engineered T-cell therapies in patients. Herein, we will expand on the development and the use of such strategies using tumor-infiltrating lymphocytes or genetically engineered T-cells. We will also comment on the requirements and potential hurdles encountered when elaborating and implementing such treatments as well as the exciting prospects for this kind of emerging personalized medicine therapy.

Safety evaluation of the mouse TCRα - transduced T cell product in preclinical models in vivo and in vitro

Adoptive cell therapy (ACT) based on TCR- or CAR-T cells has become an efficient immunotherapeutic approach for the treatment of various diseases, including cancer. Previously, we developed a novel strategy for generating therapeutic T cell products based on chain-centric TCRs, in which either α- or β-chain dominates in cognate antigen recognition. To assess the suitability of our experimental approach for the clinical application and predict its possible adverse effects, in studies here, we evaluated the safety of the experimental TCRα-modified T cell product in mouse preclinical models. Our data showed no tumorigenic or mutagenic activity in vitro of TCRα-transduced T cells, indicating no genotoxicity of viral vectors used for the generation of the experimental T cell product. Adoptive transfer of TCRα-engineered T cells in a wide dose range didn`t disturb the host homeostasis and exhibited no acute toxicity or immunotoxicity in vivo. Based on pharmacokinetics and pharmacodynamics analysis here, modified T cells rapidly penetrated and distributed in many viscera after infusion. Histological evaluations revealed no pathological changes in organs caused by T cells accumulation, indicating the absence of non-specific off-target activity or cross-reactivity of the therapeutic TCRα. Studies here provide valuable information on the potential safety of TCRα-T cell based ACT that could be extrapolated to possible effects in a human host.

Adoptive NK Cell Therapy: A Promising Treatment Prospect for Metastatic Melanoma

Simple Summary

The incidence of metastatic melanoma has been increasing over the past years with current therapies showing limited efficacy to cure the disease. Therefore, other options are being investigated, such as adoptive cell therapy (ACT) where activated immune cells are infused into a patient to attack melanoma. Natural killer (NK) cells are part of the innate immune system and extremely suitable for this kind of therapy since they show minimal toxicities in the clinical setting. In this review, we focus on current strategies for NK cell therapy and the development of new approaches that hold great promise for the treatment of advanced melanoma.

Abstract

Adoptive cell therapy (ACT) represents a promising alternative approach for patients with treatment-resistant metastatic melanoma. Lately, tumor infiltrating lymphocyte (TIL) therapy and chimeric antigen receptor (CAR)-T cell therapy have shown improved clinical outcome, compared to conventional chemotherapy or immunotherapy. Nevertheless, they are limited by immune escape of the tumor, cytokine release syndrome, and manufacturing challenges of autologous therapies. Conversely, the clinical use of Natural Killer (NK) cells has demonstrated a favorable clinical safety profile with minimal toxicities, providing an encouraging treatment alternative. Unlike T cells, NK cells are activated, amongst other mechanisms, by the downregulation of HLA class I molecules, thereby overcoming the hurdle of tumor immune escape. However, impairment of NK cell function has been observed in melanoma patients, resulting in deteriorated natural defense. To overcome this limitation, “activated” autologous or allogeneic NK cells have been infused into melanoma patients in early clinical trials, showing encouraging clinical benefit. Furthermore, as several NK cell-based therapeutics are being developed for different cancers, an emerging variety of approaches to increase migration and infiltration of adoptively transferred NK cells towards solid tumors is under preclinical investigation. These developments point to adoptive NK cell therapy as a highly promising treatment for metastatic melanoma in the future.

Tumor infiltrating lymphocytes (TIL) therapy in metastatic melanoma: boosting of neoantigen-specific T cell reactivity and long-term follow-up

Treatment of metastatic melanoma with autologous tumor infiltrating lymphocytes (TILs) is currently applied in several centers. Robust and remarkably consistent overall response rates, of around 50% of treated patients, have been observed across hospitals, including a substantial fraction of durable, complete responses.

PURPOSE

Execute a phase I/II feasibility study with TIL therapy in metastatic melanoma at the Netherlands Cancer Institute, with the goal to assess feasibility and potential value of a randomized phase III trial.

EXPERIMENTAL

Ten patients were treated with TIL therapy. Infusion products and peripheral blood samples were phenotypically characterized and neoantigen reactivity was assessed. Here, we present long-term clinical outcome and translational data on neoantigen reactivity of the T cell products.

RESULTS

Five out of 10 patients, who were all anti-PD-1 naïve at time of treatment, showed an objective clinical response, including two patients with a complete response that are both ongoing for more than 7 years. Immune monitoring demonstrated that neoantigen-specific T cells were detectable in TIL infusion products from three out of three patients analyzed. For six out of the nine neoantigen-specific T cell responses detected in these TIL products, T cell response magnitude increased significantly in the peripheral blood compartment after therapy, and neoantigen-specific T cells were detectable for up to 3 years after TIL infusion.

CONCLUSION

The clinical results from this study confirm the robustness of TIL therapy in metastatic melanoma and the potential role of neoantigen-specific T cell reactivity. In addition, the data from this study supported the rationale to initiate an ongoing multicenter phase III TIL trial.

Low-dose interferon-alpha preconditioning and adoptive cell therapy in patients with metastatic melanoma refractory to standard (immune) therapies: a phase I/II study

BACKGROUND

Adoptive cell therapy (ACT) with tumor-reactive T cells has shown consistent clinical efficacy. We evaluated the response to ACT in combination with interferon alpha (IFNa) preconditioning in patients with stage IV metastatic melanoma, most of which were progressive on cytotoxic T-lymphocyte-associated protein 4 and/or programmed cell death protein 1 checkpoint blockade therapy.

METHODS

Thirty-four patients were treated with ex vivo expanded tumor reactive T cells, derived from mixed lymphocyte autologous tumor cultures, or with autologous tumor-infiltrating lymphocytes and evaluated for clinical response. Clinical and immunological parameters associated with response were also evaluated.

RESULTS

Best overall response defined as clinical benefit, comprising either complete response, partial response or stable disease >6 months, was observed in 29% of the patients. Forty-three per cent of the 14 immunotherapy-naïve patients and 20% of the 20 patients progressive on prior immunotherapy benefited from ACT. The overall survival (OS) was 90% versus 28.6% at 1 year and 46.7% versus 0% at 3 years follow-up, of responder and non-responder patients, respectively. Median OS was 36 versus 7 months, respectively. IFNa pretreatment resulted in leukopenia, neutropenia and lymphopenia, which was sustained during the treatment in clinical responders and associated with response. Differences in antigen specificity, but not in phenotype, cytokine profile or CD8+ T cell number of the ACT products correlated with clinical response. Cross-reactivity of the ACT products to one or more allogeneic human leukocyte antigen-matched melanoma cell lines was associated with short OS after treatment while the ACT products of very long-term survivors showed no cross-reactivity but recognized patient-specific neoantigens.

CONCLUSION

This study demonstrates that ACT in combination with a mild IFNa preconditioning regimen can induce clinical benefit even in immunotherapy pretreated patients, although with lower success than in immunotherapy-naïve patients. ACT products comprising neoantigen reactivity may be more effective.

The Potential of Tissue-Resident Memory T Cells for Adoptive Immunotherapy against Cancer

Tissue-resident memory T cells (T_RM) comprise an important memory T cell subset that mediates local protection upon pathogen re-encounter. T_RM populations preferentially localize at entry sites of pathogens, including epithelia of the skin, lungs and intestine, but have also been observed in secondary lymphoid tissue, brain, liver and kidney. More recently, memory T cells characterized as T_RM have also been identified in tumors, including but not limited to melanoma, lung carcinoma, cervical carcinoma, gastric carcinoma and ovarian carcinoma. The presence of these memory T cells has been strongly associated with favorable clinical outcomes, which has generated an interest in targeting T_RM cells to improve immunotherapy of cancer patients. Nevertheless, intratumoral T_RM have also been found to express checkpoint inhibitory receptors, such as PD-1 and LAG-3. Triggering of such inhibitory receptors could induce dysfunction, often referred to as exhaustion, which may limit the effectiveness of T_RM in countering tumor growth. A better understanding of the differentiation and function of T_RM in tumor settings is crucial to deploy these memory T cells in future treatment options of cancer patients. The purpose of this review is to provide the current status of an important cancer immunotherapy known as TIL therapy, insight into the role of T_RM in the context of antitumor immunity, and the challenges and opportunities to exploit these cells for TIL therapy to ultimately improve cancer treatment.

Strategies to Overcome Failures in T-Cell Immunotherapies by Targeting PI3K-δ and -γ

PI3K-δ and PI3K-γ are critical regulators of T-cell differentiation, senescence, and metabolism. PI3K-δ and PI3K-γ signaling can contribute to T-cell inhibition via intrinsic mechanisms and regulation of suppressor cell populations, including regulatory T-cells and myeloid derived suppressor cells in the tumor. We examine an exciting new role for using selective inhibitors of the PI3K δ- and γ-isoforms as modulators of T-cell phenotype and function in immunotherapy. Herein we review the current literature on the implications of PI3K-δ and -γ inhibition in T-cell biology, discuss existing challenges in adoptive T-cell therapies and checkpoint blockade inhibitors, and highlight ongoing efforts and future directions to incorporate PI3K-δ and PI3K-γ as synergistic T-cell modulators in immunotherapy.

ACT Up TIL Now: The Evolution of Tumor-Infiltrating Lymphocytes in Adoptive Cell Therapy for the Treatment of Solid Tumors

The past decades of cancer immunotherapy research have provided profound evidence that the immune system is capable of inducing durable tumor regression. Although many commercialized anti-cancer immunotherapies are available to patients, these treatment options only scrape the surface of the potential immune-related treatment possibilities for cancer. Additionally, many individuals are ineligible for established immunotherapies due to their cancer type. The adoptive cell transfer of autologous tumor-infiltrating lymphocytes has been used in humans for over 30 years to treat metastatic melanoma, and continued modifications are making it increasingly more effective against other types of cancer. This comprehensive review outlines this therapy from its infancy through to the present day, bringing to light modifications and optimizations to the traditional workflow, as well as highlighting the influence of new methods and technologies.

Therapeutic Advancements Across Clinical Stages in Melanoma, With a Focus on Targeted Immunotherapy

Melanoma is the most fatal skin cancer. In the early stages, it can be safely treated with surgery alone. However, since 2011, there has been an important revolution in the treatment of melanoma with new effective treatments. Targeted therapy and immunotherapy with checkpoint inhibitors have changed the history of this disease. To date, more than half of advanced melanoma patients are alive at 5 years; despite this breakthrough, approximately half of the patients still do not respond to treatment. For these reasons, new therapeutic strategies are required to expand the number of patients who can benefit from immunotherapy or combination with targeted therapy. Current research aims at preventing primary and acquired resistance, which are both responsible for treatment failure in about 50% of patients. This could increase the effectiveness of available drugs and allow for the evaluation of new combinations and new targets. The main pathways and molecules under study are the IDO inhibitor, TLR9 agonist, STING, LAG-3, TIM-3, HDAC inhibitors, pegylated IL-2 (NKTR-214), GITR, and adenosine pathway inhibitors, among others (there are currently about 3000 trials that are evaluating immunotherapeutic combinations in different tumors). Other promising strategies are cancer vaccines and oncolytic viruses. Another approach is to isolate and remove immune cells (DCs, T cells, and NK cells) from the patient's blood or tumor infiltrates, add specific gene fragments, expand them in culture with growth factors, and re-inoculate into the same patient. TILs, TCR gene transfer, and CAR-T therapy follow this approach. In this article, we give an overview over the current status of melanoma therapies, the clinical rationale for choosing treatments, and the new immunotherapy approaches.

The therapeutic potential of multiclonal tumoricidal T cells derived from tumor infiltrating lymphocyte-1derived iPS cells

Tumor-infiltrating lymphocytes (TIL), which include tumor-specific T lymphocytes with frequency, are used for adoptive cell transfer therapy (ACT) in clinical practice. The optimization of TIL preparation has been investigated to reduce the senescence and increase the abundance of TIL, as both the quality and quantity of the transferred cells have great influence on the outcome of TIL-based ACT (TIL-ACT). Considering the effects of cell reprogramming on senescence, we expected that the anti-tumor effect could be enhanced by TIL regeneration. To confirm this hypothesis, we established tumor-specific TIL-derived iPS cells (TIL-iPSC) with human colorectal cancer specimens. T cells differentiated from TIL-iPSC (TIL-iPS-T) retained not only intrinsic T cell functions and tumor specificity, but also exhibited improved proliferation capacity and additional killing activity. Moreover, less differentiated profiles and prolonged persistency were seen in TIL-iPS-T compared with primary cells. Our findings imply that iPSC technology has great potential for TIL-ACT.

microRNA expression patterns in tumor infiltrating lymphocytes are strongly associated with response to adoptive cell transfer therapy

Adoptive cell transfer (ACT) using autologous tumor infiltrating lymphocytes (TILs) was previously shown to yield clinical response in metastatic melanoma patients as an advanced line. Unfortunately, there is no reliable marker for predicting who will benefit from the treatment. We analyzed TIL samples from the infusion bags used for treatment of 57 metastatic melanoma patients and compared their microRNA profiles. The discovery cohort included six responding patients and seven patients with progressive disease, as defined by RECIST1.1. High throughput analysis with NanoString nCounter demonstrated significantly higher levels of miR-34a-5p and miR-22-3p among TIL from non-responders. These results were validated in TIL infusion bag samples from an independent cohort of 44 patients, using qRT-PCR of the individual microRNAs. Using classification trees, a data-driven predictive model for response was built, based on the level of expression of these microRNAs. Patients that achieved stable disease were classified with responders, setting apart the patients with progressive disease. Moreover, the expression levels of miR-34a-5p in the infused TIL created distinct survival groups, which strongly supports its role as a potential biomarker for TIL-ACT therapy. Indeed, when tested against autologous melanoma cells, miR^Low TIL cultures exhibited significantly higher cytotoxic activity than miR^High TIL cultures, and expressed features of terminally exhausted effectors. Finally, overexpression of miR-34a-5p or miR-22-3p in TIL inhibited their cytotoxic ability in vitro. Overall, we show that a two-microRNA signature correlates with failure of TIL-ACT therapy and survival in melanoma patients.

Bone marrow toxicity and immune reconstitution in melanoma and non-melanoma solid cancer patients after non-myeloablative conditioning with chemotherapy and checkpoint inhibition

BACKGROUND AIMS

Lymphodepletion with non-myeloablative (NMA) chemotherapy is currently a prerequisite for adoptive cell therapy (ACT). ACT based on tumor-infiltrating lymphocytes has long been used in malignant melanoma (MM), but with the advance of ACT into new cancer diagnoses, the patient predisposition will change. The authors here evaluate the bone marrow (BM) toxicity of NMA in combination with checkpoint inhibition and a priori risk factors in a wide range of cancer diagnoses.

METHODS

Thirty-one non-MM and MM patients were included from two different clinical trials with ACT. The treatment history was extracted from the medical records, together with the hematology data. Immune monitoring with flow cytometry was performed before and at several time points after therapy.

RESULTS

NMA induced reversible myelosuppression in all patients. No significant differences in BM toxicity between MM and non-MM patients were found. The overall hematology counts were reconstituted within 3-6 months but with great individual heterogeneity, including eight patients who developed a second phase of neutropenia after hospital discharge. A performance status >0 was found, and shorter overall survival and sex were statistically associated with longer duration of anemia. By contrast, high expression of co-stimulatory markers CD28+ and CD27+ on T cells at baseline was significantly correlated with shorter duration of neutropenia (P = 0.010 and P = 0.009, respectively), anemia (P = 0.001 and P = 0.001, respectively) and thrombocytopenia (P = 0.017 and P = 0.030, respectively). In addition, following NMA, the authors saw a significant differentiation of T-cell phenotype associated with old age.

CONCLUSIONS

ACT with NMA and checkpoint inhibition is tolerable in patients with multiple cancer diagnoses and therapy backgrounds but comes with substantial transient BM toxicity that is comparable in both non-MM and MM patients. Baseline T-cell CD28/CD27 expression level is predictive of duration of BM toxicity. Furthermore, NMA conditioning induces changes in the immune system that may affect a patient's immunocompetence for many months following therapy.

The evolving landscape of immunotherapy in solid tumors

While surgical resection, local and cytotoxic therapies have long formed the basis of cancer care, immunotherapy now plays a key role in supplementing and even replacing these agents in the first line. Here we review the early success of programmed cell death protein 1 (PD-1) and cytotoxic T-lymphocyte associated protein 4 blockade and discuss biomarkers of therapeutic response. We next highlight a select group of novel targets in Phase III trials both as monotherapies and in combination with PD-1 inhibitors. Finally, we discuss innovations which seek to improve outcomes in therapy-resistant solid tumors.

The Factors Affecting Expansion of Reactive Tumor Infiltrating Lymphocytes (TIL) From Bladder Cancer and Potential Therapeutic Applications

Tumor infiltrating lymphocytes (TIL) therapy was shown to provide durable objective response in patients with metastatic melanoma. As a fundamental first step to bring TIL therapy to clinical use, identification of patients whose tumors yield optimal numbers of reactive TIL is indispensable. We have previously shown that expansion of tumor reactive TIL from primary bladder tumors and lymph node metastases is feasible. Here, we performed TIL harvesting from additional surgical specimens (additional 31 primary tumors and 10 lymph nodes) to generate a heterogenous cohort of 53 patients with bladder cancer (BC) to evaluate the tumor characteristics that lead to tumor-reactive TIL expansion. Among a total of 53 patients, overall TIL growth from tumor samples were 37/53 (69.8%) and overall anti-tumor reactive TIL were 26/35 (74.3%). Mixed urothelial carcinoma is associated with higher anti-tumor reactivity of expanded TIL than pure urothelial carcinoma (89.5% vs. 56.3%, p=0.049). The anti-tumor reactivity of expanded TIL from primary tumors previously treated with BCG immunotherapy were lower (33.3% vs. 82.6%, p=0.027) although T-cell phenotype (CD3+, CD4+, CD8+, and CD56+) was similar regardless prior of BCG therapy. Addition of agonistic 4-1BB antibody in culture media with IL-2 improved the number of expanded TIL from primary tumors previously treated with BCG immunotherapy. There was no significant difference between basal and luminal subtype tumors in terms of viable and reactive TIL growth. Our study demonstrates that TIL expansion is feasible across all BC patients and BC subtypes, and we suggest that TIL therapy can be a reasonable treatment strategy for various manifestations of BC.

Bioreactors get personal

Adoptive cell transfer immunotherapy against melanoma is highly effective. However, this therapy has seen limited dissemination, mainly due to the complexity and costs of cell expansion protocols. Two bioreactors have recently been described that simplify and streamline the production of individualized cell therapies. Such bioreactors might increase the number of patients that get access to this promising therapeutic modality.

TIL therapy broadens the tumor-reactive CD8(+) T cell compartment in melanoma patients

There is strong evidence that both adoptive T cell transfer and T cell checkpoint blockade can lead to regression of human melanoma. However, little data are available on the effect of these cancer therapies on the tumor-reactive T cell compartment. To address this issue we have profiled therapy-induced T cell reactivity against a panel of 145 melanoma-associated CD8(+) T cell epitopes. Using this approach, we demonstrate that individual tumor-infiltrating lymphocyte cell products from melanoma patients contain unique patterns of reactivity against shared melanoma-associated antigens, and that the combined magnitude of these responses is surprisingly low. Importantly, TIL therapy increases the breadth of the tumor-reactive T cell compartment in vivo, and T cell reactivity observed post-therapy can almost in full be explained by the reactivity observed within the matched cell product. These results establish the value of high-throughput monitoring for the analysis of immuno-active therapeutics and suggest that the clinical efficacy of TIL therapy can be enhanced by the preparation of more defined tumor-reactive T cell products.

CD137+ T-Cells: Protagonists of the Immunotherapy Revolution

Simple Summary

The CD137 receptor is expressed by activated antigen-specific T-cells. CD137⁺ T-cells were identified inside TILs and PBMCs of different tumor types and have proven to be the naturally occurring antitumor effector cells, capable of expressing a wide variability in terms of TCR specificity against both shared and neoantigenic tumor-derived peptides. The aim of this review is thus summarizing and highlighting their role as drivers of patients’ immune responses in anticancer therapies as well as their potential role in future and current strategies of immunotherapy.

Abstract

The CD137 receptor (4-1BB, TNF RSF9) is an activation induced molecule expressed by antigen-specific T-cells. The engagement with its ligand, CD137L, is capable of increasing T-cell survival, proliferation, and cytokine production. This allowed to identify the CD137⁺ T-cells as the real tumor-specific activated T-cell population. In fact, these cells express various TCRs that are specific for a wide range of tumor-derived peptides, both shared and neoantigenic ones. Moreover, their prevalence in sites close to the tumor and their unicity in killing cancer cells both in vitro and in vivo, raised particular interest in studying their potential role in different strategies of immunotherapy. They indeed showed to be a reliable marker able to predict patient’s outcome to immune-based therapies as well as monitor their response. In addition, the possibility of isolating and expanding this population, turned promising in order to generate effector antitumor T-cells in the context of adoptive T-cell therapies. CD137-targeting monoclonal antibodies have already shown their antitumor efficacy in cancer patients and a number of clinical trials are thus ongoing to test their possible introduction in different combination approaches of immunotherapy. Finally, the intracellular domain of the CD137 receptor was introduced in the anti-CD19 CAR-T cells that were approved by FDA for the treatment of pediatric B-cell leukemia and refractory B-cell lymphoma.