B cells and the coordination of immune checkpoint inhibitor response in patients with solid tumors.

Immunotherapy profoundly changed the landscape of cancer therapy by providing long-lasting responses in subsets of patients and is now the standard of care in several solid tumor types. However, immunotherapy activity beyond conventional immune checkpoint inhibition is plateauing, and biomarkers are overall lacking to guide treatment selection. Most studies have focused on T cell engagement and response, but there is a growing evidence that B cells may be key players in the establishment of an organized immune response, notably through tertiary lymphoid structures. Mechanisms of B cell response include antibody-dependent cellular cytotoxicity and phagocytosis, promotion of CD4+ and CD8+ T cell activation, maintenance of antitumor immune memory. In several solid tumor types, higher levels of B cells, specific B cell subpopulations, or the presence of tertiary lymphoid structures have been associated with improved outcomes on immune checkpoint inhibitors. The fate of B cell subpopulations may be widely influenced by the cytokine milieu, with versatile roles for B-specific cytokines B cell activating factor and B cell attracting chemokine-1/CXCL13, and a master regulatory role for IL-10. Roles of B cell-specific immune checkpoints such as TIM-1 are emerging and could represent potential therapeutic targets. Overall, the expanding field of B cells in solid tumors of holds promise for the improvement of current immunotherapy strategies and patient selection.

Impact of immunosuppressive agents on the management of immune-related adverse events of immune checkpoint blockers.

BACKGROUND: Immune checkpoint blockers (ICBs) can induce immune-related adverse events (irAEs) whose management is based on expert opinion and may require the prescription of steroids and/or immunosuppressants (ISs). Recent data suggest that these treatments can reduce the effectiveness of ICBs. OBJECTIVE: To investigate the relationship between the use of steroids and/or ISs and overall survival (OS) and progression-free survival (PFS) among ICB-treated patients with an irAE. METHODS: We prospectively collected data from the medical records of patients with solid tumors or lymphoma in the French REISAMIC cohort and who had been treated with ICBs between June 2014 and June 2020. RESULTS: 184 ICB-treated patients experienced at least one Common Terminology Criteria for Adverse Events grade ≥ 2 irAE. 107 (58.2%) were treated with steroids alone, 20 (10.9%) with steroids plus IS, 57 (31.0%) not received steroids or IS. The median OS was significantly shorter for patients treated with steroids alone (25.2 months [95% confidence interval (CI): 22.3-32.4] than for patients treated without steroids or IS (63 months [95%CI: 40.4-NA]) and those receiving an IS with steroids (53.4 months [95%CI: 47.3-NA]) (p < 0.001). The median PFS was significantly shorter for patients treated with steroids alone (17.0 months [95%CI: 11.7-22.9]) than for patients treated without steroids or IS (33.9 months [95%CI: 18.0-NA]) and those receiving an IS with steroids (41.1 months [95%CI: 26.2-NA]) (p = 0.006). There were no significant intergroup differences in the hospital admission and infection rates. CONCLUSION: In a prospective cohort of ICB-treated patients, the use of IS was not associated with worse OS or PFS, contrasting with the use of steroids for the management of irAEs.

Antibody drug conjugates in older patients: State of the art.

More than half of cancer cases occur in patients aged 65 years or older. The efficacy and safety of antibody drug conjugates (ADCs) in older patients remains an unclear subject as available evidence is limited. Geriatric population is underrepresented in clinical trials. Consequently, most of our knowledge regarding innovative therapeutics was studied on a younger population. In this review of published literature, we report the available information on efficacy, safety and pharmacokinetics of FDA approved ADCs for hematologic malignancies and solid tumors in the geriatric population. We explore the results of clinical trials dedicated for older individuals as well as subgroup analyses of the geriatric population in major trials evaluating these drugs. Available data suggest a similar efficacy in older adults as compared to general population. However, older patients might be prone to a higher rate of adverse events in incidence with a potential impact on quality of life. We lack data to support primary dose reductions or schedule modifications in this category of patients. No pharmacokinetic differences were reported between age groups. It is crucial to encourage the development of clinical trials dedicated to older patients with geriatric parameters (G8 score, G-CODE…) so that results can be more representative of this population outside of clinical trials.

Immune checkpoints are predominantly co-expressed by clonally expanded CD4+FoxP3+ intratumoral T-cells in primary human cancers.

BACKGROUND: In addition to anti-PD(L)1, anti-CTLA-4 and anti-LAG-3, novel immune checkpoint proteins (ICP)-targeted antibodies have recently failed to demonstrate significant efficacy in clinical trials. In these trials, patients were enrolled without screening for drug target expression. Although these novel ICP-targeted antibodies were expected to stimulate anti-tumor CD8 + T-cells, the rationale for their target expression in human tumors relied on pre-clinical IHC stainings and transcriptomic data, which are poorly sensitive and specific techniques for assessing membrane protein expression on immune cell subsets. Our aim was to describe ICP expression on intratumoral T-cells from primary solid tumors to better design upcoming neoadjuvant cancer immunotherapy trials. METHODS: We prospectively performed multiparameter flow cytometry and single-cell RNA sequencing (scRNA-Seq) paired with TCR sequencing on freshly resected human primary tumors of various histological types to precisely determine ICP expression levels within T-cell subsets. RESULTS: Within a given tumor type, we found high inter-individual variability for tumor infiltrating CD45 + cells and for T-cells subsets. The proportions of CD8+ T-cells (~ 40%), CD4+ FoxP3- T-cells (~ 40%) and CD4+ FoxP3+ T-cells (~ 10%) were consistent across patients and indications. Intriguingly, both stimulatory (CD25, CD28, 4-1BB, ICOS, OX40) and inhibitory (PD-1, CTLA-4, PD-L1, CD39 and TIGIT) checkpoint proteins were predominantly co-expressed by intratumoral CD4+FoxP3+ T-cells. ScRNA-Seq paired with TCR sequencing revealed that T-cells with high clonality and high ICP expressions comprised over 80% of FoxP3+ cells among CD4+ T-cells. Unsupervised clustering of flow cytometry and scRNAseq data identified subsets of CD8+ T-cells and of CD4+ FoxP3- T-cells expressing certain checkpoints, though these expressions were generally lower than in CD4+ FoxP3+ T-cell subsets, both in terms of proportions among total T-cells and ICP expression levels. CONCLUSIONS: Tumor histology alone does not reveal the complete picture of the tumor immune contexture. In clinical trials, assumptions regarding target expression should rely on more sensitive and specific techniques than conventional IHC or transcriptomics. Flow cytometry and scRNAseq accurately characterize ICP expression within immune cell subsets. Much like in hematology, flow cytometry can better describe the immune contexture of solid tumors, offering the opportunity to guide patient treatment according to drug target expression rather than tumor histological type.

Human virome profiling identified CMV as the major viral driver of a high accumulation of senescent CD8+ T cells in patients with advanced NSCLC.

Circulating senescent CD8+ T (T8sen) cells are characterized by a lack of proliferative capacities but retain cytotoxic activity and have been associated to resistance to immunotherapy in patients with advanced non-small cell lung cancer (aNSCLC). We aimed to better characterize T8sen and to determine which factors were associated with their accumulation in patients with aNSCLC. Circulating T8sen cells were characterized by a higher expression of SA-ßgal and the transcription factor T-bet, confirming their senescent status. Using whole virome profiling, cytomegalovirus (CMV) was the only virus associated with T8sen. CMV was necessary but not sufficient to explain high accumulation of T8sen (T8senhigh status). In CMV+ patients, the proportion of T8sen cells increased with cancer progression. Last, CMV-induced T8senhigh phenotype but not CMV seropositivity itself was associated with worse progression-free and overall survival in patients treated with anti-PD-(L)1 therapy but not with chemotherapy. Overall, CMV is the unique viral driver of T8sen-driven resistance to anti-PD-(L)1 antibodies in patients with aNSCLC.

Immunosuppressant mycophenolate mofetil for patients with steroid-refractory immune-related hepatitis induced by checkpoint inhibitors in oncology.

BACKGROUND: Immune-checkpoint inhibitor (ICI) hepatitis, which does not improve with steroids and requires additional immunosuppressant, is defined as steroid-refractory ICI hepatitis. The outcome of patients with steroid-refractory ICI hepatitis remains poorly determined. Herein, we investigated the incidence, clinical features, and outcome of patients treated with second-line immunosuppressant for steroid-refractory ICI hepatitis. METHODS: This is a retrospective analysis of patients who presented ICI hepatitis from 1st June 2016 to 30th September 2022. Steroid-refractory ICI hepatitis was defined as no clinical and biological improvement after systemic steroid therapy ≥1 mg/kg/d. Main objectives were to assess the frequency and risk factors associated with steroid-refractory ICI hepatitis and to evaluate the efficacy of second-line immunosuppressants. RESULTS: In total, 130 patients with grade ≥3 ICI hepatitis were screened, of them 60 (46.2%) were treated with systemic steroids. In total, 11/130 (8.5%) had steroid-refractory hepatitis. Statistically significant factors associated with steroid-refractory hepatitis included previous liver comorbidities (54.5% versus 11.6%; p < 0.01), hyperbilirubinemia (p < 0.001), and general symptoms (fever, jaundice, ascites, and/or encephalopathy) associated with hepatitis (72.7% versus 30.8%; p = 0.015). The 11 patients with steroid-refractory hepatitis were treated with mycophenolate mofetil. In total, resolution or return to grade ≤1 for hepatitis was observed in 81.8% (9/11) of patients. CONCLUSIONS: Steroid-refractory ICI hepatitis accounted for 8.5% of patients with grade ≥3 immune-related hepatitis and was statistically associated with previous liver comorbidities, hyperbilirubinemia, and general symptoms. Mycophenolate mofetil was a suitable option of therapy for steroid-refractory ICI hepatitis.

Intratumoral Immunotherapy: Is It Ready for Prime Time?

PURPOSE OF REVIEW: This review presents the rationale for intratumoral immunotherapy, technical considerations and safety. Clinical results from the latest trials are provided and discussed. RECENT FINDINGS: Intratumoral immunotherapy is feasible and safe in a wide range of cancer histologies and locations, including lung and liver. Studies mainly focused on multi-metastatic patients, with some positive trials such as T-VEC in melanoma, but evidence of clinical benefit is still lacking. Recent results showed improved outcomes in patients with a low tumor burden. Intratumoral immunotherapy can lower systemic toxicities and boost local and systemic immune responses. Several studies have proven the feasibility, repeatability, and safety of this approach, with some promising results in clinical trials. The clinical benefit might be improved in patients with a low tumor burden. Future clinical trials should focus on adequate timing of treatment delivery during the course of the disease, particularly in the neoadjuvant setting.

Liquid Biopsies for Circulating Tumor DNA Detection May Reveal Occult Hematologic Malignancies in Patients With Solid Tumors.

PURPOSE: High-risk clonal hematopoiesis (CH) is frequently incidentally found in patients with solid tumors undergoing plasma cell-free DNA sequencing. Here, we aimed to determine if the incidental detection of high-risk CH by liquid biopsy may reveal occult hematologic malignancies in patients with solid tumors. MATERIALS AND METHODS: Adult patients with advanced solid cancers enrolled in the Gustave Roussy Cancer Profiling study (ClinicalTrials.gov identifier: NCT04932525) underwent at least one liquid biopsy (FoundationOne Liquid CDx). Molecular reports were discussed within the Gustave Roussy Molecular Tumor Board (MTB). Potential CH alterations were observed, and patients referred to hematology consultation in the case of pathogenic mutations in JAK2, MPL, or MYD88, irrespective of the variant allele frequency (VAF), or in DNMT3A, TET2, ASXL1, IDH1, IDH2, SF3B1, or U2AF1 with VAF ≥ 10%, while also considering patient cancer-related prognosis. TP53 mutations were discussed case-by-case. RESULTS: Between March and October 2021, 1,416 patients were included. One hundred ten patients (7.7%) carried at least one high-risk CH mutation: DNMT3A (n = 32), JAK2 (n = 28), TET2 (n = 19), ASXL1 (n = 18), SF3B1 (n = 5), IDH1 (n = 4), IDH2 (n = 3), MPL (n = 3), and U2AF1 (n = 2). The MTB advised for hematologic consultation in 45 patients. Overall, 9 patients of 18 actually addressed had confirmed hematologic malignancies that were occult in six patients: two patients had myelodysplastic syndrome, two essential thrombocythemia, one a marginal lymphoma, and one a Waldenström macroglobulinemia. The other three patients were already followed up in hematology. CONCLUSION: The incidental findings of high-risk CH through liquid biopsy may trigger diagnostic hematologic tests and reveal an occult hematologic malignancy. Patients should have a multidisciplinary case-by-case evaluation.

Genomic Instability and Protumoral Inflammation Are Associated with Primary Resistance to Anti-PD-1 + Antiangiogenesis in Malignant Pleural Mesothelioma.

Cancer immunotherapy combinations have recently been shown to improve the overall survival of advanced mesotheliomas, especially for patients responding to those treatments. We aimed to characterize the biological correlates of malignant pleural mesotheliomas' primary resistance to immunotherapy and antiangiogenics by testing the combination of pembrolizumab, an anti-PD-1 antibody, and nintedanib, a pan-antiangiogenic tyrosine kinase inhibitor, in the multicenter PEMBIB trial (NCT02856425). Thirty patients with advanced malignant pleural mesothelioma were treated and explored. Unexpectedly, we found that refractory patients were actively recruiting CD3+CD8+ cytotoxic T cells in their tumors through CXCL9 tumor release upon treatment. However, these patients displayed high levels of somatic copy-number alterations in their tumors that correlated with high blood and tumor levels of IL6 and CXCL8. Those proinflammatory cytokines resulted in higher tumor secretion of VEGF and tumor enrichment in regulatory T cells. Advanced mesothelioma should further benefit from stratified combination therapies adapted to their tumor biology. SIGNIFICANCE: Sequential explorations of fresh tumor biopsies demonstrated that mesothelioma resistance to anti-PD-1 + antiangiogenics is not due to a lack of tumor T-cell infiltration but rather due to adaptive immunosuppressive pathways by tumors, involving molecules (e.g., IL6, CXCL8, VEGF, and CTLA4) that are amenable to targeted therapies. This article is highlighted in the In This Issue feature, p. 799.

Immune-related generalised oedema - A new category of adverse events with immune checkpoint inhibitors.

BACKGROUND: Generalised oedema was occasionally reported associated with immune checkpoint inhibitors (ICPIs). The purpose of this study is to investigate immune-related generalised oedema (ir-GE) drug related to ICPI, through frequency, clinical and pathological characteristics, and patient's outcome. PATIENTS AND METHODS: Objectives of the study were to report on ir-GE associated with ICPI to define frequency, associated signs and symptoms, pathological characteristics, severity, and response to corticosteroids. To be included in the study, adult patients had to have ir-GE related to ICPI with certain or likely link, without any other known causes of generalised oedema. The study design was observational, over the period 2014-2020, from pharmacovigilance databases in France, including the prospective Registre des Effets Indésirables Sévères des Anticorps Monoclonaux Immunomodulateurs en Cancérologie (REISAMIC) registry. Calculation of the frequency of ir-GE was restricted to the prospective REISAMIC registry. RESULTS: Over 6633 screened patients, 20 had ir-GE confirmed drug related to ICPI. Based on the prospective REISAMIC registry, the frequency of ir-GE was 0.19% of ICPI-treated patients (3 cases out of 1598 screened patients). The 20 patients with ir-GE had a median (range) age of 62 (26-81) years, most frequent tumour types were melanoma (n = 9; 45%) and lung cancer (n = 6; 30%). The most frequent localisations of oedema were peripheral (n = 17; 85%), pleural (n = 13; 65%), and peritoneal (n = 10; 50%). Polyserositis was observed in 11 (55%) patients. The median (range) weight gain per patient was 9 (2-30) kg. Associated signs and symptoms met criteria for capillary leak syndrome (n = 4; 20%), sinusoidal obstruction syndrome/veno-occlusive disease (SOS/VOD) (n = 3; 15%), or subcutaneous autoimmune syndrome (n = 2; 10%). Corticosteroids were administered to 15 patients; of them, 10 (67%) improved clinically after corticosteroids. Based on CTCAEV5.0, the highest severity of ir-GE was grade ≥4 in 11 (55%) patients and four (20%) patients died due to ir-GE. CONCLUSIONS: Generalised immune system-related oedema is a new category of adverse event with immune checkpoint inhibitors and is often associated with a life-threatening condition. The pathophysiology may in some cases be related to endothelial dysfunctions, such as SOS/VOD or capillary leak syndrome.

Immune-related arthritis following pelvic radiation therapy in a patient with lung cancer receiving long-term immune checkpoint blocker treatment: Case report.

Radiotherapy can trigger immune-related out-of-field "abscopal" response. We report a patient with advanced NSCLC (non-small cell lung cancer) receiving long-term anti-PD1 (programmed cell death protein 1) who have developed out-of-field immune-related arthritis following pelvic irradiation.

Synergizing liver systemic treatments with interventional oncology: friend or foe?

Interventional radiology techniques provide excellent local tumor control for small tumors in various organs, but several limitations can hamper the oncological outcomes such as the tumor size or the number of lesions. Technical improvements, optimal patient selection and combination with systemic therapies, including immune checkpoint inhibitors, have been successfully developed to overcome these barriers.In this setting, chemotherapy and targeted therapies aim to diminish the tumor burden in addition to local treatments, while immunotherapies may have a synergistic effect in terms of mechanism of action on the tumor cell as well as the immune environment, with multiple treatment combinations being available. Finally, interventional Rrdiology treatments often increase tumor antigen exposure to the immune system, and thus stimulate a specific antitumor immune response that can act beyond the treated site. Notwithstanding their many benefits, combination treatment may also result in complications, the most feared may be auto-immune-related adverse events.In early studies, several combined therapies have shown promising levels of safety and efficacy, particularly in hepatocellular carcinoma.This review provides a comprehensive and up-to-date overview of results of combined therapies for primary and secondary liver malignancies. Recent advances and future perspectives will be discussed.

Escherichia coli-Specific CXCL13-Producing TFH Are Associated with Clinical Efficacy of Neoadjuvant PD-1 Blockade against Muscle-Invasive Bladder Cancer.

Biomarkers guiding the neoadjuvant use of immune-checkpoint blockers (ICB) are needed for patients with localized muscle-invasive bladder cancers (MIBC). Profiling tumor and blood samples, we found that follicular helper CD4+ T cells (TFH) are among the best therapeutic targets of pembrolizumab correlating with progression-free survival. TFH were associated with tumoral CD8 and PD-L1 expression at baseline and the induction of tertiary lymphoid structures after pembrolizumab. Blood central memory TFH accumulated in tumors where they produce CXCL13, a chemokine found in the plasma of responders only. IgG4+CD38+ TFH residing in bladder tissues correlated with clinical benefit. Finally, TFH and IgG directed against urothelium-invasive Escherichia coli dictated clinical responses to pembrolizumab in three independent cohorts. The links between tumor infection and success of ICB immunomodulation should be prospectively assessed at a larger scale. SIGNIFICANCE: In patients with bladder cancer treated with neoadjuvant pembrolizumab, E. coli-specific CXCL13 producing TFH and IgG constitute biomarkers that predict clinical benefit. Beyond its role as a biomarker, such immune responses against E. coli might be harnessed for future therapeutic strategies. This article is highlighted in the In This Issue feature, p. 2221.

Safety, recommended dose, efficacy and immune correlates for nintedanib in combination with pembrolizumab in patients with advanced cancers.

BACKGROUND: We aimed to determine the safety and efficacy of nintedanib, an oral anti-angiogenic tyrosine kinase inhibitor, in combination with pembrolizumab, an anti-PD1 immunotherapy, in patients with advanced solid tumors (PEMBIB trial; NCT02856425). METHODS: In this monocentric phase Ib dose escalation cohort, we evaluated escalating doses of nintedanib (Dose level 1 (DL1) = 150 mg bid [bis in die, as twice a day]; DL2 = 200 mg bid, oral delivery) in combination with pembrolizumab (200 mg Q3W, IV). Patients received a 1-week lead-in dose of nintedanib monotherapy prior starting pembrolizumab. The primary objective was to establish the maximum tolerated dose (MTD) of the combination based on dose limiting toxicity (DLT) occurrence during the first 4 weeks. Secondary objectives were to assess the anti-tumor efficacy and to identify the associated immune and angiogenic parameters in order to establish the recommended nintedanib dose for expansion cohorts. Flow cytometry (FC), Immuno-Histo-Chemistry (IHC) and electrochemiluminescence multi-arrays were prospectively performed on baseline & on-treatment tumor and blood samples to identify immune correlates of efficacy. RESULTS: A total of 12/13 patients enrolled were evaluable for DLT (1 patient withdrew consent prior receiving pembrolizumab). Three patients at 200 mg bid experienced a DLT (grade 3 liver enzymes increase). Four patients developed grade 1-2 immune related adverse events (irAE). Eight patients died because of cancer progression. Median follow-up was 23.7 months (95%CI: 5.55-40.5). Three patients developed a partial response (PR) (ORR = 25%) and five patients (42%) had durable clinical benefit (DCB), defined as PR or stable disease (SD) ≥ 6 months. At baseline, patients with DCB had higher plasma levels of Tie2, CXCL10, CCL22 and circulating CD4+ PD1+ OX40+ T cells than patients without DCB. Patients with DCB presented also with more DC-LAMP+ dendritic cells, CD3+ T cells and FOXP3+ Tregs in baseline tumor biopsies. For DCB patients, the nintedanib lead-in monotherapy resulted in higher blood CCL3, Tregs and CCR4+ CXCR3+ CXCR5- memory CD4 T cells. After the first pembrolizumab infusion, patients with DCB showed lower IL-6, IL-8, IL-27 plasma levels. CONCLUSION: Nintedanib 150 mg bid is the recommended dose for combination with pembrolizumab and is currently investigated in multiple expansion cohorts. Early tumoral and circulating immune factors were associated with cancer outcome under nintedanib & pembrolizumab therapy. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02856425 . Registered August 4, 2016 - Prospectively registered.

Feasibility, safety and efficacy of human intra-tumoral immuno-therapy. Gustave Roussy's initial experience with its first 100 patients.

PURPOSE: Many intratumoural (IT) immunotherapies are currently developed in the clinic with the aim of overcoming primary and secondary resistance and/or to limit on-target/off-tumour toxicities of immune checkpoint targeted therapies. This study aimed to describe the feasibility, safety and efficacy of IT immunotherapy treatments. DESIGN: This retrospective single-centre study included the first 100 consecutive patients enrolled in Gustave Roussy's Human IntraTumoral-ImmunoTherapy (HIT-IT) program. Patient characteristics, target description, image guidance, safety and response according to iRECIST (Response Evaluation Criteria in Solid Tumours for immunotherapy trials) were recorded. Predictive factors of complications and responses were analysed. Survival was also reported. RESULTS: From 09/2015 to 05/2020, 100 patients had 115 tumours injected during 423 treatment cycles. Most frequent primary tumour arose from the skin (n = 49), digestive track (n = 4) or head and neck (n = 8). Injected tumours' mean diameter was 37 ± 23 mm, and a median number of 4 IT injections per patient (interquartile range:3-5) were performed. Targeted tumours for IT injections were superficial lymph nodes (36.5%), subcutaneous lesions (25.2%), liver tumours (20.9%) and others (17.4% including tumour sites such as deep lymph nodes or lung). Most patients (72%) received systemic immunotherapy in combination with HIT-IT. Procedure- and drug-related adverse events (AEs) occurred in 11.3% and 33.3% of the treatment cycles, respectively. Only 3 procedure-related AEs were grade-3 (0.7%); and no grade-4 or 5 occurred. Among all cycles, 7 grade-3 and 1 grade-5 drug-related AEs were reported. Complete and partial responses were achieved for 5% and 18% of patients, respectively, while stable disease was the best response for 11%. Patients receiving HIT-IT as a 1st-line treatment (24%), or not previously pre-treated with immunotherapy (53%) responded better, p = 0.001 and p = 0.004, respectively. From 1st cycle of IT, 12-month overall progression-free survival and overall survival were 21% (14-31%) and 57% (47-68%), respectively. CONCLUSIONS: This retrospective study, conducted on patients with cancer and treated within clinical trials at Gustave Roussy, demonstrates the feasibility and safety of the IT immunotherapy strategy.

BCG therapy downregulates HLA-I on malignant cells to subvert antitumor immune responses in bladder cancer.

Patients with high-risk, nonmuscle-invasive bladder cancer (NMIBC) frequently relapse after standard intravesical bacillus Calmette-Guérin (BCG) therapy and may have a dismal outcome. The mechanisms of resistance to such immunotherapy remain poorly understood. Here, using cancer cell lines, freshly resected human bladder tumors, and samples from cohorts of patients with bladder cancer before and after BCG therapy, we demonstrate 2 distinct patterns of immune subversion upon BCG relapse. In the first pattern, intracellular BCG infection of cancer cells induced a posttranscriptional downregulation of HLA-I membrane expression via inhibition of autophagy flux. Patients with HLA-I-deficient cancer cells following BCG therapy had a myeloid immunosuppressive tumor microenvironment (TME) with epithelial-mesenchymal transition (EMT) characteristics and dismal outcomes. Conversely, patients with HLA-I-proficient cancer cells after BCG therapy presented with CD8+ T cell tumor infiltrates, upregulation of inflammatory cytokines, and immune checkpoint-inhibitory molecules. The latter patients had a very favorable outcome. We surmise that HLA-I expression in bladder cancers at relapse following BCG does not result from immunoediting but rather from an immune subversion process directly induced by BCG on cancer cells, which predicts a dismal prognosis. HLA-I scoring of cancer cells by IHC staining can be easily implemented by pathologists in routine practice to stratify future treatment strategies for patients with urothelial cancer.

CD8+PD-1+ to CD4+PD-1+ ratio (PERLS) is associated with prognosis of patients with advanced NSCLC treated with PD-(L)1 blockers.

BACKGROUND: Programmed cell death protein-1 (PD-1) expression has been associated with activation and exhaustion of both the CD4 and CD8 populations in advanced non-small cell lung cancer (aNSCLC). Nevertheless, the impact of the balance between circulating CD8+PD-1+ and CD4+PD-1+ in patients treated with immune checkpoint blockers (ICB) is unknown. METHODS: The CD8+PD-1+ to CD4+PD-1+ ratio (PD-1-Expressing Ratio on Lymphocytes in a Systemic blood sample, or 'PERLS') was determined by cytometry in fresh whole blood from patients with aNSCLC before treatment with single-agent ICB targeting PD-1 or programmed cell death-ligand 1 (PD-L1 (discovery cohort). A PERLS cut-off was identified by log-rank maximization. Patients treated with ICB (validation cohort) or polychemotherapy (control cohort) were classified as PERLS+/- (above/below cut-off). Circulating immune cell phenotype and function were correlated with PERLS. A composite score (good, intermediate and poor) was determined using the combination of PERLS and senescent immune phenotype as previously described in aNSCLC. RESULTS: In the discovery cohort (N=75), the PERLS cut-off was 1.91, and 11% of patients were PERLS+. PERLS + correlated significantly with median progression-free survival (PFS) of 9.63 months (95% CI 7.82 to not reached (NR)) versus 2.69 months (95% CI 1.81 to 5.52; p=0.03). In an independent validation cohort (N=36), median PFS was NR (95% CI 7.9 to NR) versus 2.00 months (95% CI 1.3 to 4.5; p=0.04) for PERLS + and PERLS-, respectively; overall survival (OS) followed a similar but non-significant trend. In the pooled cohort (N=111), PERLS + correlated significantly with PFS and OS. PERLS did not correlate with outcome in the polychemotherapy cohort. PERLS did not correlate with clinical characteristics but was significantly associated with baseline circulating naïve CD4+ T cells and the increase of memory T cells post-ICB treatment. Accumulation of memory T cells during treatment was linked to CD4+ T cell polyfunctionality. The composite score was evaluated in the pooled cohort (N=68). The median OS for good, intermediate and poor composite scores was NR (95% CI NR to NR), 8.54 months (95% CI 4.96 to NR) and 2.42 months (95% CI 1.97 to 15.5; p=0.001), respectively. The median PFS was 12.60 months (95% CI 9.63 to NR), 2.58 months (95% CI 1.74 to 7.29) and 1.76 months (95% CI 1.31 to 4.57; p<0.0001), respectively. CONCLUSIONS: Elevated PERLS, determined from a blood sample before immunotherapy, was correlated with benefit from PD-(L)1 blockers in aNSCLC.

The Polarity and Specificity of Antiviral T Lymphocyte Responses Determine Susceptibility to SARS-CoV-2 Infection in Patients with Cancer and Healthy Individuals.

Vaccination against coronavirus disease 2019 (COVID-19) relies on the in-depth understanding of protective immune responses to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). We characterized the polarity and specificity of memory T cells directed against SARS-CoV-2 viral lysates and peptides to determine correlates with spontaneous, virus-elicited, or vaccine-induced protection against COVID-19 in disease-free and cancer-bearing individuals. A disbalance between type 1 and 2 cytokine release was associated with high susceptibility to COVID-19. Individuals susceptible to infection exhibited a specific deficit in the T helper 1/T cytotoxic 1 (Th1/Tc1) peptide repertoire affecting the receptor binding domain of the spike protein (S1-RBD), a hotspot of viral mutations. Current vaccines triggered Th1/Tc1 responses in only a fraction of all subject categories, more effectively against the original sequence of S1-RBD than that from viral variants. We speculate that the next generation of vaccines should elicit Th1/Tc1 T-cell responses against the S1-RBD domain of emerging viral variants. SIGNIFICANCE: This study prospectively analyzed virus-specific T-cell correlates of protection against COVID-19 in healthy and cancer-bearing individuals. A disbalance between Th1/Th2 recall responses conferred susceptibility to COVID-19 in both populations, coinciding with selective defects in Th1 recognition of the receptor binding domain of spike. See related commentary by McGary and Vardhana, p. 892. This article is highlighted in the In This Issue feature, p. 873.