Programmed Cell Death-1 Blockade Research Articles

PD1 blockade improves survival and CD8+ cytotoxic capacity, without increasing inflammation, during normal microbial experience in old mice.

By 2030, individuals 65 years of age or older will make up approximately 20% of the world's population1. Older individuals are at the highest risk for mortality from infections, largely due to the pro-inflammatory, dysfunctional immune response, which is collectively known as immunosenescence2. During aging, CD8+ T cells acquire an exhausted phenotype, including increased expression of inhibitory receptors, such as programmed cell death 1 (PD1), a decline in effector function and elevated expression of inflammatory factors3-7. PD1 reduces T cell receptor activity via SHP2-dependent dephosphorylation of multiple pathways; accordingly, inhibiting PD1 activity through monoclonal antibodies increases CD8+ T cell effector response in young mice8-11. Attempts to improve CD8+ T cell responses by blocking inhibitory receptors are attractive; however, they can lead to adverse immune events due to overamplification of T cell receptor signaling and T cell activation12,13. Here we investigated the effect of monoclonal anti-PD1 immunotherapy during normal microbial experience, otherwise known as exposure to dirty mice, to determine whether it either improves exhausted CD8+ T cell responses in old mice or leads to a heightened inflammatory response and increased mortality.

Effect of anti-claudin 18.2 monoclonal antibody zolbetuximab alone or combined with chemotherapy or programmed cell death-1 blockade in syngeneic and xenograft gastric cancer models

The development of targeted cancer therapies based on monoclonal antibodies against tumor-associated antigens has progressed markedly over recent decades. This approach is dependent on the identification of tumor-specific, normal tissue-sparing antigenic targets. The transmembrane protein claudin-18 splice variant 2 (CLDN18.2) is frequently and preferentially displayed on the surface of primary gastric adenocarcinomas, making it a promising monoclonal antibody target. Phase 3 studies of zolbetuximab, a chimeric immunoglobulin G1 monoclonal antibody targeting CLDN18.2, combined with 5-fluorouracil/leucovorin plus oxaliplatin (modified FOLFOX6) or capecitabine plus oxaliplatin (CAPOX) in advanced or metastatic first-line gastric or gastroesophageal junction (G/GEJ) adenocarcinoma have demonstrated favorable clinical results with zolbetuximab. In studies using xenograft or syngeneic models with gastric cancer cell lines, zolbetuximab mediated death of CLDN18.2-positive human cancer cell lines via antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity in vitro and demonstrated anti-tumor efficacy as monotherapy and combined with chemotherapy in vivo. Mice treated with zolbetuximab plus chemotherapy displayed a significantly higher frequency of tumor-infiltrating CD8+ T cells versus vehicle/isotype control-treated mice. Furthermore, zolbetuximab combined with an anti-mouse programmed cell death-1 antibody more potently inhibited tumor growth compared with either agent alone. These results support the potential of zolbetuximab as a novel treatment option for G/GEJ adenocarcinoma.

Abstract CT211: Safety of prompt initiation of durvalumab or STRIDE (single tremelimumab regular interval durvalumab) regimen as hepatocellular carcinoma (HCC) treatment for patients with chronic active hepatitis B

Abstract Background: Chronic hepatitis B is an etiology of HCC. Clinical trials using immune checkpoint inhibitors (ICIs) as HCC treatment typically exclude patients with chronic active hepatitis B (serum hepatitis B virus [HBV] viral load > 2000 IU/mL) or require the HBV viral load to be below a certain level using anti-HBV medications. In the phase 3 HIMALAYA study, the STRIDE regimen was superior to sorafenib and durvalumab was noninferior to sorafenib in overall survival benefits. This study explored the safety of concurrent administration of STRIDE or durvalumab with anti-HBV mediations for patients with chronic, active hepatitis B infection. Methods: We enrolled patients with advanced HCC, Child-Pugh A liver function reserve, and chronic active hepatitis B not under anti-HBV treatment. Initially, only patients naïve to ICIs were eligible, and patients received durvalumab 1500mg iv every 4 weeks until disease progression, occurrence of unacceptable toxicities, or the maximum treatment duration of 2 years. After the positive results of the HIMALAYA study, we added tremelimumab 300mg iv on D1 following the STRIDE regimen and allowed enrollment of patients who had received prior programmed cell death-1 blockade therapy. Patients initiated entecavir as HBV treatment within 7 days of starting ICI therapy. The plan was to enroll 30 patients, with the primary outcome of HBV reactivation (a ≥2 log increase in serum HBV DNA compared to the baseline level). Results: The study is still ongoing and as of 31 Aug 2023, 19 patients were enrolled. Two patients were female, and the median age was 65.5 years. Ten patients received durvalumab alone, and 9 received the STRIDE regimen. The ALBI grade was 1 and 2 in 3 (16%) and 16 (84%) patients, respectively. Macrovascular invasion and extrahepatic spread were present in 11 (58%) and 11 (58%) patients, respectively; 12 (63%) patients had alpha-fetoprotein level ≥ 400 ng/mL. Eleven (58%) patients had received prior systemic therapy for HCC, such as sorafenib (n = 9), lenvatinib (n = 5), and regorafenib (n = 4). The mean±standard deviation baseline HBV viral load was 1.18±0.44 mIU/mL. With the median follow-up on 6.1 months, no patients experienced HBV reactivation or HBV-associated hepatitis. Hepatitis flare (ALT increase to ≥3 times the baseline level) was noted in 4 (21%) patients, but none were considered HBV-associated. The best objective tumor response was complete and partial response in 0 and 5 (26.3%) patients, respectively, and the disease control rate was 63.2%. Conclusion: In the preliminary results, simultaneous initiation of immunotherapy and anti-HBV medications in patients with HCC and chronic active hepatitis B did not increase HBV reactivation rate. This study was supported by AstraZeneca (NCT04294498). Citation Format: Yu-Yun Shao, Ching-Tso Chen, Tsung-Che Wu, Tsung-Hao Liu, Chien-Huai Chuang, Ann-Lii Cheng, Chih-Hung Hsu. Safety of prompt initiation of durvalumab or STRIDE (single tremelimumab regular interval durvalumab) regimen as hepatocellular carcinoma (HCC) treatment for patients with chronic active hepatitis B [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT211.

PD-1 Blockade in Treatment of NSCLC: A Comprehensive Review of Clinical Efficacy, Safety and Cost-effective

Non-small cell lung cancer, also called NSCLC, makes up 85% incidence in lung cancer, presents a considerable challenge for its high mortality rate and poor prognosis. In recent years, the invention of programmed cell death 1 (PD-1) inhibitor nivolumab, which is a type of immune checkpoint inhibitors, emerging as a groundbreaking drug, has offered a potential solution to tackle the inescapable drawbacks of traditional cancer treatments. Several clinical trials assessing nivolumab's efficacy and safety in the form of monotherapy or combination therapy, demonstrated that nivolumab has remarkably increased the progression-free survival and overall survival for NSCC, in both first- and second-line. Notably, compared to chemotherapy drugs, nivolumab showed a favorable safety profile with fewer immune-related adverse events. Given the high cost and escalating use of nivolumab, finding more cost-effective treatment regimen is imperative. The purpose of this review is to delve into the clinical efficacy and safety of PD-1 inhibitor nivolumab as immunotherapy remedy against NSCLC, providing some therapeutic recommendations for cost-effective. While continued research and development are vital to further enhance nivolumab's potential as a more potent tool to combat cancer.

Abstract 6686: The mechanism of gut microbiome-mediated immune activation on the clinical efficacy of PD-1 blocking treatment in solid tumors

Abstract Gut microbiota is associated with antitumor efficacy of immune checkpoint blockade therapies, yet the mechanism is not largely understood. Here, we show that a novel bacterial strain of Ruminococcaceae isolated from the feces of patients who respond to PD-1 (programmed cell death 1) blockade efficiently primes/activates tumor-specific CD8+ T cells through effective stimulation/maturation of CD103+ dendritic cells (DCs) during migration from the gut to the tumor microenvironment (TME). The administration of this bacteria strain with PD-1 blockade significantly inhibited tumor growth, even when adding them to fecal transplantation of non-responder patients in animal models. Mechanistically, the bacterial strain promoted the IRF8-driven differentiation of CD103+ DCs by stimulating multiple Toll-like receptors and the accumulation of these DCs in tumors and tumor-draining lymph nodes. These CD103+ DCs prolonged engagement with cognate antigen-specific CD8+ T cells, which induced the activation of CD8+ T cells specific for a wide variety of tumor antigens and fostered their PD-1 expression through enhanced T-cell activation signals with NFATc1 nuclear translocation, thereby leading to abundant PD-1+CD8+ T cells, a key effector cell population in PD-1 blockade, with a broader T-cell receptor repertoire in the TME. Our findings with novel single bacterium isolated from feces of responder patients demonstrate the mode of action by gut microbiota to augment antitumor immunity. Citation Format: Nina Yi-Tzu Lin, Shota Fukuoka, Daisuke Motooka, Yuko Shigeno, Takuma Irie, Dieter M. Tourlousse, Kazutoshi Murotomi, Yuji Sekiguchi, Hideyuki Tamaki, Mariko Shindo, Takahiro Tsuji, Hiroaki Wake, Koichi Goto, Toshihiko Doi, Kohei Shitara, Keisuke Watanabe, Yuka Maeda, Shota Nakamura, Yoshimi Benno, Hiroyoshi Nishikawa, Shohei Koyama. The mechanism of gut microbiome-mediated immune activation on the clinical efficacy of PD-1 blocking treatment in solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6686.

Abstract 1399: The role of CCN5 in regulation of tumor-infiltrating lymphocytes (TILS) in triple-negative breast cancer (TNBC) cells

Abstract TNBC accounts for about 15-20 percent of all breast cancer cases, with a high incidence in young and African-American women. TNBC lacks the expression of estrogen receptor, progesterone receptor, and normal human epidermal growth factor receptor type 2 (HER2) copy number with expression. Thus, TNBC is not sensitive to endocrine and targeted molecular therapies. Therefore, surgery and systemic chemotherapy are the primary treatment methods for TNBC. The adjuvant therapy regimen includes anthracycline, paclitaxel, or both in (Neo-) early TNBC. However, this treatment is often ineffective after recurrence or metastasis. Therefore, continuously searching for new targeted therapies and immunotherapies becomes a focus in TNBC treatment in patients with diverse communities. The studies showed that TNBC is more immunogenic than other subtypes of breast cancers with tumor-infiltrating lymphocytes (TILs) in its microenvironment. More importantly, Cytotoxic CD8+ TILs of the adaptive immune system are the most potent effectors in the anticancer immune response and constitute the backbone of cancer immunotherapy. Therefore, a high number of CD8+TILs in TNBC patients' tumors are considered a better prognosis following neoadjuvant chemotherapy. Hence, increasing and activating CD8+ TILs could be an exciting and appropriate approach to treating TNBC. Blocking immune checkpoints can inverse the microenvironment immunosuppressive state and enhance the function of tumor cell clearance. One of the major immune checkpoint therapies has involved a monoclonal antibody against programmed cell death-1 (PD-1)/programmed cell death-ligand 1 (PD-L1), expressed in various tumor cells, including TNBC and immune cells. The studies found that PD-1/PD-L1 negatively regulates CD8+ TILs in cancers, and blockade of PD-1 can induce CD8+ TILs responses in advanced melanoma. Interestingly, PD-1/PD-L1 immunotherapy has also progressed in suppressing TNBC growth and progression. However, the currently available immune checkpoint therapies have therapeutic limitations with the toxicity of the drugs. Thus, new therapeutic options are urgently needed. Our studies found that the expression of CCN5, an anti-invasive gene, correlates with the number of cytotoxic CD8+ TILs in ER+ and HER-2 positive breast cancer samples. Furthermore, we also observed that PD-L1 (programmed death-ligand 1), which was found to have high and low expression in MDA-MB-231 and 4T1, respectively, was suppressed in MDA-MB-231 and 4T1 TNBC cell lines by CCN5 recombinant protein treatment for 48 h. These findings might provide a novel immune checkpoint mechanistic explanation of CCN5 that mediates TNBC growth and progression suppression. Citation Format: Upasana Biswas, Anjali Kambhampati, Noor Haideri, Archana De, Sunil Upadhyay, Snigdha Banerjee, Sushanta Banerjee. The role of CCN5 in regulation of tumor-infiltrating lymphocytes (TILS) in triple-negative breast cancer (TNBC) cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1399.

Circular RNA circNCOA3 promotes tumor progression and anti-PD-1 resistance in colorectal cancer.

Aim: Circular RNAs (circRNAs) have been found to be involved in tumor progression, but their role in colorectal cancer (CRC) immune escape remains to be elucidated. Methods: circRNAs differentially expressed in responsive and resistant CRC tissues to programmed cell death 1 (PD-1) antibody therapy were identified by microarray analysis. The clinical and pathological significance of circNCOA3 was validated in a separate cohort of CRC samples. The function of circNCOA3 was explored experimentally. RNA immunoprecipitation and luciferase activity assays were conducted to identify downstream targets of circNCOA3. Results: The circNCOA3 was markedly overexpressed in CRC samples resistant to PD-1 blockade. circNCOA3 expression was significantly correlated with adverse tumor phenotypes and poor outcomes in CRC patients. Knockdown of circNCOA3 expression markedly suppressed the proliferative and invasive capability of CRC cells. Moreover, knockdown of circNCOA3 increased the proportion of CD8+ T cells while decreasing the proportion of myeloid-derived suppressor cells (MDSCs). Knockdown of circNCOA3 inhibited tumor growth and increased the sensitivity to PD-1 antibody treatment in mouse tumor models. Further studies revealed that circNCOA3 acted as a competing endogenous RNA (ceRNA) for miR-203a-3p.1 to influence the level of CXCL1. Conclusion: Our findings indicate that circNCOA3 might be useful as a potential biomarker to predict the efficacy and prognosis of CRC patients treated with anti-PD-1 therapy.

Neoadjuvant-Adjuvant vs Neoadjuvant-Only PD-1 and PD-L1 Inhibitors for Patients With Resectable NSCLC

Neoadjuvant therapy combining programmed cell death 1 (PD-1) and programmed death ligand 1 (PD-L1) inhibitors with platinum-based chemotherapy has demonstrated significant improvement in pathologic response and survival rates among patients with resectable non-small cell lung cancer (NSCLC). However, it remains controversial whether PD-1 blockade therapy given before and after surgery (neoadjuvant-adjuvant treatment) is associated with better outcomes than when given only before surgery (neoadjuvant-only treatment). To compare the efficacy and safety associated with neoadjuvant-adjuvant anti-PD-1 and anti-PD-L1 therapy with neoadjuvant-only anti-PD-1 and anti-PD-L1 therapy for patients with resectable NSCLC. A systematic search was conducted across databases including PubMed, Embase, and the Cochrane Library, as well as major oncology conferences, through July 31, 2023. Randomized clinical trials comparing neoadjuvant-adjuvant or neoadjuvant-only PD-1 and PD-L1 inhibitor therapy vs chemotherapy alone for patients with resectable NSCLC were selected. Following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline, 2 authors independently extracted data. Hazard ratios (HRs) and 95% CIs for event-free survival (EFS) and overall survival (OS) were extracted and then pooled through the generic inverse-variance methods. Relative risks (RRs) for treatment-related adverse events (TRAEs) were derived via the Mantel-Haenszel method. Using chemotherapy as a common comparator, indirect comparisons between neoadjuvant-adjuvant immunotherapy and neoadjuvant-only immunotherapy were conducted using frequentist methods. A random or fixed model was used based on intertrial heterogeneity identified through the Cochran Q test. The primary outcome was EFS, with secondary outcomes including OS and TRAEs. The study encompassed 4 trials of neoadjuvant-adjuvant immunotherapy and 1 trial of neoadjuvant-only immunotherapy, involving 2385 patients. Direct meta-analysis revealed significant improvements in EFS for both neoadjuvant-adjuvant and neoadjuvant-only immunotherapy compared with chemotherapy alone. In indirect meta-analysis, the addition of adjuvant immunotherapy to neoadjuvant immunotherapy was not associated with improved EFS (HR, 0.90; 95% CI, 0.63-1.30; P = .59) or OS (HR, 1.18; 95% CI, 0.73-1.90; P = .51) compared with neoadjuvant-only immunotherapy. Moreover, the incidence of any grade of TRAEs significantly increased with the addition of adjuvant immunotherapy (RR, 1.08; 95% CI, 1.00-1.17; P = .04). This meta-analysis suggests that adding PD-1 or PD-L1 inhibitors in the adjuvant phase to neoadjuvant treatment with PD-1 or PD-L1 inhibitors and chemotherapy may not improve survival outcomes for patients with resectable NSCLC and may be associated with increased adverse events. Future validation of these findings is warranted through head-to-head randomized clinical trials.

Inhibition of SFTSV replication in humanized mice by a subcutaneously administered anti-PD1 nanobody

Severe fever with thrombocytopenia syndrome (SFTS) is a life-threatening disease caused by a novel bunyavirus (SFTSV), mainly transmitted by ticks. With no effective therapies or vaccines available, understanding the disease’s mechanisms is crucial. Recent studies found increased expression of programmed cell death-1 (PD-1) on dysfunctional T cells in SFTS patients. However, the role of the PD-1/programmed cell death-ligand 1 (PD-L1) pathway in SFTS progression remains unclear. We investigated PD-1 blockade as a potential therapeutic strategy against SFTSV replication. Our study analyzed clinical samples and performed in vitro experiments, revealing elevated PD-1/PD-L1 expression in various immune cells following SFTSV infection. An anti-PD-1 nanobody, NbP45, effectively inhibited SFTSV infection in peripheral blood mononuclear cells (PBMCs), potentially achieved through the mitigation of apoptosis and the augmentation of T lymphocyte proliferation. Intriguingly, subcutaneous administration of NbP45 showed superior efficacy compared to a licensed anti-PD-1 antibody in an SFTSV-infected humanized mouse model. These findings highlight the involvement of the PD-1/PD-L1 pathway during acute SFTSV infection and suggest its potential as a host target for immunotherapy interventions against SFTSV infection.

Tumor cell-intrinsic PD-1 promotes Merkel cell carcinoma growth by activating downstream mTOR-mitochondrial ROS signaling.

Merkel cell carcinoma (MCC) is a rare and aggressive skin cancer. Inhibitors targeting the programmed cell death 1 (PD-1) immune checkpoint have improved MCC patient outcomes by boosting antitumor T cell immunity. Here, we identify PD-1 as a growth-promoting receptor intrinsic to MCC cells. In human MCC lines and clinical tumors, RT-PCR-based sequencing, immunoblotting, flow cytometry, and immunofluorescence analyses demonstrated PD-1 gene and protein expression by MCC cells. MCC-PD-1 ligation enhanced, and its inhibition or silencing suppressed, in vitro proliferation and in vivo tumor xenograft growth. Consistently, MCC-PD-1 binding to PD-L1 or PD-L2 induced, while antibody-mediated PD-1 blockade inhibited, protumorigenic mTOR signaling, mitochondrial (mt) respiration, and ROS generation. Last, pharmacologic inhibition of mTOR or mtROS reversed MCC-PD-1:PD-L1-dependent proliferation and synergized with PD-1 checkpoint blockade in suppressing tumorigenesis. Our results identify an MCC-PD-1-mTOR-mtROS axis as a tumor growth-accelerating mechanism, the blockade of which might contribute to clinical response in patients with MCC.

Discovery of Novel PD-L1 Inhibitors That Induce the Dimerization, Internalization, and Degradation of PD-L1 Based on the Fragment Coupling Strategy.

Tumor cells can evade immune surveillance through overexpressing programmed cell death-ligand 1 (PD-L1) to interact with programmed cell death-1 (PD-1). Besides, tumor-intrinsic PD-L1 is involved in tumor progression without interaction with PD-1, which provides more challenges for the discovery of PD-L1 inhibitors. Herein, we report the discovery of novel PD-L1 inhibitors using the fragment coupling strategy. Among them, B9 was found to inhibit the PD-1/PD-L1 interaction with the best IC50 value of 1.8 ± 0.7 nM. Beyond the blockade of the PD-1/PD-L1 axis, B9 promotes the dimerization, internalization, and degradation of PD-L1. Furthermore, B9 displayed high in vivo antitumor efficacy in the CT26 mouse model and activated the immune microenvironment and induced PD-L1 degradation of PD-L1 in the tumor. These results show that B9 is a promising lead PD-L1 inhibitor through the blockade of PD-1/PD-L1 interaction and functional inhibition of the PD-L1 signal pathway.

Platinum-Based Chemotherapy Attenuates the Effector Response of CD8 T Cells to Concomitant PD-1 Blockade.

Combination of chemotherapy with programmed cell death 1 (PD-1) blockade is a front-line treatment for lung cancer. However, it remains unknown whether and how chemotherapy affects the response of exhausted CD8 T cells to PD-1 blockade. We used the well-established mouse model of T-cell exhaustion with chronic lymphocytic choriomeningitis virus (LCMV) infection to assess the effect of chemotherapy (cisplatin+pemetrexed) on T-cell response to PD-1 blockade, in the absence of the impact of chemotherapy on antigen release and presentation observed in tumor models. When concomitantly administered with PD-1 blockade, chemotherapy affected the differentiation path of LCMV-specific CD8 T cells from stem-like to transitory effector cells, thereby reducing their expansion and production of IFNγ. After combination treatment, these restrained effector responses resulted in impaired viral control, compared with PD-1 blockade alone. The sequential combination strategy, where PD-1 blockade followed chemotherapy, proved to be superior to the concomitant combination, preserving the proliferative response of exhausted CD8 T cells to PD-1 blockade. Our findings suggest that the stem-like CD8 T cells themselves are relatively unaffected by chemotherapy partly because they are quiescent and maintained by slow self-renewal at the steady state. However, upon the proliferative burst mediated by PD-1 blockade, the accelerated differentiation and self-renewal of stem-like cells may be curbed by concomitant chemotherapy, ultimately resulting in impaired overall CD8 T-cell effector functions. In a translational context, we provide a proof-of-concept to consider optimizing the timing of chemo-immunotherapy strategies for improved CD8 T-cell functions. See related commentary by Vignali and Luke, p. 1705.

Impact of prophylactic dexamethasone on the efficacy of immune checkpoint inhibitors plus platinum-based chemotherapy in patients with advanced Non-Squamous Non-Small-Cell lung cancer

BackgroundBaseline corticosteroids exposure is associated with inferior clinical outcomes in patients with non-small-cell lung cancer (NSCLC) treated with programmed cell death-1 (PD-1) axis blockade. Dexamethasone is a potent corticosteroid used in the prevention of chemotherapy-associated adverse events (CAAEs). ObjectiveSince dexamethasone has immunosuppressive properties, this study attempted to elucidate its effects on the efficacy of immunotherapy plus chemotherapy in patients with non-squamous NSCLC. MethodsThe study retrospectively analyzed the medical records of 254 advanced non-squamous NSCLC patients who received front-line treatment with a PD-1 pathway inhibitor and platinum-based chemotherapy at three academic institutions. The average dosage of prophylactic dexamethasone per chemotherapy cycle was calculated. Patients were divided into three groups based on the dose of dexamethasone: High-d (≥24 mg), Moderate-d (12–24 mg), and Low-d (<12 mg). Spearman's rank correlation was used to assess the correlation between the dosage of dexamethasone and progression-free survival (PFS). Logistic regression was used to assess the correlation between dexamethasone dosage and the occurrence of immune related adverse effects (irAE). Univariate and multivariate Cox proportional hazards regression models were used to analyze the differences in survival among the different dexamethasone dosage groups. ResultThe dosage of prophylactic dexamethasone was not significantly correlated with PFS (Spearman’s rho = -0.103, P = 0.098). Results from the univariate [hazard ratio (HR)Low-d/High-d, 1.00; P = 0.997; HRModerate-d/High-d, 0.85; P = 0.438] and multivariate (HRLow-d/High-d, 0.71; P = 0.174; HRModerate-d/High-d, 0.87; P = 0.512) analyses showed no significant association between dexamethasone and PFS. Dexamethasone did not have significant effect on the objective response rate, disease control rate or overall survival. The toxicity profiles of irAE were similar across all three groups. ConclusionThe results of this study suggest that the use of prophylactic dexamethasone does not have an adverse effect on the clinical outcomes of non-squamous NSCLC patients treated with PD-1 blockade therapy and chemotherapy. Routine use of dexamethasone for preventing CAAEs should be recommended for patients undergoing combined immunotherapy and chemotherapy.

Blockade of PD-1 and LAG-3 expression on CD8+ T cells promotes the tumoricidal effects of CD8+ T cells.

The diffuse large B-cell lymphoma (DLBCL) has the highest incidence of all lymphomas worldwide. To investigate the functions of lymphocyte activation gene 3 (LAG-3) and programmed cell death 1 (PD-1) in tissues and peripheral blood of patients with DLBCL, the expression of LAG-3 and PD-1 genes in DLBCL-TCGA were analyzed. LAG-3 and PD-1 mRNA levels in DLBCL were analyzed using data from The Cancer Genome Atlas (TCGA) database. Utilize the Genotype-Tissue Expression (GTEx) database for assessing the variance in the expression of LAG-3, PD-1, and other associated factors between the tissues of DLBCL patients and healthy individuals. Immunohistochemistry was applied to detect the expression of LAG-3 and PD-1 levels in 137 cases of DLBCL tissues and 20 cases of reactive lymphoid hyperplasia. The prognostic value of LAG-3 and PD-1 were assessed using the Kaplan-Meier curve. The Estimation of Stromal and Immune cells in Malignant Tumor tissues using Expression data (ESTIMATE) and ssGSEA algorithm were used to explore the immune microenvironment of DLBCL. Additionally, the expression and co-expression of LAG-3 and PD-1 were detected on CD4 and CD8 T cells in peripheral blood samples from 100 cases of DLBCL tissues and 30 cases of healthy individuals using flow cytometry. According to TCGA database, LAG-3 and PD-1 gene expression levels were significantly up-regulated in DLBCL tissues. LAG-3 and PD-1 levels were also strongly positively correlated with those of most infiltrating immune cells. Overall survival of patients with high LAG-3 and PD-1 co-expression was significantly shorter than that of patients with low co-expression. In DLBCL patients, LAG-3 and PD-1 were highly expressed in peripheral blood CD8+ T cells. In addition, LAG-3 was highly expressed in CD4+ T cells, while the expression of PD-1 in CD4+ T cells of DLBCL patients showed no significant difference compared to healthy individuals. Additionally, CD8+ T cells and SU-DHL6/OCI-LY3 from patients with DLBCL were co-cultured in vitro; after addition of LAG-3 and/or PD-1 inhibitors alone, an increased perforin and granzyme B secretion levels by CD8+ T cells were detected, as well as an increase in the overall proportion of tumor cells undergoing apoptosis. High LAG-3 and PD-1 levels significantly inhibit CD8+ T cell function, resulting in weakened ability to kill tumor cells. Combined LAG-3 and PD-1 blockade can restore CD8+ T cell function and provides a potential avenue for development of personalized cellular immunotherapy for DLBCL.

The level of macrophage migration inhibitory factor is negatively correlated with the efficacy of PD-1 blockade immunotherapy combined with chemotherapy as a neoadjuvant therapy for esophageal squamous cell carcinoma

PurposeThis study aimed to screen biomarkers to predict the efficacy of programmed cell death 1 (PD-1) blockade immunotherapy combined with chemotherapy as neoadjuvant therapy for esophageal squamous cell carcinoma (ESCC). MethodsIn the first stage of the study, the baseline concentrations of 40 tumor-related chemokines in the serum samples of 50 patients were measured to screen for possible biomarkers. We investigated whether the baseline concentration of the selected chemokine was related to the therapeutic outcomes and tumor microenvironment states of patients treated with the therapy. In the second stage, the reliability of the selected biomarkers was retested in 34 patients. ResultsThe baseline concentration of macrophage migration inhibitory factor (MIF) was negatively correlated with disease-free survival (DFS) and overall survival (OS) in patients treated with the therapy. In addition, a low baseline expression level of MIF is related to a better tumor microenvironment for the treatment of ESCC. A secondary finding was that effective treatment decreased the serum concentration of MIF. ConclusionBaseline MIF levels were negatively correlated with neoadjuvant therapy efficacy. Thus, MIF may serve as a predictive biomarker for this therapy. The accuracy of the prediction could be improved if the serum concentration of MIF is measured again after the patient received several weeks of treatment.

Synergistic efficacy of simultaneous anti-TGF-β/VEGF bispecific antibody and PD-1 blockade in cancer therapy

BackgroundRecently, therapeutic antibodies against programmed cell death 1 (PD-1) and its ligand (PD-L1) have exerted potent anticancer effect in a variety of tumors. However, blocking the PD-1/PD-L1 axis alone is not sufficient to restore normal immune response. Other negative regulators of antitumor immunity, like TGF-β and VEGFA, are also involved in immune escape of tumor cells and induce immunotherapy resistance.MethodsWe developed a novel anti-TGF-β/VEGF bispecific antibody Y332D based on the Nano-YBODY™ technology platform. The CCK-8, flow cytometry, SBE4 luciferase reporter assay, western blotting and transwell assays were used to measure the biological activities of the anti-TGF-β moiety. The NFAT luciferase reporter assay, luminescent cell viability assay and tube formation assay were used to measure the biological activities of the anti-VEGF moiety. The in vivo anticancer efficacy of Y332D alone or in combination with PD-1 blockade was evaluated in H22, EMT-6, 4T1, and AKT/Ras-driven murine hepatocellular carcinoma tumor models. Immunofluorescent staining, flow cytometry, RNA-seq and quantitative RT-PCR were adopted to analyze the alterations in the tumor microenvironment.ResultsY332D could maintain specific binding affinities for TGF-β and VEGFA. Y332D almost entirely counteracted the in vitro biological functions of TGF-β and VEGFA, including immunosuppression, activated TGF-β signaling, epithelial-mesenchymal transition (EMT), activated VEGF/VEGFR signaling, HUVEC proliferation and tube formation. The in vivo experiment data demonstrated that Y332D was more effective in inhibiting tumor growth and metastasis than anti-TGF-β and anti-VEGF monotherapies. In combination therapies, Y332D plus PD-1 blockade exhibited the most potent and durable anticancer effect. Mechanistically, Y332D plus PD-1 blockade upregulated the density and function of tumor-infiltrating lymphocytes and exerted reinvigorated antitumor immunity.ConclusionY332D could simultaneously block TGF-β and VEGF signalings. In comparison with the monotherapies, Y332D combined with PD-1 blockade exerts superior antitumor effect through improving immune microenvironment.

Role of Next Generation Immune Checkpoint Inhibitor (ICI) Therapy in Philadelphia Negative Classic Myeloproliferative Neoplasm (MPN): Review of the Literature.

The Philadelphia chromosome-negative (Ph-) myeloproliferative neoplasms (MPNs), which include essential thrombocythemia (ET), polycythemia vera (PV), and myelofibrosis (MF), are enduring and well-known conditions. These disorders are characterized by the abnormal growth of one or more hematopoietic cell lineages in the body's stem cells, leading to the enlargement of organs and the manifestation of constitutional symptoms. Numerous studies have provided evidence indicating that the pathogenesis of these diseases involves the dysregulation of the immune system and the presence of chronic inflammation, both of which are significant factors. Lately, the treatment of cancer including hematological malignancy has progressed on the agents aiming for the immune system, cytokine environment, immunotherapy agents, and targeted immune therapy. Immune checkpoints are the molecules that regulate T cell function in the tumor microenvironment (TME). The first line of primary immune checkpoints are programmed cell death-1 (PD-1)/programmed cell death ligand-1 (PD-L1), and cytotoxic T-lymphocyte antigen-4 (CTLA-4). Immune checkpoint inhibitor therapy (ICIT) exerts its anti-tumor actions by blocking the inhibitory pathways in T cells and has reformed cancer treatment. Despite the impressive clinical success of ICIT, tumor internal resistance poses a challenge for oncologists leading to a low response rate in solid tumors and hematological malignancies. A Phase II trial on nivolumab for patients with post-essential thrombocythemia myelofibrosis, primary myelofibrosis, or post-polycythemia myelofibrosis was performed (Identifier: NCT02421354). This trial tested the efficacy of a PD-1 blockade agent, namely nivolumab, but was terminated prematurely due to adverse events and lack of efficacy. A multicenter, Phase II, single-arm open-label study was conducted including pembrolizumab in patients with primary thrombocythemia, post-essential thrombocythemia or post-polycythemia vera myelofibrosis that were ineligible for or were previously treated with ruxolitinib. This study showed that pembrolizumab treatment did not have many adverse events, but there were no pertinent clinical responses hence it was terminated after the first stage was completed. To avail the benefits from immunotherapy, the paradigm has shifted to new immune checkpoints in the TME such as lymphocyte activation gene-3 (LAG-3), T cell immunoglobulin and mucin domain 3 (TIM-3), T cell immunoglobulin and ITIM domain (TIGIT), V-domain immunoglobulin-containing suppressor of T cell activation (VISTA), and human endogenous retrovirus-H long terminal repeat-associating protein 2 (HHLA2) forming the basis of next-generation ICIT. The primary aim of this article is to underscore and elucidate the significance of next-generation ICIT in the context of MPN. Specifically, we aim to explore the potential of monoclonal antibodies as targeted immunotherapy and the development of vaccines targeting specific MPN epitopes, with the intent of augmenting tumor-related immune responses. It is anticipated that these therapeutic modalities rooted in immunotherapy will not only expand but also enhance the existing treatment regimens for patients afflicted with MPN. Preliminary studies from our laboratory showed over-expressed MDSC and over-expressed VISTA in MDSC, and in progenitor and immune cells directing the need for more clinical trials using next-generation ICI in the treatment of MPN.

Hyperprogressive disease during PD-1 blockade in patients with advanced pancreatic cancer

ABSTRACT The occurrence of markedly accelerated tumor growth during immunotherapy is considered a new mode of progression called hyperprogressive disease (HPD) and its impact on pancreatic cancer (PC) patients receiving immunotherapy is unknown. In this study, we described and explored the incidence, prognosis and predictors of HPD in patients with advanced PC treated with programmed cell death-1 (PD-1) inhibitors. We retrospectively analyzed clinicopathological data from 104 patients with advanced pancreatic cancer who were treated with PD-1 inhibitors at our institution during 2015–2020 and identified 10 (9.6%) patients with HPD. Overall survival (OS) was significantly poorer in patients with HPD compared to patients with progressive disease (PD) (median OS: 5.6 vs. 3.6 months, p < .01). Clinicopathological factors associated with the occurrence of HPD included smoking, metastatic sites >2, liver metastasis, antibiotic therapy within 21 days before immunotherapy (Abx B21), hemoglobin (Hb) level <110 g/L, and PD-1 inhibitor treatment line >2. Subgroup analysis showed that high levels of CA19-9 at baseline were associated with the development of subsequent HPD (p = .024) and a worse prognosis (mOS:16.2 months vs. 6.1 months, p < .01). Our study demonstrated that HPD may occur in PC patients treated with PD-1 inhibitors and is associated with several clinicopathological characteristics and poor prognosis. The baseline tumor marker CA19-9 may be one of the early predictors of HPD development in PC patients receiving immunotherapy.

Mechanisms underlying response and resistance to immune checkpoint blockade in cancer immunotherapy.

Cancer immunotherapies targeting immune checkpoint pathways, such as programmed cell death-1 (PD-1)/programmed cell death ligand-1 (PD-L1) and cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), have achieved unprecedented therapeutic success in treating various types of cancer. The prominent and persistent clinical responses to immune checkpoint blockade (ICB) therapy are currently constrained to a subset of patients. Owing to discrete individual tumor and immune heterogeneity, most patients fail to benefit from ICB treatment, demonstrating either primary or acquired resistance. A thorough comprehension of the mechanisms restricting the efficacy of immune checkpoint inhibitors (ICIs) is required to extend their clinical applicability to a broader spectrum of patients and cancer types. Numerous studies are presently investigating potential prognostic markers of responsiveness, the complex dynamics underlying the therapeutic and adverse effects of ICB, and tumor immune evasion throughout the course of immunotherapy. In this article, we have reviewed the extant literature elucidating the mechanisms underlying the response and resistance to ICB, with a particular emphasis on PD-1 and CTLA-4 pathway blockade in the context of anti-tumor immunity. Furthermore, we aimed to explore potential approaches to overcome cancer therapeutic resistance and develop a rational design for more personalized ICB-based combinational regimens.

CDX-585, a Bispecific Antibody with Dual Targeting of ILT4 and PD-1 Checkpoint Pathways

Immunoglobulin-like transcript 4 (ILT4) is an immunosuppressive molecule predominantly expressed on myeloid cells. Recent studies combining ILT4 suppression with programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1) blockade have shown promising signs of activity in immune checkpoint inhibitor refractory patients. We theorized that coupling ILT4 and PD-1/PD-L1 blockade in a bispecific antibody (bsAb) may provide greater immune activating properties than combining the individual mAbs due to enhanced bridging of APCs to T cells. To test this approach, we developed CDX-585, a tetravalent ILT4xPD-1 IgG1-scFv bsAb from novel PD-1 and ILT-4 mAbs. CDX-585 is a potent antagonist of both PD-1 and ILT4. CDX-585 promotes M1 macrophage polarization and enhances pro-inflammatory cytokine secretion in response to lipopolysaccharide or CD40 agonist mAb treatment. In mixed lymphocyte reaction (MLR) assays, CDX-585 is more potent than the combination of parental antibodies. In a humanized NCG mouse SK-MEL-5 tumor model, CDX-585 exhibits greater antitumor activity than the combination of parental mAbs. A pilot study of CDX-585 in cynomolgus macaques confirmed a mAb-like pharmacokinetic profile without noted toxicities. These studies demonstrate that CDX-585 effectively combines ILT4 and the PD-1 blockade into one molecule that is more potent than the combination of the parental antibodies, providing the rationale to advance this bsAb into clinical studies.