Search

Myeloid cells represent a dominant cellular compartment of tumor lesions and play key roles in tumor inception, progression, metastasis, and response to treatment. Mononuclear phagocytes (MNPs), which include dendritic cells and macrophages, are unique among myeloid cells, as they not only shape both the broader composition and state of the tumor microenvironment but can also specifically instruct cancer-specific, T cell–mediated tumor cell killing, making them especially attractive targets for cancer treatment. Although MNPs remain difficult to modulate therapeutically, our understanding of MNP biology in the antitumor immune response has expanded significantly, offering hope for new possibilities in cancer immunotherapy. Here, we review the recent advances in our study of the cellular identity, molecular diversity, and spatial organization of MNPs in tumors, and we discuss the importance of tailoring therapeutic strategies to incorporate these new insights into cancer treatment design.

IMbrave150 has established the superiority of atezolizumab plus bevacizumab over sorafenib in patients with unresectable hepatocellular carcinoma (HCC).We generated a prospectively maintained database including patients treated with atezolizumab plus bevacizumab for unresectable HCC across Europe, Asia and USA. Clinico-pathologic characteristics were assessed for their prognostic influence on overall survival (OS) and progression-free survival (PFS) in univariable and multivariate analyses. Overall response rate by RECIST v1.1 and treatment-related adverse events (TRAEs) per CTCAE v.5.0 were reported.Out of 433 patients, 296 Child-Pugh A and ECOG performance status01 patients received atezolizumab plus bevacizumab in first line and were included. Patients were mostly male (82.7%), cirrhotic (75%) with history of viral hepatitis (65.9%). Overall, 68.9% had Barcelona Clinic Liver Cancer C-stage HCC with portal vein tumour thrombosis (PVTT, 35%) and extrahepatic spread (EHS, 51.7%). After a median follow-up of 10.0 months (95% confidence interval (CI): 9.4-10.4), median OS and PFS were 15.7 (95% CI: 14.5-NE) and 6.9 months (95% CI: 6.1-8.3), respectively. In the response-evaluable patients (n = 273), overall response rate was 30.8%. Overall, 221 patients (74.6%) developed TRAEs, with 70 (23.6%) reporting grade 3 or higher TRAEs; 25 (8.4%) patients had bleeding events. OS was independently associated with baseline Albumin-bilirubin (ALBI) grade and PVTT. Shorter PFS was associated with AFP≥ 400 ng/ml, worse ALBI and presence of EHS.This global observational study confirms the reproducible safety and efficacy of atezolizumab plus bevacizumab in routine clinical practice. Within Child-Pugh-A criteria, the presence of PVTT and higher ALBI grade identify patients with poorer survival.

Background and Aims Combination atezolizumab/bevacizumab is the gold standard for first-line treatment of unresectable hepatocellular carcinoma (HCC). Our study investigated the efficacy and safety of combination therapy in older patients with HCC. Methods 191 consecutive patients from eight centres receiving atezolizumab and bevacizumab were included. Overall survival (OS), progression-free survival (PFS), overall response rate (ORR) and disease control rate (DCR) defined by RECIST v1.1 were measured in older (age ≥ 65 years) and younger (age

It is currently accepted that cancer-associated fibroblasts (CAF) participate in T-cell exclusion from tumor nests. To unbiasedly test this, we used single-cell RNA sequencing coupled with multiplex imaging on a large cohort of lung tumors. We identified four main CAF populations, two of which are associated with T-cell exclusion: (i) MYH11+αSMA+ CAF, which are present in early-stage tumors and form a single cell layer lining cancer aggregates, and (ii) FAP+αSMA+ CAF, which appear in more advanced tumors and organize in patches within the stroma or in multiple layers around tumor nests. Both populations orchestrate a particular structural tissue organization through dense and aligned fiber deposition compared with T cell–permissive CAF. Yet they produce distinct matrix molecules, including collagen IV (MYH11+αSMA+ CAF) and collagen XI/XII (FAP+αSMA+ CAF). Hereby, we uncovered unique molecular programs of CAF driving T-cell marginalization, whose targeting should increase immunotherapy efficacy in patients bearing T cell–excluded tumors. Significance: The cellular and molecular programs driving T-cell marginalization in solid tumors remain unclear. Here, we describe two CAF populations associated with T-cell exclusion in human lung tumors. We demonstrate the importance of pairing molecular and spatial analysis of the tumor microenvironment, a prerequisite to developing new strategies targeting T cell–excluding CAF. See related commentary by Sherman, p. 2501. This article is highlighted in the In This Issue feature, p. 2483

PURPOSE Compared with people living without HIV (PWOH), people living with HIV (PWH) and cancer have traditionally been excluded from immune checkpoint inhibitor (ICI) trials. Furthermore, there is a paucity of real-world data on the use of ICIs in PWH and cancer. METHODS This retrospective study included PWH treated with anti–PD-1- or anti–PD-L1-based therapies for advanced cancers. Kaplan-Meier method was used to estimate overall survival (OS) and progression-free survival (PFS). Objective response rates (ORRs) were measured per RECIST 1.1 or other tumor-specific criteria, whenever feasible. Restricted mean survival time (RMST) was used to compare OS and PFS between matched PWH and PWOH with metastatic NSCLC (mNSCLC). RESULTS Among 390 PWH, median age was 58 years, 85% (n = 331) were males, 36% (n = 138) were Black; 70% (n = 274) received anti–PD-1/anti–PD-L1 monotherapy. Most common cancers were NSCLC (28%, n = 111), hepatocellular carcinoma ([HCC]; 11%, n = 44), and head and neck squamous cell carcinoma (HNSCC; 10%, n = 39). Seventy percent (152/216) had CD4+ T cell counts ≥200 cells/µL, and 94% (179/190) had HIV viral load CONCLUSION Among PWH, ICIs demonstrated differential activity across cancer types with no excess toxicity. Safety and activity of ICIs were similar between matched cohorts of PWH and PWOH with mNSCLC.

Overlapping peptides covering the entire NY-ESO-1 protein

Supplementary Figure from Spatial Positioning and Matrix Programs of Cancer-Associated Fibroblasts Promote T-cell Exclusion in Human Lung Tumors

Descriptions of Supplementary Figures 1, 2, and 3, and supplementary table 1

Supplementary Table from Spatial Positioning and Matrix Programs of Cancer-Associated Fibroblasts Promote T-cell Exclusion in Human Lung Tumors

Supplementary Fig 2

Supplementary Fig 1

It is currently accepted that cancer-associated fibroblasts (CAF) participate in T-cell exclusion from tumor nests. To unbiasedly test this, we used single-cell RNA sequencing coupled with multiplex imaging on a large cohort of lung tumors. We identified four main CAF populations, two of which are associated with T-cell exclusion: (i) MYH11+αSMA+ CAF, which are present in early-stage tumors and form a single cell layer lining cancer aggregates, and (ii) FAP+αSMA+ CAF, which appear in more advanced tumors and organize in patches within the stroma or in multiple layers around tumor nests. Both populations orchestrate a particular structural tissue organization through dense and aligned fiber deposition compared with T cell–permissive CAF. Yet they produce distinct matrix molecules, including collagen IV (MYH11+αSMA+ CAF) and collagen XI/XII (FAP+αSMA+ CAF). Hereby, we uncovered unique molecular programs of CAF driving T-cell marginalization, whose targeting should increase immunotherapy efficacy in patients bearing T cell–excluded tumors.Significance:The cellular and molecular programs driving T-cell marginalization in solid tumors remain unclear. Here, we describe two CAF populations associated with T-cell exclusion in human lung tumors. We demonstrate the importance of pairing molecular and spatial analysis of the tumor microenvironment, a prerequisite to developing new strategies targeting T cell–excluding CAF.See related commentary by Sherman, p. 2501.This article is highlighted in the In This Issue feature, p. 2483

Given its ability to induce both humoral and cellular immune responses, NY-ESO-1 has been considered a suitable antigen for a cancer vaccine. Despite promising results from early-phase clinical studies in patients with melanoma, NY-ESO-1 vaccine immunotherapy has not been widely investigated in larger trials; consequently, many questions remain as to the optimal vaccine formulation, predictive biomarkers, and sequencing and timing of vaccines in melanoma treatment. We conducted an adjuvant phase I/II clinical trial in high-risk resected melanoma to optimize the delivery of poly-ICLC, a TLR-3/MDA-5 agonist, as a component of vaccine formulation. A phase I dose-escalation part was undertaken to identify the MTD of poly-ICLC administered in combination with NY-ESO-1 and montanide. This was followed by a randomized phase II part investigating the MTD of poly-ICLC with NY-ESO-1 with or without montanide. The vaccine regimens were generally well tolerated, with no treatment-related grade 3/4 adverse events. Both regimens induced integrated NY-ESO-1–specific CD4+ T-cell and humoral responses. CD8+ T-cell responses were mainly detected in patients receiving montanide. T-cell avidity toward NY-ESO-1 peptides was higher in patients vaccinated with montanide. In conclusion, NY-ESO-1 protein in combination with poly-ICLC is safe, well tolerated, and capable of inducing integrated antibody and CD4+ T-cell responses in most patients. Combination with montanide enhances antigen-specific T-cell avidity and CD8+ T-cell cross-priming in a fraction of patients, indicating that montanide contributes to the induction of specific CD8+ T-cell responses to NY-ESO-1.

Supplementary Fig 3

Transfer does not induce homeostatic inhibition on CD4+ T-cells

T-cell transfer into lymphodepleted recipients induces homeostatic activation and potentiates antitumor efficacy. In contrast to canonical T-cell receptor–induced activation, homeostatic activation yields a distinct phenotype and memory state whose regulatory mechanisms are poorly understood. Here, we show in patients and murine models that, following transfer into lymphodepleted bone marrow transplant (BMT) recipients, CD8+ T cells undergo activation but also simultaneous homeostatic inhibition manifested by upregulation of immune-checkpoint molecules and functional suppression. T cells transferred into BMT recipients were protected from homeostatic inhibition by PD-1/CTLA4 dual checkpoint blockade (dCB). This combination of dCB and BMT—”immunotransplant”—increased T-cell homeostatic activation and antitumor T-cell responses by an order of magnitude. Like homeostatic activation, homeostatic inhibition is IL7/IL15-dependent, revealing mechanistic coupling of these two processes. Marked similarity in ex vivo modulation of post-BMT T cells in mice and patients is promising for the clinical translation of immunotransplant (NCT03305445) and for addressing homeostatic inhibition in T-cell therapies.Significance:For optimal anticancer effect, T-cell therapies including chimeric antigen receptor T-cell, tumor-infiltrating lymphocyte, and transgenic T-cell therapies require transfer into lymphodepleted recipients and homeostatic activation; however, concomitant homeostatic inhibition mitigates T-cell therapies' efficacy. Checkpoint blockade uncouples homeostatic inhibition from activation, amplifying T-cell responses. Conversely, tumors nonresponsive to checkpoint blockade or BMT are treatable with immunotransplant.See related commentary by Ansell, p. 1487.This article is highlighted in the In This Issue feature, p. 1469

Background Atezolizumab plus bevacizumab (Atezo/Bev) is first line-treatment for unresectable hepatocellular carcinoma (HCC). Body mass index (BMI) has demonstrated predictive value for response to immunotherapy in non-HCC cancer types. Our study investigated the effect of BMI on safety and efficacy of real-life use of Atezo/Bev for unresectable HCC. Methods 191 consecutive patients from seven centres receiving Atezo/Bev were included in the retrospective study. Overall survival (OS), progression-free survival (PFS), overall response rate (ORR) and disease control rate (DCR) defined by RECIST v1.1 were measured in overweight (BMI ≥ 25) and non-overweight (BMI Results Patients in the overweight cohort (n = 94) had higher rates of non-alcoholic fatty liver disease (NAFLD) and lower rates of Hepatitis B compared to non-overweight cohort (n = 97). Baseline Child–Pugh class and Barcelona Clinic Liver Cancer stage were similar between cohorts, with lower rates of extrahepatic spread in the overweight group. Overweight patients had similar OS compared to non-overweight (median OS 15.1 vs. 14.9 months; p = 0.99). BMI did not influence median PFS (7.1 vs. 6.1 months; p = 0.42), ORR (27.2% vs. 22.0%; p = 0.44) and DCR (74.1% vs. 71.9%; p = 0.46). There were higher rates of atezolizumab-related fatigue (22.3% vs. 10.3%; p = 0.02) and bevacizumab-related thrombosis (8.5% vs. 2.1%; p = 0.045) in the overweight patients, but overall trAEs and treatment discontinuation were comparable between cohorts. Conclusion Atezo/Bev has comparable efficacy in overweight HCC patients, with an increase in treatment-related fatigue and thrombosis. Combination therapy is safe and efficacious to use in overweight patients, including those with underlying NAFLD.

The treatment paradigm for hepatocellular carcinoma (HCC) had been stagnant until recently, with new combinations of targeted and immunotherapies entering the first- and second-line setting for patients with advanced disease. This improvement in therapeutic options is well timed given the rise in rates of HCC globally; additionally, screening high-risk patients has also led to an increase in detection of early HCC lesions, identifying patients who can be treated with curative intent approaches such as surgery. Unfortunately, the vast majority of patients who undergo surgical resection develop recurrent HCC, either due to disease recurrence from residual micrometastatic disease or de novo primaries, and there are no perioperative therapies that have demonstrated the ability to significantly improve survival for these patients. Given the survival benefit that immunotherapy has imparted to patients with advanced HCC, and recent studies in other tumor types demonstrating perioperative-in particular neoadjuvant-immunotherapy significantly improves outcomes, there is substantial interest in neoadjuvant immunotherapy for patients with resectable HCC. Three recently reported small studies looking at anti-PD-1 antibodies alone or in combination have demonstrated significant pathologic response to brief pre-operative interventions, and support exploring this approach in larger registrational studies. With these developments the clinical outlook for HCC patients, with both early and advanced disease, is rapidly improving.

Atezolizumab plus bevacizumab (AtezoBev) is the standard of care for first-line treatment of unresectable HCC. No evidence exists as to its use in routine clinical practice in patients with impaired liver function.In 216 patients with HCC who were consecutively treated with AtezoBev across 11 tertiary centers, we retrospectively evaluated treatment-related adverse events (trAEs) graded (G) according to Common Terminology Criteria for Adverse Events v5.0, including in the analysis all patients treated according to label (n = 202, 94%). We also assessed overall survival (OS), progression-free survival (PFS), overall response (ORR), and disease control rates (DCR) defined by Response Evaluation Criteria in Solid Tumors v1.1. Disease was mostly secondary to viral hepatitis, namely hepatitis C (n = 72; 36%) and hepatitis B infection (n = 35, 17%). Liver function was graded as Child-Pugh (CP)-A in 154 patients (76%) and CP-B in 48 (24%). Any grade trAEs were reported by 143 patients (71%), of which 53 (26%) were G3 and 3 (2%) G4. Compared with CP-A, patients with CP-B showed comparable rates of trAEs. Presence and grade of varices at pretreatment esophagogastroduodenoscopy did not correlate with bleeding events. After a median follow-up of 9.0 months (95% CI, 7.8-10.1), median OS was 14.9 months (95% CI, 13.6-16.3), whereas median PFS was 6.8 months (95% CI, 5.2-8.5). ORR and DCR were respectively 25% and 73%, with no difference across CP classes.This study confirms reproducible safety and efficacy of AtezoBev in routine practice. Patients with CP-B reported similar tolerability compared with CP-A, warranting prospective evaluation of AtezoBev in this treatment-deprived population.

BACKGROUND: Surgical resection of early stage hepatocellular carcinoma is standard clinical practice; however, most tumours recur despite surgery, and no perioperative intervention has shown a survival benefit. Neoadjuvant immunotherapy has induced pathological responses in multiple tumour types and might decrease the risk of postoperative recurrence in hepatocellular carcinoma. We aimed to evaluate the clinical activity of neoadjuvant cemiplimab (an anti-PD-1) in patients with resectable hepatocellular carcinoma. METHODS: For this single-arm, open-label, phase 2 trial, patients with resectable hepatocellular carcinoma (stage Ib, II, and IIIb) were enrolled and received two cycles of neoadjuvant cemiplimab 350 mg intravenously every 3 weeks followed by surgical resection. Eligible patients were aged 18 years or older, had confirmed resectable hepatocellular carcinoma, an Eastern Cooperative Oncology Group performance status of 0 or 1, and adequate liver function. Patients were excluded if they had metastatic disease, if the surgery was not expected to be curative, if they had a known additional malignancy requiring active treatment, or if they required systemic steroid treatment or any other immunosuppressive therapy. After resection, patients received an additional eight cycles of cemiplimab 350 mg intravenously every 3 weeks in the adjuvant setting. The primary endpoint was significant tumour necrosis on pathological examination (defined as >70% necrosis of the resected tumour). Secondary endpoints included delay of surgery, the proportion of patients with an overall response, change in CD8(+) T-cell density, and adverse events. Tumour necrosis and response were analysed in all patients who received at least one dose of cemiplimab and completed surgical resection; safety and other endpoints were analysed in the intention-to-treat population. Patients underwent pre-treatment biopsies and blood collection throughout treatment. This trial is registered with ClinicalTrials.gov (NCT03916627, Cohort B) and is ongoing. FINDINGS: Between Aug 5, 2019, and Nov 25, 2020, 21 patients were enrolled. All patients received neoadjuvant cemiplimab, and 20 patients underwent successful resection. Of the 20 patients with resected tumours, four (20%) had significant tumour necrosis. Three (15%) of 20 patients had a partial response, and all other patients maintained stable disease. 20 (95%) patients had a treatment-emergent adverse event of any grade during the neoadjuvant treatment period. The most common adverse events of any grade were increased aspartate aminotransferase (in four patients), increased blood creatine phosphokinase (in three), constipation (in three), and fatigue (in three). Seven patients had grade 3 adverse events, including increased blood creatine phosphokinase (in two patients) and hypoalbuminaemia (in one). No grade 4 or 5 events were observed. One patient developed pneumonitis, which led to a delay in surgery by 2 weeks. INTERPRETATION: This report is, to our knowledge, the largest clinical trial of a neoadjuvant anti-PD-1 monotherapy reported to date in hepatocellular carcinoma. The observed pathological responses to cemiplimab in this cohort support the design of larger trials to identify the optimal treatment duration and definitively establish the clinical benefit of preoperative PD-1 blockade in patients with hepatocellular carcinoma. FUNDING: Regeneron Pharmaceuticals.

Background and Rationale: Immune checkpoint inhibitor (ICI) therapy is an expanding therapeutic option for hepatocellular carcinoma (HCC). Antibiotics (ATB) taken prior to or early during ICI therapy can impact immunotherapy efficacy across indications; however, the effect of ATB is undefined in HCC. Methods: In a large international cohort of 450 ICI recipients from Europe, North America, and Asia, we categorized patients according to timing of ATB focusing on exposure within −30 to +30 days from ICI (early immunotherapy period [EIOP]). EIOP was evaluated in association with overall survival (OS), progression-free survival (PFS), and best radiologic response using RECIST 1.1 criteria. Results: Our study comprised mostly cirrhotic (329, 73.3%) males (355, 79.1%) with a Child-Turcotte Pugh class of A (332, 73.9%), receiving ICI after 1 therapy line (251, 55.9%) for HCC of Barcelona clinic liver cancer stage C (325, 72.4%). EIOP (n = 170, 37.9%) was independent of baseline clinicopathologic features of HCC and correlated with longer PFS (6.1 vs. 3.7 months, log-rank p = 0.0135). EIOP+ patients had similar OS, overall response, and disease control rates (DCRs) compared to EIOP. The effect of EIOP persisted in landmark time analyses and in multivariable models, confirming the independent predictive role of EIOP in influencing PFS following adjustment for covariates reflective of tumor burden, liver function, and ICI regimen administered. In patients receiving programmed cell death-1 receptor/ligand inhibitors monotherapy, EIOP was also associated with higher DCRs (61.4% vs. 50.9%, p = 0.0494). Conclusions: Unlike other oncological indications, ATB in the 30 days before or after ICI initiation is associated with improved benefit from immunotherapy, independent of disease and treatment-related features. Evaluation of the immune microbiologic determinants of response to ICI in HCC warrants further investigation.

Different approaches are available after progression of disease (PD) to immune checkpoint inhibitors (ICI) for hepatocellular carcinoma (HCC), including continuation of ICI, treatment switching to tyrosine kinase inhibitors (TKIs) and cessation of anticancer therapy. We sought to characterise the relationship between radiologic patterns of progression and survival post-ICI, also appraising treatment strategies.We screened 604 HCC patients treated with ICIs, including only those who experienced PD by data cut-off. We evaluated post-progression survival (PPS) according to treatment strategy at PD and verified its relationship with radiologic patterns of progression: intrahepatic growth (IHG), new intrahepatic lesion (NIH), extrahepatic growth (EHG), new extrahepatic lesion (NEH) and new vascular invasion (nVI).Of 604 patients, 364 (60.3%) experienced PD during observation. Median PPS was 5.3 months (95%CI: 4.4-6.9; 271 events). At data cut-off, 165 patients (45%) received no post-progression anticancer therapy; 64 patients (17.6%) continued ICI beyond PD. IHG (HR 1.64 [95%CI:1.21-2.22]; p=0.0013) and nVI (HR 2.15 [95%CI:1.38-3.35]; p=0.0007) were associated with shorter PPS. Multivariate models adjusted for progression patterns, treatment line, and ALBI grade and ECOG-PS at PD confirmed receipt of ICI beyond PD with (HR 0.17, 95%CI 0.09-0.32; p0.0001), or without subsequent TKI (HR 0.39, 95%CI 0.26-0.58; p0.0001) as predictors of prolonged PPS versus no anticancer therapy.ICI-TKI sequencing is a consolidated option in advanced HCC. nVI and IHG predict poorer prognosis. Despite lack of recommendation, continuation of ICI beyond progression in HCC is adopted clinically: future efforts should appraise which patients benefit from this approach.

Simple Summary The investigation of predictive and prognostic markers is pivotal in patients affected by hepatocellular carcinoma treated with immune-checkpoint-inhibitors. Inflammation has a central role in hepatocellular carcinoma development and progression; however, its role in influencing outcomes in the context of immunotherapy has not been fully elucidated yet. In the following study, we investigated the prognostic role of bloods derived inflammatory markers and we found that they predict survival and response of patients treated with immunotherapy for advanced hepatocellular carcinoma. Abstract Systemic inflammation is a hallmark of cancer, and it has a pivotal role in hepatocellular carcinoma (HCC) development and progression. We conducted a retrospective study including 362 patients receiving immune check-point inhibitors (ICIs) across three continents, evaluating the influence of neutrophiles to lymphocytes ratio (NLR), platelets to lymphocytes ratio (PLR), and prognostic nutritional index (PNI) on overall (OS), progression free survival (PFS), and radiologic responses. In our 362 patients treated with immunotherapy, median OS and PFS were 9 and 3.5 months, respectively. Amongst tested inflammatory biomarkers, patients with NLR ≥ 5 had shorter OS (7.7 vs. 17.6 months, p < 0.0001), PFS (2.1 vs. 3.8 months, p = 0.025), and lower objective response rate (ORR) (12% vs. 22%, p = 0.034); similarly, patients with PLR ≥ 300 reported shorter OS (6.4 vs. 16.5 months, p < 0.0001) and PFS (1.8 vs. 3.7 months, p = 0.0006). NLR emerged as independent prognostic factors for OS in univariate and multivariate analysis (HR 1.95, 95%CI 1.45–2.64, p < 0.001; HR 1.73, 95%CI 1.23–2.42, p = 0.002) and PLR remained an independent prognostic factor for both OS and PFS in multivariate analysis (HR 1.60, 95%CI 1.6–2.40, p = 0.020; HR 1.99, 95%CI 1.11–3.49, p = 0.021). Systemic inflammation measured by NLR and PLR is an independent negative prognostic factor in HCC patients undergoing ICI therapy. Further studies are required to understand the biological mechanisms underlying this association and to investigate the predictive significance of circulating inflammatory biomarkers in HCC patients treated with ICIs.

Purpose: We evaluated ctDNA as a pharmacodynamic and predictive biomarker in patients (pts) with resectable HCC treated with cemiplimab (anti-programmed cell death-1). Background: A biomarker-focused study of neoadjuvant cemiplimab in resectable HCC demonstrated acceptable safety and pathologic responses that were associated with immune signatures of intratumoral T-cell response (Marron TU et al. Lancet Gastroenterol. Hepatol. 2022). ctDNA is emerging as a tool to monitor therapy responses and predict RFS in perioperative HCC studies. Methods: We enrolled 21 pts who received 2 cycles of neoadjuvant cemiplimab (350 mg intravenous every 3 weeks), followed by surgical resection and 8 cycles of adjuvant cemiplimab (NCT03916627). The primary endpoint was significant tumor necrosis (STN; >70% necrosis). Secondary endpoints included safety, RFS, and overall survival. A post hoc analysis examined pathological response (≥50% necrosis). Pts underwent pretreatment biopsies and longitudinal blood collection for ctDNA analyses using bespoke multiplex PCR-next generation sequencing (Signatera). We evaluated correlatives of ctDNA changes and the prognostic value undetectable ctDNA after surgery on RFS. Results: Median pt age was 68 years; 52% were Asian, 43% white, and 5% Black; 19% were also Hispanic; 62% had a history of viral hepatitis. ctDNA measurements at baseline and after 1 dose of cemiplimab were available from 19 pts who completed neoadjuvant cemiplimab and underwent successful surgical resection. Pre-surgical absolute ctDNA levels decreased by >50% in 10 pts, including all with greater than 50% tumor necrosis. As of August 1, 2022; median follow-up for the adjuvant period was 23 months (interquartile range: 20-26 months). 8 pts of the 19 pts have relapsed. Pts with a >50% decrease in ctDNA had median RFS of 28 months (95% CI 10, 28), vs 17 months (95% CI 4, not evaluable [NE]) in those with ≤50% decrease in ctDNA. 17 pts had a baseline ctDNA measurement, surgical resection, and data following surgery. ctDNA detection following surgery was associated with disease relapse (Fischer’s exact test, p=0.015), shorter RFS (median 10 months, 95% CI: 4, 28) compared to ctDNA-negative pts (not reached, 95% CI 13 months, NE; hazard ratio 0.14, p=0.006), and identified molecular relapse based on ctDNA with a median lead time of 5 months before imaging relapse. 20 pts (95%) were alive at last follow-up. Interpretation: Changes in ctDNA identify early response to immunotherapy more accurately than standard modalities such as imaging, correlating closely with pathological responses and RFS. ctDNA monitoring during neoadjuvant treatment and following surgery may identify pts with early antitumor responses, improve the prediction of disease relapse or RFS, and inform additional early treatment decisions. Citation Format: Thomas U. Marron, Laura Brennan, Pauline Hamon, Maria Isabel Fiel, Stephen C. Ward, Yuan O. Zhu, Edward Kim, Alice O. Kamphorst, Pradeep Thanigaimani, Thomas S. Uldrick, Natalie Lucas, Kathy Wu, Olivia Hapanowicz, Paula King, Siyu Li, Elizabeth Miller, Nina Bhardwaj, Gavin Thurston, Israel Lowy, Sacha Gnjatic, Myron E. Schwartz, Vladimir Jankovic, Miriam Merad. Circulating tumor DNA (ctDNA) correlates closely with tumor necrosis and relapse-free survival (RFS) in hepatocellular carcinoma (HCC) patients treated with perioperative cemiplimab [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2178.

Immune checkpoint inhibitor (ICI) therapy is an increasingly used treatment modality across the various stages of hepatocellular cancer (HCC). There is currently no standard peri-operative therapy for HCC, despite a high probability of recurrence. Emerging studies in a variety of tumors demonstrate significant pathologic and immune responses to neoadjuvant immunotherapy. Unlike kinase inhibitors and other targeted therapies, which demonstrated no benefit in the adjuvant setting and fail to induce significant responses, ICIs can induce radiologically appreciable reduction in disease burden, which make ICI combinations an appealing downstaging strategy in patients early or locally advanced disease. Additionally, induction of anti-tumor immunity in the pre-operative setting may induce protracted T-cell response that, in the post-operative phase, may be capable of eliminating micro-metastatic disease and prevent future recurrence. In this review, we discuss the rationale and clinical hurdles that underlie optimal integration of immunotherapy in the pre-operative setting, highlighting the positive impact on surgical and oncological outcomes in patients with early-stage HCC.

Here, we leveraged a large neoadjuvant PD-1 blockade trial in patients with hepatocellular carcinoma (HCC) to search for correlates of response to immune checkpoint blockade (ICB) within T cell-rich tumors. We show that ICB response correlated with the clonal expansion of intratumoral CXCL13+ CH25H+ IL-21+ PD-1+ CD4 T helper cells (CXCL13+ Th) and Granzyme K+ PD-1+ effector-like CD8 T cells, whereas terminally exhausted CD39hi TOXhi PD-1hi CD8 T cells dominated in non-responders. Strikingly, most T cell receptor (TCR) clones that expanded post-treatment were found in pre-treatment biopsies. Notably, PD-1+ TCF-1+ progenitor-like CD8 T cells were present in tumors of responders and non-responders and shared clones mainly with effector-like cells in responders or terminally differentiated cells in non-responders, suggesting that local CD8 T cell differentiation occurs upon ICB. We found that these progenitor CD8 T cells interact with CXCL13+ Th cells within cellular triads around dendritic cells enriched in maturation and regulatory molecules, or “mregDC”. Receptor-ligand analysis revealed unique interactions within these triads that may promote the differentiation of progenitor CD8 T cells into effector-like cells upon ICB. These results suggest that discrete intratumoral niches that include mregDC and CXCL13+ Th cells control the differentiation of tumor-specific progenitor CD8 T cell clones in patients treated with ICB.

Window-of-opportunity trials, during which patients receive short-duration pre-surgical therapies, provide a platform for understanding the therapies’ mechanisms of action, but will require a paradigm shift in trial design, specimen collection and analysis.

A damaging inflammatory response is implicated in the pathogenesis of severe coronavirus disease 2019 (COVID-19), but mechanisms contributing to this response are unclear. In two prospective cohorts, early non-neutralizing, afucosylated immunoglobulin G (IgG) antibodies specific to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were associated with progression from mild to more severe COVID-19. To study the biology of afucosylated IgG immune complexes, we developed an in vivo model that revealed that human IgG–Fc-gamma receptor (FcγR) interactions could regulate inflammation in the lung. Afucosylated IgG immune complexes isolated from patients with COVID-19 induced inflammatory cytokine production and robust infiltration of the lung by immune cells. In contrast to the antibody structures that were associated with disease progression, antibodies that were elicited by messenger RNA SARS-CoV-2 vaccines were highly fucosylated and enriched in sialylation, both modifications that reduce the inflammatory potential of IgG. Vaccine-elicited IgG did not promote an inflammatory lung response. These results show that human IgG-FcγR interactions regulate inflammation in the lung and define distinct lung activities mediated by the IgG that are associated with protection against, or progression to, severe COVID-19.

Several studies have revealed that the hyper-inflammatory response induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a major cause of disease severity and death. However, predictive biomarkers of pathogenic inflammation to help guide targetable immune pathways are critically lacking. We implemented a rapid multiplex cytokine assay to measure serum interleukin (IL)-6, IL-8, tumor necrosis factor (TNF)-α and IL-1β in hospitalized patients with coronavirus disease 2019 (COVID-19) upon admission to the Mount Sinai Health System in New York. Patients (n = 1,484) were followed up to 41 d after admission (median, 8 d), and clinical information, laboratory test results and patient outcomes were collected. We found that high serum IL-6, IL-8 and TNF-α levels at the time of hospitalization were strong and independent predictors of patient survival (P

Checkpoint blockade therapies have improved cancer treatment, but such immunotherapy regimens fail in a large subset of patients. Conventional type 1 dendritic cells (DC1s) control the response to checkpoint blockade in preclinical models and are associated with better overall survival in patients with cancer, reflecting the specialized ability of these cells to prime the responses of CD8+ T cells1–3. Paradoxically, however, DC1s can be found in tumours that resist checkpoint blockade, suggesting that the functions of these cells may be altered in some lesions. Here, using single-cell RNA sequencing in human and mouse non-small-cell lung cancers, we identify a cluster of dendritic cells (DCs) that we name ‘mature DCs enriched in immunoregulatory molecules’ (mregDCs), owing to their coexpression of immunoregulatory genes (Cd274, Pdcd1lg2 and Cd200) and maturation genes (Cd40, Ccr7 and Il12b). We find that the mregDC program is expressed by canonical DC1s and DC2s upon uptake of tumour antigens. We further find that upregulation of the programmed death ligand 1 protein—a key checkpoint molecule—in mregDCs is induced by the receptor tyrosine kinase AXL, while upregulation of interleukin (IL)-12 depends strictly on interferon-γ and is controlled negatively by IL-4 signalling. Blocking IL-4 enhances IL-12 production by tumour-antigen-bearing mregDC1s, expands the pool of tumour-infiltrating effector T cells and reduces tumour burden. We have therefore uncovered a regulatory module associated with tumour-antigen uptake that reduces DC1 functionality in human and mouse cancers. After taking up tumour-associated antigens, dendritic cells in mouse and human tumours upregulate a regulatory gene program that limits dendritic cell immunostimulatory function, and modulating this program can rescue antitumor immunity in mice.

BackgroundHepatocellular carcinoma (HCC) is the fourth most common cause of cancer-related death. Immune checkpoint inhibitors targeting PD-1 have limited activity in HCC as monotherapy, with response rates ranging from 14–17%. Tumor neoantigens derived from tumor-specific mutations can be incorporated into personalized therapeutic cancer vaccines to generate tumor-specific T cell immunity, potentially priming the immune system for anti-PD1 therapy. DNA vaccines have been shown to elicit strong CD8 and CD4 T cell responses in preclinical and clinical trials. GNOS-PV02 is a personalized DNA vaccine, encoding up to 40 patient-specific neoantigens. In the GT-30 trial, it is used in combination with INO-9012 (plasmid-encoded IL-12) and pembrolizumab for the treatment of advanced HCC.MethodsGT-30 is a single-arm phase I/II clinical trial to assess the safety, immunogenicity, and preliminary efficacy of GNOS-PV02 in combination with INO-9012 and pembrolizumab in patients with advanced HCC. Twenty-four patients are anticipated to be enrolled. Patients are recruited upon diagnosis or during first-line treatment with tyrosine kinase inhibitors (TKI). Tumors are biopsied for exome and transcriptome sequencing, and peripheral blood collected for germline sequencing and histogenetics. The tumor specific vaccine is designed, optimized and manufactured during first-line therapy. Each vaccine encodes up to 40 neoantigens. After progression or intolerance with first-line therapy, patients commence concurrent personalized vaccine and pembrolizumab. GNOS-PV02 + INO-9012 are administered Q3w for the first 4 doses and Q9w thereafter. Pembrolizumab is delivered Q3w.ResultsWe performed a data cut-off on the first 12 patients. The median age was 66 years (range 55–75 years). GNOS-PV02 + INO-9012 with pembrolizumab has had no reported DLTs or drug related SAEs. The most common treatment-related AE were grade 1 fatigue (25%) and grade 1 injection site reactions (17%). By including up to 40 epitopes in the vaccine we were able to target all neoantigens present in 83% of the patients. The objective response rate was 25% (3/12 partial response, 5/12 stable disease, 4/12 progressive disease). Analysis of the TCR repertoire in peripheral blood and tumor tissue identified novel and significantly expanded T cell clones post-vaccination in all patients analyzed. Many of the novel peripheral T cell clones were also identified to have trafficked to the TME at week 9, potentially mediating the observed tumor regressions.ConclusionsThese data demonstrate the potential of GNOS-PV02 + INO-9012 with pembrolizumab to target multiple neoepitopes, and provide initial support for the safety and efficacy of this regimen in patients with advanced HCC.Trial RegistrationNCT04251117Ethics ApprovalThe study obtained IRB approval (IRB) and all patients signed informed consent prior to taking part in the clinical trial. NZCR EC: 20/NTA/6; JHU: IRB00227771; Mount Sinai: HS#: 20–00076

BackgroundImmune checkpoint inhibitors (ICIs) are approved by the U.S. Food&Drug Administration in over 17 tumor types. Older adult patients make up about a quarter of all cancer patients but are historically understudied in cancer clinical trials. ICIs are associated with immune-related adverse events (irAEs), which may be particularly morbid for older adult patients with underlying comorbidities and impaired functional status. In this study, we provide insight into the real-world safety and efficacy of ICIs among older adult patients (≥80 years) with cancer.MethodsThis is a multicenter, international retrospective study of tumor-agnostic older adult patients with cancer treated with single-agent ICIs between 2010–2019 from 18 academic centers in the U.S. and Europe. A cohort of 928 patients aged ≥80 years during treatment with ICI was assembled and analyzed to evaluate clinical outcomes and irAE patterns in older adult patients treated with single-agent ICIs.ResultsMedian age at ICI initiation was 83.0 years (range 75.8–97.0). Most patients (86.9%) were treated with anti-PD-1 therapy. Among the full cohort, the three most common tumors were non-small cell lung cancer (NSCLC, 37.2%,n=345), melanoma (35.5%,n=329), and genitourinary (GU) tumors (16.5%,n=153). Objective response rates for patients with NSCLC, melanoma, and GU tumors were 32.2%, 39.3%, and 26.2%, respectively. Median progression-free survival (PFS) was 6.7 months (95%CI, 5.2–8.6) for patients with NSCLC, 11.1 months (95%CI, 8.9–16.0) for patients with melanoma, and 6.0 months (95% CI, 5.0–10.7) for patients with GU malignancy. Median overall survival (OS) was 10.9 months (95%CI, 8.6–13.1) for patients with NSCLC, 30.0 months (95%CI, 23.6–46.4) for patients with melanoma, and 15.0 months (95%CI 9.1–25.4) for GU patients (Figure 1A-C). Within histology-specific cohorts (NSCLC, melanoma and GU), clinical outcomes were similar across age subgroups (90). Among all patients (N=928), 41.3% experienced ≥1 irAE(s), including 12.2% reported to be grade (G)3–4. No irAE-related deaths occurred. The median time to irAE onset was 9.8 weeks; 57% occurred within the first 3 months after ICI initiation. ICI was discontinued due to irAEs in 16.1% patients. There was no significant difference in the rate of irAEs among patients age ConclusionsICIs are effective and generally well-tolerated among older patients with cancer. However, ICI discontinuation due to irAE is more frequent with increasing age.

Summary ParagraphTwo years into the SARS-CoV-2 pandemic, the post-acute sequelae of infection are compounding the global health crisis. Often debilitating, these sequelae are clinically heterogeneous and of unknown molecular etiology. Here, a transcriptome-wide investigation of this new condition was performed in a large cohort of acutely infected patients followed clinically into the post-acute period. Gene expression signatures of post-acute sequelae were already present in whole blood during the acute phase of infection, with both innate and adaptive immune cells involved. Plasma cells stood out as driving at least two distinct clusters of sequelae, one largely dependent on circulating antibodies against the SARS-CoV-2 spike protein and the other antibody-independent. Altogether, multiple etiologies of post-acute sequelae were found concomitant with SARS-CoV-2 infection, directly linking the emergence of these sequelae with the host response to the virus.

Predicting COVID-19 severity is difficult, and the biological pathways involved are not fully understood. To approach this problem, we measured 4,701 circulating human protein abundances in two independent cohorts totaling 986 individuals. We then trained prediction models including protein abundances and clinical risk factors to predict adverse COVID-19 outcomes in 417 subjects and tested these models in a separate cohort of 569 individuals. For severe COVID-19, a baseline model including age and sex provided an area under the receiver operator curve (AUC) of 65% in the test cohort. Selecting 92 proteins from the 4,701 unique protein abundances improved the AUC to 88% in the training cohort, which remained relatively stable in the testing cohort at 86%, suggesting good generalizability. Proteins selected from different adverse COVID-19 outcomes were enriched for cytokine and cytokine receptors, but more than half of the enriched pathways were not immune-related. Taken together, these findings suggest that circulating proteins measured at early stages of disease progression are reasonably accurate predictors of adverse COVID-19 outcomes. Further research is needed to understand how to incorporate protein measurement into clinical care.

Post-acute sequelae of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are debilitating, clinically heterogeneous and of unknown molecular etiology. A transcriptome-wide investigation was performed in 165 acutely infected hospitalized individuals who were followed clinically into the post-acute period. Distinct gene expression signatures of post-acute sequelae were already present in whole blood during acute infection, with innate and adaptive immune cells implicated in different symptoms. Two clusters of sequelae exhibited divergent plasma-cell-associated gene expression patterns. In one cluster, sequelae associated with higher expression of immunoglobulin-related genes in an anti-spike antibody titer-dependent manner. In the other, sequelae associated independently of these titers with lower expression of immunoglobulin-related genes, indicating lower non-specific antibody production in individuals with these sequelae. This relationship between lower total immunoglobulins and sequelae was validated in an external cohort. Altogether, multiple etiologies of post-acute sequelae were already detectable during SARS-CoV-2 infection, directly linking these sequelae with the acute host response to the virus and providing early insights into their development.

Purpose The development of treatment-related adverse events (trAE) correlates favorably with clinical outcomes in multiple studies of patients receiving immune checkpoint inhibitors (ICI); however, this relationship is undefined in patients with hepatocellular carcinoma (HCC). Patients and methods We derived a cohort of 406 patients with unresectable/advanced HCC receiving ICI therapy as part of international clinical trials submitted to the US Food and Drug Administration (FDA) in support of marketing applications. We tested whether the development of clinically significant trAE (i.e. graded ≥2, trAE2) predicted improved overall survival (OS), progression-free survival (PFS), and objective response rates (ORR) following ICI. We established an international consortium of 10 tertiary-care referral centres located in Europe (n = 67), United States (US, n = 248) and Asia (n = 42) to validate this association. Results In the FDA dataset of 406 patients, 325 (80%) with Barcelona Clinic Liver Cancer (BCLC) stage C HCC mostly treated with ICI monotherapy (n = 258, 64%), trAE2 were reported in 228 patients (56.1%). Development of trAE2 was associated with longer OS (16.7 versus 11.2 months) and PFS (5.5 versus 2.2 months) and persisted as an independent predictor of outcome after adjusting for viral aetiology, gender, Child-Pugh class, BCLC stage, AFP levels, ECOG-PS, ICI regimen (mono/combination therapy) and receipt of corticosteroid therapy. In a multi-institutional cohort of 357 patients with similar characteristics mostly treated with ICI monotherapy (n = 304, 85%), the development of trAE2 was associated with longer OS (23.3 versus 12.1 months) and PFS (9.6 versus 3.9 months). TrAE2 were confirmed predictors of improved OS (HR 0.43; 95% CI:0.25–0.75) and PFS (HR 0.48; 95% CI: 0.31–0.75), with multivariable analyses confirming their association with outcome independent of clinicopathologic features of interest. Additional time-varying multivariable analyses also indicated that trAEs were associated with a decreased risk of progression (HR 0.56, 95% CI: 0.46–0.67) in the FDA dataset and death (HR 0.55; 95% CI: 0.32–0.95) in the multi-institutional dataset. Conclusion Development of trAE2 correlates with improved outcomes in patients with HCC receiving ICI in clinical trials and in routine practice. Prospective studies aimed at understanding the underlying immunologic foundations of such relationships are warranted to identify predictive biomarkers of toxicity and response.

Macrophages have a key role in shaping the tumour microenvironment (TME), tumour immunity and response to immunotherapy, which makes them an important target for cancer treatment1,2. However, modulating macrophages has proved extremely difficult, as we still lack a complete understanding of the molecular and functional diversity of the tumour macrophage compartment. Macrophages arise from two distinct lineages. Tissue-resident macrophages self-renew locally, independent of adult haematopoiesis3–5, whereas short-lived monocyte-derived macrophages arise from adult haematopoietic stem cells, and accumulate mostly in inflamed lesions1. How these macrophage lineages contribute to the TME and cancer progression remains unclear. To explore the diversity of the macrophage compartment in human non-small cell lung carcinoma (NSCLC) lesions, here we performed single-cell RNA sequencing of tumour-associated leukocytes. We identified distinct populations of macrophages that were enriched in human and mouse lung tumours. Using lineage tracing, we discovered that these macrophage populations differ in origin and have a distinct temporal and spatial distribution in the TME. Tissue-resident macrophages accumulate close to tumour cells early during tumour formation to promote epithelial–mesenchymal transition and invasiveness in tumour cells, and they also induce a potent regulatory T cell response that protects tumour cells from adaptive immunity. Depletion of tissue-resident macrophages reduced the numbers and altered the phenotype of regulatory T cells, promoted the accumulation of CD8+ T cells and reduced tumour invasiveness and growth. During tumour growth, tissue-resident macrophages became redistributed at the periphery of the TME, which becomes dominated by monocyte-derived macrophages in both mouse and human NSCLC. This study identifies the contribution of tissue-resident macrophages to early lung cancer and establishes them as a target for the prevention and treatment of early lung cancer lesions. Single-cell RNA sequencing and imaging of macrophages in human non-small cell lung cancer and in a mouse model of lung adenocarcinoma show that tissue-resident macrophages have a key role in early tumour progression.

Serologic markers that predict severe COVID-19 disease trajectories could enable early medical interventions and reduce morbidity and mortality. We found that distinct features of IgG Fab and Fc domain structures were present within three days of a positive test that predicted two separate disease trajectories in a prospective cohort of patients with COVID-19. One trajectory was defined by early production of neutralizing antibodies and led to mild disease. A distinct trajectory, characterized by an initial period of mild symptoms followed by rapid progression to more severe outcomes, was predicted by the absence of early neutralizing antibody responses with concomitant production of afucosylated IgGs. Elevated frequencies of monocytes expressing the receptor for afucosylated IgGs, FcγRIIIa (CD16a), were an additional antecedent in patients with the more severe outcomes. In mechanistic studies, afucosylated immune complexes in the lung triggered an inflammatory infiltrate and cytokine production that was dependent on CD16a. Finally, in healthy subjects, mRNA SARS-CoV-2 vaccination elicited neutralizing antibodies that were enriched for Fc fucosylation and sialylation and distinct from both infection-induced trajectories. These data show the importance of combined Fab and Fc domain functions in the antiviral response, define an early antibody signature in people who progressed to more severe COVID-19 outcomes and have implications for novel therapeutic strategies targeting FcγRIIIa pathways.

Hepatocellular carcinoma (HCC) can have viral or non-viral causes1–5. Non-alcoholic steatohepatitis (NASH) is an important driver of HCC. Immunotherapy has been approved for treating HCC, but biomarker-based stratification of patients for optimal response to therapy is an unmet need6,7. Here we report the progressive accumulation of exhausted, unconventionally activated CD8+PD1+ T cells in NASH-affected livers. In preclinical models of NASH-induced HCC, therapeutic immunotherapy targeted at programmed death-1 (PD1) expanded activated CD8+PD1+ T cells within tumours but did not lead to tumour regression, which indicates that tumour immune surveillance was impaired. When given prophylactically, anti-PD1 treatment led to an increase in the incidence of NASH–HCC and in the number and size of tumour nodules, which correlated with increased hepatic CD8+PD1+CXCR6+, TOX+, and TNF+ T cells. The increase in HCC triggered by anti-PD1 treatment was prevented by depletion of CD8+ T cells or TNF neutralization, suggesting that CD8+ T cells help to induce NASH–HCC, rather than invigorating or executing immune surveillance. We found similar phenotypic and functional profiles in hepatic CD8+PD1+ T cells from humans with NAFLD or NASH. A meta-analysis of three randomized phase III clinical trials that tested inhibitors of PDL1 (programmed death-ligand 1) or PD1 in more than 1,600 patients with advanced HCC revealed that immune therapy did not improve survival in patients with non-viral HCC. In two additional cohorts, patients with NASH-driven HCC who received anti-PD1 or anti-PDL1 treatment showed reduced overall survival compared to patients with other aetiologies. Collectively, these data show that non-viral HCC, and particularly NASH–HCC, might be less responsive to immunotherapy, probably owing to NASH-related aberrant T cell activation causing tissue damage that leads to impaired immune surveillance. Our data provide a rationale for stratification of patients with HCC according to underlying aetiology in studies of immunotherapy as a primary or adjuvant treatment., In hepatocellular carcinoma driven by non-alcoholic steatohepatitis, aberrant T cell activation and impaired immune surveillance seem to make hepatocellular carcinoma less responsive to anti-PD1 or anti-PDL1 immunotherapy.

Indolent non-Hodgkin’s lymphomas (iNHLs) are incurable with standard therapy and are poorly responsive to checkpoint blockade. Although lymphoma cells are efficiently killed by primed T cells, in vivo priming of anti-lymphoma T cells has been elusive. Here, we demonstrate that lymphoma cells can directly prime T cells, but in vivo immunity still requires cross-presentation. To address this, we developed an in situ vaccine (ISV), combining Flt3L, radiotherapy, and a TLR3 agonist, which recruited, antigen-loaded and activated intratumoral, cross-presenting dendritic cells (DCs). ISV induced anti-tumor CD8+ T cell responses and systemic (abscopal) cancer remission in patients with advanced stage iNHL in an ongoing trial ( NCT01976585 ). Non-responding patients developed a population of PD1+CD8+ T cells after ISV, and murine tumors became newly responsive to PD1 blockade, prompting a follow-up trial of the combined therapy. Our data substantiate that recruiting and activating intratumoral, cross-priming DCs is achievable and critical to anti-tumor T cell responses and PD1-blockade efficacy. In situ vaccine recruits and activates cross-presenting dendritic cells and augments PD1 blockade efficacy in patients with indolent non-Hodgkin’s lymphoma.