What Happens to the Immune Microenvironment After PD-1 Inhibitor Therapy?

Evaluating the impact of PD-1 inhibitor treatment on key health outcomes for cancer patients in China

BACKGROUND

There is a lack of studies examining the influence of programmed cell death protein 1 (PD-1) inhibitors on the health outcomes of cancer patients in China.

AIM

This study aimed to evaluate prospective health outcomes associated with introducing PD-1 inhibitor treatment in China over five years.

METHOD

We constructed a partitioned survival model to assess disparities in health outcomes over a 5-year time frame between two scenarios: one involving the availability of PD-1 inhibitor class with standard of care and the other involving standard of care alone. The impact on various health outcomes were assessed, including life years (LYs) gained, quality-adjusted life years (QALYs) gained, progression-free survival (PFS) years gained, the reduction in the number of grade 3-5 adverse events (AEs), and the improvement in objective remission rates (ORR). A sensitivity analysis was conducted to assess the robustness and reliability of the model.

RESULTS

From 2023 to 2027, the incorporation of PD-1 inhibitor class treatments was anticipated to yield substantial improvements in health outcomes, with an estimated increase of 1,336,332 LYs (+ 24.7%), 1,065,359 QALYs (+ 30.3%), and 1,177,564 PFS years (+ 57.4%) compared to standard of care alone. Simultaneously, the number of grade 3-5 AEs decreased by 334,976 (- 13.0%), and the ORR saw a 19.1% increase (+ 105.6%) relative to standard of care treatment alone.

CONCLUSION

This study provides a analysis of the potential beneficial effects on health outcomes in the Chinese population after introducing PD-1 inhibitor class treatment. The findings suggest the PD-1 inhibitor class will significantly improve patient survival.

Assessing Longitudinal Treatment Efficacies and Alterations in Molecular Markers Associated with Glutamatergic Signaling and Immune Checkpoint Inhibitors in a Spontaneous Melanoma Mouse Model

Previous work done by our laboratory described the use of an immunocompetent spontaneous melanoma-prone mouse model, TGS (TG-3/SKH-1), to evaluate treatment outcomes using inhibitors of glutamatergic signaling and immune checkpoint for 18 weeks. We showed a significant therapeutic efficacy with a notable sex-biased response in male mice. In this follow-up 18-week study, the dose of the glutamatergic signaling inhibitor was increased (from 1.7 mg/kg to 25 mg/kg), which resulted in improved responses in female mice but not male mice. The greatest reduction in tumor progression was observed in male mice treated with single-agent troriluzole and anti-PD-1. Furthermore, a randomly selected group of mice was removed from treatment after 18 weeks and maintained for up to an additional 48 weeks demonstrating the utility of the TGS mouse model to perform a ≥1-year preclinical therapeutic study in a physiologically relevant tumor-host environment. Digital spatial imaging analyses were performed in tumors and tumor microenvironments across treatment modalities using antibody panels for immune cell types and immune cell activation. The results suggest that immune cell populations and cytotoxic activities of T cells play critical roles in treatment responses in these mice. Examination of a group of molecular protein markers based on the proposed mechanisms of action of inhibitors of glutamatergic signaling and immune checkpoint showed that alterations in expression levels of xCT, γ-H2AX, EAAT2, PD-L1, and PD-1 are likely associated with the loss of treatment responses. These results suggest the importance of tracking changes in molecular markers associated with the mechanism of action of therapeutics over the course of a longitudinal preclinical therapeutic study in spatial and temporal manners.

Prognostic impact of radiological tumor burden in patients with metastatic urothelial carcinoma treated with pembrolizumab

PURPOSE

Radiological tumor burden has been reported to be prognostic in many malignancies in the immunotherapy era, yet whether it is prognostic in patients with metastatic urothelial carcinoma (mUC) treated with pembrolizumab remains uninvestigated. We sought to assess the predictive and prognostic value of radiological tumor burden in patients with mUC.

METHODS

We performed a retrospective analysis of 308 patients with mUC treated with pembrolizumab. Radiological tumor burden was represented by baseline tumor size (BTS) and baseline tumor number (BTN). Optimal cut-off value of BTS was determined as 50 mm using the Youden index (small BTS: n = 194, large BTS: n = 114). Overall (OS), cancer-specific (CSS), progression-free survival (PFS), and objective response rate (ORR) were compared. Non-linear associations between BTS and OS and CSS were evaluated using restricted cubic splines.

RESULTS

Patients with large BTS were less likely to have undergone the surgical resection of the primary tumor (P = 0.01), and more likely to have liver metastasis (P < 0.001) and more metastatic lesions (P < 0.001). On multivariable analyses controlling for the effects of confounders (resection of primary tumor, metastatic site, number of metastases and lactate dehydrogenase level), large BTS and high BTN were independently associated with worse OS (HR 1.52; P = 0.015, and HR 1.69; P = 0.018, respectively) and CSS (HR 1.59; P = 0.01, and HR 1.66; P = 0.031, respectively), but not PFS. Restricted cubic splines revealed BTS was correlated with OS and CSS in linear relationships. Additionally, large BTS was significantly predictive of lower ORR and complete response rate on univariable analyses (P = 0.041 and P = 0.032, respectively), but its association disappeared on multivariable analyses.

CONCLUSION

Radiological tumor burden has independent prognostic value with a linear relationship in pembrolizumab-treated patients with mUC and might help drive the earlier introduction of second-line pembrolizumab and/or switching to subsequent therapies.

Adjusting the dose of traditional drugs combined with immunotherapy: reshaping the immune microenvironment in lung cancer

Immunotherapy is currently the most promising clinical treatment for lung cancer, not only revolutionizing second-line therapy but now also approved for first-line treatment. However, its clinical efficiency is not high and not all patients benefit from it. Thus, finding the best combination strategy to expand anti-PD-1/PD-L1-based immunotherapy is now a hot research topic. The conventional use of chemotherapeutic drugs and targeted drugs inevitably leads to resistance, toxic side effects and other problems. Recent research, however, suggests that by adjusting the dosage of drugs and blocking the activation of mutational mechanisms that depend on acquired resistance, it is possible to reduce toxic side effects, activate immune cells, and reshape the immune microenvironment of lung cancer. Here, we discuss the effects of different chemotherapeutic drugs and targeted drugs on the immune microenvironment. We explore the effects of adjusting the dosing sequence and timing, and the mechanisms of such responses, and show how the effectiveness and reliability of combined immunotherapy provide improved treatment outcomes.

Single-cell RNA sequencing reveals enhanced antitumor immunity after combined application of PD-1 inhibitor and Shenmai injection in non-small cell lung cancer

BACKGROUND

Immune checkpoint inhibitors (ICIs) have altered the clinical management of non-small cell lung cancer (NSCLC). However, the low response rate, severe immune-related adverse events (irAEs), and hyperprogressive disease following ICIs monotherapy require attention. Combination therapy may overcome these limitations and traditional Chinese medicine with immunomodulatory effects provides a promising approach. Shenmai injection (SMI) is a clinically effective adjuvant treatment for cancer with chemotherapy and radiotherapy. Therefore, the combined effects and mechanisms of SMI and programmed death-1 (PD-1) inhibitor against NSCLC was focused on this study.

METHODS

A Lewis lung carcinoma mouse model and a lung squamous cell carcinoma humanized mouse model were used to investigate the combined efficacy and safety of SMI and PD-1 inhibitor. The synergistic mechanisms of the combination therapy against NSCLC were explored using single-cell RNA sequencing. Validation experiments were performed using immunofluorescence analysis, in vitro experiment, and bulk transcriptomic datasets.

RESULTS

In both models, combination therapy alleviated tumor growth and prolonged survival without increasing irAEs. The GZMA^high and XCL1^high natural killer (NK) cell subclusters with cytotoxic and chemokine signatures increased in the combination therapy, while malignant cells from combination therapy were mainly in the apoptotic state, suggesting that mediating tumor cell apoptosis through NK cells is the main synergistic mechanisms of combination therapy. In vitro experiment confirmed that combination therapy increased secretion of Granzyme A by NK cells. Moreover, we discovered that PD-1 inhibitor and SMI combination blocked inhibitory receptors on NK and T cells and restores their antitumoral activity in NSCLC better than PD-1 inhibitor monotherapy, and immune and stromal cells exhibited a decrease of angiogenic features and attenuated cancer metabolism reprogramming in microenvironment of combination therapy.

CONCLUSIONS

This study demonstrated that SMI reprograms tumor immune microenvironment mainly by inducing NK cells infiltration and synergizes with PD-1 inhibitor against NSCLC, suggested that targeting NK cells may be an important strategy for combining with ICIs. Video Abstract.

Immunotherapy Plus Radiotherapy for the Treatment of Sarcomas: Is There a Potential for Synergism?

Soft tissue sarcoma (STS) is a highly heterogeneous malignant tumor derived from mesenchymal tissue. Advanced STS has a poor response to the current anti-cancer therapeutic options, with a median overall survival of less than two years. Thus, new and more effective treatment methods for STS are needed. Increasing evidence has shown that immunotherapy and radiotherapy have synergistic therapeutic effects against malignant tumors. In addition, immunoradiotherapy has yielded positive results in clinical trials for various cancers. In this review, we discuss the synergistic mechanism of immunoradiotherapy in cancer treatment and the application of this combined regimen for the treatment of several cancers. In addition, we summarize the existing evidence on the use of immunoradiotherapy for the treatment of STS and the relevant clinical trials that are currently ongoing. Furthermore, we identify challenges in the use of immunoradiotherapy for the treatment of sarcomas and propose methods and precautions for overcoming these challenges. Lastly, we propose clinical research strategies and future research directions to help in the research and treatment of STS.

Chemotherapy postimmunotherapy for recurrent metastatic head and neck squamous cell carcinoma

PURPOSE OF REVIEW

Clinical data on salvage chemotherapy used after checkpoints inhibitors in oncology are reviewed, with a special focus on recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC).

RECENT FINDINGS

Converging evidence is emerging about high response and/or disease control rates associated with salvage chemotherapy after immunotherapy failure in advanced solid tumours. This phenomenon is mainly reported in retrospective studies for "hot tumours" such as R/M HNSCC, melanoma, lung, urothelial or gastric cancers, but also in haematological malignancies. Some physiopathological hypotheses have been raised.

SUMMARY

Several independent series show increased response rates associated with postimmuno chemotherapy when compared with retrospective series in similar settings. Several mechanisms could be involved such as a "carry-over" allowed by a persistence of the checkpoint inhibitor, a modulation of tumour microenvironment components but also an intrinsic immunomodulatory effect of chemotherapy, increased by a specific immunologic state induced by the therapeutic pressure of checkpoint inhibitors. These data establish a rationale for prospectively evaluating the features of postimmunotherapy salvage chemotherapy.

IFN-γ blockade after genetic inhibition of PD-1 aggravates skeletal muscle damage and impairs skeletal muscle regeneration

BACKGROUND

Innate immune responses play essential roles in skeletal muscle recovery after injury. Programmed cell death protein 1 (PD-1) contributes to skeletal muscle regeneration by promoting macrophage proinflammatory to anti-inflammatory phenotype transition. Interferon (IFN)-γ induces proinflammatory macrophages that appear to hinder myogenesis in vitro. Therefore, we tested the hypothesis that blocking IFN-γ in PD-1 knockout mice may dampen inflammation and promote skeletal muscle regeneration via regulating the macrophage phenotype and neutrophils.

METHODS

Anti-IFN-γ antibody was administered in PD-1 knockout mice, and cardiotoxin (CTX) injection was performed to induce acute skeletal muscle injury. Hematoxylin and eosin (HE) staining was used to view morphological changes of injured and regenerated skeletal muscle. Masson's trichrome staining was used to assess the degree of fibrosis. Gene expressions of proinflammatory and anti-inflammatory factors, fibrosis-related factors, and myogenic regulator factors were determined by real-time polymerase chain reaction (PCR). Changes in macrophage phenotype were examined by western blot and real-time PCR. Immunofluorescence was used to detect the accumulation of proinflammatory macrophages, anti-inflammatory macrophages, and neutrophils.

RESULTS

IFN-γ blockade in PD-1 knockout mice did not alleviate skeletal muscle damage or improve regeneration following acute cardiotoxin-induced injury. Instead, it exacerbated skeletal muscle inflammation and fibrosis, and impaired regeneration via inhibiting macrophage accumulation, blocking macrophage proinflammatory to anti-inflammatory transition, and enhancing infiltration of neutrophils.

CONCLUSION

IFN-γ is crucial for efficient skeletal muscle regeneration in the absence of PD-1.

Programmed cell death 1 inhibitor plus chemotherapy vs. chemotherapy in advanced drive-gene-negative non-small-cell lung cancer patients: A real-world study

Objective

Programmed cell death 1 (PD-1) inhibitor has been in the market in China for several years, which lacks sufficient domestic evidence regarding its application in lung cancer. Thus, this study intended to assess the treatment outcome and tolerance of PD-1 inhibitor plus chemotherapy in advanced, driver-gene-negative, nonsquamous, non-small-cell lung cancer (NSCLC) patients in a real clinical setting.

Methods

This retrospective cohort study analyzed 68 advanced driver-gene-negative nonsquamous NSCLC patients, among which 38 cases received PD-1 inhibitor plus chemotherapy and 30 cases adopted chemotherapy alone. Disease control rate (DCR), objective response rate (ORR), progression-free survival (PFS), overall survival (OS), and adverse events were reviewed.

Results

Generally, PD-1 inhibitor plus chemotherapy achieved a more satisfying ORR compared with chemotherapy alone (52.6% vs. 30.0%, P = 0.061), while the DCR did not vary between PD-1 inhibitor plus chemotherapy and chemotherapy (84.2% vs. 73.3%, P = 0.271). Patients receiving PD-1 inhibitor plus chemotherapy exhibited favorable PFS (median: 10.1 vs. 7.1 months, P = 0.040) and OS (median: 17.4 vs. 13.9 months, P = 0.049) than patients adopting chemotherapy alone. Additionally, after adjustment using multivariable Cox's analyses, PD-1 inhibitor plus chemotherapy (vs. chemotherapy) could independently realize prolonged PFS (P = 0.020) and OS (P = 0.029). Moreover, the majority of adverse events were manageable; meanwhile, grade 3-4 adverse events included leukopenia (13.2%), neutropenia (13.2%), nausea and vomiting (7.9%), anemia (5.3%), elevated transaminase (5.3%), thrombopenia (2.6%), anorexia (2.6%), peripheral neuropathy (2.6%), and rash (2.6%).

Conclusion

PD-1 inhibitor plus chemotherapy exhibits a better efficacy and equal tolerance compared with chemotherapy alone in advanced driver-gene-negative nonsquamous NSCLC patients.

PD-1/L1 inhibitor plus chemotherapy in the treatment of sarcomas

There is an urgent clinical need for new therapeutic regimens for the effective treatment of advanced sarcomas. Accumulating evidence suggests that programmed death receptor-1/programmed death protein ligand-1 (PD-1/L1) inhibitors have synergistic effects with chemotherapy and have been approved for treatment of lung cancer, gastroesophageal cancer, and breast cancer. In this review, we reviewed the synergistic mechanism of PD-1/L1 inhibitors plus chemotherapy in the treatment of cancers, and the application of this combined regimen in several cancers, followed by a summary of the current evidence on the application of this combined regimen in the treatment of sarcomas as well as the main clinical trials currently underway. Based on the findings of this review, we believe that this combined approach will play an important role in the treatment of some subtypes of sarcomas in the future.

Neoadjuvant transarterial chemoembolization (TACE) plus PD-1 inhibitor bridging to tumor resection in intermediate-stage hepatocellular carcinoma patients

BACKGROUND

Programmed cell death protein 1 (PD-1) inhibitor is widely utilized in advanced-stage carcinomas including hepatocellular carcinoma (HCC), while its neoadjuvant application plus transarterial chemoembolization (TACE) in HCC remains unexplored. Thereby, the current study aimed to investigate the efficacy and safety of TACE plus PD-1 inhibitor as neoadjuvant therapy bridging to surgical resection in intermediate-stage HCC patients.

METHODS

Twenty intermediate-stage HCC (China Liver Cancer (CNLC) stage II) patients treated with neoadjuvant TACE plus PD-1 inhibitor (camrelizumab or sintilimab) bridging to surgery were consecutively enrolled.

RESULTS

The objective response rate (ORR) and disease control rate (DCR) to neoadjuvant therapy were 75.0% and 100.0%, respectively; meanwhile, alpha-fetoprotein (AFP) was decreased after the neoadjuvant therapy (P < 0.001). Moreover, 14 (70.0%) patients had successful downstaging (patients converted to CNLC stage I). Neither median disease-free survival (DFS) nor median overall survival (OS) was reached; additionally, the 1-year accumulating DFS rate was 86.6%; meanwhile, the 1-year and 2-year accumulating OS rates were 100.0% and 76.4%, separately. Moreover, patients with successful downstaging had a prolonged DFS (P = 0.014) compared to patients with failed downstaging; meanwhile, this trend was also observed in assessing accumulating OS (P = 0.067) (without statistical significance). Main adverse events included pain (50.0%), fever (25.0%), neutropenia (25.0%), nausea and vomiting (25.0%), fatigue (25.0%), peripheral neuropathy (20.0%), anemia (15.0%), thrombopenia (15.0%), diarrhea (15.0%), anorexia (15.0%), and rash (15.0%).

CONCLUSION

Neoadjuvant TACE plus PD-1 inhibitor realizes a satisfying downstaging rate, acceptable survival profile, and tolerance in intermediate-stage HCC patients.

The performance and perspectives of dendritic cell vaccines modified by immune checkpoint inhibitors or stimulants

Therapeutic dendritic cell (DC) vaccines stimulate the elimination of tumor cells by the immune system. However, while antigen-specific T cell responses induced by DC vaccines are commonly observed, the clinical response rate is relatively poor, necessitating vaccine optimization. There is evidence that the suppression of DC function by immune checkpoints hinders the anti-tumor immune responses mediated by DC vaccines, ultimately leading to the immune escape of the tumor cells. The use of immune checkpoint inhibitors (ICIs) and immune checkpoint activators (ICAs) has extended the immunotherapeutic range. It is known that both inhibitory and stimulatory checkpoint molecules are expressed by most DC subsets and can thus be used to manipulate the effectiveness of DC vaccines. Such manipulation has been investigated using strategies such as chemotherapy, agonistic or antagonistic antibodies, siRNA, shRNA, CRISPR-Cas9, soluble antibodies, lentiviruses, and adenoviruses to maximize the efficacy of DC vaccines. Thus, a deeper understanding of immune checkpoints may assist in the development of improved DC vaccines. Here, we review the actions of various ICIs or ICAs shown by preclinical studies, as well as their potential application in DC vaccines. New therapeutic interventional strategies for blocking and stimulating immune checkpoint molecules in DCs are also described in detail.

Ferroptosis-Related Gene MT1G as a Novel Biomarker Correlated With Prognosis and Immune Infiltration in Colorectal Cancer

Ferroptosis, a newly discovered way of cell death, has been proved to be involved in the oncogenesis and development of cancers, including colorectal cancer (CRC). Here, by identifying the differentially expressed genes (DEGs) from three CRC transcriptome microarray datasets (GSE20842, GSE23878, and GSE25070), we found that the expression of MT1G was significantly decreased in CRC tissues, and the patients with a high level of MT1G displayed a poor prognosis. Quantitative PCR (qPCR) further confirmed the downregulated MT1G in two CRC cells, HCT8 and HCT116. The colony-forming assay indicated that the MT1G overexpression exhibited a remarkable inhibition of cell proliferation in HCT8 and HCT116 cells. In addition, we explored the co-expressed genes of MT1G to gain a better understanding of its potential signaling pathways. Aberrantly expressed MT1G also affected the immune response of CRC patients. Collectively, these findings might deepen our comprehension on the potential biological implications of MT1G in CRC.