Shinjiro Sakamoto

PD-1 expression on peripheral blood T-cell subsets correlates with prognosis in non-small cell lung cancer

PD‐1 expression in peripheral blood T‐cells has been reported in several kinds of cancers, including lung cancer. However, the relationship between PD‐1 expression in peripheral blood T‐cells and prognosis after treatment with a cancer vaccine has not been reported. To elucidate this relationship, we analyzed PD‐1 expression in the peripheral blood T‐cells of patients with non‐small cell lung cancer. The blood samples used in this study were obtained from patients enrolled in phase II clinical trials of a personalized peptide vaccine. Seventy‐eight samples obtained before and after a single vaccination cycle (consisting of six or eight doses) were subjected to the analysis. PD‐1 was expressed on lymphocytes in the majority of samples. The relative contents of PD1+CD4+ T‐cells against total lymphocytes before and after the vaccination cycle correlated with overall survival (OS) with a high degree of statistical significance (P < 0.0001 and P = 0.0014). A decrease in PD‐1+CD8+ T‐cells after one cycle of vaccination also correlated with longer OS (P = 0.032). The IgG response to the non‐vaccinated peptides suggested that the epitope spreading seemed to occur more frequently in high‐PD‐1+CD4+ T‐cell groups. Enrichment of CD45RA−CCR7− effector‐memory phenotype cells in PD‐1+ T‐cells in PBMCs was also shown. These results suggest that PD‐1 expression on the peripheral blood T‐cell subsets can become a new prognostic marker in non‐small cell lung cancer patients treated with personalized peptide vaccination.

Prospect and progress of personalized peptide vaccinations for advanced cancers.

ABSTRACT Introduction: The field of cancer immunotherapy has made dramatic progress in the past 20 years, in part due to the identification of numerous tumor-associated antigens (TAAs). We have developed a novel immunotherapeutic approach called the personalized peptide vaccine (PPV), in which a maximum of four human leukocyte antigen (HLA)-matched vaccine peptides are selected based on the pre-existing host immunity before vaccination. Areas covered: This review describes recent progress in the use of PPV for various types of advanced cancer. Expert opinion: Although various approaches for therapeutic cancer immunotherapies, including peptide-based vaccines, have been developed and clinically examined, the diverse and heterogeneous characteristics of tumor cells and host immunity seem to limit their therapeutic efficacy. Selection of suitable peptide vaccines for individual patients based on the pre-existing host immunity before vaccination could resolve this limitation and could be a rational approach for developing effective cancer vaccines.

A randomized phase II trial of personalized peptide vaccine with low dose cyclophosphamide in biliary tract cancer.

Since the prognosis of advanced biliary tract cancer (aBTC) still remains very poor, new therapeutic approaches, including immunotherapies, need to be developed. In the current study, we conducted an open‐label randomized phase II study to test whether low dose cyclophosphamide (CPA) could improve antigen‐specific immune responses and clinical efficacy of personalized peptide vaccination (PPV) in 49 previously treated aBTC patients. Patients with aBTC refractory to at least one regimen of chemotherapies were randomly assigned to receive PPV with low dose CPA (100 mg/day for 7 days before vaccination) (PPV/CPA, n = 24) or PPV alone (n = 25). A maximum of four HLA‐matched peptides were selected based on the pre‐existing peptide‐specific IgG responses, followed by subcutaneous administration. T cell responses to the vaccinated peptides in the PPV/CPA arm tended to be greater than those in the PPV alone arm. The PPV/CPA arm showed significantly better progression‐free survival (median time: 6.1 vs 2.9 months; hazard ratio (HR): 0.427; P = 0.008) and overall survival (median time: 12.1 vs 5.9 months; HR: 0.376; P = 0.004), compared to the PPV alone arm. The PPV alone arm, but not the PPV/CPA arm, showed significant increase in plasma IL‐6 after vaccinations, which might be associated with inhibition of antigen‐specific T cell responses. These results suggested that combined treatment with low dose CPA could provide clinical benefits in aBTC patients under PPV, possibly through prevention of IL‐6‐mediated immune suppression. Further clinical studies would be recommended to clarify the clinical efficacy of PPV/CPA in aBTC patients.

Feasibility Study of Personalized Peptide Vaccination for Advanced Small Cell Lung Cancer

Introduction The prognosis of patients with small cell lung cancer (SCLC) remains very poor. Therefore, the development of new therapeutic approaches, including immunotherapies, is desirable. Patients and Methods We conducted a phase II study of personalized peptide vaccination (PPV), in which a maximum of 4 human leukocyte antigen‐matched peptides were selected from 31 pooled peptides according to the pre‐existing peptide‐specific IgG responses before vaccination. The PPV was subcutaneously administered. Results Forty‐six patients were enrolled (median age, 63 years; 40 patients were men). Grade 1 (n = 13), 2 (n = 10), or 3 (n = 1) skin reactions at the injection sites were observed; however, no other severe adverse events related to the PPV were observed. The median survival time was 466, 397, 401, and 107 days in the subgroups with 0 (n = 5), 1 (n = 15), 2 (n = 12), and ≥ 3 (n = 14) previous chemotherapy regimens, respectively. Peptide‐specific IgG responses to the vaccinated peptides were augmented in 70% and 95% of patients after 1 and 2 vaccination cycles, respectively. The overall survival (OS) of patients with augmented IgG responses to a greater number of nonvaccinated peptides after the second cycle of vaccination was significantly longer (median survival time, 1237 days vs. 382 days; P = .010). In addition, augmentation of IgG responses specific to 6 peptides, including Lck‐derived peptides, was significantly related to better OS (P < .05, in each peptide). Conclusion These results suggest the feasibility of PPV for SCLC patients from the viewpoints of safety, immune boosting, and possible prolongation of OS. Therefore, further evaluation of PPV for advanced SCLC in prospective randomized trials is warranted. Micro‐Abstract We conducted a phase II study of personalized peptide vaccination (PPV) for 46 patients with advanced small cell lung cancer (SCLC). We observed immune boosting and possible prolongation of overall survival after PPV without severe adverse events. These results suggest that PPV has potential as a new treatment modality for SCLC.

Immunological evaluation of peptide vaccination for cancer patients with the HLA-A26 allele

To develop a peptide vaccine for cancer patients with the HLA‐A26 allele, which is a minor population worldwide, we investigated the immunological responses of HLA‐A26+/A26+ cancer patients to four different CTL epitope peptides under personalized peptide vaccine regimens. In personalized peptide vaccine regimens, two to four peptides showing positive peptide‐specific IgG responses in pre‐vaccination plasma were selected from the four peptide candidates applicable for HLA‐A26+/A26+ cancer patients and administered s.c. Peptide‐specific CTL and IgG responses along with cytokine levels were measured before and after vaccination. Cell surface markers in PBMCs and plasma cytokine levels were also measured. In this study, 21 advanced cancer patients, including seven lung, three breast, two pancreas, and two colon cancer patients, were enrolled. Their HLA‐A26 genotypes were HLA‐A26:01 (n = 24), HLA‐A26:03 (n = 10), and HLA‐A26:02 (n = 8). One, 14, and 6 patients received two, three, and four peptides, respectively. Grade 1 or 2 skin reactions at the injection sites were observed in the majority of patients, but no severe adverse events related to the vaccination were observed. Peptide‐specific CTL responses were augmented in 39% or 22% of patients after one or two cycles of vaccination, respectively. Notably, peptide‐specific IgG were augmented in 63% or 100% of patients after one or two cycles of vaccination, respectively. Personalized peptide vaccines with these four CTL epitope peptides could be feasible for HLA‐A26+ advanced cancer patients because of their safety and higher rates of immunological responses.

Evaluation of prognostic significance of granulocyte-related factors in cancer patients undergoing personalized peptide vaccination

Since cancer vaccines do not always elicit beneficial effects in treated patients, identification of biomarkers for predicting clinical outcomes would be highly desirable. We previously reported that abnormal granulocytes present in peripheral blood mononuclear cells (PBMC) may contribute to poor prognosis in advanced prostate cancer patients receiving personalized peptide vaccination (PPV). In the current study, we examined whether soluble factors derived from granulocytes, such as matrix metalloproteinase 9 (MMP-9), myeloperoxidase (MPO), and arginase 1 (ARG1), and inhibitory cytokine TGFβ in pre-vaccination plasma were useful for predicting prognosis after PPV in advanced cancer patients. In biliary tract cancer (n=25), multivariate Cox regression analysis demonstrated that patients with higher plasma MMP-9 levels had a significantly worse overall survival (OS) [hazard ratio (HR) = 4.637, 95% confidence interval (CI) = 1.670 - 12.877, P = 0.003], whereas MPO, ARG1, or TGFβ levels were not correlated with OS. Similarly, patients with higher MMP-9 levels showed worse prognosis than those with lower MMP-9 levels in other types of advanced cancers, including non-small cell lung cancer (n=32, P = 0.037 by log-rank test), and pancreatic cancer (n=41, P = 0.042 by log-rank test). Taken together, plasma MMP-9 levels before vaccination might be potentially useful as a biomarker for selecting advanced cancer patients who would benefit from PPV.

Bevacizumab with Single-agent Chemotherapy in Previously Treated Non-squamous Non-small-cell Lung Cancer: Phase II Study

Aim: This study was designed to evaluate the efficacy and tolerability of bevacizumab with docetaxel or pemetrexed in previously treated patients with non-squamous non-small cell lung cancer. Patients and Methods: This study enrolled patients who had received at least one chemotherapy regimen, regardless of prior use of bevacizumab. Combinations of docetaxel or pemetrexed were chosen by attending physicians. The primary endpoint was progression-free survival, and secondary endpoints were safety, disease control rate, and overall survival. Results: Thirty patients from two institutions were eligible. The median progression-free and overall survival were 5.0 months (95% confidence interval=3.2-8.8 months) and 15.8 months (95% confidence interval=10.5-19.6 months), respectively. The disease control rate was 66.7%. Treatments were well tolerated, but the development rate of osteonecrosis of the jaw was 10%. Conclusion: Addition of bevacizumab in a salvage setting might be effective, but the development of osteonecrosis of the jaw needs to be monitored.

Alternate‑day administration of S‑1 for elderly patients with advanced non‑small‑cell lung carcinoma: A prospective feasibility study

S-1 is an oral fluoropyrimidine agent used for the treatment of non-small-cell lung cancer (NSCLC). Although S-1 monotherapy has been reported to exhibit lesser hematotoxicity compared with other third-generation chemotherapeutics, digestive toxicity was also frequently observed. Alternate-day administration of S-1 has shown a lower rate of severe digestive toxicity than the daily standard administration in patients with NSCLC. However, the safety of alternate-day S-1 therapy in elderly patients aged 75 years or older has not been investigated. The present study was a multi-center and prospective feasibility study aimed to evaluate the safety of alternate-day S-1 therapy in elderly patients with NSCLC. The patients received S-1 orally twice daily for 4 days (Monday, Wednesday, Friday, and Sunday) every week until disease progression or unacceptable toxicity. The primary endpoint was safety, which was evaluated as the number of grade ≥3 adverse events, and the secondary endpoints were progression-free survival (PFS), 1-year survival, and disease control rate (DCR). A total of 10 patients were enrolled, but 2 patients failed to initiate the treatment protocol. Finally, 8 patients were treated with the study protocol regimen. No grade 3 or higher adverse events were observed. Four (50%) and 1 (12.5%) patient had grade 2 or lower digestive symptoms such as anorexia, diarrhea, or stomatitis and grade 1 lacrimation, respectively. Moreover, 2 (25%), 1 (12.5%), and 1 (12.5%) patients had grade 2 renal dysfunction, grade 2 ileus, and elevated blood bilirubin, respectively. The median PFS was 1.5 months (95% confidence interval: 0.9-1.8), and the 1-year survival rate was 42.9%. The DCR was 12.5%. In conclusion, alternate-day S-1 administration can be a safe treatment regimen for elderly patients with NSCLC, but its therapeutic efficacy and safety for elderly patients with NSCLC should be compared against the standard S-1 administration in a large-scale study.

Nivolumab-induced severe pancytopenia in a patient with lung adenocarcinoma

Severe leukopenia, thrombocytopenia, and bi-cytopenia due to nivolumab have been reported. In this report, we present the first case of nivolumab-induced severe pancytopenia in a patient with lung adenocarcinoma. A 56-year-old Japanese man with lung adenocarcinoma received nivolumab therapy as second-line treatment. After 3 cycles of this therapy, although computed tomography (CT) showed a reduced tumor size, laboratory findings revealed pancytopenia and a bone marrow biopsy showed a severely hypoplastic marrow. The pancytopenia was diagnosed as an adverse effect of nivolumab; filgrastim (75 μg/day), steroid-pulse therapy (intravenous methylprednisolone: 500 mg/day), and subsequently intravenous prednisolone (50 mg/day) were administered. Furthermore, intravenous administration of immunoglobulins was also performed. However, these treatments were ineffective. He was further diagnosed with fungal pneumonia and a catheter-related bloodstream infection. Anti-bacterial chemotherapy was administered. Two months after hospitalization, the neutrophil count improved to 1000/μL, but multiple red blood cell and platelet transfusions were needed. Therefore, further chemotherapy for lung adenocarcinoma could not be initiated, and the patient died due to progression of lung cancer 118 days after the onset of pancytopenia. The possibility of severe pancytopenia as an immune-related adverse event should be considered as a mandatory prerequisite for nivolumab therapy.

AGER rs2070600 polymorphism elevates neutrophil-lymphocyte ratio and mortality in metastatic lung adenocarcinoma

Background The receptor for advanced glycation end-product (RAGE) is a multi-ligand receptor involved in inflammation. In the gene encoding RAGE (AGER), there are three well-known polymorphisms; rs2070600, rs1800624, and rs1800625, which potentially increase the risk of lung cancer. Remarkably, AGER rs2070600 polymorphism, which increases ligand-binding affinity, is a potential prognostic factor in non-small cell lung cancer, but the underlying mechanism is unclear. The neutrophil-lymphocyte ratio (NLR) reflects tumor-associated systemic inflammatory conditions; high ratios are associated with poor prognosis in multiple cancers. Additionally, some humoral factors via RAGE-signaling are associated with elevated NLR in cancer patients. Objectives Associations of AGER polymorphisms with disease susceptibility, prognosis, and NLR were investigated in Japanese patients with lung adenocarcinoma. Methods We included 189 patients with lung adenocarcinoma, 96 of which had distant metastases, and 303 healthy controls. The correlation between AGER polymorphisms (rs2070600, rs1800624, rs1800625) and disease susceptibility and factors elevating the mortality and NLR in patients with metastases were evaluated. Results Only the minor allele of rs2070600 was associated with a higher NLR (β = 0.209, p = 0.043) and a poor prognosis (Hazard ratio = 2.06, 95% Confidence interval = 1.09–3.77, p = 0.028) in patients with metastatic disease, independently of background characteristics, including EGFR mutation status. All three polymorphisms were not associated with the risk of lung adenocarcinoma. Conclusions The AGER rs2070600 polymorphism was independently associated with systemic inflammation and poor prognosis in patients with metastatic lung adenocarcinoma.