Design, Synthesis, and Evaluation of 8-(o-Tolyl)quinazoline Derivatives as Small-Molecule PD-1/PD-L1 Antagonists

Small-molecule inhibitors targeting programmed cell death-1/programmed cell death-ligand 1 (PD-1/PD-L1) interactions can compensate for the shortcomings of antibody-based inhibitors and have attracted considerable attention, some of which have already entered clinical trials. Herein, based on our previous study on small-molecule PD-L1 inhibitors, we reported a series of 8-(o-tolyl)quinazoline derivatives by the skeleton merging strategy. Homogenous time-resolved fluorescence (HTRF) assay against PD-1/PD-L1 interaction identified compound A5, which showed the most potent inhibition with an IC50 value of 23.78 nM. Meanwhile, based on the results of HTRF assay, the structure-activity relationships (SARs) of the tail were focused on. Cell-based PD-1/PD-L1 blockade assay further revealed that A5 significantly blocked the PD-1/PD-L1 interaction at 1.1 μM in the co-culture system of Jurkat-NFAT-PD-1 cells and Hep3B-OS8-hPD-L1 cells with no significant cytotoxicity on Jurkat cells. Moreover, the proposed binding mode of A5 was investigated by a docking analysis. These results indicate that compound A5 is a promising lead compound that deserves further investigation.

Incidence risk of peripheral edema in cancer patients treated with PD-1/PD-L1 inhibitors: A PRISMA guideline systematic review and meta-analysis

PURPOSE

To elucidate the relationship between peripheral edema and programmed cell death-1/programmed cell death ligand 1 (PD-1/PD-L1) inhibitors, the meta-analysis was performed.

METHOD

Following the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-analyses, all-grade and grade 3-5 of peripheral edema data extracted from clinical trials were taken into account for the final comprehensive assessments.

RESULTS

Twenty-seven PD-1/PD-L1-related clinical trials with peripheral edema data were collected. Compared with chemotherapy (PD-1/PD-L1 vs chemotherapy), the risk of developing peripheral edema for all-grade was much lower (odds ratio [OR] = 0.36, 95% confidence interval [CI]: [0.23, 0.56], Z = 4.55 [P < .00001]). When PD-1/PD-L1 plus chemotherapy were compared with chemotherapy, no significant analysis results for all-grade was found (OR = 1.15, 95% CI:[0.93, 1.44], I2 = 25%, Z = 1.27 [P = .20]). Similar risk trends could also be found when the incidence risk of peripheral edema for grade 3-5 was evaluated. No obvious publication bias was identified throughout the total analysis process.

CONCLUSION

The effect of PD-1/PD-L1 inhibitor on the risk of developing peripheral edema was weaker than that of chemotherapy, and the combination with chemotherapy slightly increased the incidence risk of developing peripheral edema without statistical significance.

Odds ratio of programmed cell death-1 or ligand 1 inhibitor-related endocrine dysfunction in patients with lung cancer: A systematic review and meta-analysis

PURPOSE

We designed the study to investigate the incidence risk of Programmed Cell Death-1 (PD-1) or Ligand 1 (PD-L1) inhibitor-related endocrine dysfunction in patients with lung cancer.

METHOD

All the data were collected by 1 primary reviewer and then independently reviewed by 2 secondary reviewers according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISM) guidelines. Incidence risk of all-grade and grade 3-5 PD-1/PD-L1 inhibitors related endocrine dysfunction in patients with lung cancer were taken into account.

RESULTS

Overall, 12 clinical trials comprising 6108 patients were identified in this systematic review and meta-analysis. The incidence risk of hypothyroidism, hyperthyroidism and adrenal insufficiency was higher in NSCLC patients receiving combination treatments. The incidence rate of all-grade of hypothyroidism was lower in PD-1/PD-L1 inhibitor subgroup compared to chemotherapy (OR = 22.62, 95%CI:9.79-52.25), while the similar result was seen in another treatment regimen (PD-1 + platinum-based chemotherapy vs platinum-based chemotherapy) (OR = 2.93, 95%CI: [2.08, 4.11). The different result can be seen in the group related to the other treatment regimen (1PD-1/PD-L1 inhibitor vs 2 PD-1/PD-L1 inhibitors) (OR = 0.40, 95%CI:0.21-0.76). All the results of the above analysis were considered to be statistical significant. Similar result could also be seen in meta-analysis related to hyperthyroidism and adrenal insufficiency.

CONCLUSION

The incidence risk of endocrine dysfunctions, including hypothyroidism, hyperthyroidism and adrenal insufficiency, were higher for PD-1/PD-L1 inhibitors group.

Inhibition of histone lysine-specific demethylase 1 elicits breast tumor immunity and enhances antitumor efficacy of immune checkpoint blockade

Immunotherapy strategies have been emerging as powerful weapons against cancer. Early clinical trials reveal that overall response to immunotherapy is low in breast cancer patients, suggesting that effective strategies to overcome resistance to immunotherapy are urgently needed. In this study, we investigated whether epigenetic reprograming by modulating histone methylation could enhance effector T lymphocyte trafficking and improve therapeutic efficacy of immune checkpoint blockade in breast cancer with focus on triple-negative breast cancer (TNBC) subtype. In silico analysis of The Cancer Genome Atlas (TCGA) data shows that expression of histone lysine-specific demethylase 1 (LSD1) is inversely associated with the levels of cytotoxic T cell-attracting chemokines (C-C motif chemokine ligand 5 (CCL5), C-X-C motif chemokine ligand 9 and 10 (CXCL9, CXCL10)) and programmed death-ligand 1 (PD-L1) in clinical TNBC specimens. Tiling chromatin immunoprecipitation study showed that re-expression of chemokines by LSD1 inhibition is associated with increased H3K4me2 levels at proximal promoter regions. Rescue experiments using concurrent treatment with small interfering RNA or inhibitor of chemokine receptors blocked LSD1 inhibitor-enhanced CD8+ T cell migration, indicating a critical role of key T cell chemokines in LSD1-mediated CD8+ lymphocyte trafficking to the tumor microenvironment. In mice bearing TNBC xenograft tumors, anti-PD-1 antibody alone failed to elicit obvious therapeutic effect. However, combining LSD1 inhibitors with PD-1 antibody significantly suppressed tumor growth and pulmonary metastasis, which was associated with reduced Ki-67 level and augmented CD8+ T cell infiltration in xenograft tumors. Overall, these results suggest that LSD1 inhibition may be an effective adjuvant treatment with immunotherapy as a novel management strategy for poorly immunogenic breast tumors.

Breast Cancer Immunotherapy: Facts and Hopes

Immunotherapy is revolutionizing the management of multiple solid tumors, and early data have revealed the clinical activity of programmed cell death-1/programmed death ligand-1 (PD-1/PD-L1) antagonists in small numbers of patients with metastatic breast cancer. Clinical activity appears more likely if the tumor is triple negative, PD-L1+, and/or harbors higher levels of tumor-infiltrating leukocytes. Responses to atezolizumab and pembrolizumab appear to be durable in metastatic triple-negative breast cancer (TNBC), suggesting that these agents may transform the lives of responding patients. Current clinical efforts are focused on developing immunotherapy combinations that convert nonresponders to responders, deepen those responses that do occur, and surmount acquired resistance to immunotherapy. Identifying biomarkers that can predict the potential for response to single-agent immunotherapy, identify the best immunotherapy combinations for a particular patient, and guide salvage immunotherapy in patients with progressive disease are high priorities for clinical development. Smart clinical trials testing rational immunotherapy combinations that include robust biomarker evaluations will accelerate clinical progress, moving us closer to effective immunotherapy for almost all patients with breast cancer. Clin Cancer Res; 24(3); 511-20. ©2017 AACR.

Ex Vivo PD-L1/PD-1 Pathway Blockade Reverses Dysfunction of Circulating CEA-Specific T Cells in Pancreatic Cancer Patients

Purpose: Carcinoembryonic antigen (CEA) is a candidate target for cellular immunotherapy of pancreatic cancer. In this study, we have characterized the antigen-specific function of autologous cytotoxic T lymphocytes (CTL) specific for the HLA-A2-restricted peptide, pCEA691-699, isolated from the peripheral T-cell repertoire of pancreatic cancer patients and sought to determine if ex vivo PD-L1 and TIM-3 blockade could enhance CTL function.Experimental Design: CD8⁺ T-cell lines were generated from peripheral blood mononuclear cells of 18 HLA-A2⁺ patients with pancreatic cancer and from 15 healthy controls. In vitro peptide-specific responses were evaluated by flow cytometry after staining for intracellular cytokine production and carboxy fluorescein succinimydyl ester cytotoxicity assays using pancreatic cancer cell lines as targets.Results: Cytokine-secreting functional CEA691-specific CTL lines were successfully generated from 10 of 18 pancreatic cancer patients, with two CTL lines able to recognize and kill both CEA691 peptide-loaded T2 cells and CEA⁺ HLA-A2⁺ pancreatic cancer cell lines. In the presence of ex vivo PD-L1 blockade, functional CEA691-specific CD8⁺ T-cell responses, including IFNγ secretion and proliferation, were enhanced, and this effect was more pronounced on Ag-specific T cells isolated from tumor draining lymph nodes.Conclusions: These data demonstrate that CEA691-specific CTL can be readily expanded from the self-restricted T-cell repertoire of pancreatic cancer patients and that their function can be enhanced by PD-L1 blockade. Clin Cancer Res; 23(20); 6178-89. ©2017 AACR.