Hiroto Matsui

A phase I clinical trial of vaccination with KIF20A-derived peptide in combination with gemcitabine for patients with advanced pancreatic cancer.

KIF20A (RAB6KIFL) belongs to the kinesin superfamily of motor proteins, which play critical roles in the trafficking of molecules and organelles during the growth of pancreatic cancer. Immunotherapy using a previously identified epitope peptide for KIF20A is expected to improve clinical outcomes. A phase I clinical trial combining KIF20A-derived peptide with gemcitabine (GEM) was therefore conducted among patients with advanced pancreatic cancer who had received prior therapy such as chemotherapy and/or radiotherapy. GEM was administered at a dose of 1000 mg/m2 on days 1, 8, and 15 in a 28-day cycle. The KIF20A-derived peptide was injected subcutaneously on a weekly basis in a dose-escalation manner (doses of 0.5, 1, and 3 mg/body; 3 patients/cohort). Safety and immunologic parameters were assessed. No severe adverse effects of grade 3 or higher related to KIF20A-derived peptide were observed. Of the 9 patients who completed at least one course of treatment, interferon-&ggr; (IFN-&ggr;)-producing cells were induced in 4 of 9 patients (P2, P3, P6, and P7), and IFN-&ggr;-producing cells were increased in 4 of the 9 patients (P1, P5, P8, and P9). Four of the 9 patients achieved stable disease. The disease control rate was 44%. The median survival time after first vaccination was 173 days and 1-year survival rate was 11.1%. IFN-&ggr;-producing cells were induced by the KIF20A-derived peptide vaccine at a high rate, even in combination with GEM. These results suggest that this combination therapy will be feasible and promising for the treatment of advanced pancreatic cancer.

Phase II clinical trial of peptide cocktail therapy for patients with advanced pancreatic cancer: VENUS-PC study

We previously conducted a phase I clinical trial combining the HLA‐A*2402‐restricted KIF20A‐derived peptide vaccine with gemcitabine for advanced pancreatic cancer (PC) and confirmed its safety and immunogenicity in cancer patients. In this study, we conducted a multicenter, single‐armed, phase II trial using two antiangiogenic cancer vaccines targeting VEGFR1 and VEGFR2 in addition to the KIF20A peptide. We attempted to evaluate the clinical benefit of the cancer vaccination in combination with gemcitabine. Chemotherapy naïve PC patients were enrolled to evaluate primarily the 1‐year survival rate, and secondarily overall survival (OS), progression free survival (PFS), response rate (RR), disease control rate (DCR) and the peptide‐specific immune responses. All enrolled patients received therapy without the HLA‐A information, and the HLA genotypes were used for classification of the patients. Between June 2012 and May 2013, a total of 68 patients were enrolled. No severe systemic adverse effects of Grade 3 or higher related to these three peptides were observed. The 1‐year survival rates between the HLA‐A*2402‐matched and ‐unmatched groups were not significantly different. In the HLA‐A*2402 matched group, patients showing peptide‐specific CTL induction for KIF20A or VEGFR1 showed a better prognosis compared to those without such induction (P = 0.023, P = 0.009, respectively). In the HLA‐A*2402‐matched group, the patients who showed a strong injection site reaction had a better survival rate (P = 0.017) compared to those with a weak or no injection site reaction. This phase II study demonstrated that this therapeutic peptide cocktail might be effective in patients who demonstrate peptide‐specific immune reactions although predictive biomarkers are needed for patient selection in its further clinical application.

Combined adjuvants of poly(I:C) plus LAG-3-Ig improve antitumor effects of tumor-specific T cells, preventing their exhaustion.

Therapeutic cancer vaccines are designed to treat cancer by boosting the endogenous immune system to fight against the cancer. In the development of clinically effective cancer vaccines, one of the most practical objectives is to identify adjuvants that are capable of optimizing the vaccine effects. In this study, we explored the potential of polyinosinic–polycytidylic acid (poly(I:C)) and LAG‐3‐Ig (soluble recombinant protein of lymphocyte activation gene‐3 [LAG‐3] extracellular domain fused with human IgG Fc region) as adjuvants for P1A tumor antigen peptide vaccine in a pre‐established P815 mouse tumor model with a transfer of tumor‐specific T cells. Whereas the use of poly(I:C) or LAG‐3‐Ig as a signal adjuvant induced a slight enhancement of P1A vaccine effects compared to incomplete Freunds adjuvant, combined treatment with poly(I:C) plus LAG‐3‐Ig remarkably potentiated antitumor effects, leading to complete rejection of pre‐established tumor and long‐term survival of mice. The potent adjuvant effects of poly(I:C) plus LAG‐3‐Ig were associated with an enhanced infiltration of T cells in the tumor tissues, and an increased proliferation and Th1‐type cytokine production of tumor‐reactive T cells. Importantly, the combined adjuvant of poly(I:C) plus LAG‐3‐Ig downregulated expressions of PD‐1, LAG‐3, and TIGIT on P1A‐specific T cells, indicating prevention of T cell exhaustion. Taken together, the results of the current study show that the combined adjuvants of poly(I:C) plus LAG‐3‐Ig with tumor peptide vaccine induce profound antitumor effects by activating tumor‐specific T cells.

Predictive biomarkers for the efficacy of peptide vaccine treatment: based on the results of a phase II study on advanced pancreatic cancer

BackgroundThe purpose of the present study was to explore novel biomarkers that can predict the clinical outcome of patients before treatment or during vaccination. These would be useful for the selection of appropriate patients who would be expected to exhibit better treatment outcomes from vaccination, and for facilitating the development of cancer vaccine treatments.MethodsFrom a single-arm, non-randomized, human leukocyte antigen (HLA)-A-status-blind phase II trial of a vaccine treatment using three HLA-A*2402-restricted peptides for advanced pancreatic cancer (PC), we obtained peripheral blood samples from 36 patients of an HLA-A*2402-matched group and 27 patients of an HLA-A*2402-unmatched group.ResultsMultivariate analysis (HR = 2.546; 95% CI = 1.138 to 5.765; p = 0.0231) and log-rank test (p = 0.0036) showed that a high expression level of programmed death-1 (PD-1) on CD4+ T cells was a negative predictive biomarker of overall survival in the HLA-A*2402-matched group . Moreover, a high expression level of PD-1 on CD4+ T cells was a negative predictor for the induction of cytotoxic T lymphocytes (p = 0.0007). After treatment, we found that the upregulation of PD-1 and T cell immunoglobulin mucin-3 (Tim-3) expression on CD4+ and CD8+ T cells was significantly associated with a poor clinical outcome in the HLA-A*2402-matched group (p = 0.0330, 0.0282, 0.0046, and 0.0068, respectively). In contrast, there was no significant difference for these factors in the HLA-A*2402-unmatched group.ConclusionsOur results indicate that the upregulation of PD-1 and Tim-3 expression on CD4+ and CD8+ T cells may restrict T cell responses in advanced PC patients; therefore, combination immunotherapy with blockade of PD-1 and Tim-3 to restore T cell responses may be a potential therapeutic approach for advanced PC patients.Trial registrationClinical-Trail-Registration: UMIN000008082.

Novel Indications for Surgical Resection of Metachronous Lung Metastases From Pancreatic Cancer After Curative Resection.

Few reports exist regarding surgical resection of metachronous lung metastases (MLM) from pancreatic ductal adenocarcinoma (PDA) after curative resection. To elucidate the indications for surgical resection of MLM and long-term survival, we analyzed Japanese case reports of MLM from PDA. Between 1983 and 2014, 17 Japanese case reports concerning surgical resection of MLM from PDA were published. We determined long-term survival in 16 patients (considering the published data of 15 patients and 1 of our own) by using a questionnaire survey and analyzing the relationships between background factors and long-term survival. In 16 patients with long-term survival, 4 patients were still alive without recurrence. The remaining 12 patients died of disease after recurrence. The median survival after the initial lobectomy was 37 months and the 3- and 5-year survival for all patients after lobectomy was 50% and 41%, respectively. Fourteen patients had a disease-free interval after initial resection of the primary pancreatic tumor of >20 months. These patients had a longer median survival period after lobectomy (46 vs. 25.5 mo, P=0.19). Seven patients had MLM of <16 mm. These patients had a statistically longer overall survival after lobectomy (83 vs. 16 mo, P=0.04). Three of 4 patients with primary stage I tumors were still alive without recurrence. We found that the conventional criteria for surgical resection of MLM from PDA (first disease-free interval of >20 mo with no other metastatic lesions) were appropriate. In addition, it is possible that MLM of <16 mm or primary stage I tumors are novel criteria.

Postoperative Adjuvant Therapy for Resectable Pancreatic Cancer With Gemcitabine and Adoptive Immunotherapy

Objectives We previously described adoptive immunotherapy (AIT) with cytotoxic T lymphocytes (CTLs) stimulated by the mucin 1 (MUC1)–expressing human pancreatic cancer cell line YPK-1 (MUC1-CTLs) and demonstrated that MUC1-CTLs might prevent liver metastasis. In the present study, we combined gemcitabine (GEM) and AIT for the treatment of pancreatic cancer. Methods A total of 43 patients who underwent radical pancreatectomy received treatment with MUC1-CTLs and GEM. After surgery, MUC1-CTLs were induced and administered intravenously 3 times, and GEM administered according to the standard regimen for 6 months. The patients whose relative dose intensity of GEM was 50% or more and who received 2 or more MUC1-CTL treatments were used as the adequate treatment group (n = 21). Results In the adequate treatment group, disease-free survival was 15.8 months, and overall survival was 24.7 months. Liver metastasis was found only in 7 patients (33%), and local recurrence occurred in 4 patients (19%). The independent prognostic factor of long-term disease-free survival on multivariate analysis was the average number of CTLs administered (P = 0.0133). Conclusions The combination therapy with AIT and GEM prevented liver metastasis and local recurrence. Moreover, the disease free-survival was improved in patients who received sufficient CTLs.

A new prognostic model for hepatocellular carcinoma recurrence after curative hepatectomy

We previously reported the effectiveness of the product of tumor number and size (NxS factor) for the prognosis of hepatocellular carcinoma (HCC) in patients following hepatectomy. The present study aimed to propose a new score based on the NxS factor to predict HCC recurrence following hepatectomy. A total of 406 patients who underwent hepatectomy for HCC at Osaka University Graduate School of Medicine were retrospectively analyzed to develop the new score. Among clinicopathological factors, including the NxS factor, the marker subset that achieved the best performance for prediction of early recurrence was assessed, and a prognostic model for HCC recurrence after curative hepatectomy (REACH) was developed. As the validation set, 425 patients who underwent hepatectomy for HCC at Yamaguchi University Graduate School of Medicine and Shimonoseki Medical Center were analyzed, and the prognostic ability of the REACH score was compared with that of well-known staging systems. Following analysis, the REACH score was constructed using six covariates (NxS factor, microscopic hepatic vein invasion, differentiation, serum albumin, platelet count and indocyanine green retention rate at 15 min). In the validation set, the REACH score predicted early recurrence in 73 of 81 samples, with a sensitivity of 89% and a specificity of 58%. The area under the curve (AUC) of the receiver operating characteristic curve of the REACH score was 0.78 and 0.74, respectively, for 1- and 2-year recurrence after hepatectomy; each AUC was higher than that of any of the other staging systems. Survival analysis indicated the REACH score had the best predictive value in disease-free and overall survival. The present findings demonstrated that the REACH score may be used to classify patients with HCC into high- and low-risk of recurrence, and to predict subsequent survival following hepatic resection.

Outcomes following liver resection for multinodular Barcelona Clinic Liver Cancer‑B hepatocellular carcinoma

Management of multinodular hepatocellular carcinoma (HCC) in the intermediate Barcelona Clinic Liver Cancer (BCLC)-B stage is controversial. The aim of the present study as to identify the subgroup of patients with BCLC-B HCC who could benefit from liver resection. The present study retrospectively analyzed the outcomes of 65 patients (training cohort) who underwent liver resection for multinodular BCLC-B HCC. Coxs regression analysis was conducted to identify the independent prognostic factors for overall survival and to develop the prognostic score. As some authors have reported that maximum tumor size (cm) plus tumor number (N+S) is a prognostic factor in patients with BCLC-B HCC who undergo chemoembolization, the usefulness of this factor in patients who underwent liver resection was also evaluated. Subsequently, the validity of the prognostic score was assessed in an independent validation cohort (n=132). Multivariate analysis revealed that positivity for hepatitis C virus antibody (HCV-ab), platelet count ≤1010/l, N+S >8, and des-γ-carboxy prothrombin (DCP) >400 mAU/ml were independent prognostic factors for overall survival. The prognostic score differentiated two groups (≤2, ≥3) with distinct outcomes (median survival time 68.3 months vs. 29.1 months; P<0.0001). This result was confirmed in an external validation cohort. Therefore, surgery can promote long-term survival in patients with multinodular HCC although the indications for surgery are limited. HCV-Ab status, preoperative platelet count, DCP level and N+S may be useful for patient selection.

Combination treatment of advanced pancreatic cancer using novel vaccine and traditional therapies

ABSTRACT Introduction: Pancreatic cancer is a highly malignant disease with high treatment resistance. Many patients are diagnosed in a very advanced state, and few patients can be curatively resected. With FOLFIRINOX and nab-paclitaxel plus gemcitabine, the prognosis of advanced pancreatic cancer has improved, yet many patients cannot survive longer than a year. Therefore, new therapeutic approaches are needed. Cancer vaccine therapy is characterized by controlling cancer by a cancer-specific immune reaction with few adverse events. Thus, a cancer peptide vaccine is considered promising for pancreatic cancer patients, who are often in poor general condition at diagnosis. Areas covered: This article reviews available data from recent clinical trials of the novel cancer vaccine therapy in combination with traditional chemotherapy or radiotherapy for pancreatic cancer, and the prospect will be described. Expert commentary: In clinical trials of the novel cancer vaccine therapy in combination with traditional therapy, many studies have failed to outperform traditional therapy, although some effects were recognized in subgroups. What is necessary in the future for cancer vaccine therapy to improve the prognosis of pancreatic cancer is combination of immune-checkpoint blockade to release immune escape mechanism and combination with strong multi-drug combination chemotherapy.

Abstract 1927: The significance of calreticulin in pancreatic cancer: a molecule highly expressed in pancreatic cancer stem-like cells

Cancer stem-like cells (CSLCs) in solid tumors are thought to be resistant to conventional chemotherapy or molecular targeting therapy and to contribute to cancer recurrence and metastasis. In this study, we aimed to identify a biomarker of pancreatic CSLCs (P-CSLCs). P-CSLC-enriched population was generated from pancreatic cancer cell lines using our previously reported method and its protein expression profile was compared with that of parental cells by two-dimensional electrophoresis and tandem mass spectrometry. The results indicated that a chaperone protein calreticulin (CRT) was significantly upregulated in P-CSLCs compared to parental cells. Flow cytometry analysis demonstrated that CRT was mostly localized to the surface of P-CSLCs and did not correlate with the levels of CD44v9, another P-CSLC biomarker. Furthermore, the side population in CRThigh/CD44v9low population is much higher than that in CRTlow/CD44v9high population. CRT expression was also assessed by immunohistochemistry in pancreatic cancer tissues (n = 80) obtained after radical resection and was found to be associated with patients’ clinicopathological features and disease outcomes in the Cox’s proportional hazard regression model. Multivariate analysis identified CRT as an independent prognostic factor for pancreatic cancer patients, along with age and post-operative therapy. Our results suggest that CRT can serve as a biomarker of P-CSLCs and a prognostic factor associated with poorer survival of pancreatic cancer patients. This novel biomarker can be useful for detecting P-CSLCs independently, which had been detectable by multiple surface markers like CD24, CD44 and ESA. We will present CSLCs properties of CRThigh population in P-CSLCs. Citation Format: Satoshi Matsukuma, Kiyoshi Yoshimura, Atsunori Oga, Moeko Inoue, Takuya Fujimtoto, Atsuo Kuramasu, Masanori Fuse, Ryouichi Tsunedomi, Hidetoshi Eguchi, Hiroto Matsui, Shinsuke Kanekiyo, Yukio Tokumitsu, Shinobu Tomochika, Michihisa Iida, Yoshihiro Tokuhisa, Kazuhiko Sakamoto, Nobuaki Suzuki, Tomoko Furuya-Kondo, Hiroshi Itoh, Shigeru Takeda, Shigeru Yamamoto, Shigefumi Yoshino, Shoichi Hazama, Tomio Ueno, Hiroaki Nagano. The significance of calreticulin in pancreatic cancer: a molecule highly expressed in pancreatic cancer stem-like cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1927. doi:10.1158/1538-7445.AM2017-1927