Platinum-based chemotherapy attenuates the effector response of CD8 T cells to concomitant PD-1 blockade.

PURPOSE: Combination of chemotherapy (CT) with programmed cell death (PD)-1 blockade is a front-line treatment for lung cancer. However, it remains unknown whether and how CT affects the response of exhausted CD8 T cells to PD-1 blockade. EXPERIMENTAL DESIGN: We used the well-established mouse model of T cell exhaustion with chronic lymphocytic choriomeningitis virus (LCMV) infection to assess the effect of CT (cisplatin+pemetrexed) on T cell response to PD-1 blockade, in the absence of the impact of CT on antigen release and presentation observed in tumor models. RESULTS: When concomitantly administered with PD-1 blockade, CT affected the differentiation path of LCMV-specific CD8 T cells from stem-like to transitory effector cells, thereby reducing their expansion and production of interferon (IFN)-γ. After combination treatment, these restrained effector responses resulted in impaired viral control, compared to PD-1 blockade alone. The sequential combination strategy, where PD-1 blockade followed CT, proved to be superior to the concomitant combination, preserving the proliferative response of exhausted CD8 T cells to PD-1 blockade. Our findings suggest that the stem-like CD8 T cells themselves are relatively unaffected by CT partly because they are quiescent and maintained by slow self-renewal at the steady state. However, upon the proliferative burst mediated by PD-1 blockade, the accelerated differentiation and self-renewal of stem-like cells may be curbed by concomitant CT, ultimately resulting in impaired overall CD8 T cell effector functions. CONCLUSIONS: In a translational context, we provide a proof-of-concept to consider optimizing the timing of chemo-immunotherapy strategies for improved CD8 T cell functions.

What is the optimal duration, dose and frequency for anti-PD1 therapy of non-small cell lung cancer?

Over the past decade, immune checkpoint inhibitors (ICIs) have transformed the management of multiple malignancies including lung cancer. However, the optimal use of these agents in terms of duration, dose and administration frequency remains unknown. Focusing on anti-PD1 agents nivolumab and pembrolizumab in the context of non-small cell lung cancer, we argue that several lines of evidence suggest current administration regimens of these drugs may result in overtreatment with potentially important implications for cost, quality of life and toxicity. This review summarizes evidence for the scope to optimize anti-PD1 regimens, the limitations of existing data and potential approaches to solve these problems including with a novel multi-arm clinical trial design implemented in the recently opened REFINE-Lung study.

Cancer cell-intrinsic mechanisms driving acquired immune tolerance.

Immune evasion is a hallmark of cancer, enabling tumors to survive contact with the host immune system and evade the cycle of immune recognition and destruction. Here, we review the current understanding of the cancer cell-intrinsic factors driving immune evasion. We focus on T cells as key effectors of anti-cancer immunity and argue that cancer cells evade immune destruction by gaining control over pathways that usually serve to maintain physiological tolerance to self. Using this framework, we place recent mechanistic advances in the understanding of cancer immune evasion into broad categories of control over T cell localization, antigen recognition, and acquisition of optimal effector function. We discuss the redundancy in the pathways involved and identify knowledge gaps that must be overcome to better target immune evasion, including the need for better, routinely available tools that incorporate the growing understanding of evasion mechanisms to stratify patients for therapy and trials.

Immunotherapy for GTN: a new paradigm.

Background Immune checkpoint immunotherapy (CPI) targeting PD1/PD-L1 has been shown to be an effective treatment for gestational trophoblastic neoplasia (GTN). This includes those with multidrug resistance, ultra-high risk disease and ETT/PSTT subtypes that are inherently chemotherapy resistant, but there is also emerging evidence in low-risk disease. Objectives We set out to generate an overview of the current data supporting the use of CPI for GTN in both high risk and low risk disease and to consider future research goals and directions in order to implement CPI in current treatment guidelines. Methods We identified and reviewed the published data on the use of CPI agents in GTN. Outcome 133 patients were identified who had been treated with CPI for GTN with pembrolizumab (23), avelumab (22), camrelizumab (57), toripalimab (15) or other anti-PD-1 agents (16), of whom 118 had high risk disease, relapse or multi drug resistant disease, and 15 low risk disease. Overall 85 patients achieved complete remission, 77 (of 118) with high risk disease and 8 (of 15) with low risk disease. 1 patient with complete remission in the high risk group developed a relapse 22 months after anti-PD-1 treatment had been stopped. Treatment was generally well tolerated across studies. Conclusions and Outlook The majority of high risk patients (77/118) treated with CPI are cured and this is particularly relevant amongst those with chemotherapy resistant disease who otherwise have very limited treatment options. Priorities for future research include determining whether these agents have a role earlier in the disease course, the utility of combination with chemotherapy, and effects on future fertility. Treatment availability remains a concern due to the high price of these agents.

REFINE-Lung implements a novel multi-arm randomised trial design to address possible immunotherapy overtreatment.

Increasing evidence suggests that some immunotherapy dosing regimens for patients with advanced cancer could result in overtreatment. Given the high costs of these agents, and important implications for quality of life and toxicity, new approaches are needed to identify and reduce unnecessary treatment. Conventional two-arm non-inferiority designs are inefficient in this context because they require large numbers of patients to explore a single alternative to the standard of care. Here, we discuss the potential problem of overtreatment with anti-PD-1 directed agents in general and introduce REFINE-Lung (NCT05085028), a UK multicentre phase 3 study of reduced frequency pembrolizumab in advanced non-small-cell lung cancer. REFINE-Lung uses a novel multi-arm multi-stage response over continuous interventions (MAMS-ROCI) design to determine the optimal dose frequency of pembrolizumab. Along with a similarly designed basket study of patients with renal cancer and melanoma, REFINE-Lung and the MAMS-ROCI design could contribute to practice-changing advances in patient care and form a template for future immunotherapy optimisation studies across cancer types and indications. This new trial design is applicable to many new or existing agents for which optimisation of dose, frequency, or duration of therapy is desirable.

Novel approaches to managing gestational trophoblastic tumors in the age of immunotherapy.

The discovery that anti-programmed death-1 antibody (anti-PD-1) immunotherapy can cure patients with multidrug-resistant gestational trophoblastic neoplasia provides a new powerful and low toxicity treatment. This heralds an era within which the majority of patients, including those with previously difficult to treat disease, can expect to achieve long-term remission. This development should prompt a rethink of how patients with this rare disease are managed, focusing on maximizing cure rate with minimal exposure to toxic chemotherapy.

Two faces: IL-22 effects prevail over defense against metastasis.

Interleukin-22 (IL-22) is a cytokine with pleotropic and opposing roles in physiological and pathological states. In this issue of Immunity, Giannou et al. and Briukhovetska et al. demonstrate how IL-22 is involved in promoting cancer metastasis formation.

REFINE (REduced Frequency ImmuNE checkpoint inhibition in cancers): A multi-arm phase II basket trial testing reduced intensity immunotherapy across different cancers.

BACKGROUND: Immune checkpoint inhibitors (ICI) have revolutionised treating advanced cancers. ICI are administered intravenously every 2-6 weeks for up to 2 years, until cancer progression/unacceptable toxicity. Physiological efficacy is observed at lower doses than those used as standard of care (SOC). Pharmacodynamic studies indicate sustained target occupancy, despite a pharmacological half-life of 2-3 weeks. Reducing frequency of administration may be possible without compromising outcomes. The REFINE trial aims to limit individual patient exposure to ICI whilst maintaining efficacy, with potential benefits in quality of life and reduced drug treatment/attendance costs. METHODS/DESIGN: REFINE is a randomised phase II, multi-arm, multi-stage (MAMS) adaptive basket trial investigating extended interval administration of ICIs. Eligible patients are those responding to conventionally dosed ICI at 12 weeks. In stage I, patients (n = 160 per tumour-specific cohort) will be randomly allocated (1:1) to receive maintenance ICI at SOC vs extended dose interval. REFINE is currently recruiting UK patients with locally advanced or metastatic renal cell carcinoma (RCC) who have tolerated and responded to initial nivolumab/ipilimumab, randomised to receive maintenance nivolumab SOC (480 mg 4 weekly) vs extended interval (480 mg 8 weekly). Additional tumour cohorts are planned. Subject to satisfactory outcomes (progression-free survival) stage II will investigate up to 5 different treatment intervals. Secondary outcome measures include overall survival, quality-of-life, treatment-related toxicity, mean incremental pathway costs and quality-adjusted life-years per patient. REFINE is funded by the Jon Moulton Charity Trust and Medical Research Council, sponsored by University College London (UCL), and coordinated by the MRC CTU at UCL. Trial Registration ISRCTN79455488. NCT04913025 EUDRACT #: 2021-002060-47. CTA 31330/0008/001-0001; MREC approval: 21/LO/0593. REFINE Protocol version 4.0.

Sensitive screening of single nucleotide polymorphisms in cell free DNA for diagnosis of gestational tumours.

Tumours expressing human chorionic gonadotropin (hCG), the majority of which are difficult to biopsy due to their vascularity, have disparate prognoses depending on their origin. As optimal management relies on accurate diagnosis, we aimed to develop a sensitive cell free DNA (cfDNA) assay to non-invasively distinguish between cases of gestational and non-gestational origin. Deep error-corrected Illumina sequencing of 195 common single nucleotide polymorphisms (SNPs) in cfDNA and matched genomic DNA from 36 patients with hCG-secreting tumours (serum hCG 5 to 3,042,881 IU/L) and 7 controls with normal hCG levels (≤4 IU/L) was performed. cfDNA from confirmed gestational tumours with hCG levels ranging from 1497 to 700,855 IU/L had multiple (n ≥ 12) 'non-host' alleles (i.e. alleles of paternal origin). In such cases the non-host fraction of cfDNA ranged from 0.3 to 40.4% and correlated with serum hCG levels. At lower hCG levels the ability to detect non-host cfDNA was variable, with the detection limit dependent on the type of causative pregnancy. Patients with non-gestational tumours were identifiable by the absence of non-host cfDNA, with copy number alterations detectable in the majority of cases. Following validation in a larger cohort, our sensitive assay will enable clinicians to better inform patients, for whom biopsy is inappropriate, of their prognosis and provide optimum management.

Determinants of anti-PD-1 response and resistance in clear cell renal cell carcinoma.

ADAPTeR is a prospective, phase II study of nivolumab (anti-PD-1) in 15 treatment-naive patients (115 multiregion tumor samples) with metastatic clear cell renal cell carcinoma (ccRCC) aiming to understand the mechanism underpinning therapeutic response. Genomic analyses show no correlation between tumor molecular features and response, whereas ccRCC-specific human endogenous retrovirus expression indirectly correlates with clinical response. T cell receptor (TCR) analysis reveals a significantly higher number of expanded TCR clones pre-treatment in responders suggesting pre-existing immunity. Maintenance of highly similar clusters of TCRs post-treatment predict response, suggesting ongoing antigen engagement and survival of families of T cells likely recognizing the same antigens. In responders, nivolumab-bound CD8+ T cells are expanded and express GZMK/B. Our data suggest nivolumab drives both maintenance and replacement of previously expanded T cell clones, but only maintenance correlates with response. We hypothesize that maintenance and boosting of a pre-existing response is a key element of anti-PD-1 mode of action.

Predictors for single-agent resistance in FIGO score 5 or 6 gestational trophoblastic neoplasia: a multicentre, retrospective, cohort study.

BACKGROUND: Patients with gestational trophoblastic neoplasia who have an International Federation of Gynaecology and Obstetrics (FIGO) risk score of 5 or 6 usually receive non-toxic single-agent chemotherapy as a first-line treatment. Previous studies suggest that only a third of patients have complete remission, with the remaining patients requiring toxic multiagent chemotherapy to attain remission. As stratification factors are unknown, some centres offer multiagent therapy upfront, resulting in overtreatment of many patients. We aimed to identify predictive factors for resistance to single-agent therapy to inform clinicians on which patients presenting with a FIGO score of 5 or 6 are likely to benefit from upfront multiagent chemotherapy. METHODS: We did a multicentre, retrospective, cohort study of patients with gestational trophoblastic neoplasia presenting with a FIGO score of 5 or 6, who received treatment at three gestational trophoblastic neoplasia reference centres in the UK, Brazil, and the USA between Jan 1, 1964, and Dec 31, 2018. All patients who had been followed up for at least 12 months after remission were included. Patients were excluded if they had received a non-standard single-agent treatment (eg, etoposide); had been given a previously established first-line multiagent chemotherapy regimen; or had incomplete data for our analyses. Patient data were retrieved from medical records. The primary outcome was the incidence of chemoresistance after first-line or second-line single-agent chemotherapy. Variables associated with chemoresistance to single-agent therapies were identified by logistic regression analysis. In patient subgroups defined by choriocarcinoma histology and metastatic disease status, we did bootstrap modelling to define thresholds of pretreatment human chorionic gonadotropin concentrations and identify groups of patients with a greater than 80% risk (ie, a positive predictive value [PPV] of 0·8) of resistance to single-agent chemotherapy. FINDINGS: Of 5025 patients with low-risk gestational trophoblastic neoplasia, we identified 431 patients with gestational trophoblastic neoplasia presenting with a FIGO risk score of 5 or 6. All patients were followed up for a minimum of 2 years. 141 (40%) of 351 patients developed resistance to single-agent treatments and required multiagent chemotherapy to achieve remission. Univariable and multivariable logistic regression revealed metastatic disease status (multivariable logistic regression analysis, odds ratio [OR] 1·9 [95% CI 1·1-3·2], p=0·018), choriocarcinoma histology (3·7 [1·9-7·4], p=0·0002), and pretreatment human chorionic gonadotropin concentration (2·8 [1·9-4·1], p<0·0001) as significant predictors of resistance to single-agent therapies. In patients with no metastatic disease and without choriocarcinoma, a pretreatment human chorionic gonadotropin concentration of 411 000 IU/L or higher yielded a PPV of 0·8, whereas in patients with either metastases or choriocarcinoma, a pretreatment human chorionic gonadotropin concentration of 149 000 IU/L or higher yielded the same PPV for resistance to single-agent therapy. INTERPRETATION: Approximately 60% of women with gestational trophoblastic neoplasia presenting with a FIGO risk score of 5 or 6 achieve remission with single-agent therapy; almost all remaining patients have complete remission with subsequent multiagent chemotherapy. Primary multiagent chemotherapy should only be given to patients with metastatic disease and choriocarcinoma, regardless of pretreatment human chorionic gonadotropin concentration, or to those defined by our new predictors. FUNDING: None. TRANSLATION: For the Portuguese translation of the abstract see Supplementary Materials section.

Progress to international harmonisation of care and future developments.

Considerable differences exist in the management of gestational trophoblastic disease (GTD) both nationally and internationally despite numerous efforts to harmonise patient care. This partly reflects differences in healthcare systems and availability of resources. However, even in first world equivalent economies with similar healthcare systems differences remain, which appear to impact survival. Recently, new international guidelines have been established in Europe through a series of consensus meetings. Improvement of outcomes will depend on the establishment of dedicated centres with appropriate patient pathways according to these guidelines. This review will highlight some of the differences and efforts to unify the management of GTD across the globe and discuss areas for future development.

The T cell differentiation landscape is shaped by tumour mutations in lung cancer.

Tumour mutational burden (TMB) predicts immunotherapy outcome in non-small cell lung cancer (NSCLC), consistent with immune recognition of tumour neoantigens. However, persistent antigen exposure is detrimental for T cell function. How TMB affects CD4 and CD8 T cell differentiation in untreated tumours, and whether this affects patient outcomes is unknown. Here we paired high-dimensional flow cytometry, exome, single-cell and bulk RNA sequencing from patients with resected, untreated NSCLC to examine these relationships. TMB was associated with compartment-wide T cell differentiation skewing, characterized by loss of TCF7-expressing progenitor-like CD4 T cells, and an increased abundance of dysfunctional CD8 and CD4 T cell subsets, with significant phenotypic and transcriptional similarity to neoantigen-reactive CD8 T cells. A gene signature of redistribution from progenitor-like to dysfunctional states associated with poor survival in lung and other cancer cohorts. Single-cell characterization of these populations informs potential strategies for therapeutic manipulation in NSCLC.

Following chemotherapy for gestational trophoblastic neoplasia, do residual lung lesions increase the risk of relapse?

BACKGROUND: There remains uncertainty about the prognostic significance of residual lung lesion on imaging after completion of treatment of low- or high-risk gestational trophoblastic neoplasia (GTN). Here, we determine if such residual lung lesions are associated with an increased risk of relapse. METHODS: We retrospectively screened our electronic database to identify patients with low- or high-risk GTN and lung metastases between 2004 and 18. Recurrences among patients with or without residual lung lesions on imaging were compared. Chi square analysis and Kaplan-Meier survival curves were constructed. As the numbers of cases were low, we combined this data with our previously published and non-overlapping patient cohort (1995-2004). RESULTS: Of 1304 GTN patients treated at our centre between 2004 and 18, 99 had lung metastases without other distant sites. There were 40 patients (40.4%) with residual lung lesions. Whilst an increased rate of relapse was observed among patients with residual lung lesions (4/40; 10.0%) compared to without such lesions (3/59; 5.1%), this difference was not statistically significant (p = .35). By combining the data with our previous cohort, there was an increase in relapse rate of patients with residual lung lesions (5/63; 7.9%) compared to those without such lesions (4/112; 3.6%). However, this difference was also not statistically significant (p = .21). CONCLUSION: Residual lung lesions on imaging after completion of GTN treatment are common. However, this finding did not statistically increase relapse rate. Due to low number of recurrent events, a multi-centre, larger dataset would be needed to provide more definitive evidence.

Publisher Correction: Spatial heterogeneity of the T cell receptor repertoire reflects the mutational landscape in lung cancer.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Marrow-Infiltrating Regulatory T Cells Correlate with the Presence of Dysfunctional CD4+PD-1+ Cells and Inferior Survival in Patients with Newly Diagnosed Multiple Myeloma.

PURPOSE: Immune dysregulation is described in multiple myeloma. While preclinical models suggest a role for altered T-cell immunity in disease progression, the contribution of immune dysfunction to clinical outcomes remains unclear. We aimed to characterize marrow-infiltrating T cells in newly diagnosed patients and explore associations with outcomes of first-line therapy. EXPERIMENTAL DESIGN: We undertook detailed characterization of T cells from bone marrow (BM) samples, focusing on immune checkpoints and features of immune dysfunction, correlating with clinical features and progression-free survival. RESULTS: We found that patients with multiple myeloma had greater abundance of BM regulatory T cells (Tregs) which, in turn, expressed higher levels of the activation marker CD25 compared with healthy donors. Patients with higher frequencies of Tregs had shorter PFS and a distinct Treg immune checkpoint profile (increased PD-1, LAG-3) compared with patients with lower frequencies of Tregs. Analysis of CD4 and CD8 effectors revealed that low CD4effector (CD4eff):Treg ratio and increased frequency of PD-1-expressing CD4eff cells were independent predictors of early relapse over and above conventional risk factors, such as genetic risk and depth of response. Ex vivo functional analysis and RNA sequencing revealed that CD4 and CD8 cells from patients with greater abundance of CD4effPD-1+ cells displayed transcriptional and secretory features of dysfunction. CONCLUSIONS: BM-infiltrating T-cell subsets, specifically Tregs and PD-1-expressing CD4 effectors, negatively influence clinical outcomes in newly diagnosed patients. Pending confirmation in larger cohorts and further mechanistic work, these immune parameters may inform new risk models, and present potential targets for immunotherapeutic strategies.

Regulatory T Cells Restrain Interleukin-2- and Blimp-1-Dependent Acquisition of Cytotoxic Function by CD4+ T Cells.

In addition to helper and regulatory potential, CD4+ T cells also acquire cytotoxic activity marked by granzyme B (GzmB) expression and the ability to promote rejection of established tumors. Here, we examined the molecular and cellular mechanisms underpinning the differentiation of cytotoxic CD4+ T cells following immunotherapy. CD4+ transfer into lymphodepleted animals or regulatory T (Treg) cell depletion promoted GzmB expression by tumor-infiltrating CD4+, and this was prevented by interleukin-2 (IL-2) neutralization. Transcriptional analysis revealed a polyfunctional helper and cytotoxic phenotype characterized by the expression of the transcription factors T-bet and Blimp-1. While T-bet ablation restricted interferon-γ (IFN-γ) production, loss of Blimp-1 prevented GzmB expression in response to IL-2, suggesting two independent programs required for polyfunctionality of tumor-reactive CD4+ T cells. Our findings underscore the role of Treg cells, IL-2, and Blimp-1 in controlling the differentiation of cytotoxic CD4+ T cells and offer a pathway to enhancement of anti-tumor activity through their manipulation.

CD25-Treg-depleting antibodies preserving IL-2 signaling on effector T cells enhance effector activation and antitumor immunity.

Intratumoral regulatory T cell (Treg) abundance associates with diminished anti-tumor immunity and poor prognosis in human cancers. Recent work demonstrates that CD25, the high affinity receptor subunit for IL-2, is a selective target for Treg depletion in mouse and human malignancies; however, anti-human CD25 antibodies have failed to deliver clinical responses against solid tumors due to bystander IL-2 receptor signaling blockade on effector T cells, which limits their anti-tumor activity. Here we demonstrate potent single-agent activity of anti-CD25 antibodies optimized to deplete Tregs whilst preserving IL-2-STAT5 signaling on effector T cells, and demonstrate synergy with immune checkpoint blockade in vivo. Pre-clinical evaluation of an anti-human CD25 (RG6292) antibody with equivalent features demonstrates, in both non-human primates and humanized mouse models, efficient Treg depletion with no overt immune-related toxicities. Our data supports the clinical development of RG6292 and evaluation of novel combination therapies incorporating non-IL-2 blocking anti-CD25 antibodies in clinical studies.

Spatial heterogeneity of the T cell receptor repertoire reflects the mutational landscape in lung cancer.

Somatic mutations together with immunoediting drive extensive heterogeneity within non-small-cell lung cancer (NSCLC). Herein we examine heterogeneity of the T cell antigen receptor (TCR) repertoire. The number of TCR sequences selectively expanded in tumors varies within and between tumors and correlates with the number of nonsynonymous mutations. Expanded TCRs can be subdivided into TCRs found in all tumor regions (ubiquitous) and those present in a subset of regions (regional). The number of ubiquitous and regional TCRs correlates with the number of ubiquitous and regional nonsynonymous mutations, respectively. Expanded TCRs form part of clusters of TCRs of similar sequence, suggestive of a spatially constrained antigen-driven process. CD8+ tumor-infiltrating lymphocytes harboring ubiquitous TCRs display a dysfunctional tissue-resident phenotype. Ubiquitous TCRs are preferentially detected in the blood at the time of tumor resection as compared to routine follow-up. These findings highlight a noninvasive method to identify and track relevant tumor-reactive TCRs for use in adoptive T cell immunotherapy.