Targeting two radiation-induced immunosuppressive pathways to improve the efficacy of normofractionated radiation therapy in a preclinical colorectal cancer model.

PURPOSE: We have previously demonstrated in a murine colorectal cancer model that normofractionated RT (normoRT: 18 × 2 Gy) induced MDSC infiltration and PD-L1 expression, while hypofractionated RT (hypoRT: 3 × 8 Gy) induced Treg. Here, we wanted to assess whether the association of normoRT with treatments that target two radiation-induced immunosuppressive pathways (MDSC and PD-L1) could improve tumor control. MATERIALS AND METHODS: Subcutaneous tumors were induced using colon tumor cells (CT26) in immunocompetent mice (BALB/c) and were treated with RT alone (18 × 2 Gy or 3 × 8 Gy), or concomitantly with 5-Fluorouracil (5FU) (10 mg/kg) to deplete MDSC, and/or anti-PD-L1 (10 mg/kg). We assessed the impact of these combinations on tumor growth and immune cells infiltration by flow cytometry. In addition, we performed tumor rechallenge experiments and IFN-γ ELISpots to study the long-term memory response. RESULTS: Even though tumor growth was significantly delayed in the RT + 5FU compared to 5FU and untreated groups (p < .05), there was no significant difference between RT + 5FU (CRT) and RT alone. The rate of MDSC increased significantly 1 week after the end of normoRT (8.09% ± 1.03%, p < .05) and decreased with the addition of 5FU (3.39% ± 0.69%, p < .05). PD-L1 expressing tumor cells were increased after treatment. Adding anti-PD-L1 significantly delayed tumor growth, achieved the highest complete response rate, and induced a long-lasting protective specific anti-tumor immunity. CONCLUSIONS: These results tend to demonstrate the interest of inhibiting two radiation-induced immunosuppressive mechanisms. In patients, the combination of normoRT with 5FU is already the standard of care in locally advanced rectal cancer. Adding an anti-PD-L1 to this treatment could show promising results.

Characterization of atypical T cells generated during ex vivo expansion process for T cell-based adoptive immunotherapy.

Engineered T cell-based adoptive immunotherapies met promising success for the treatment of hematological malignancies. Nevertheless, major hurdles remain to be overcome regarding the management of relapses and the translation to solid tumor settings. Properties of T cell-based final product should be appropriately controlled to fine-tune the analysis of clinical trial results, to draw relevant conclusions, and finally to improve the efficacy of these immunotherapies. For this purpose, we addressed the existence of atypical T cell subsets and deciphered their phenotypic and functional features in an HPV16-E7 specific and MHC II-restricted transgenic-TCR-engineered T cell setting. To note, atypical T cell subsets include mismatched MHC/co-receptor CD8 or CD4 and miscommitted CD8+ or CD4+ T cells. We generated both mismatched and appropriately matched MHC II-restricted transgenic TCR on CD8 and CD4-expressing T cells, respectively. We established that CD4+ cultured T cells exhibited miscommitted phenotypic cytotoxic pattern and that both interleukin (IL)-2 or IL-7/IL-15 supplementation allowed for the development of this cytotoxic phenotype. Both CD4+ and CD8+ T cell subsets, transduced with HPV16-E7 specific transgenic TCR, demonstrated cytotoxic features after exposure to HPV-16 E7-derived antigen. Ultimately, the presence of such atypical T cells, either mismatched MHC II-restricted TCR/CD8+ T cells or cytotoxic CD4+ T cells, is likely to influence the fate of patient-infused T cell product and would need further investigation.

THBS1+ myeloid cells expand in SLD hepatocellular carcinoma and contribute to immunosuppression and unfavorable prognosis through TREM1.

Hepatocellular carcinoma (HCC) is an inflammation-associated cancer arising from viral or non-viral etiologies including steatotic liver diseases (SLDs). Expansion of immunosuppressive myeloid cells is a hallmark of inflammation and cancer, but their heterogeneity in HCC is not fully resolved and might underlie immunotherapy resistance. Here, we present a high-resolution atlas of innate immune cells from patients with HCC that unravels an SLD-associated contexture characterized by influx of inflammatory and immunosuppressive myeloid cells, including a discrete population of THBS1+ regulatory myeloid (Mreg) cells expressing monocyte- and neutrophil-affiliated genes. THBS1+ Mreg cells expand in SLD-associated HCC, populate fibrotic lesions, and are associated with poor prognosis. THBS1+ Mreg cells are CD163+ but distinguished from macrophages by high expression of triggering receptor expressed on myeloid cells 1 (TREM1), which contributes to their immunosuppressive activity and promotes HCC tumor growth in vivo. Our data support myeloid subset-targeted immunotherapies to treat HCC.

First-line durvalumab and tremelimumab with chemotherapy in RAS-mutated metastatic colorectal cancer: a phase 1b/2 trial.

Although patients with microsatellite instable metastatic colorectal cancer (CRC) benefit from immune checkpoint blockade, chemotherapy with targeted therapies remains the only therapeutic option for microsatellite stable (MSS) tumors. The single-arm, phase 1b/2 MEDITREME trial evaluated the safety and efficacy of durvalumab plus tremelimumab combined with mFOLFOX6 chemotherapy in first line, in 57 patients with RAS-mutant unresectable metastatic CRC. Safety was the primary objective of phase Ib; no safety issue was observed. The phase 2 primary objective of efficacy in terms of 3-month progression-free survival (PFS) in patients with MSS tumors was met, with 3-month PFS of 90.7% (95% confidence interval (CI): 79.2-96%). For secondary objectives, response rate was 64.5%; median PFS was 8.2 months (95% CI: 5.9-8.6); and overall survival was not reached in patients with MSS tumors. We observed higher tumor mutational burden and lower genomic instability in responders. Integrated transcriptomic analysis underlined that high immune signature and low epithelial-mesenchymal transition were associated with better outcome. Immunomonitoring showed induction of neoantigen and NY-ESO1 and TERT blood tumor-specific T cell response associated with better PFS. The combination of durvalumab-tremelimumab with mFOLFOX6 was tolerable with promising clinical activity in MSS mCRC. Clinicaltrials.gov identifier: NCT03202758 .

Durable response of lung carcinoma patients to EGFR tyrosine kinase inhibitors is determined by germline polymorphisms in some immune-related genes.

BACKGROUND: Non-small cell lung cancer is a very poor prognosis disease. Molecular analyses have highlighted several genetic alterations which may be targeted by specific therapies. In clinical practice, progression-free survival on EGFR TKI treatment is between 12 and 14 months. However, some patients progress rapidly in less than 6 months, while others remain free of progression for 16 months or even longer during EGFR TKI treatment. METHODS: We sequenced tumor exomes from 135 lung cancer patients (79 with EGFR-wildtype (WT), 56 with EGFR-mutant tumors) enrolled in the ALCAPONE trial (genomic analysis of lung cancers by next generation sequencing for personalized treatment). RESULTS: Some germline polymorphisms were enriched in the EGFR-mutant subset compared to EGFR-WT tumors or to a reference population. However, the most interesting observation was the negative impact of some germline SNPs in immunity-related genes on survival on EGFR TKI treatment. Indeed, the presence of one of three particular SNPs in the HLA-DRB5 gene was associated with a decreased PFS on EGFR TKI. Moreover, some SNPs in the KIR3DL1 and KIR3DL2 genes were linked to a decrease in both progression-free and overall survival of patients with EGFR-mutant tumors. CONCLUSION: Our data suggest that SNPs in genes expressed by immune cells may influence the response to targeted treatments, such as EGFR TKIs. This indicates that the impact of these cells may not be limited to modulating the response to immunotherapies. Further studies are needed to determine the exact mechanisms underlying this influence and to identify the associated predictive and prognostic markers that would allow to refine treatments and so improve lung cancer patient outcomes. TRIAL REGISTRATION: NCT02281214: NGS Genome Analysis in Personalization of Lung Cancer Treatment (ALCAPONE).

Evaluation of the interest to combine a CD4 Th1-inducer cancer vaccine derived from telomerase and atezolizumab plus bevacizumab in unresectable hepatocellular carcinoma: a randomized non-comparative phase II study (TERTIO - PRODIGE 82).

BACKGROUND: Several cancer immunotherapies that target the PD-L1/PD-1 pathway show promising clinical activity in patients with hepatocellular carcinoma (HCC). However, the standard of care in first-line treatment with atezolizumab (anti-PD-L1 therapy) in combination with bevacizumab is associated with a limited objective response rate. Telomerase reverse transcriptase (TERT) activation meets the criteria of oncogenic addiction in HCC and could be actionable therapeutic target and a relevant tumor antigen. Therefore we hypothesized that combining anti-PD-1/PD-L1 therapy with an anti-telomerase vaccine might be an attractive therapy in HCC. UCPVax is a therapeutic cancer vaccine composed of two separate peptides derived from telomerase (human TERT). UCPVax has been evaluated in a multicenter phase I/II study in non-small cell lung cancers and has demonstrated to be safe and immunogenic, and is under evaluation in combination with atezolizumab in a phase II clinical trial in tumors where telomerase reactivation contributes to an oncogene addiction (HPV+ cancers). The aim of the TERTIO study is to determine the clinical interest and immunological efficacy of a treatment combining the CD4 helper T-inducer cancer anti-telomerase vaccine (UCPVax) with atezolizumab and bevacizumab in unresectable HCC in a multicenter randomized phase II study. METHODS: Patients with locally advanced, metastatic or unresectable HCC who have not previously received systemic anti-cancer treatment are eligible. The primary end point is the objective response rate at 6 months. Patients will be allocated to a treatment arm with a randomization 2:1. In both arms, patients will receive atezolizumab at fixed dose of 1200 mg IV infusion and bevacizumab at fixed dose of 15 mg/kg IV infusion, every 3 weeks, according to the standard of care. In the experimental arm, these treatments will be combined with the UCPVax vaccine at 0.5 mg subcutaneously. DISCUSSION: Combining anti-PD-1/PD-L1 therapy with an anti-telomerase vaccine gains serious consideration in HCC, in order to extend the clinical efficacy of anti-PD-1/PD-L1. Indeed, anti-cancer vaccines can induce tumor-specific T cell expansion and activation and therefore restore the cancer-immunity cycle in patients lacking pre-existing anti-tumor responses. Thus, there is a strong rational to combine immune checkpoint blockade therapy and anticancer vaccine (UCPVax) in order to activate antitumor T cell immunity and bypass the immunosuppression in the tumor microenvironment in HCC. This pivotal proof of concept study will evaluate the efficacy and safety of the combination of a CD4 Th1-inducer cancer vaccine derived from telomerase (UCPVax) and atezolizumab plus bevacizumab in unresectable HCC, as well as confirming their synergic mechanism, and settling the basis for a new combination for future clinical trials. TRIAL REGISTRATION: NCT05528952.

Chemotherapy to potentiate the radiation-induced immune response.

Chemoradiation (CRT) is a conventional therapy used in local cancers, especially when they are locally advanced. Studies have shown that CRT induces strong anti-tumor responses involving several immune effects in pre-clinical models and humans. In this review, we have described the various immune effects involved in CRT efficacy. Indeed, effects such as immunological cell death, activation and maturation of antigen-presenting cells, and activation of an adaptive anti-tumor immune response are attributed to CRT. As often described in other therapies, various immunosuppressive mechanisms mediated, in particular, by Treg and myeloid populations may reduce the CRT efficacy. We have therefore discussed the relevance of combining CRT with other therapies to potentiate the CRT-induced anti-tumor effects.

Response to Chemoimmunotherapy Is Associated With Expansion of Systemic Antitumor CD4 + Th1 Response in Metastatic Non-Small Cell Lung Cancer.

Limited data have reported the evolution of antitumor immune responses under chemoimmunotherapy (chemo-IO) in patients with metastatic non-small cell lung cancer. In this concise study, we performed dynamic monitoring of antitumor CD4 + T helper 1 (Th1) response in peripheral blood from 12 patients receiving a first-line chemo-IO. Tumor-reactive CD4 + Th1 cells were assessed within blood lymphocytes using interferon-gamma enzyme-linked immunospot assay to detect telomerase (TERT)-specific T cells at baseline, 3 and 12 months after treatment. An induction of circulating anti-TERT CD4 + Th1 response were found in 6 of 12 patients at 3 months after chemo-IO. In contrast, 3 patients had a substantial decrease in their preexisting response and 3 remained nonimmune responders. Among patients with chemo-IO-induced immune response, half achieved an objective clinical response and had long-lasting circulating anti-TERT CD4 + Th1 cells detected for at least 1 year. In contrast, no objective response was documented in nonimmune responders and a link between the loss of anti-TERT CD4 + Th1 responses were observed in patients with progressive disease. This preliminary work supports a relationship between the efficacy of combinatorial chemo-IO and circulating anti-TERT CD4 + Th1 responses and highlights the interest to implement blood-based monitoring of tumor-reactive CD4 + T cells that could be additional help for patient management.

Development of a new heparan sulfate proteoglycan (HSPG) chromolith LC column to study the pH dependence binding of peptide vaccines to HSPG and role of human serum albumin on its binding.

Heparan sulfate proteoglycan (HSPG) expressed on immune cell surface participate in antitumor T-cell responses generated in the acidic lymph node (LN) microenvironment. In this work, HSPG was immobilized for the first time on a HPLC chromolith support for studying the effect of extra cellular acidosis in LNs on the binding to HSPG of two peptide vaccines (universal cancer peptide UCP2 and UCP4). This home-made HSPG column enabling to work at high flow-rates, was resistance to change in pH, had a long - life time, an excellent repeatability and negligible non-specific binding sites. The performance of this affinity HSPG column was confirmed by the evaluation of recognition assay for a series of known ligand of HSPG. It was shown that at 37 °C, the UCP2 binding to HSPG versus pH described a sigmoidal shape while UCP4 remained relatively constant in the pH range 5.0-7.5 and lower than the one of UCP2. By the use of an HSA HPLC column, it was shown at 37 °C and in acidic conditions a loss of affinity of UCP2 and UCP4 to HSA. It was demonstrated that upon UCP2/HSA binding, the protonation of the histidine residue in the cluster R(arg) Q(Gln) Hist (H) of the UCP2 peptide allowed to expose more favorably than UCP4 its polar and cationic groups to the negative net charge of HSPG on immune cells. Acidic pHs led to the protonation of the UCP2 residue histidine by flipping the His switch to the on position with a concomitant increase in affinity for the negative net charge of HSPG confirming that UCP2 was more immunogenic than UCP4. As well this HSPG chromolith LC column developed in this work could be used in the feature for other protein - HSPG binding studies or for a separative mode.

Safety, Immunogenicity, and 1-Year Efficacy of Universal Cancer Peptide-Based Vaccine in Patients With Refractory Advanced Non-Small-Cell Lung Cancer: A Phase Ib/Phase IIa De-Escalation Study.

PURPOSE: Universal cancer peptide-based vaccine (UCPVax) is a therapeutic vaccine composed of two highly selected helper peptides to induce CD4+ T helper-1 response directed against telomerase. This phase Ib/IIa trial was designed to test the safety, immunogenicity, and efficacy of a three-dose schedule in patients with metastatic non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: Patients with refractory NSCLC were assigned to receive three vaccination doses of UCPVax (0.25 mg, 0.5 mg, and 1 mg) using a Bayesian-based phase Ib followed by phase IIa de-escalating design. The primary end points were dose-limiting toxicity and immune response after three first doses of vaccine. Secondary end points were overall survival (OS) and progression-free survival at 1 year. RESULTS: A total of 59 patients received UCPVax; 95% had three prior lines of systemic therapy. No dose-limiting toxicity was observed in 15 patients treated in phase Ib. The maximum tolerated dose was 1 mg. Fifty-one patients were eligible for phase IIa. The third and sixth dose of UCPVax induced specific CD4+ T helper 1 response in 56% and 87.2% of patients, respectively, with no difference between three dose levels. Twenty-one (39%) patients achieved disease control (stable disease, n = 20; complete response, n = 1). The 1-year OS was 34.1% (95% CI, 23.1 to 50.4), and the median OS was 9.7 months, with no significant difference between dose levels. The 1-year progression-free survival and the median OS were 17.2% (95% CI, 7.8 to 38.3) and 11.6 months (95% CI, 9.7 to 16.7) in immune responders (P = .015) and 4.5% (95% CI, 0.7 to 30.8) and 5.6 months (95% CI, 2.5 to 10) in nonresponders (P = .005), respectively. CONCLUSION: UCPVax was highly immunogenic and safe and provide interesting 1-year OS rate in heavily pretreated advanced NSCLC.

Interplay between plasmacytoid dendritic cells and tumor-specific T cells in peripheral blood influences long-term survival in non-small cell lung carcinoma.

Plasmacytoid dendritic cells (pDCs) represent a subset of antigen-presenting cells that play an ambivalent role in cancer immunity. Here, we investigated the clinical significance of circulating pDCs and their interaction with tumor-specific T cell responses in patients with non-small cell lung cancer (NSCLC, n = 126) . The relation between intratumoral pDC signature and immune checkpoint inhibitors efficacy was also evaluated. Patients with NSCLC had low level but activated phenotype pDC compared to healthy donors. In overall population, patients with high level of pDC (pDChigh) had improved overall survival (OS) compared to patients with pDClow, median OS 30.4 versus 20.7 months (P = 0.013). This clinical benefit was only observed in stage I to III patients, but not in metastatic disease. We showed that patients harboring pDChigh profile had high amount of Th1-diffentiation cytokine interleukin-12 (IL-12) in blood and had functional T cells directed against a broad range of tumor antigens. Furthermore, a high pDC signature in the tumor microenvironment was associated with improved clinical outcome in patients treated with anti-PD-(L)1 therapy. Overall, this study showed that circulating pDChigh is associated with long-term OS in NSCLC and highlighted the predictive value of intratumor pDC signature in the efficacy of immune checkpoint inhibitors.

The ATG8 Family Proteins GABARAP and GABARAPL1 Target Antigen to Dendritic Cells to Prime CD4+ and CD8+ T Cells.

Vaccine therapy is a promising method of research to promote T cell immune response and to develop novel antitumor immunotherapy protocols. Accumulating evidence has shown that autophagy is involved in antigen processing and presentation to T cells. In this work, we investigated the potential role of GABARAP and GABARAPL1, two members of the autophagic ATG8 family proteins, as surrogate tumor antigen delivery vectors to prime antitumor T cells. We showed that bone marrow-derived dendritic cells, expressing the antigen OVALBUMIN (OVA) fused with GABARAP or GABARAPL1, were able to prime OVA-specific CD4+ T cells in vitro. Interestingly, the fusion proteins were also degraded by the proteasome pathway and the resulting peptides were presented by the MHC class I system. We then asked if the aforementioned fusion proteins could improve tumor cell immunogenicity and T cell priming. The B16-F10 melanoma was chosen as the tumor cell line to express the fusion proteins. B16-F10 cells that expressed the OVA-ATG8 fused proteins stimulated OVA-specific CD8+ T cells, but demonstrated no CD4+ T cell response. In the future, these constructions may be used in vaccination trials as potential candidates to control tumor growth.

Plasma CD27, a Surrogate of the Intratumoral CD27-CD70 Interaction, Correlates with Immunotherapy Resistance in Renal Cell Carcinoma.

PURPOSE: CD70 is a costimulatory molecule known to activate CD27-expressing T cells. CD27-CD70 interaction leads to the release of soluble CD27 (sCD27). Clear-cell renal cell carcinoma (ccRCC) expresses the highest levels of CD70 among all solid tumors; however, the clinical consequences of CD70 expression remain unclear. EXPERIMENTAL DESIGN: Tumor tissue from 25 patients with ccRCC was assessed for the expression of CD27 and CD70 in situ using multiplex immunofluorescence. CD27+ T-cell phenotypes in tumors were analyzed by flow cytometry and their gene expression profile were analyzed by single-cell RNA sequencing then confirmed with public data. Baseline sCD27 was measured in 81 patients with renal cell carcinoma (RCC) treated with immunotherapy (35 for training cohort and 46 for validation cohort). RESULTS: In the tumor microenvironment, CD27+ T cells interacted with CD70-expressing tumor cells. Compared with CD27- T cells, CD27+ T cells exhibited an apoptotic and dysfunctional signature. In patients with RCC, the intratumoral CD27-CD70 interaction was significantly correlated with the plasma sCD27 concentration. High sCD27 levels predicted poor overall survival in patients with RCC treated with anti-programmed cell death protein 1 in both the training and validation cohorts but not in patients treated with antiangiogenic therapy. CONCLUSIONS: In conclusion, we demonstrated that sCD27, a surrogate marker of T-cell dysfunction, is a predictive biomarker of resistance to immunotherapy in RCC. Given the frequent expression of CD70 and CD27 in solid tumors, our findings may be extended to other tumors.

TIE-2 Signaling Activation by Angiopoietin 2 On Myeloid-Derived Suppressor Cells Promotes Melanoma-Specific T-cell Inhibition.

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous group of immune suppressive cells detected in several human cancers. In this study, we investigated the features and immune suppressive function of a novel subset of monocytic MDSC overexpressing TIE-2 (TIE-2+ M-MDSC), the receptor for the pro-angiogenic factor angiopoietin 2 (ANGPT2). We showed that patients with melanoma exhibited a higher circulating rate of TIE-2+ M-MDSCs, especially in advanced stages, as compared to healthy donors. The distribution of the TIE-2+ M-MDSC rate toward the melanoma stage correlated with the serum level of ANGPT2. TIE-2+ M-MDSC from melanoma patients overexpressed immune suppressive molecules such as PD-L1, CD73, TGF-ß, and IL-10, suggesting a highly immunosuppressive phenotype. The exposition of these cells to ANGPT2 increased the expression of most of these molecules, mainly Arginase 1. Hence, we observed a profound impairment of melanoma-specific T-cell responses in patients harboring high levels of TIE-2+ M-MDSC along with ANGPT2. This was confirmed by in vitro experiments indicating that the addition of ANGPT2 increased the ability of TIE-2+ M-MDSC to suppress antitumor T-cell function. Furthermore, by using TIE-2 kinase-specific inhibitors such as regorafenib or rebastinib, we demonstrated that an active TIE-2 signaling was required for optimal suppressive activity of these cells after ANGPT2 exposition. Collectively, these results support that TIE-2+ M-MDSC/ANGPT2 axis represents a potential immune escape mechanism in melanoma.

A Phase II Study Evaluating the Interest to Combine UCPVax, a Telomerase CD4 TH1-Inducer Cancer Vaccine, and Atezolizumab for the Treatment of HPV Positive Cancers: VolATIL Study.

Background: There is a strong rational of using anti-programmed cell death protein-1 and its ligand (anti-PD-1/L1) antibodies in human papillomavirus (HPV)-induced cancers. However, anti-PD-1/L1 as monotherapy induces a limited number of objective responses. The development of novel combinations in order to improve the clinical efficacy of an anti-PD-1/L1 is therefore of interest. Combining anti-PD-1/L1 therapy with an antitumor vaccine seems promising in HPV-positive (+) cancers. UCPVax is a therapeutic cancer vaccine composed of two separate peptides derived from telomerase (hTERT, human telomerase reverse transcriptase). UCPVax is being evaluated in a multicenter phase I/II study in NSCLC (non-small cell lung cancer) and has demonstrated to be safe and immunogenic. The aim of the VolATIL study is to evaluate the combination of atezolizumab (an anti-PD-L1) and UCPVax vaccine in a multicenter phase II study in patients with HPV+ cancers. Methods: Patients with HPV+ cancer (anal canal, head and neck, and cervical or vulvar), at locally advanced or metastatic stage, and refractory to at least one line of systemic chemotherapy are eligible. The primary end point is the objective response rate (ORR) at 4 months. Patients will receive atezolizumab every 3 weeks at a fixed dose of 1,200 mg in combination with the UCPVax vaccine at 1 mg subcutaneously. Discussion: Anti-cancer vaccines can restore cancer-immunity via the expansion and activation of tumor-specific T cells in patients lacking pre-existing anti-tumor responses. Moreover, preclinical data showed that specific TH1 CD4 T cells sustain the quality and homing of an antigen-specific CD8+ T-cell immunity. In previous clinical studies, the induction of anti-hTERT immunity was significantly correlated to survival in patients with advanced squamous anal cell carcinoma. Thus, there is a strong rational to combine an anti-cancer hTERT vaccine and an immune checkpoint inhibitor to activate and promote antitumor T-cell immunity. This pivotal proof of concept study will evaluate the efficacy and safety of the combination of a telomerase-based TH1 inducing vaccine (UCPVax) and an anti-PD-L1 (atezolizumab) immunotherapy in HPV+ cancers, as well as confirming their synergic mechanism, and settling the basis for a new combination for future clinical trials. Clinical Trial Registration: https://www.clinicaltrials.gov/, identifier NCT03946358.

Antitumor CAR T-cell Screening Platform: Many Are Called, but Few Are Chosen.

Treatment with T cells expressing chimeric antigen receptors (CAR) is a promising anticancer therapy. However, this approach has several limitations and has not yet been effectively applied to treat solid tumors. The study by Panowski and colleagues represents the first comparative analysis of multiple single chain fragment variable (scFv)-based anti-CD70 CAR T-cell clones for the development of a clinical product to treat renal cell carcinoma (RCC). Despite the risk of T-cell fratricide due to CD70 expression on T cells, CD70 CAR T cells were produced successfully thanks to the protective CD70 masking phenomenon. Two distinct classes of CAR T cells were identified with different memory phenotypes, activation statuses, and cytotoxic activity. CD70 CAR T cells presented high cytotoxic activity against RCC both in vitro in RCC cell lines and in vivo in patient-derived xenograft mouse models. The off-target effects expected on the lymphoid compartment were confirmed by tissue cross-reactivity staining and in a cynomolgus monkey preclinical model with CD3-CD70 bispecific antibody treatment. The efficacy and the toxicity profile of the lead CD70 CAR T-cell candidate instigated the researchers to proceed with upscaled clinical production. This article emphasizes the influence of the scFv of the CARs on their efficacy:toxicity balance. Ultimately, they successfully managed to develop a highly effective CAR T-cell candidate to treat a solid tumor by an allogeneic approach, thereby overcoming two major hurdles to broaden application of CAR T-cell therapy. See related article by Panowski et al., p. 2610.

Umbilical Cord Blood as a Source of Less Differentiated T Cells to Produce CD123 CAR-T Cells.

Chimeric Antigen Receptor (CAR) therapy has led to great successes in patients with leukemia and lymphoma. Umbilical Cord Blood (UCB), stored in UCB banks, is an attractive source of T cells for CAR-T production. We used a third generation CD123 CAR-T (CD28/4-1BB), which was previously developed using an adult's Peripheral Blood (PB), to test the ability of obtaining CD123 CAR-T from fresh or cryopreserved UCB. We obtained a cell product with a high and stable transduction efficacy, and a poorly differentiated phenotype of CAR-T cells, while retaining high cytotoxic functions in vitro and in vivo. Moreover, CAR-T produced from cryopreserved UCB are as functional as CAR-T produced from fresh UCB. Overall, these data pave the way for the clinical development of UCB-derived CAR-T. UCB CAR-T could be transferred in an autologous manner (after an UCB transplant) to reduce post-transplant relapses, or in an allogeneic setting, thanks to fewer HLA restrictions which ease the requirements for a match between the donor and recipient.

Prognostic value of CD4+ T lymphopenia in non-small cell lung Cancer.

BACKGROUND: There is a paucity of data regarding the prognostic influence of peripheral blood CD4+ T lymphopenia in non-small cell lung cancer (NSCLC). Therefore, we investigated the prognostic value of T lymphopenia in NSCLC. MATERIALS: Treatment-naive patients with a pathological diagnosis of NSCLC, at clinical stage I to IV were included in the prospective TELOCAP1 study. Lymphocytes count was evaluated in peripheral blood by flow cytometry. CD4+ and CD8+ T lymphopenia were defined as an absolute count of < 500/µL and < 224/µL respectively. The prognostic value of T lymphopenia was analyzed in the whole population, in local/loco-regional (stage I-IIIB) and in advanced (stage IV) NSCLC disease, using the Kaplan-Meier method and Cox regression models for survival curves and multivariate analysis, respectively. RESULTS: Between July 2010 and January 2014, 169 evaluable patients with clinical stage I to IV NSCLC were prospectively enrolled. The prevalence of CD4+ and CD8+ T lymphopenia was similar in the study population (around 29%). Patients with CD4+ T lymphopenia showed lower overall survival than those with CD4+ T lymphocytes count > 500/µL (median overall survival (OS) 16.1 versus 21.7 months, hazard ratio (HR): 1.616 [95% CI: 1.1-2.36], p = 0.012). This association with OS was especially marked in local/loco-regional NSCLC stages (median OS, 21.8 versus 72 months, respectively, HR: 1.88 [95% CI: 0.9-3.8], p = 0.035). Multivariate analysis confirmed the worse prognosis associated with CD4+ T lymphopenia in local/loco-regional NSCLC, but not in metastatic patients (HR 2.028 [95% CI = 1.065-3.817] p = 0.02). Restricted cubic spline analysis showed that patients with CD4+ T lymphocytes count ≤500/µL displayed a high risk of death regardless of NSCLC clinical stage. There was no obvious relationship between CD8+ T lymphopenia and clinical outcome. CONCLUSION: We identified CD4+ T lymphopenia as an independent prognostic factor in local/loco-regional stages of NSCLC and CD4+ T lymphopenia is also associated with a high risk of death, regardless of NSCLC clinical stage. TRIAL REGISTRATION: EUDRACT: 2009-A00642-55.

c-Maf enforces cytokine production and promotes memory-like responses in mouse and human type 2 innate lymphoid cells.

Group-2 innate lymphoid cells (ILC2s), which are involved in type 2 inflammatory diseases such as allergy, can exhibit immunological memory, but the basis of this ILC2 "trained immunity" has remained unclear. Here, we found that stimulation with IL-33/IL-25 or exposure to the allergen papain induces the expression of the transcription factor c-Maf in mouse ILC2s. Chronic papain exposure results in high production of IL-5 and IL-13 cytokines and lung eosinophil recruitment, effects that are blocked by c-Maf deletion in ILCs. Transcriptomic analysis revealed that knockdown of c-Maf in ILC2s suppresses expression of type 2 cytokine genes, as well as of genes linked to a memory-like phenotype. Consistently, c-Maf was found highly expressed in human adult ILC2s but absent in cord blood and required for cytokine production in isolated human ILC2s. Furthermore, c-Maf-deficient mouse or human ILC2s failed to exhibit strengthened ("trained") responses upon repeated challenge. Thus, the expression of c-Maf is indispensable for optimal type 2 cytokine production and proper memory-like responses in group-2 innate lymphoid cells.