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Background: Tumor heterogeneity is a hurdle to effective therapy, as illustrated by the 'mixed responses' frequently seen in immunotherapy-treated patients. Previously, AXL+ tumor cells were identified to be highly resistant to targeted therapy, whereas more differentiated MITF+ tumor cells do respond to RAF and MEK inhibitors., Patients and Methods: In this study, we analyzed tumor heterogeneity and explored the presence of the previously described AXL+ or MITF+ melanoma subpopulations in metastatic tissues by NanoString gene expression analysis, single-cell RNA sequencing and in situ multiplex immunofluorescence. Furthermore, we analyzed how these subpopulations correlate with immunological pressure and response to immunotherapy by immunomodulating antibodies or autologous tumor lysate-loaded dendritic cell vaccination., Results: Our data demonstrate large interpatient variability and variable therapy-induced changes independent of the type of therapy. We identify the presence of previously described AXL+ and MITF+ subpopulations in metastatic tissues both at the mRNA level and in situ at the protein level, and demonstrate that MITF+ melanoma cells are significantly decreased upon immunotherapy, while AXL+ melanoma cell numbers are stable. MITF+ tumor cells showed the most significant inverse correlation with CD8+ T cells. Our patient cohort also shows that immunotherapy-induced changes in the abundance of AXL+ or MITF+ tumor cells did not correlate with improved survival., Conclusions: Overall, this study suggests that more differentiated MITF+ tumors are efficiently targeted by immunotherapy, while AXL+ tumor cells may be more resistant, analogous to their response to targeted therapy., (© 2024 The Author(s).)

The gut microbiota influences multiple aspects of human health and disease. Several studies have indicated an association between the gut microbiota and response to immune checkpoint inhibitors in various cancers, but there is scarce data from breast cancer. The randomized ALICE trial demonstrated improved progression-free survival (PFS) from adding the programmed cell death 1 ligand 1 (PD-L1) inhibitor atezolizumab (atezo) to immunomodulating chemotherapy (chemo) in metastatic triple-negative breast cancer (mTNBC), even for PD-L1 negative disease. Herein, we investigated the microbiota composition and dynamics in the ALICE patients and their association with clinical outcome, by analyzing fecal samples collected at baseline and after 8 weeks. We applied 16S (V3-V4) rRNA sequencing to characterize the diversity and taxonomic composition. Kaplan-Meier and Cox proportional hazard models were used for time-to-event analyses. We found that high alpha diversity by Faith's phylogenetic diversity (PD) at baseline was associated with prolonged PFS in the total study population and in the atezo-chemo arm, but not in the placebo-chemo arm. Moreover, Faith's PD appeared to be predictive of benefit from atezolizumab. Patients with high Faith's PD exhibited a PFS hazard ratio of 0.34 (P = 0.018) in favor of the atezo-chemo arm, compared to 0.83 (P = 0.62) in the low Faith's PD group. Faith's PD was significantly reduced during treatment. At baseline, Bifidobacterium was significantly overrepresented in patients without clinical benefit in the atezo-chemo arm, but not in the placebo-chemo arm. These findings suggest that alpha diversity by Faith's PD should be further investigated as a prognostic and predictive biomarker in patients with mTNBC receiving chemo-immunotherapy., (© 2024 The Author(s). Molecular Oncology published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.)

Immune checkpoint inhibitors (ICIs) have been introduced in breast cancer (BC) treatment and better biomarkers are needed to predict benefit. Circulating tumor cells (CTCs) are prognostic in BC, but knowledge is limited on CTCs in the context of ICI therapy. In this study, serial sampling of CTCs (CellSearch system) was evaluated in 82 patients with metastatic BC enrolled in two randomized trials investigating ICI plus chemotherapy. Programmed death-ligand 1 (PD-L1) expression on CTCs was also measured. Patients with ≥ 2 CTCs per 7.5 mL at baseline had gene expression profiles in tumor suggestive of increased T-cell activity, including increased tumor inflammation signature (TIS) in both triple-negative (P = 0.010) and hormone receptor-positive (P = 0.024) disease. Patients with luminal A BC had higher CTC levels. The association between CTC status and outcome was most apparent 4 weeks into therapy. PD-L1 expression in CTCs was observed in 6/17 CTC-positive patients and was associated with inferior survival. In conclusion, our study indicates that CTC numbers may inform on tumor immune composition, as well as prognosis. These findings suggest a potential of using CTCs as an accessible biomarker source in BC patients treated with immunotherapy., (© 2024 The Author(s). Molecular Oncology published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.)

Immunotherapies blocking the PD-1/PD-L1 checkpoint show some efficacy in metastatic breast cancer (mBC) but are often hindered by immunosuppressive mechanisms. Understanding these mechanisms is crucial for personalized treatments, with peripheral blood monitoring representing a practical alternative to repeated biopsies. In the present study, we performed a comprehensive mass cytometry analysis of peripheral blood immune cells in 104 patients with HER2 negative mBC and 20 healthy donors (HD). We found that mBC patients had significantly elevated monocyte levels and reduced levels of CD4 + T cells and plasmacytoid dendritic cells, when compared to HD. Furthermore, mBC patients had more effector T cells and regulatory T cells, increased expression of immune checkpoints and other activation/exhaustion markers, and a shift to a Th2/Th17 phenotype. Furthermore, T-cell phenotypes identified by mass cytometry correlated with functionality as assessed by IFN-γ production. Additional analysis indicated that previous chemotherapy and CDK4/6 inhibition impacted the numbers and phenotype of immune cells. From 63 of the patients, fresh tumor samples were analyzed by flow cytometry. Paired PBMC-tumor analysis showed moderate correlations between peripheral CD4 +  T and NK cells with their counterparts in tumors. Further, a CD4 + T cell cluster in PBMCs, that co-expressed multiple checkpoint receptors, was negatively associated with CD4 +  T cell tumor infiltration. In conclusion, the identified systemic immune signatures indicate an immune-suppressed environment in mBC patients who had progressed/relapsed on standard treatments, and is consistent with ongoing chronic inflammation. These activated immuno-suppressive mechanisms may be investigated as therapeutic targets, and for use as biomarkers of response or treatment resistance., (© 2024. The Author(s).)

Background: Immune checkpoint inhibitors have shown minimal clinical activity in hormone receptor-positive metastatic breast cancer (HR + mBC). Doxorubicin and low-dose cyclophosphamide are reported to induce immune responses and counter regulatory T cells (Tregs). Here, we report the efficacy and safety of combined programmed cell death protein-1/cytotoxic T-lymphocyte-associated protein 4 blockade concomitant with or after immunomodulatory chemotherapy for HR + mBC., Methods: Patients with HR + mBC starting first-/second- line chemotherapy (chemo) were randomized 2:3 to chemotherapy (pegylated liposomal doxorubicin 20 mg/m 2 every second week plus cyclophosphamide 50 mg by mouth/day in every other 2-week cycle) with or without concomitant ipilimumab (ipi; 1 mg/kg every sixth week) and nivolumab (nivo; 240 mg every second week). Patients in the chemo-only arm were offered cross-over to ipi/nivo without chemotherapy. Co-primary endpoints were safety in all patients starting therapy and progression-free survival (PFS) in the per-protocol (PP) population, defined as all patients evaluated for response and receiving at least two treatment cycles. Secondary endpoints included objective response rate, clinical benefit rate, Treg changes during therapy and assessment of programmed death-ligand 1 (PD-L1), mutational burden and immune gene signatures as biomarkers., Results: Eighty-two patients were randomized and received immune-chemo (N=49) or chemo-only (N=33), 16 patients continued to the ipi/nivo-only cross-over arm. Median follow-up was 41.4 months. Serious adverse events occurred in 63% in the immune-chemo arm, 39% in the chemo-only arm and 31% in the cross-over-arm. In the PP population (N=78) median PFS in the immune-chemo arm was 5.1 months, compared with 3.6 months in the chemo-only arm, with HR 0.94 (95% CI 0.59 to 1.51). Clinical benefit rates were 55% (26/47) and 48% (15/31) in the immune-chemo and chemo-only arms, respectively. In the cross-over-arm (ipi/nivo-only), objective responses were observed in 19% of patients (3/16) and clinical benefit in 25% (4/16). Treg levels in blood decreased after study chemotherapy. High-grade immune-related adverse events were associated with prolonged PFS. PD-L1 status and mutational burden were not associated with ipi/nivo benefit, whereas a numerical PFS advantage was observed for patients with a high Treg gene signature in tumor., Conclusion: The addition of ipi/nivo to chemotherapy increased toxicity without improving efficacy. Ipi/nivo administered sequentially to chemotherapy was tolerable and induced clinical responses., Trial Registration Number: ClinicalTrials.gov Identifier: NCT03409198., Competing Interests: Competing interests: JAK has in the last 5 years received research support from Bristol Myers Squibb, F. Hoffmann-La Roche, NanoString, and NEC OncoImmunity and has previously received advisory board/lecture honoraria from pharmaceutical companies, including Bristol Myers Squibb. CQ has received honoraria for advisory board from AstraZeneca. BG has received honoraria for advisory boards from Eli Lilly, Gilead, Daiichi Sankyo, Roche, and Pierre Fabre. LJ has received lecture honoraria from Pfizer, Novartis, and AstraZeneca. AG has received travel grants or honoraria for advisory boards from Lilly, Daiichi Sankyo, Seagen, Pfizer, and AstraZeneca. HGR has received research support from Illumina and NanoString. OCL has over the last 2 years received honoraria for work as statistical advisor for Novartis. All other authors declare no competing interests., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

We have developed a chimeric antigen receptor (CAR) against the six-transmembrane epithelial antigen of prostate-1 (STEAP1), which is expressed in prostate cancer, Ewing sarcoma, and other malignancies. In the present study, we investigated the effect of substituting costimulatory domains and spacers in this STEAP1 CAR. We cloned four CAR constructs with either CD28 or 4-1BB costimulatory domains, combined with a CD8a-spacer (sp) or a mutated IgG-spacer. The CAR T-cells were evaluated in short- and long-term in vitro T-cell assays, measuring cytokine production, tumor cell killing, and CAR T-cell expansion and phenotype. A xenograft mouse model of prostate cancer was used for in vivo comparison. All four CAR constructs conferred CD4 + and CD8 + T cells with STEAP1-specific functionality. A CD8sp_41BBz construct and an IgGsp_CD28z construct were selected for a more extensive comparison. The IgGsp_CD28z CAR gave stronger cytokine responses and killing in overnight caspase assays. However, the 41BB-containing CAR mediated more killing (IncuCyte) over one week. Upon six repeated stimulations, the CD8sp_41BBz CAR T cells showed superior expansion and lower expression of exhaustion markers (PD1, LAG3, TIGIT, TIM3, and CD25). In vivo, both the CAR T variants had comparable anti-tumor activity, but persisting CAR T-cells in tumors were only detected for the 41BBz variant. In conclusion, the CD8sp_41BBz STEAP1 CAR T cells had superior expansion and survival in vitro and in vivo, compared to the IgGsp_CD28z counterpart, and a less exhausted phenotype upon repeated antigen exposure. Such persistence may be important for clinical efficacy.

Estrogen receptor-positive (ER+)/HER2-negative (HER2-), the so-called luminal-type breast cancer, is the most frequent subset, accounting for around 70% of all breast cancer cases. Endocrine therapy (ET) combined with cyclin-dependent kinases (CDK) 4/6 inhibitors is the standard first option in the management of advanced luminal breast cancer independently of disease extension. Classically, patients undergo multiple lines of ET ± targeted treatments until endocrine resistance occurs and palliative chemotherapy is proposed. Understanding endocrine resistance mechanisms and development of novel ET options is one of the main challenges in current clinical research. Another area of utmost interest is the improvement of post-endocrine therapeutic approaches. Among others, the development of antibody-drug conjugates (ADCs) is very promising, and some of these drugs will probably soon become a part of the therapeutic arsenal against this incurable disease. This review paper provides an overview of currently available treatment options in ER+/HER2- metastatic breast cancer and extensively discusses new approaches in late clinical development., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Therapy employing T cells modified with chimeric antigen receptors (CARs) is effective in hematological malignancies but not yet in solid cancers. CAR T cell activity in solid tumors is limited by immunosuppressive factors, including transforming growth factor β (TGFβ). Here, we describe the development of a switch receptor (SwR), in which the extracellular domains of the TGFβ receptor are fused to the intracellular domains from the IL-2/15 receptor. We evaluated the SwR in tandem with two variants of a CAR that we have developed against STEAP1, a protein highly expressed in prostate cancer. The SwR-CAR T cell activity was assessed against a panel of STEAP1 +/- prostate cancer cell lines with or without over-expression of TGFβ, or with added TGFβ, by use of flow cytometry cytokine and killing assays, Luminex cytokine profiling, cell counts, and flow cytometry phenotyping. The results showed that the SwR-CAR constructs improved the functionality of CAR T cells in TGFβ-rich environments, as measured by T cell proliferation and survival, cytokine response, and cytotoxicity. In assays with four repeated target-cell stimulations, the SwR-CAR T cells developed an activated effector memory phenotype with retained STEAP1-specific activity. In conclusion, the SwR confers CAR T cells with potent and durable in vitro functionality in TGFβ-rich environments. The SwR may be used as an add-on construct for CAR T cells or other forms of adoptive cell therapy.

Immune checkpoint inhibitors have shown efficacy against metastatic triple-negative breast cancer (mTNBC) but only for PD-L1 positive disease. The randomized, placebo-controlled ALICE trial ( NCT03164993 , 24 May 2017) evaluated the addition of atezolizumab (anti-PD-L1) to immune-stimulating chemotherapy in mTNBC. Patients received pegylated liposomal doxorubicin (PLD) and low-dose cyclophosphamide in combination with atezolizumab (atezo-chemo; n = 40) or placebo (placebo-chemo; n = 28). Primary endpoints were descriptive assessment of progression-free survival in the per-protocol population (>3 atezolizumab and >2 PLD doses; n = 59) and safety in the full analysis set (FAS; all patients starting therapy; n = 68). Adverse events leading to drug discontinuation occurred in 18% of patients in the atezo-chemo arm (7/40) and in 7% of patients in the placebo-chemo arm (2/28). Improvement in progression-free survival was indicated in the atezo-chemo arm in the per-protocol population (median 4.3 months versus 3.5 months; hazard ratio (HR) = 0.57; 95% confidence interval (CI) 0.33-0.99; log-rank P = 0.047) and in the FAS (HR = 0.56; 95% CI 0.33-0.95; P = 0.033). A numerical advantage was observed for both the PD-L1 positive (n = 27; HR = 0.65; 95% CI 0.27-1.54) and PD-L1 negative subgroups (n = 31; HR = 0.57, 95% CI 0.27-1.21). The progression-free proportion after 15 months was 14.7% (5/34; 95% CI 6.4-30.1%) in the atezo-chemo arm versus 0% in the placebo-chemo arm. The addition of atezolizumab to PLD/cyclophosphamide was tolerable with an indication of clinical benefit, and the findings warrant further investigation of PD1/PD-L1 blockers in combination with immunomodulatory chemotherapy., (© 2022. The Author(s).)

The expression of human epidermal growth factor receptor 2 (HER2) is a key classification factor in breast cancer. Many breast cancers express isoforms of HER2 with truncated carboxy-terminal fragments (CTF), collectively known as p95HER2. A common p95HER2 isoform, 611-CTF, is a biomarker for aggressive disease and confers resistance to therapy. Contrary to full-length HER2, 611-p95HER2 has negligible normal tissue expression. There is currently no approved diagnostic assay to identify this subgroup and no therapy targeting this mechanism of tumor escape. The purpose of this study was to develop a monoclonal antibody (mAb) against 611-CTF-p95HER2. Hybridomas were generated from rats immunized with cells expressing 611-CTF. A hybridoma producing a highly specific Ab was identified and cloned further as a mAb. This mAb, called Oslo-2, gave strong staining for 611-CTF and no binding to full-length HER2, as assessed in cell lines and tissues by flow cytometry, immunohistochemistry and immunofluorescence. No cross-reactivity against HER2 negative controls was detected. Surface plasmon resonance analysis demonstrated a high binding affinity (equilibrium dissociation constant 2 nM). The target epitope was identified at the N-terminal end, using experimental alanine scanning. Further, the mAb paratope was identified and characterized with hydrogen-deuterium-exchange, and a molecular model for the (Oslo-2 mAb:611-CTF-p95HER2) complex was generated by an experimental-information-driven docking approach. We conclude that the Oslo-2 mAb has a high affinity and is highly specific for 611-CTF-p95HER2. The Ab may be used to develop potent and safe therapies, overcoming p95HER2-mediated tumor escape, as well as for developing diagnostic assays.

Background: We have previously reported that the safety and efficacy of ipilimumab in real-world patients with metastatic melanoma were comparable to clinical trials. Few studies have explored health-related quality of life (HRQL) in real-world populations receiving checkpoint inhibitors. This study reports HRQL in real-world patients receiving ipilimumab and assesses the prognostic value of patient-reported outcome measures., Patients and Methods: Ipi4 (NCT02068196) was a prospective, multicentre, interventional phase IV trial. Real-world patients (N = 151) with metastatic melanoma were treated with ipilimumab 3 mg/kg intravenously as labelled. HRQL was assessed by the European Organisation of Research and Treatment of Cancer Quality of Life Questionnaire at baseline and after 10-12 weeks., Results: The European Organisation of Research and Treatment of Cancer Quality of Life Questionnaire was completed by 93% (141/151 patients) at baseline, and by 82% at 10-12 weeks. Poor performance status and elevated C-reactive protein (CRP) were associated with worse baseline HRQL. Clinically relevant and statistically significant deteriorations in HRQL from baseline to weeks 10-12 were reported (P <0.05). Baseline physical functioning [hazard ratio (HR) 1.96, P = 0.016], role functioning (HR 2.15, P <0.001), fatigue (HR 1.60, P = 0.030), and appetite loss (HR 1.76, P = 0.012) were associated with poorer overall survival independent of performance status, lactate dehydrogenase (LDH), and CRP. We further developed a prognostic model, combining HRQL outcomes with performance status, LDH, and CRP. This model identified three groups with large and statistically significant differences in survival., Conclusions: Systemic inflammation is associated with impaired HRQL. During treatment with ipilimumab, HRQL deteriorated significantly. Combining HRQL outcomes with objective risk factors provided additional prognostic information that may aid clinical decision making., Competing Interests: Disclosure EA, KDJ, KTH, KH, SK, SA, and TKG have received clinical research support from the Norwegian Ministry of Health and Care Services. MN has received personal fees and honoraria for lectures and expert meetings from Bristol-Myers Squibb, Merck Sharpe and Dohme, Novartis, and Pierre Fabre. JAK has received honoraria for lectures and clinical research support from the Norwegian Ministry of Health and Care Services, Bristol-Myers Squibb, and Roche. OH reports honoraria for lectures from Bristol-Myers Squibb and Merck Sharpe and Dohme and research funding from Novartis. CK reports former employment with Roche. The remaining authors have declared no conflicts of interests. Data sharing The datasets generated during and analysed during the current trial are available from the corresponding author on reasonable request. Ethics approval and consent to participate The Ipi4 trial (https://clinicaltrials.gov/ct2/show/NCT02068196) was approved by the Regional Committee for Medical and Health Research Ethics South East (REC ID 2013/1518) and conducted in accordance with the ethical principles of the Declaration of Helsinki (1964). All patients provided written informed consent to participate in the trial., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Chimeric antigen receptors (CARs) that retarget T cells against CD19 show clinical efficacy against B cell malignancies. Here, we describe the development of a CAR against the six-transmembrane epithelial antigen of prostate-1 (STEAP1), which is expressed in ∼90% of prostate cancers, and subgroups of other malignancies. STEAP1 is an attractive target, as it is associated with tumor invasiveness and progression and only expressed at low levels in normal tissues, apart from the non-vital prostate gland. We identified the antibody coding sequences from a hybridoma and designed a CAR that is efficiently expressed in primary T cells. The T cells acquired the desired anti-STEAP1 specificity, with a polyfunctional response including production of multiple cytokines, proliferation, and the killing of cancer cells. The response was observed for both CD4 + and CD8 + T cells, and against all STEAP1 + target cell lines tested. We evaluated the in vivo CAR T activity in both subcutaneous and metastatic xenograft mouse models of prostate cancer. Here, the CAR T cells infiltrated tumors and significantly inhibited tumor growth and extended survival in a STEAP1-dependent manner. We conclude that the STEAP1 CAR exhibits potent in vitro and in vivo functionality and can be further developed toward potential clinical use., Competing Interests: J.A.K. and Yixin Jin are inventors on a patent application related to the work described in this article., (© 2022 The Author(s).)

Background: Matching treatment based on tumour molecular characteristics has revolutionized the treatment of some cancers and has given hope to many patients. Although personalized cancer care is an old concept, renewed attention has arisen due to recent advancements in cancer diagnostics including access to high-throughput sequencing of tumour tissue. Targeted therapies interfering with cancer specific pathways have been developed and approved for subgroups of patients. These drugs might just as well be efficient in other diagnostic subgroups, not investigated in pharma-led clinical studies, but their potential use on new indications is never explored due to limited number of patients., Methods: In this national, investigator-initiated, prospective, open-label, non-randomized combined basket- and umbrella-trial, patients are enrolled in multiple parallel cohorts. Each cohort is defined by the patient's tumour type, molecular profile of the tumour, and study drug. Treatment outcome in each cohort is monitored by using a Simon two-stage-like 'admissible' monitoring plan to identify evidence of clinical activity. All drugs available in IMPRESS-Norway have regulatory approval and are funded by pharmaceutical companies. Molecular diagnostics are funded by the public health care system., Discussion: Precision oncology means to stratify treatment based on specific patient characteristics and the molecular profile of the tumor. Use of targeted drugs is currently restricted to specific biomarker-defined subgroups of patients according to their market authorization. However, other cancer patients might also benefit of treatment with these drugs if the same biomarker is present. The emerging technologies in molecular diagnostics are now being implemented in Norway and it is publicly reimbursed, thus more cancer patients will have a more comprehensive genomic profiling of their tumour. Patients with actionable genomic alterations in their tumour may have the possibility to try precision cancer drugs through IMPRESS-Norway, if standard treatment is no longer an option, and the drugs are available in the study. This might benefit some patients. In addition, it is a good example of a public-private collaboration to establish a national infrastructure for precision oncology. Trial registrations EudraCT: 2020-004414-35, registered 02/19/2021; ClinicalTrial.gov: NCT04817956, registered 03/26/2021., (© 2022. The Author(s).)

Therapy with T cells equipped with chimeric antigen receptors (CARs) shows strong efficacy against leukaemia and lymphoma, but not yet against solid cancers. This has been attributed to insufficient T cell persistence, tumour heterogeneity and an immunosuppressive tumour microenvironment. The present article provides an overview of key strategies that are currently investigated to overcome these hurdles. Basic aspects of CAR design are revisited, relevant for tuning the stimulatory signal to the requirements of solid tumours. Novel approaches for enhancing T cell persistence are highlighted, based on epigenetic or post-translational modifications. Further, the article describes CAR T strategies that are being developed for overcoming tumour heterogeneity and the escape of cancer stem cells, as well as for countering prevalent mechanisms of immune suppression in solid cancers. In general, personalised medicine is faced with a lack of drugs matching the patient's profile. The advances and flexibility of modern gene engineering may allow for the filling of some of these gaps with tailored CAR T approaches addressing mechanisms identified as important in the individual patient. At this point, however, CAR T cell therapy remains unproved in solid cancers. The further progress of the field will depend on bringing novel strategies into clinical evaluation, while maintaining safety.

Ipilimumab was the first treatment that improved survival in advanced melanoma. Efficacy and toxicity in a real-world setting may differ from clinical trials, due to more liberal eligibility criteria and less intensive monitoring. Moreover, high costs and lack of biomarkers have raised cost-benefit concerns about ipilimumab in national healthcare systems and limited its use. Here, we report the prospective, interventional study, Ipi4 (NCT02068196), which aimed to investigate the toxicity and efficacy of ipilimumab in a real-world population with advanced melanoma. This national, multicentre, phase IV trial included 151 patients. Patients received ipilimumab 3 mg/kg intravenously and were followed for at least 5 years or until death. Treatment interruption or cessation occurred in 38%, most frequently due to disease progression (19%). Treatment-associated grade 3 to 4 toxicity was observed in 28% of patients, and immune-related toxicity in 56%. The overall response rate was 9%. Median overall survival was 12.1 months (95% CI: 8.3-15.9); and progression-free survival 2.7 months (95% CI: 2.6-2.8). After 5 years, 20% of patients were alive. In a landmark analysis from 6 months, improved survival was associated with objective response (HR 0.16, P = .001) and stable disease (HR 0.49, P = .005) compared to progressive disease. Poor performance status, elevated lactate dehydrogenase and C-reactive protein were identified as biomarkers. This prospective trial represents the longest reported follow-up of a real-world melanoma population treated with ipilimumab. Results indicate safety and efficacy comparable to phase III trials and suggest that the use of ipilimumab can be based on current cost-benefit estimates., (© 2021 The Authors. International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.)

Human telomerase reverse transcriptase (hTERT) is a target antigen for cancer immunotherapy in patients with non-small cell lung cancer (NSCLC). We have tested a novel hTERT vaccine, UV1, designed to give high population coverage. UV1 is composed of three synthetic long peptides containing multiple epitopes identified by epitope spreading data from long-term survivors from previous hTERT vaccination trials. Eighteen non-HLA-typed patients with stage III/IV NSCLC with no evidence of progression after prior treatments, were enrolled in a phase I dose-escalation study of UV1 vaccination with GM-CSF as adjuvant, evaluating safety, immune response, and long-term clinical outcome. Treatment with UV1 was well tolerated with no serious adverse events observed. Seventeen patients were evaluable for tumor response; 15 patients had stable disease as best response. The median progression free survival (PFS) was 10.7 months, and the median overall survival (OS) was 28.2 months. The OS at 4 years was 39% (7/18). Five patients are alive (median survival 5.6 years), and none of these are known to have received checkpoint therapy after vaccination. UV1 induced specific T-cell responses in the majority (67%) of patients. Immune responses were dynamic and long lasting. Both immune response (IR) and OS were dose related. More patients in the highest UV1 dosage group (700 μg) developed IRs compared to the other groups, and the IRs were stronger and occurred earlier. Patients in this group had a 4-year OS of 83%. The safety and clinical outcome data favor 700 μg as the preferred UV1 dose in this patient population. These results provide a rationale for further clinical studies in NSCLC with UV1 vaccination in combination with immune checkpoint blockade., Clinical Trial Registration: https://www.clinicaltrials.gov, identifier NCT0178909., Competing Interests: GG and EMI are inventors on the UV1 vaccine patent. WR, GG, and EMI are shareholders of Ultimovacs ASA. WR, GG, and SA are Ultimovacs ASA employees. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2020 Brunsvig, Guren, Nyakas, Steinfeldt-Reisse, Rasch, Kyte, Juul, Aamdal, Gaudernack and Inderberg.)

Background: Immunotherapy with checkpoint inhibitors (CPI) targeting PD-1 or CTLA-4 has emerged as an important treatment modality for several cancer forms. In hormone receptor positive breast cancer (HR + BC), this therapeutic approach is largely unexplored. We have started a clinical trial, ICON (CA209-9FN), evaluating CPI combined with selected chemotherapy in patients with metastatic HR + BC. The tumor lymphocyte infiltration is predictive for the effect of chemotherapy in BC. In ICON, we use anthracycline, which are considered as "immunogenic" chemotherapy, and low-dose cyclophosphamide, which has been reported to counter immunosuppressive cells., Methods: ICON is a randomized exploratory phase IIb study evaluating the safety and efficacy of combining nivolumab (nivo; anti-PD-1) and ipilimumab (ipi; anti-CTLA-4) with chemotherapy in subjects with metastatic HR + BC. Primary objectives are aassessment of toxicity and progression-free survival. The trial will enrol 75 evaluable subjects, randomized 2:3 into two arms (A:B). Patients in Arm A receive only chemotherapy, i.e. pegylated liposomal doxorubicin (PLD 20 mg/m 2 intravenously every 2nd week) + cyclophosphamide (cyclo; 50 mg per day, first 2 weeks in each 4 week cycle). Patients in Arm B receive PLD + cyclo + ipilimumab (1 mg intravenously every 6th week) + nivolumab (240 mg intravenously every 2nd week). Patients in arm A will be offered ipi + nivo after disease progression., Discussion: ICON is among the first clinical trials combining chemotherapy with PD-1 and CTLA-4 blockade, and the first in BC. There is a strong preclinical rationale for exploring if anthracyclines, which are considered to induce immunogenic cell death, synergize with CPI, and for combining PD-1 and CTLA-4 blockade, as these checkpoints are important in different phases of the immune response. If the ICON trial suggests acceptable safety and provide a signal of clinical efficacy, further studies are warranted. The cross-over patients from Arm A receiving ipilimumab/nivolumab without concomitant chemotherapy represent the first BC cohort receiving this therapy. The ICON trial includes a series of translational sub-projects addressing clinically important knowledge gaps. These studies may uncover biomarkers or mechanisms of efficacy and resistance, thereby informing the development of novel combinatory regimes and of personalised biomarker-based therapy. Trial registration NCT03409198, Jan 24th 2018; https://clinicaltrials.gov/ct2/show/record/NCT03409198.

Background: Immunotherapy with checkpoint inhibitors (CI) represents an important novel development in cancer treatment. Metastatic triple-negative breast cancer (mTNBC) is incurable, with a median survival of only ~ 13 months. We have initiated the randomized placebo-controlled phase IIb study ALICE, evaluating PD-L1 blockade combined with immunogenic chemotherapy in mTNBC patients (n = 75). Intriguingly, the host immune response is strongly predictive for the effect of chemotherapy in mTNBC. In the ALICE trial, we release the brake on the immune response by use of atezolizumab, an inhibitory antibody against PD-L1. We utilize anthracyclines, shown to trigger the immune system, and low-dose cyclophosphamide, which has been reported to counter immunosuppressive cells., Methods: ALICE is a randomized, double-blind, placebo-controlled exploratory phase II study evaluating the safety and efficacy of atezolizumab when combined with immunogenic chemotherapy in subjects with mTNBC. The trial will enroll 75 evaluable subjects, randomized 2:3 into two arms (A:B). The patients receive identical chemotherapy, i.e. pegylated liposomal doxorubicin (PLD 20 mg/m 2 intravenously every 2nd week) + cyclophosphamide (50 mg per day, first 2 weeks in each 4 week cycle). Patients in arm A receive placebo, while patients in arm B receive atezolizumab. The primary objectives are assessment of toxicity and progression-free survival. The secondary objectives include overall survival, tumor response rate, clinical benefit rate, patient reported outcomes, biomarkers and assessment of tumor-immune evolution during therapy., Discussion: The question of how CI should be combined with chemotherapy, is a key challenge facing the field. There is a strong preclinical rationale for exploring if anthracyclines, which are considered to induce immunogenic cell death, synergize with PD-L1 blockade, and if low-dose cyclophosphamide counters tumor tolerance. However, the data from patients is as yet very limited, and the clinical evaluation of these hypotheses is among the key objectives in the ALICE trial. The study includes extensive biobanking and translational sub-projects, also addressing other clinically important questions. These analyses may uncover mechanisms of drug efficacy or tumor resistance, and identify biomarkers allowing personalized therapy. If the trial suggests acceptable safety of the ALICE therapy and provide a signal of clinical efficacy, further studies are warranted. Trial registration NCT03164993, May 24th 2017; https://clinicaltrials.gov/ct2/show/record/NCT03164993.

The gene transfer of T-cell receptors (TCRs) is an attractive strategy for adoptive cell therapy, allowing the transfer of reactivity against antigens that may not otherwise engender an immune response. The TCRs recognize intracellular or extracellular antigens presented in the context of MHC class I or II, respectively. This broadens the range of targets considerably, compared to antibodies and chimeric antigen receptors, that are generally confined to surface antigens. However, TCR transfer must overcome some technical hurdles, relating to interference with endogenous α- and β-TCR chains and competition with other existing TCR infrastructure of T cells. In this review, we will outline the challenges facing TCR gene transfer and compare several approaches to address them. We will then focus upon one of the most promising amongst these-RNA interference-and detail the methods involved in designing and using this technology.

How mixtures of immune cells associate with cancer cell phenotype and affect pathogenesis is still unclear. In 15 breast cancer gene expression datasets, we invariably identify three clusters of patients with gradual levels of immune infiltration. The intermediate immune infiltration cluster (Cluster B) is associated with a worse prognosis independently of known clinicopathological features. Furthermore, immune clusters are associated with response to neoadjuvant chemotherapy. In silico dissection of the immune contexture of the clusters identified Cluster A as immune cold, Cluster C as immune hot while Cluster B has a pro-tumorigenic immune infiltration. Through phenotypical analysis, we find epithelial mesenchymal transition and proliferation associated with the immune clusters and mutually exclusive in breast cancers. Here, we describe immune clusters which improve the prognostic accuracy of immune contexture in breast cancer. Our discovery of a novel independent prognostic factor in breast cancer highlights a correlation between tumor phenotype and immune contexture.

Adoptive cell therapy (ACT) with retargeted T cells has produced remarkable clinical responses against cancer, but also serious toxicity. Telomerase is overexpressed in most cancers, but also expressed in some normal cells, raising safety concerns. We hypothesize that ACT with T-helper cell receptors may overcome tumour tolerance, mobilize host immune cells and induce epitope spreading, with limited toxicity. From long term survivors after cancer vaccination, we have isolated telomerase-specific T cell receptors (TCRs) from T-helper cells. Herein, we report the development of transient retargeting of T cells with mRNA-based TCRs. This strategy allows for safer clinical testing and meaningful dose escalation. DP4 is the most common HLA molecule. We cloned two telomerase-specific, DP4-restricted TCRs into the mRNA expression vector pCIpA102, together with the sorter/marker/suicide gene RQR8. Donor T cells were electroporated with mRNA encoding TCR&#95;RQR8. The results showed that both TCR&#95;RQR8 constructs were expressed in >90% of T cells. The transfected T cells specifically recognized the relevant peptide, as well as naturally processed epitopes from a 177aa telomerase protein fragment, and remained functional for six days. A polyfunctional and Th1-like cytokine profile was observed. The TCRs were functional in both CD4+and CD8+recipient T cells, even though DP4-restricted. The findings demonstrate that the cloned TCRs confer recipient T cells with the desired telomerase-specificity and functionality. Preclinical experiments may provide limited information on the efficacy and toxicity of T-helper TCRs, as these mobilize the host immune system. We therefore intend to use the mRNA-based TCRs for a first-in-man trial.

Cancers elicit an immune response by modifying the microenvironment. The immune system plays a pivotal role in cancer recognition and eradication. While the potential clinical value of infiltrating lymphocytes at the tumor site has been assessed in breast cancer, circulating cytokines - the molecules coordinating and fine-tuning immune response - are still poorly characterized. Using two breast cancer cohorts (MicMa, n = 131, DCTB, n = 28) and the multiplex Luminex platform, we measured the levels of 27 cytokines in the serum of breast cancer patients prior to treatment. We investigated the cytokine levels in relation to clinicopathological characteristics and in perspective of the tumor infiltrating immune cells predicted from the bulk mRNA expression data. Unsupervised clustering analysis of the serum cytokine levels in the MicMa cohort identified a cluster of pro-inflammatory, pro-angiogenic, and Th2-related cytokines which was associated with poor prognosis. Notably high levels of platelet derived growth factor BB (PDGF) reflected a more aggressive tumor phenotype and larger tumor size. A significant positive correlation between serum levels of interferon gamma-induced protein 10 (IP10) and its mRNA expression at the tumor site suggested that tumor-IP10-production may outflow to the bloodstream. High IP10 serum levels were associated with a worse prognosis. Finally, we found serum levels of both PDGF and IP10 associated with enrichment scores of specific tumor infiltrating immune cells. Our study suggests that monitoring cytokine circulating levels in breast cancer could be used to characterize breast cancers and the immune composition of their microenvironment through readily available biological material.

A high concentration of circulating vascular endothelial growth factor (VEGF) in cancer patients is associated with an aggressive tumor phenotype. Here, serum levels of 27 cytokines and blood cell counts were assessed in breast cancer patients receiving neoadjuvant chemotherapy with or without bevacizumab (Bev) in a randomized cohort of 132 patients with non-metastatic HER2-negative tumors. Cytokine levels were determined prior to treatment and at various time-points. The cytotoxic chemotherapy regimen of fluorouracil, epirubicin, and cyclophosphamide (FEC) had a profound impact on both circulating white blood cells and circulating cytokine levels. At the end of FEC treatment, the global decrease in cytokine levels correlated with the drop in white blood cell counts and was significantly greater in the patients of the Bev arm for cytokines, such as VEGF-A, IL-12, IP-10 and IL-10. Among patients who received Bev, those with pathological complete response (pCR) exhibited significantly lower levels of VEGF-A, IFN-γ, TNF-α and IL-4 than patients without pCR. This effect was not observed in the chemotherapy-only arm. Certain circulating cytokine profiles were found to correlate with different immune cell types at the tumor site. For the Bev arm patients, the serum cytokine levels correlated with higher levels of cytotoxic T cells at the end of the therapy regimen, which was indicative of treatment response. The higher response rate for Bev-treated patients and stronger correlations between serum cytokine levels and infiltrating CD8T cells merits further investigation.

Natural killer (NK) cells hold potential as a source of allogeneic cytotoxic effector cells for chimeric antigen receptor (CAR)-mediated therapies. Here, we explored the feasibility of transfecting CAR-encoding mRNA into primary NK cells and investigated how the intrinsic potential of discrete NK-cell subsets affects retargeting efficiency. After screening five second- and third-generation anti-CD19 CAR constructs with different signaling domains and spacer regions, a third-generation CAR with the CH2-domain removed was selected based on its expression and functional profiles. Kinetics experiments revealed that CAR expression was optimal after 3 days of IL15 stimulation prior to transfection, consistently achieving over 80% expression. CAR-engineered NK cells acquired increased degranulation toward CD19 + targets, and maintained their intrinsic degranulation response toward CD19 - K562 cells. The response of redirected NK-cell subsets against CD19 + targets was dependent on their intrinsic thresholds for activation determined through both differentiation and education by killer cell immunoglobulin-like receptors (KIR) and/or CD94/NKG2A binding to self HLA class I and HLA-E, respectively. Redirected primary NK cells were insensitive to inhibition through NKG2A/HLA-E interactions but remained sensitive to inhibition through KIR depending on the amount of HLA class I expressed on target cells. Adaptive NK cells, expressing NKG2C, CD57, and self-HLA-specific KIR(s), displayed superior ability to kill CD19 + , HLA low, or mismatched tumor cells. These findings support the feasibility of primary allogeneic NK cells for CAR engineering and highlight a need to consider NK-cell diversity when optimizing efficacy of cancer immunotherapies based on CAR-expressing NK cells. Cancer Immunol Res; 6(4); 467-80. ©2018 AACR ., (©2018 American Association for Cancer Research.)

Purpose: Radiation therapy effectively kills cancer cells and elicits local effects in the irradiated tissue. The aim of this study was to investigate the kinetics of cytokines in the serum of patients with lung cancer undergoing radiation therapy and to identify associations with metabolic tumor burden as determined by 2-deoxy-2-fluoro-D-glucose ( 18 F-FDG) positron emission tomography (PET)., Methods and Materials: Forty-five patients with advanced non-small cell lung cancer were included in a phase 2 clinical trial and randomized between fractionated thoracic radiation therapy alone or concurrent with an epidermal growth factor receptor inhibitor. Blood was sampled at 4 different time points: prior to treatment, midtherapy, at the end of therapy, and 6 to 8 weeks after the start of treatment. The serum concentrations of 48 cytokines and 9 matrix metalloproteinases were measured with multiplex immunoassays. A subset of patients was examined by 18 F-FDG PET/computed tomography before, during, and after radiation therapy. The maximum standardized uptake values (SUV max ) of the primary lung tumor, whole-body metabolic tumor volume, and total lesion glycolysis were calculated, and correlations between the PET parameters and cytokines were investigated., Results: The SUV max decreased from baseline through midtherapy to posttherapy 18 F-FDG PET/computed tomography ( P  = .018). The serum levels of C-C motif chemokine ligand (CCL) 23, CCL24, C-X3-C motif chemokine ligand 1, and interleukin-8 (C-X-C motif ligand [CXCL]8) were significantly correlated to SUV max , metabolic tumor volume, and total lesion glycolysis before, during, and after radiation therapy. CXCL2 ( P  = .030) and CXCL6 ( P  = .010) decreased after the start of therapy and changed significantly across the sample time points. Serum concentrations of CCL15 ( P  = .031), CXCL2 ( P  = .028), and interleukin-6 ( P  = .007) were positively correlated to the irradiated volume during the second week of treatment., Conclusions: Cytokine serum levels vary and correlate with metabolic tumor burden in patients with advanced non-small cell lung cancer undergoing palliative thoracic radiation therapy.

Background: The aim of this study was to investigate the prognostic value of the PAM50 intrinsic subtypes and risk of recurrence (ROR) score in patients with early breast cancer and long-term follow-up. A special focus was placed on hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) pN0 patients not treated with chemotherapy., Methods: Patients with early breast cancer (n = 653) enrolled in the observational Oslo1 study (1995-1998) were followed for distant recurrence and breast cancer death. Clinicopathological parameters were collected from hospital records. The primary tumors were analyzed using the Prosigna® PAM50 assay to determine the prognostic value of the intrinsic subtypes and ROR score in comparison with pathological characteristics. The primary endpoints were distant disease-free survival (DDFS) and breast cancer-specific survival (BCSS)., Results: Of 653 tumors, 52.2% were classified as luminal A, 26.5% as luminal B, 10.6% as HER2-enriched, and 10.7% as basal-like. Among the HR+/HER2- patients (n = 476), 37.8% were categorized as low risk by ROR score, 22.7% as intermediate risk, and 39.5% as high risk. Median follow-up durations for BCSS and DDFS were 16.6 and 7.1 years, respectively. Multivariate analysis showed that intrinsic subtypes (all patients) and ROR risk classification (HR+/HER2- patients) yielded strong prognostic information. Among the HR+/HER2- pN0 patients with no adjuvant treatment (n = 231), 53.7% of patients had a low ROR, and their prognosis at 15 years was excellent (15-year BCSS 96.3%). Patients with intermediate risk had reduced survival compared with those with low risk (p = 0.005). In contrast, no difference in survival between the low- and intermediate-risk groups was seen for HR+/HER2- pN0 patients who received tamoxifen only. Ki-67 protein, grade, and ROR score were analyzed in the unselected, untreated pT1pN0 HR+/HER2- population (n = 171). In multivariate analysis, ROR score outperformed both Ki-67 and grade. Furthermore, 55% of patients who according to the PREDICT tool ( http://www.predict.nhs.uk/ ) would be considered chemotherapy candidates were ROR low risk (33%) or luminal A ROR intermediate risk (22%)., Conclusions: The PAM50 intrinsic subtype classification and ROR score improve classification of patients with breast cancer into prognostic groups, allowing for a more precise identification of future recurrence risk and providing an improved basis for adjuvant treatment decisions. Node-negative patients with low ROR scores had an excellent outcome at 15 years even in the absence of adjuvant therapy.

This report covers the Immunotherapy sessions of the 2016 Organisation of European Cancer Institutes (OECI) Oncology Days meeting, which was held on 15th-17th June 2016 in Brussels, Belgium. Immunotherapy is a potential cancer treatment that uses an individual's immune system to fight the tumour. In recent years significant advances have been made in this field in the treatment of several advanced cancers. Cancer immunotherapies include monoclonal antibodies that are designed to attack a very specific part of the cancer cell and immune checkpoint inhibitors which are molecules that stimulate or block the inhibition of the immune system. Other cancer immunotherapies include vaccines and T cell infusions. This report will summarise some of the research that is going on in this field and will give us an update on where we are at present.

Development of lung cancer is closely related to smoking in a majority of patients. Most smokers, however, do not develop lung cancer in spite of a high mutational load accumulating in the lung tissue. Here we investigate whether a cancer-specific footprint can be revealed by investigating circulating inflammatory markers in patients with non-small cell lung cancer (NSCLC) compared with patients with chronic obstructive pulmonary disease (COPD), both cohorts characterised by similar smoking history. Serum concentrations of 57 cytokines and matrix metalloproteinases (MMPs) from 43 patients with advanced NSCLC were evaluated by multiplex immunoassays and compared with serum samples from 35 patients with COPD. Unsupervised hierarchical clustering and non-parametric analyses were performed. False discovery rate was used to adjust for multiple testing. Clustering of cytokine and MMP concentrations in the serum revealed a distinct separation of the NSCLC patients from the COPD group. Individual concentrations of thymus and activation-regulated cytokine (C-C motif chemokine ligand 17), Gro-b (C-X-C motif chemokine ligand 2 (CXCL2)), CXCL13, interleukin (IL)-1ra, IL-6, IL-8 (CXCL8), IL-16, IL-17A, macrophage migration inhibitory factor (MIF), granulocyte colony-stimulating factor, platelet-derived growth factor subunit B, MMP-2, MMP-8 and MMP-12 were significantly different in serum from NSCLC and COPD patients. Moreover, the interferon-γ/IL-10 ratio was lower in cancer patients compared with COPD patients, consistent with a cytokine milieu favouring tumour tolerance. Our results suggest that NSCLC is characterised by a distinct inflammatory signature in serum. The different cytokine profiles in NSCLC and COPD patients may represent tumour-promoting and tumour-suppressing immune responses developing in response to mucosal inflammation and mutations induced by smoking.

We herein report retargeting of T-helper (Th) cells against the universal cancer antigen telomerase for use in adoptive cell therapy. The redirected Th cells may counter tumor tolerance, transform the inflammatory milieu, and induce epitope spreading and cancer senescence. We have previously conducted a series of trials evaluating vaccination with telomerase peptides. From long-term survivors, we isolated >100 CD4 + Th-cell clones recognizing telomerase epitopes. The clones were characterized with regard to HLA restriction, functional avidity, fine specificity, proliferative capacity, cytokine profile, and recognition of naturally processed epitopes. DP4 is the most prevalent HLA molecule worldwide. Two DP4-restricted T-cell clones with different functional avidity, C13 and D71, were selected for molecular T-cell receptor (TCR) cloning. Both clones showed a high proliferative capacity, recognition of naturally processed telomerase epitopes, and a polyfunctional and Th1-weighted cytokine profile. TCR C13 and D71 were cloned into the retroviral vector MP71 together with the compact and GMP-applicable marker/suicide gene RQR8. Both TCRs were expressed well in recipient T cells after PBMC transduction. The transduced T cells co-expressed RQR8 and acquired the desired telomerase specificity, with a polyfunctional response including production of TNFa, IFNγ, and CD107a. Interestingly, the DP4-restricted TCRs were expressed and functional both in CD4 + and CD8 + T cells. The findings demonstrate that the cloned TCRs confer recipient T cells with the desired hTERT-specificity and functionality. We hypothesize that adoptive therapy with Th cells may offer a powerful novel approach for overcoming tumor tolerance and synergize with other forms of immunotherapy.

The most effective anticancer immune responses are probably directed against patient-specific neoantigens. We have developed a melanoma vaccine targeting this individual mutanome based on dendritic cells (DCs) loaded with autologous tumor-mRNA. Here, we report a phase I/II trial evaluating toxicity, immune response and clinical outcome in 31 metastatic melanoma patients. The first cohort (n = 22) received the vaccine without any adjuvant; the next cohort (n = 9) received adjuvant IL2. Each subject received four weekly intranodal or intradermal injections, followed by optional monthly vaccines. Immune response was evaluated by delayed-type hypersensitivity (DTH), T cell proliferation and cytokine assays. Data were collected for 10 y after inclusion of the last patient. No serious adverse events were detected. In the intention-to-treat-cohort, we demonstrated significantly superior survival compared to matched controls from a benchmark meta-analysis (1 y survival 43% vs. 24%, 2 y 23% vs. 6.6%). A tumor-specific immune response was demonstrated in 16/31 patients. The response rate was higher after intradermal than intranodal vaccination (80% vs. 38%). Immune responders had improved survival compared to non-responders (median 14 mo vs. 6 mo; p = 0.030), and all eight patients surviving >20 mo were immune responders. In addition to the tumor-specific response, most patients developed a response against autologous DC antigens. The cytokine profile was polyfunctional and did not follow a Th1/Th2 dichotomy. We conclude that the favorable safety profile and evidence of a possible survival benefit warrant further studies of the RNA/DC vaccine. The vaccine appears insufficient as monotherapy, but there is a strong rationale for combination with checkpoint modulators.

The immune checkpoint inhibitor ipilimumab provides long term survival in some metastatic melanoma patients, but the majority has no benefit, and may experience serious side effects. Here, we investigated the dynamics of plasma cytokine concentrations and their potential utility for predicting treatment response, adverse events and overall survival (OS) in patients with metastatic melanoma undergoing ipilimumab monotherapy. A cohort of 148 patients was examined, with plasma samples collected prior to treatment initiation and at the end of the first and second treatment cycles. Concentrations of 48 plasma proteins were measured using a multiplex immunoassay. The results revealed a general increase in cytokine levels following the first ipilimumab dose, consistent with immune activation. Patients not responding to treatment exhibited significantly elevated baseline levels of G-CSF, IL-2RA, MIP-1a, and SCF, compared to tumor responders ( p  < 0.05). Furthermore, high levels of IL-2RA, IFNγ, PDGF-bb and MIG were linked to inferior OS, while high concentrations of MIF and RANTES were associated with improved OS ( p  < 0.05). A multivariate model containing CRP, LDH, ECOG, IL-2RA and PDGF-bb identified a subgroup of patients with poor OS. Patients who experienced severe immune-related adverse events within three months of treatment initiation had higher baseline concentrations of several cytokines, indicating a potential association between preexisting inflammation and adverse events. These findings indicate that the first dose of ipilimumab induces a systemic response with increased levels of circulating cytokines and suggest candidate biomarkers for clinical response, immune-mediated toxicity and survival. Further studies in independent patient cohorts are required to confirm the findings.

We have previously reported two trials in non-small cell lung cancer (NSCLC) evaluating vaccine therapy with the telomerase peptide GV1001. The studies demonstrated considerable differences in survival among immune responders, highlighting that an immune response is not necessarily beneficial. In the present study, we conducted long-term clinical follow-up and investigated immunological factors hypothesized to influence clinical efficacy. Peripheral blood mononuclear cells from 33 NSCLC trial patients and 15 healthy donors were analyzed by flow cytometry for T regulatory cells (Tregs, CD4(+)CD25(+)CD127(low/-)FOXP3(+)) and two types of myeloid-derived suppressor cells (MDSCs, HLA-DR (low) CD14 (+) or Lin (-/lo) HLA-DR (-) CD33 (+) CD11b (+)). T cell cultures were analyzed for 17 cytokines. The results demonstrated that immune responders had increased overall survival (OS, p < 0.001) and progression-free survival (p = 0.003), compared to subjects without immunological response. The mean OS advantage was 54 versus 13 months. Six patients were still alive at the last clinical update, all belonging to the immune responders. No serious toxicity had developed (maximum observation 13 years). Most patients developed a polyfunctional cytokine profile, with high IFNγ/IL-4 and IFNγ/IL-10 ratios. Low Treg levels were associated with improved OS (p = 0.037) and a favorable cytokine profile, including higher IFNγ/IL-10 ratios. High CD33(+) MDSC levels were associated with poorer immune response rate (p = 0.005). The levels of CD14(+) MDSC were significantly higher in patients than in healthy controls (p = 0.012). We conclude that a randomized GV1001 trial in NSCLC is warranted. The findings suggest that Tregs and MDSCs are associated with a tolerogenic cytokine milieu and impaired clinical efficacy of vaccine responses.

Cancer therapy with T cells expressing chimeric antigen receptors (CARs) has produced remarkable clinical responses in recent trials, but also severe side effects. Whereas most protocols use permanently reprogrammed T cells, we have developed a platform for transient CAR expression by mRNA electroporation. This approach may be useful for safe clinical testing of novel receptors, or when a temporary treatment period is desirable. Herein, we investigated therapy with transiently redirected T cells in vitro and in a xenograft mouse model. We constructed a series of CD19-specific CARs with different spacers and co-stimulatory domains (CD28, OX40 or CD28-OX40). The CAR constructs all conferred T cells with potent CD19-specific activity in vitro. Unexpectedly, the constructs incorporating a commonly used IgG1-CH2CH3 spacer showed lack of anti-leukemia activity in vivo and induced severe, partly CD19-independent toxicity. By contrast, identical CAR constructs without the CH2-domain eradicated leukemia in vivo, without notable toxicity. Follow-up studies demonstrated that the CH2CH3-spacer bound soluble mouse Fcγ-receptor I and mediated off-target T-cell activation towards murine macrophages. Our findings highlight the importance of non-signalling CAR elements and of in vivo studies. Finally, the results show that transiently redirected T cells control leukemia in mice and support the rationale for developing an mRNA-CAR platform.

Cancer cells escape T-cell-mediated destruction by losing human leukocyte antigen (HLA) class I expression via various mechanisms, including loss of beta2-microglobulin (β2m). Our study illustrates the immune escape of HLA class I-negative tumor cells and chronological sequence of appearance of tumor β2m gene mutation in successive lesions obtained from a patient with metastatic melanoma. We observed a gradual decrease in HLA expression in consecutive lesions with few HLA-negative nodules in the primary tumor and the emergence of a totally negative lesion at later stages of the disease. We detected loss of β2m in β2m-negative nests of the primary tumor caused by a combination of two alterations: (i) a mutation (G to T substitution) in codon 67 in exon 2 of β2m gene, producing a stop codon and (ii) loss of the second gene copy by loss of heterozygosity (LOH) in chromosome 15. The same β2m mutation was found in a homogeneously β2m-negative metastasis 10 months later and in a cell line established from a biopsy of a postvaccination lymph node. Microsatellite analysis revealed the presence of LOH in chromosomes 6 and 15 in tumor samples, showing an accumulation of chromosomal loss at specific short tandem repeats in successive metastases during disease progression. HLA loss correlated with decreased tumor CD8+ T-cell infiltration. Early incidence of β2m defects can cause an immune selection and expansion of highly aggressive melanoma clones with irreversible genetic defects causing total loss of HLA class I expression and should be taken into consideration as a therapeutic target in the development of cancer immunotherapy protocols., (© 2013 UICC.)

Purpose: We report two clinical trials in non-small cell lung cancer (NSCLC) patients evaluating immune response, toxicity, and clinical outcome after vaccination with the telomerase peptide GV1001: a phase II trial (CTN-2006) in patients vaccinated after chemoradiotherapy and an 8-year update on a previously reported phase I/II trial (CTN-2000)., Experimental Design: CTN-2006: 23 inoperable stage III patients received radiotherapy (2 Gy × 30) and weekly docetaxel (20 mg/m(2)), followed by GV1001 vaccination. CTN-2000: 26 patients were vaccinated with two telomerase peptides (GV1001 and I540). The immune responses were evaluated by T-cell proliferation and cytokine assays., Results: CTN-2006 trial: a GV1001-specific immune response developed in 16/20 evaluable patients. Long-term immunomonitoring showed persisting responses in 13 subjects. Serious adverse events were not observed. Immune responders recorded a median PFS of 371 days, compared with 182 days for nonresponders (P = 0.20). CTN-2000 trial update: 13/24 evaluable subjects developed a GV1001 response. The immune responders achieved increased survival compared with nonresponders (median 19 months vs. 3.5 months; P < 0.001). Follow-up of four long-time survivors showed that they all harbored durable GV1001-specific T-cell memory responses and IFNγ(high)/IL-10(low)/IL-4(low) cytokine profiles. Two patients are free of disease after 108 and 93 months, respectively., Conclusions: Vaccination with GV1001 is well tolerated, immunizes the majority of NSCLC patients and establishes durable T-cell memory. The considerable immune response rate and low toxicity in the phase II trial support the concept of combining chemoradiotherapy with vaccination. The survival advantage observed for immune responders warrants a randomized trial., (©2011 AACR)

Purpose: The study is a proof-of-principle trial evaluating toxicity, immune response, and clinical response in melanoma patients after combined therapy with temozolomide and the telomerase peptide vaccine GV1001. Our previous GV1001 trials showed immune responses in approximately 60% of lung or pancreatic cancer patients., Experimental Design: Twenty-five subjects with advanced stage IV melanoma (M1B or M1C) received concomitant temozolomide and GV1001. Temozolomide was administered 200 mg/m² orally for 5 days every fourth week, and GV1001 as eight injections over 11 weeks. Immune response was evaluated by delayed type hypersensitivity, T-cell proliferation, and cytokine assays. The immunologic responders continued monthly vaccination., Results: The treatment was well tolerated. A GV1001-specific immune response was shown in 18 of 23 evaluated subjects (78%). Patients developing long-term T-cell memory survived more than those rapidly losing their responses. The immune response exhibited several characteristics of possible clinical significance including high IFNγ/IL-10 ratios, polyfunctional cytokine profiles, and recognition of naturally processed antigens. Survival compared favorably with matched controls from a benchmark meta-analysis (1 year: 44% vs. 24%, 2 years: 16% vs. 6.6%). The clinical responses developed gradually over years, contrary to what is expected from chemotherapy. Five patients developed partial tumor regression and six more recorded stable disease. One patient has no remaining disease on fluorodeoxyglucose positron emission tomography scans after 5 years., Conclusions: The immunologic response rate is considerable compared with previous GV1001 trials without concomitant chemotherapy, although low toxicity is retained. The results warrant further studies of GV1001/temozolomide treatment and support the general concept of combining cancer vaccination with chemotherapy.

Cancer vaccine trials frequently report on immunological responses, without any clinical benefit. This paradox may reflect the challenge of discriminating between effective and pointless immune responses and sparse knowledge on their long-term development. Here, we have analyzed T cell responses in long-term survivors after peptide vaccination. There were three main study aims: (1) to characterize the immune response in patients with a possible clinical benefit. (2) To analyze the long-term development of responses and effects of booster vaccination. (3) To investigate whether the Th1/Th2-delineation applies to cancer vaccine responses. T cell clones were generated from all nine patients studied. We find that surviving patients harbor durable tumor-specific responses against vaccine antigens from telomerase, RAS or TGFbeta receptor II. Analyses of consecutive samples suggest that booster vaccination is required to induce robust T cell memory. The responses exhibit several features of possible clinical advantage, including combined T-helper and cytotoxic functionality, recognition of naturally processed antigens and diverse HLA-restriction and fine-specificity. CD4(-)CD8(-) T cell clones display unconventional cytotoxicity and specifically kill tumor cells expressing mutated TGFbeta receptor II. Cytokine profiling on the long-term survivors demonstrates high IFN gamma/IL10-ratios, favoring immunity over tolerance, and secretion of multiple chemokines likely to mobilize the innate and adaptive immune system. Interestingly, these pro-inflammatory cytokine profiles do not follow a Th1/Th2-delineation. Most IFN gamma(high)/IL4(low)/IL10(low) cultures include high concentrations of hallmark Th2-cytokines IL-5 and IL-13. This does not reflect a mixture of Th1- and Th2-clones, but applies to 19/20 T cell clones confirmed to be monoclonal through TCR clonotype mapping. The present study identifies several factors that may promote clinical efficacy and suggests that cytokine profiling should not rely on the Th1/Th2-paradigm, but assess the overall inflammatory milieu and the balance between key cytokines.

Telomerase is highly expressed in essentially all cancer forms, while the expression in normal tissues is restricted. Moreover, telomerase activity is considered indispensable for tumor immortalization and growth. Human telomerase reverse transcriptase (hTERT), the rate-limiting subunit of the telomerase complex, is therefore an attractive target for cancer vaccination. The present review provides an update on the development of GV1001, a peptide vaccine representing a 16-aa hTERT sequence. GV1001 binds multiple HLA class II molecules and harbors putative HLA class I epitopes. The peptide may therefore elicit combined CD4/CD8 T-cell responses, considered important to initiate tumor eradication and long-term memory. Phase I/II trials in advanced pancreatic and pulmonary cancer patients have demonstrated GV1001-specific T-cell responses in > 50% of subjects, without clinically important toxicity. The results indicate a correlation between development of GV1001-specific responses and prolonged survival. However, as in most cancer vaccine trials, a large proportion of immune responders experience no clinical benefit. Long-term survivors harbor durable GV1001-specific T-cell responses with high IFN-gamma/IL-10 ratios and polyfunctional cytokine patterns. Interestingly, the cytokine profiles do not follow a T(H)1/T(H)2 delineation. Here, the author discusses how immunomonitoring may be improved to discriminate between efficient and pointless immune responses, and which questions to address in the further development of GV1001.

We have developed an individualized melanoma vaccine based on autologous dendritic cells (DCs) transfected with autologous tumor-mRNA. The vaccine targets the unique spectrum of tumor antigens in each patient and may recruit multiple T cell clones. In a recent phase I/II trial, we demonstrated T cell responses against vaccine antigens in 9/19 patients evaluable by T cell assays. Here, we report a follow-up study that was conducted to characterize interesting T cell responses and to investigate the effects of long-term booster vaccination. Two patients were selected for continued vaccine therapy. The clinical follow-up suggested a favorable clinical development in both patients. The immunological data (T cell proliferation/IFNgamma ELISPOT/Bioplex cytokine assays) indicated sustained T cell responses and suggested an enhancing effect of booster vaccinations. Both CD4(+) and CD8(+) T cell responses were demonstrated. From post-vaccination samples, we generated 39 T cell clones that responded specifically to stimulation by mRNA-transfected DCs and 12 clones that responded to mock-transfected DCs. These data clearly indicate a two-component vaccine response, against transfected and non-transfected antigens. T cell receptor (TCR) clonotype mapping, performed on 11 tDC-specific clones, demonstrated that 10/11 clones had different TCRs. The results thus indicate a broad spectrum T cell response against antigens encoded by the transfected tumor-mRNA. We generally observed mixed Th1/Th2 cytokine profiles, even in T cell clones that were confirmed to be derived from a single cell. This finding suggests that cytokine patterns after cancer vaccination may be more complex than indicated by the classic Th1/Th2 dichotomy.

Immunotherapy is in principle attractive, as it exploits the immune system's own method of recognizing and destroying tumours. Tumour cells express a number of mutated or over-expressed antigens, which make it possible for the immune system to distinguish between tumour cells and normal cells. Cancer vaccines use tumour-associated antigens to stimulate the patient's immune cells. In the clinical setting, individual differences between cancer patients is of vital importance, as the majority of tumour antigens may be unique to each individual. Genetic differences in patients' immune systems also suggest the need for individualised vaccines. This article gives a short introduction to the basic principles of tumour immunology and development of cancer vaccines. Clinical trials with emphasis on those with peptide and dendritic cell vaccines are presented, and the future development of cancer vaccines is discussed. A number of trials have shown tumour-specific immune responses and demonstrated that side-effects are generally not a problem. Limited documentation is available for the clinical effects. It is important to establish why some immune responses appear to give tumour regression while others are without clinical importance.

We have developed immuno-gene therapy for malignant melanoma and prostate cancer. The therapy is based on monocyte-derived dendritic cells (DCs) that are transfected with autologous melanoma-mRNA or mRNA from three prostate cancer cell lines (DU-145, LN-CaP and PC-3). A broad spectrum of tumour-associated antigens will be included in both DC-vaccines. The use of autologous melanoma-mRNA moreover allows targeting of individual tumour antigens that are specific to each patient. Effective protocols have been established for mRNA-transfection by square wave electroporation and for the generation of clinical grade DCs. A full scale preclinical evaluation demonstrated in vitro T cell responses in 6/6 advanced melanoma patients. The responses were specific to antigens encoded by the transfected tumour-mRNA. Recently, we have conducted two phase I/II trials, in advanced malignant melanoma and androgen-resistant prostate cancer. Successful vaccine preparations were obtained for all 41 patients elected. No serious adverse effects were observed. Specific T cell responses (T cell proliferation and/or IFNgamma ELISPOT) were demonstrated in 9/19 evaluable melanoma patients and in 12/19 prostate cancer patients. The response rates were higher for patients receiving intradermal vaccination, compared to intranodal injection. Thirteen prostate cancer patients developed a decrease in log-slope PSA. The PSA-response was significantly related to the T cell response (P=0.002). We conclude that the DC-vaccine is feasible and safe, and that T cell responses are elicited in about 50% of patients.

We have developed an individualized melanoma vaccine based on transfection of autologous dendritic cells (DCs) with autologous tumor-mRNA. Dendritic cells loaded with complete tumor-mRNA may generate an immune response against a broad repertoire of antigens, including unique patient-specific antigens. The purpose of the present phase I/II trial was to evaluate the feasibility and safety of the vaccine, and the ability of the DCs to elicit T-cell responses in melanoma patients. Further, we compared intradermal (i.d.) and intranodal (i.n.) vaccine administration. Twenty-two patients with advanced malignant melanoma were included, each receiving four weekly vaccines. Monocyte-derived DCs were transfected with tumor-mRNA by electroporation, matured and cryopreserved. We obtained successful vaccine production for all patients elected. No serious adverse effects were observed. A vaccine-specific immune response was demonstrated in 9/19 patients evaluable by T-cell assays (T-cell proliferation/interferon-gamma ELISPOT) and in 8/18 patients evaluable by delayed-type hypersensitivity (DTH) reaction. The response was demonstrated in 7/10 patients vaccinated intradermally and in 3/12 patients vaccinated intranodally. We conclude that immuno-gene-therapy with the described DC-vaccine is feasible and safe, and that the vaccine can elicit in vivo T-cell responses against antigens encoded by the transfected tumor-mRNA. The response rates do not suggest an advantage in applying i.n. vaccination.