Shunichi Odahara

Current Immunotherapeutic Approaches in Pancreatic Cancer

Pancreatic cancer is a highly aggressive and notoriously difficult to treat. As the vast majority of patients are diagnosed at advanced stage of the disease, only a small population is curative by surgical resection. Although gemcitabine-based chemotherapy is typically offered as standard of care, most patients do not survive longer than 6 months. Thus, new therapeutic approaches are needed. Pancreatic cancer cells that develop gemcitabine resistance would still be suitable targets for immunotherapy. Therefore, one promising treatment approach may be immunotherapy that is designed to target pancreatic-cancer-associated antigens. In this paper, we detail recent work in immunotherapy and the advances in concept of combination therapy of immunotherapy and chemotherapy. We offer our perspective on how to increase the clinical efficacy of immunotherapies for pancreatic cancer.

N‐3 polyunsaturated fatty acid diet therapy for patients with inflammatory bowel disease

Background: N‐3 polyunsaturated fatty acids (PUFA) are considered important pharmaconutrients for modulating mucosal immunity and therapeutic responses in patients with inflammatory bowel disease (IBD). We investigated the influence of diet therapy involving the use of an “n‐3 PUFA food exchange table” (n‐3DP) on the fatty acid composition of the erythrocyte membranes of IBD patients and its remission‐maintaining effects. Methods: We analyzed the fatty acid composition of the erythrocyte membrane before and after n‐3DP intervention in 20 initial‐onset IBD patients who had not undergone any dietary intervention. We then analyzed it again and evaluated disease activity after 12–18 months intervention in 230 IBD patients (168 ulcerative colitis, 62 Crohns disease; follow‐up group) in whom n‐3DP was introduced after remission had been achieved. The follow‐up group was divided into remission and relapse groups. Results: In the 20 initial‐onset patients, the mean n‐3/n‐6 ratio significantly increased after intervention (0.41 ± 0.16 versus 0.70 ± 0.20; P < 0.001). In the follow‐up group the ratio in the remission group (n = 145) was significantly higher than that in the relapse group (n = 85) (0.65 ± 0.28 versus 0.53 ± 0.18; P < 0.001). The ratio significantly decreased in those who suffered a relapse after the beginning of treatment (P < 0.01). Conclusions: N‐3DP significantly increased the erythrocyte membrane n‐3/n‐6 ratio in IBD patients, and this ratio was significantly higher in the remission group, suggesting that n‐3DP alters the fatty acid composition of the cell membrane and influences clinical activity in IBD patients. (Inflamm Bowel Dis 2010)

Combined TLR2/4-Activated Dendritic/Tumor Cell Fusions Induce Augmented Cytotoxic T Lymphocytes

Induction of antitumor immunity by dendritic cell (DC)-tumor fusion cells (DC/tumor) can be modulated by their activation status. In this study, to address optimal status of DC/tumor to induce efficient antigen-specific cytotoxic T lymphocytes (CTLs), we have created various types of DC/tumor: 1) un-activated DC/tumor; 2) penicillin-killed Streptococcus pyogenes (OK-432; TLR4 agonist)-activated DC/tumor; 3) protein-bound polysaccharides isolated from Coriolus versicolor (PSK; TLR2 agonist)-activated DC/tumor; and 4) Combined OK-432- and PSK-activated DC/tumor. Moreover, we assessed the effects of TGF-β1 derived from DC/tumor on the induction of MUC1-specific CTLs. Combined TLR2- and TLR4-activated DC/tumor overcame immune-suppressive effect of TGF-β1 in comparison to those single activated or un-activated DC/tumor as demonstrated by: 1) up-regulation of MHC class II and CD86 expression on DC/tumor; 2) increased fusion efficiency; 3) increased production of fusions derived IL-12p70; 4) activation of CD4+ and CD8+ T cells that produce high levels of IFN-γ; 5) augmented induction of CTL activity specific for MUC1; and 6) superior efficacy in inhibiting CD4+CD25+Foxp3+ T cell generation. However, DC/tumor-derived TGF-β1 reduced the efficacy of DC/tumor vaccine in vitro. Incorporating combined TLRs-activation and TGF-β1-blockade of DC/tumor may enhance the effectiveness of DC/tumor-based cancer vaccines and have the potential applicability to the field of adoptive immunotherapy.

Long-Term Alteration of Intestinal Microbiota in Patients with Ulcerative Colitis by Antibiotic Combination Therapy

Previous work has demonstrated that intestinal bacteria, such as Fusobacterium varium (F. varium), contribute to the clinical activity in ulcerative colitis (UC); thus, an antibiotic combination therapy (amoxicillin, tetracycline, and metronidazole (ATM)) against F. varium can induce and maintain UC remission. Therefore, we investigated whether ATM therapy induces a long-term alteration of intestinal microbiota in patients with UC. Patients with UC were enrolled in a multicenter, randomized, double-blind, placebo-controlled study. Biopsy samples at the beginning of the trial and again at 3 months after treatment completion were randomly obtained from 20 patients. The terminal restriction fragment length polymorphism (T-RFLP) in mucosa-associated bacterial components was examined to assess the alteration of the intestinal microbiota. Profile changes of T-RFLP in mucosa-associated bacterial components were found in 10 of 12 patients in the treatment group and in none of 8 in the placebo group. Dice similarity coefficients using the unweighted pair group method with arithmetic averages (Dice-UPGMA) confirmed that the similarity of mucosal microbiota from the descending colon was significantly decreased after the ATM therapy, and this change was maintained for at least 3 months. Moreover, at 3 months after treatment completion, the F. varium/β-actin ratio, examined by real-time PCR using nested PCR products from biopsy samples, was reduced less than 40% in 8 of 12 treated patients, which was higher, but not significantly, than in 4 of 8 patients in the placebo group. Together, these results suggest that ATM therapy induces long-term alterations in the intestinal microbiota of patients with UC, which may be associated, at least in part, with clinical effects of the therapy.

A Prospective Study Evaluating Metabolic Capacity of Thiopurine and Associated Adverse Reactions in Japanese Patients with Inflammatory Bowel Disease (IBD).

Azathioprine (AZA) is frequently used in patients with inflammatory bowel disease (IBD). However, toxic adverse reactions frequently develop and limit the clinical benefits. Currently, the precise mechanisms underlying thiopurine-related toxicity are not well understood. To investigate the relationship between the extent of thiopurine metabolism and adverse reactions in Japanese IBD patients, we prospectively observed 48 IBD patients who received AZA. We analyzed the thiopurine S-methyltransferase (TPMT) and inosine triphosphate pyrophosphatase (ITPA) gene mutations and measured the concentrations of 6-thioguanine nucleotide (6-TGN) continuously for 52 weeks. All patients possessed wild-type TPMT gene sequences. The ITPA 94C>A mutation was detected in 19 patients (39.6%). Adverse reactions developed in 14 of the 48 patients (29.2%), including leukopenia in 10 patients (20.8%). In the leukopenia group, the percentages of patients with 94C>A were higher than those in the without-leukopenia group (70.0% vs. 31.6%, P < 0.05). The average concentrations of 6-TGN in the patients with 94C>A were generally higher than those in the patients without 94C>A, however, there were no significant differences. Only 3 out of 10 patients with leukopenia exhibited high 6-TGN levels (30.0%). No negative correlations between white blood cell (WBC) counts and 6-TGN concentrations were observed. The cumulative incidence of leukopenia were higher for patients with 94C>A. Seven out of 19 patients (36.8%) with the ITPA 94C>A mutation developed leukopenia; however, this mutation may not unequivocally increase the risk of developing leukopenia. In addition, there are factors other than increased 6-TGN levels that are involved in the onset of leukopenia.

Comprehensive assessment of the prognosis of pancreatic cancer: peripheral blood neutrophil–lymphocyte ratio and immunohistochemical analyses of the tumour site

Abstract Objective Several studies have suggested that an elevated neutrophil–lymphocyte ratio (NLR) is associated with a poorer prognosis in patients with pancreatic cancer (PC). The correlations between the NLR and immunohistochemical (IHC) analysis with regard to the prognosis of patients with PC remain to be elucidated. By using IHC findings, we determined the value of the NLR as a prognostic factor in patients with PC. Material and methods We collected the clinico-pathological data of 28 consecutive patients who underwent surgical resection for PC between January 2008 and December 2012 at The Jikei University Kashiwa Hospital. We investigated whether the NLR and IHC results were related and ensured the consistency of the prognosis of patients with PC. Results The Kaplan–Meier curves for the disease-free survival (DFS) and the overall survival (OS) revealed that an NLR ≥ 5 is an implicit factor for decreased DFS and OS in patients with PC (p = 0.003, p < 0.001, log-rank test). The density of CD163+ macrophages and CD66b+ neutrophils was significantly higher in the high NLR group; on the contrary, the density of CD20+ lymphocytes was significantly higher in the low NLR group. Moreover, a Mann–Whitney U test showed that the NLR was significantly correlated with a high density of CD20+ lymphocytes (p = 0.031) and CD163+ macrophages (p = 0.023), while the NLR was not significantly correlated with CD66b+ neutrophils (p = 0.397). Conclusions Our results demonstrated the validity of the NLR by IHC analyses and we determined that a higher value of NLR is a trustworthy prognostic factor for patients with PC.

Augmentation of Antitumor Immunity by Fusions of Ethanol-Treated Tumor Cells and Dendritic Cells Stimulated via Dual TLRs through TGF-β1 Blockade and IL-12p70 Production

The therapeutic efficacy of fusion cell (FC)-based cancer vaccine generated with whole tumor cells and dendritic cells (DCs) requires the improved immunogenicity of both cells. Treatment of whole tumor cells with ethanol resulted in blockade of immune-suppressive soluble factors such as transforming growth factor (TGF)-β1, vascular endothelial growth factor, and IL-10 without decreased expression of major histocompatibility complex (MHC) class I and the MUC1 tumor-associated antigen. Moreover, the ethanol-treated tumor cells expressed “eat-me” signals such as calreticulin (CRT) on the cell surface and released immunostimulatory factors such as heat shock protein (HSP)90α and high-mobility group box 1 (HMGB1). A dual stimulation of protein-bound polysaccharides isolated from Coriolus versicolor (TLR2 agonist) and penicillin-inactivated Streptococcus pyogenes (TLR4 agonist) led human monocyte-derived DCs to produce HSP90α and multiple cytokines such as IL-12p70 and IL-10. Interestingly, incorporating ethanol-treated tumor cells and TLRs-stimulated DCs during the fusion process promoted fusion efficiency and up-regulated MHC class II molecules on a per fusion basis. Moreover, fusions of ethanol-treated tumor cells and dual TLRs-stimulated DCs (E-tumor/FCs) inhibited the production of multiple immune-suppressive soluble factors including TGF-β1 and up-regulated the production of IL-12p70 and HSP90α. Most importantly, E-tumor/FCs activated T cells capable of producing high levels of IFN-γ, resulting in augmented MUC1-specific CTL induction. Collectively, our results illustrate the synergy between ethanol-treated whole tumor cells and dual TLRs-stimulated DCs in inducing augmented CTL responses in vitro by FC preparations. The alternative system is simple and may provide a platform for adoptive immunotherapy.

Long-term management of gemcitabine in a patient with advanced pancreatic cancer undergoing haemodialysis

Abstract Gemcitabine application for patients with impaired renal function or undergoing haemodialysis will increase if the efficacy and safety are proved as the treatment for pancreatic cancer of these patients. However, there is no guideline about the usage of gemcitabine in patients with impaired renal function or haemodialysis. We report the case of a 70-year-old man with advanced pancreatic cancer undergoing haemodialysis. After discontinuation of 100% or 80% dosage, 60% dose of gemcitabine was administered biweekly. Serum carbohydrate antigen 19-9 and carcinoembryonic antigen levels were marked by slight variations and abdominal computed tomography (CT) showed the tumour size hardly changed. We administered gemcitabine for the patient 14 times in total, and he survived over 8 months from the definitive diagnosis. These findings confirm the efficacy and safety of treatment with a biweekly 60% dose of gemcitabine for patients with advanced pancreatic cancer undergoing haemodialysis in the face of dose modification.

Fatty Acids as Useful Serological Markers for Crohn’s Disease

Background: We have previously reported that patients with Crohn’s disease (CD) have a very specific erythrocyte membrane phospholipid fatty acid profile. The findings of this study suggest that the activities of enzymes involved in the metabolism of linoleic acid (LA), that is, delta-6 desaturase, are higher in CD patients than in healthy individuals. Methods: We evaluated the utilities of various fatty acid compositions of the plasma (p-) as new serological markers for CD compared to those of erythrocyte membranes (e-). Results: Fifty CD patients and 50 healthy individuals were enrolled. In both plasma and erythrocyte membranes, the weight percentages of palmitic acid (PA) were significantly higher, while those of LA were significantly lower in CD patients than in controls. Fatty acids with high sensitivity and specificity were p-PA (0.86 and 0.74) and e-PA (0.80 and 0.74). With PA and LA as a CD fatty acid index (CDFAi), that is, CDFAi = (PA/LA), the sensitivity and specificity of plasma CDFAi (p-CDFAi) and e-CDFAi were 0.80 and 0.80; and 0.82 and 0.88 respectively. Conclusion: In CD patients, various fatty acids were specifically altered in both plasma and erythrocytes, and p-PA and p-CDFAi are potentially useful as new serological markers for CD.

T1212 The Diet Therapy for Achieving a Dietary N-3/N-6 Ratio of Approximately 1 Increase the Remission-Maintenance Rate in Patients with Inflammatory Bowel Disease

Purpose: Balsalazide 1.1-g tablets are a new high-potency formulation of the azo-bonded 5 aminosalicylate (5-ASA) prodrug balsalazide for first-line treatment of mildly-to-moderately active ulcerative colitis (UC). Key endpoints for three phase 3, multicenter studies included evaluation of safety and tolerability of balsalazide tablets 6.6 g/d. Methods: The balsalazide tablet program consisted of 2 phase 3 double blind studies and 1 open-label extension study. Adults withmildly-to-moderately active UCwere randomized to receive either balsalazide tablets 6.6 g/d (3 tablets twice daily), placebo, or mesalamine 2.4 g/d. Safety evaluations included clinical laboratory assessments, vital sign measurements, and adverse event (AE) documentation. Eligible patients from the 2 randomized studies were offered enrollment in an open-label extension study to receive active treatment. Results: A total of 565 patients received at least 1 dose of balsalazide tablets and had at least one postbaseline safety assessment across the three studies. The mean exposure to balsalazide tablets was 225 days. The incidence of treatment emergent AEs (TEAEs) was 71% for subjects treated with balsalazide in the 3 studies, and the majority of AEs were mild or moderate in intensity. In the double-blind studies, the safety profile of the balsalazide group (n=378) was comparable with the placebo group (n=79) and the mesalamine group (n=198). Headache, the most common TEAE in the studies, occurredmore frequently in the placebo (14%) andmesalamine (10%) groups than in the balsalazide (8%) group. Worsening UC was also experienced by a larger proportion of the placebo group (15%) compared with the balsalazide (7%) and mesalamine (2%) groups. Other commonly reported AEs (eg, nausea, abdominal pain, nasopharyngitis, vomiting, urinary tract infection) were comparable across the treatment groups. Treatment-emergent serious AEs occurred more frequently in the placebo group (6%) than in either the balsalazide (3%) or mesalamine (<1%) groups. Withdrawals due to AEs were most often related to worsening UC. One death occurred in a subject diagnosed with metastatic malignant melanoma during the open-label study. The death was judged to be unrelated to study drug. Conclusions: Balsalazide 1.1-g tablets administered as 6.6 g/d (3 tablets twice daily) has a favorable safety profile in these studies. Common TEAEs were typically events frequently seen inUC patients or among the general population. The favorable safety profile of balsalazide tablets combined with a convenient, twice-daily dosing regimen, stands to improve patient adherence to therapy and clinical outcomes in the treatment of UC.