Baicalin circumvents anti-PD-1 resistance by regulating the gut microbiota metabolite short-chain fatty acids

Baicalin is a small molecule medication used to treat hepatitis. Our research group discovered that administering baicalin orally to mice following fecal microbiota transplantation from patients resistant to ICIs supported anti-PD-1 activity. However, the precise mechanisms behind this effect are presently unknown. In this present study, ATB-treated C57BL/6 J mice received FMT from patients with advanced NSCLC amenable to αPD-1. Additionally, subcutaneous LLC cells were injected into the mice. Baicalin oral gavage and αPD-1 injection were administered to the mice on days 3 and 9 after tumour inoculation. 16 S rRNA, metabolomics, and flow cytometry were utilized to clarify the mechanisms of baicalin's relief of immunosuppression. The results indicated that oral administration of baicalin enriched bacteria such as Akkermansia and Clostridia_UCG-014, resulted in an increase in SCFAs, which improved the ratio of PD-1+ (CD8+ T cell/Treg) and promoted the levels of IFN-γ+ CD8+ T cells and TNF-α+ CD8+ T cells within the tumour microenvironment. In conclusion, baicalin regulates the metabolites of the gut microbiota to improve the PD-1+ (CD8+ T cell/Treg) balance and circumvent anti-PD-1 resistance. This is achieved through the regulation of short-chain fatty acids.

Efficacy and safety of PD-1 monoclonal antibody plus rituximab in relapsed/refractory diffuse large B cell lymphoma patients

BACKGROUND

Patients with relapsed/refractory diffuse large B-cell lymphoma (r/r DLBCL) have poor outcomes and few treatment options. We report the preliminary results of the efficacy and safety of PD-1 monoclonal antibody (mab) plus Rituximab for r/r DLBCL.

METHODS

In this single-center, single-arm phase 2 and retrospective study, r/r DLBCL patients received PD-1 mab and Rituximab every 3 weeks. Immunohistochemistry, fluorescence in situ hybridization, and probe capture-based high-resolution sequencing were performed. Efficacy, safety and prognostic factors were analyzed.

RESULTS

Between October 16th, 2018, and July 10th, 2022, 36 patients (10 patients in retrospective study and 26 patients in phase 2 study) were enrolled and received at least one dose of PD-1 mab combined with Rituximab. The objective response rate was 52.8%. The median progression free survival (PFS) and overall survival was 2.8 and 19.6 months, respectively. The median duration of response was 18.7 months. Rare grade 3 or 4 treatment related adverse events were observed. B2M mutations correlated with a significantly poor PFS (p = .013) and OS (p = .009) in DLBCL patients treated with this regimen.

CONCLUSION

PD-1 mab combined with Rituximab could be a potential treatment option for r/r DLBCL with manageable safety profile.

A metabolomic and proteomic study to elucidate the molecular mechanisms of immunotherapy resistance in patients with oesophageal squamous cell carcinoma

Systemic chemotherapy, the standard first-line treatment option for patients with advanced oesophageal squamous cell carcinoma (OSCC), results in a median survival of ~1 year. Immune checkpoint inhibitors are a breakthrough oncology treatment option; however, most patients with advanced OSCC develop primary and acquired resistance to programmed death receptor-1 (PD-1) monoclonal antibody, severely affecting their prognosis. Therefore, there is an urgent need to investigate the molecular mechanism underlying resistance to treatment. The present study aimed to explore the mechanism of resistance to PD-1 monoclonal antibody. Plasma samples were collected from patients with OSCC treated with immunotherapy, who achieved pathological response/partial response (CR/PR) or stable disease/progressive disease (SD/PD) after the fourth treatment cycle. TM-widely targeted metabolomics, widely targeted lipidomics, and DIA proteomics assays were performed. Differential metabolites were screened based on fold change (FC) ≥1.5 or ≤0.67 and a VIP ≥1; differential proteins were screened based on FC >1.5 or <0.67 and P<0.05. The identified metabolites were annotated and mapped using the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway databases. The differential proteins were annotated to the Gene Ontology and KEGG pathway databases. A correlation network diagram was drawn using differential expressed proteins and metabolites with (Pearson correlation coefficient) r>0.80 and P<0.05. Finally, 197 and 113 differential metabolites and proteins were screened, respectively, in patients with CR/PR and SD/PD groups. The KEGG enrichment analysis revealed that all of these metabolites and proteins were enriched in cholesterol metabolism and in the NF-κB and phospholipase D signalling pathways. The present study is the first to demonstrate that PD-1 inhibitor resistance may be attributed to cholesterol metabolism or NF-κB and phospholipase D signalling pathway activation. This finding suggests that targeting these signalling pathways may be a promising novel therapeutic approach in OSCC which may improve prognosis in patients undergoing immunotherapy.

Increased death and exhaustion of CD69high T cells and NK cells are associated with PD-1 antibody application in the in vitro co-culture system

Background

The application of PD-1 monoclonal antibody (mAb) helps to treat non-small cell lung cancer, but acquired resistance has emerged in clinical practice. We tested the hypothesis that acquired resistance of anti-PD-1 immunotherapy is linked to death and exhaustion of activated T and NK cell.

Methods

The co-culture system of HCC827 cells and peripheral mononuclear cells (PBMCs) was established to evaluate the effect of PD-1 mAb on the death rate and exhaustion of T and NK cell. The predisposing role of CD69 for death and exhaustion was validated by using PHA-activated PBMCs of CD69^low NSCLC patients. The 10-colour/three laser flow cytometer was used to test related markers for cell activation, death and exhaustion.

Results

We found that PD-1 mAb increase the death and exhaustion of T cells and NK cells in a dose-dependent way when PBMCs from NSCLC patients whose the percentages of CD69⁺ cells in peripheral blood T cells were greater than 5% (CD69^high NSCLC patients). By analyzing PBMCs from healthy volunteers and CD69^low NSCLC patients, we found that T cells and NK cells can be induced to die by PD-1 mAb after PHA activation, and had a tendency to raise the rate of cell exhaustion.

Conclusions

Our findings imply that increased death and exhaustion of CD69^high T cells and NK cells are associated with ineffective anti-PD-1 immunotherapy in lung cancer. The CD69 expression of T cells and NK cells may be developed as a potential predictor for acquired resistance of anti-PD-1 immunotherapy. These data may provide ideas to guide individualized medication of PD-1 mAb in NSCLC patients.

Immune and inflammation: related factor alterations as biomarkers for predicting prognosis and responsiveness to PD-1 monoclonal antibodies in cervical cancer

PURPOSE

We aimed to elucidate the potential mechanisms of effective responsiveness to PD-1 monoclonal antibody and evaluate more reliable biomarkers to improve the ability to predict the populations of cervical cancer (CC) suitable for immunotherapy.

METHODS

Peripheral blood samples of CC patients undergoing anti-PD-1 therapy were collected before and after treatment. Differentially expressed genes (DEGs) were analyzed between partial response (PR) and progressive disease (PD) patients. A novel prognostic inflammation and immune-related response gene (IRRG) model was constructed and its prognostic role, correlation with tumor immunity and tumor mutation were evaluated.

RESULTS

DEGs in PR patient after treatment could predict the response to PD-1 monoclonal antibodies. Among PR-specific pathways, tumor immunity, leukocyte migration, and cytokine activities were prominently enriched. Additionally, an IRRG signature comprising CTLA4, AZU1, C5, LAT, CXCL2, GDF7, MPL, PPARG and CELA1 was established and validated to predict the prognosis of CC with great accuracy and specificity. This signature could reflect the tumor microenvironment (TME) and tumor mutational burden (TMB). We also found stimulated adaptive immunity and downregulated inflammation at baseline in patients with sensitive responses to PD-1 monoclonal antibody.

CONCLUSION

We developed an IRRG signature and verified that it was an independent prognostic factor for predicting survival and could reflect a sensitive response to PD-1 monoclonal antibody, which plays a nonnegligible role in the TME of CC. Further investigations are warranted to confirm that patients with stimulated adaptive immunity and downregulated inflammation at baseline could achieve a better survival benefit from PD-1 monoclonal antibody.

Comparison of two routes of administration of a cationic liposome formulation for a prophylactic DC vaccination in a murine melanoma model

Dendritic cell (DC) vaccination can be achieved via straight loading of vaccine into DCs ex vivo or administration to DCs in vivo. However, there is no certain consensus on which approach is preferable, and each strategy has its advantages and disadvantages, which affect the efficacy and safety of vaccines. It will also be more complicated when a vaccine delivery system is included. In this study, the efficacy of ex vivo pulsed DC-based vaccine compared with in vivo subcutaneous administration of a cationic liposomes (CLs) formulation containing gp100 antigen (gp100-CLs) was evaluated in a murine melanoma model. In combination with an anti-PD-1 antibody, the ex vivo approach of gp100-CLs yielded a significant (P < 0.01) increase in the number of antigen-specific tumors infiltrated lymphocytes (TILs) with a significant upregulation of IFN-γ (P < 0.0001) and PD-1 (P < 0.0001) expression level. They also dampened the function of immunosuppressive regulatory T cells (Tregs) via significant downregulation of IL-10 and TGF-β (P < 0.0001) expression level compared to in vivo approach in the tumor microenvironment (TME). Furthermore, prophylactic immunization with gp100-CLs pulsed DCs ex vivo delayed tumor growth and induced the survival benefit over in vivo immunization. Collectively, the ex vivo DC-based vaccination pulsed with gp100 encapsulated in liposomes synergizes with anti-PD-1 antibody and represents a preferable approach against melanoma.

[A Case Report of Checkpoint Inhibitor Pneumonitis Caused by PD-1 Antibody-Safety and Effectiveness of Pirfenidone]

背景与目的

免疫检查点抑制剂相关肺炎（checkpoint inhibitor pneumonitis, CIP）是严重的免疫检查点抑制剂副反应，急性期治疗手段已有共识，但急性期之后的肺间质纤维化治疗手段仍是临床需要解决的问题。

方法

回顾性分析了青岛市中心医院立体定向放疗科收治的1例细胞程序性死亡受体1（programmed cell death1, PD-1）单抗导致免疫检查点抑制剂相关肺炎的非小细胞肺癌（non-small cell lung cancer, NSCLC）患者的诊断、治疗过程，并文献复习。

结果

患者男性，70岁，初始诊断：左肺低分化鳞癌T3N3M0 Ⅲc期纵隔淋巴结转移表皮生长因子受体（epidermal growth factor receptor, EGFR）/间变性淋巴瘤激酶（anaplastic lymphoma kinase, ALK）/原癌基因1酪氨酸激酶（C-ros oncogene 1 receptor tyrosine kinase, ROS1）/RAF阴性PD-L1（22C3）阴性。一线化疗进展后纳武利尤单抗单药二线治疗过程中确诊为免疫检查点抑制剂相关肺炎3级。初始大剂量糖皮质激素冲击治疗后患者肺部计算机断层扫描（computed tomography, CT）影像学和临床症状部分缓解，随后给予吡非尼酮口服（300 mg tid）11个月余，治疗过程中患者CT影像学和临床症状明显好转，除1级恶心外无其他不良反应。期间吡非尼酮与化疗、安罗替尼联合应用安全性好。

结论

本病例报道为目前吡非尼酮治疗CIP的第1例报道，为CIP治疗的临床实践和临床研究提出了新的思路。

Camrelizumab Combined with FOLFOX4 Regimen as First-Line Therapy for Advanced Hepatocellular Carcinomas: A Sub-Cohort of a Multicenter Phase Ib/II Study

BACKGROUND

Immune checkpoint inhibitors and chemotherapy can synergistically increase efficacy in a variety of malignancies. We conducted this phase Ib/II study to assess the safety and efficacy of anti-PD-1 antibody camrelizumab in combination with FOLFOX4 for treatment-naive advanced hepatocellular carcinoma (aHCC).

METHODS

This open-label, multicenter phase Ib/II study (NCT03092895) enrolled patients with aHCC and without prior systemic treatment for treatment with camrelizumab (3 mg/kg) and FOLFOX4 every two weeks. First, six patients were enrolled, followed by an additional 28 patients after dose-limiting toxicity cases were determined to be <33% of patients. The primary endpoint was tolerability and safety of treatment.

RESULTS

A total of 34 aHCC patients were enrolled and received study treatment. No dose-limiting toxicity were observed in the first six patients enrolled. Twenty-nine (85.3%) of the total 34 patients had grade ≥3 treatment-related adverse events (TRAEs), with the most common ones being decreased neutrophil count (55.9%) and decreased white blood cell count (38.2%). No TRAEs-related deaths occurred. The objective response and disease control rate were 29.4% (95% CI, 15.1-47.5) and 79.4% (95% CI, 62.1-91.3), respectively. The median duration of response, progression-free survival, and overall survival was 6.9 months (range, 3.3-11.5), 7.4 months (95% CI, 3.9-9.2), and 11.7 months (95% CI, 8.2-22.0), respectively.

CONCLUSION

Camrelizumab combined with FOLFOX4 for first-line treatment of patients with aHCC showed good safety and tolerability, with promising preliminary antitumor activity.

Case Report: Longitudinal Extensive Transverse Myelitis With Novel Autoantibodies Following Two Rounds of Pembrolizumab

A 63-year-old male with metastatic non-small cell lung cancer developed longitudinal extensive transverse myelitis (LETM) following two cycles of Pembrolizumab, an immune checkpoint inhibitor (ICI) targeting the programmed cell death receptor 1 (PD-1). Magnetic resonance imaging (MRI) showed centromedullary contrast enhancement at several levels, cerebrospinal fluid (CSF) cytology showed lymphocytic pleocytosis, and indirect immunofluorescence assay (IFA) on the primate cerebellum, pancreas, and intestine revealed strong binding of neuronal autoantibodies to unknown antigens. CSF C–X–C motif ligand 13 (CXCL13) was elevated. The patient was treated with plasma exchange (PEX) and intravenous (i.v.) methylprednisolone (MP) 1 g/day for 5 days followed by oral (p.o.) MP 100 mg/day for 10 days with clinical and radiological response. However, after discontinuation of MP, LETM relapsed and the patient developed paralytic ileus presumably due to autoimmune enteropathy and suffered a fatal gastrointestinal sepsis. Findings of novel neuronal autoantibodies and highly elevated CXCL13 in CSF suggest that the severe neurological immune-related adverse event (nirAE) was B-cell mediated contrary to the commonly assumed ICI-induced T-cell toxicity. An individual evaluation of the underlying pathophysiology behind rare nirAEs is essential for choosing treatment regimens and securing optimal outcome.

Vaccination with dendritic cells pulsed ex vivo with gp100 peptide-decorated liposomes enhances the efficacy of anti PD-1 therapy in a mouse model of melanoma

BACKGROUND

Targeting antigens to dendritic cells (DCs) via nanoparticles is a powerful strategy which improves the efficacy of ex vivo antigen-pulsed DC vaccines.

METHODS

In this study, liposomes were first decorated with gp100_25-33 self-antigen and then characterized. Then, DCs were pulsed ex vivo with liposomal gp100 and injected subcutaneously in mice bearing B16F10 established melanoma tumors in combination with anti-PD-1 therapy.

RESULTS

Treatment with liposomal pulsed DC vaccine elicited the strongest anticancer immunity and enhanced intratumoral immune responses based on infiltration of gp100-specific CD4+ and CD8+ T cells to the tumor leading to significant tumor growth regression and prolonged survival rate. Treatment with liposomal pulsed DC vaccine also markedly enhanced specific cytotoxic T lymphocytes (CTL) responses with a significant higher titer of IFN-γ in the spleen. Moreover, a significant increase of PD-1 expressing CD8+ tumor infiltrating lymphocytes (TILs) was detected in tumors.

CONCLUSION

Our results demonstrate an optimum dose of liposomal gp100 significantly increases the efficacy of anti-PD-1 therapy in mice and might be an effective strategy to overcome resistance to anti-PD-1 therapy.