Clinical efficacy and safety of second line and salvage aflibercept for advanced colorectal cancer in Akita prefecture

BACKGROUNDAngiogenesis inhibitors (AIs) combination with cytotoxic chemotherapy is a promising treatment for patients with colorectal cancer (CRC). Aflibercept (AFL) is an option for second-line treatment of CRC, according to the ‘VELOUR’ trial. Currently, we can choose from three AIs, including bevacizumab, ramucirumab, and AFL. Different AIs can be used in subsequent treatment because of their distinctive mechanisms of action. We addressed the uncertainty regarding AFL efficacy and safety in heavily-treated patients by comparing outcomes of survival treatment with second-line treatment.AIMTo determine and compare the efficacy and safety profiles of AFL in the second-line and salvage therapy settings.METHODSClinical data of 41 patients with advanced CRC who received intravenous AFL combined with the folinic acid-fluorouracil-irinotecan (FOLFIRI) regimen were collected retrospectively from six institutions in Japan, for the period from May 2017 to March 2019. Patient characteristics collected included age, sex, tumor location, RAS and RAF status, metastatic sites, number of previous treatment cycles, therapeutic response, adverse events, duration of previous AI treatment, and survival time. The end points were time to AFL treatment failure (aTTF) and median survival time post-AFL (aMST). Statistical analyses were performed to compare the efficacy and safety in the second-line setting with those of the salvage therapy setting, which was defined as the days since the end of second-line therapy. RESULTSAll 41 patients who received AFL + FOLFIRI for advanced CRC had metastatic or unresectable cancer. Twenty-two patients received AFL in the second-line setting and nineteen in the salvage therapy setting. The patient characteristics were similar in the two groups, except for two factors. The median duration of the previous AI administration was shorter in the second-line patients compared with that in the salvage therapy patients (144 d vs 323 d, P = 0.006). In the second-line and salvage therapy groups, the objective response rates were 11% and 0%, respectively (P = 0.50), and the disease control rates were 53% and 50%, respectively (P = 1.00). In the second-line and salvage therapy groups, the aTTF (123 d vs 71 d, respectively), aMST (673 d vs 396 d, respectively), and incidence of adverse events of grade 3 [8 (36%) vs 9 (47%)] were not significantly different between the two groups.CONCLUSIONAFL can be used to treat advanced CRC patients, with a similar safety and efficacy in the salvage therapy setting as in the second-line setting.     

Efficacy of modified bevacizumab-XELOX therapy in Japanese patients with stage IV recurrent or non-resectable colorectal cancer

BackgroundNeoadjuvant chemotherapy (NAC) has been conducted for patients with non-resectable colorectal cancer; however, few reports of a systematic approach to NAC exist. At our hospital, bevacizumab with capecitabine and oxaliplatin (B-mab XELOX) has been used as chemotherapy for Stage IV colorectal cancer since 2014. We aimed to evaluate the efficacy and safety of NAC with a molecular-targeting agent for Stage IV colorectal cancer.MethodsA retrospective, single-institute analysis was performed including 27 patients with advanced recurrent cancer following primary tumor resection and 43 patients with non-resectable tumors and remote metastasis. At the time of resection, 17 were receiving chemotherapy. All 70 patients received at least 3 cycles of B-mab XELOX (total: 920 cycles). We determined the 1-year progression-free survival (1Y-PFS), 1-year overall survival (1Y-OS), 3Y-PFS, 3Y-OS, and number of treatment cycles. The objective response rate, clinical benefit rate, and adverse events were assessed. The number of chemotherapy cycles, survival time, and R0 surgery rate were determined for patients who underwent RO conversion surgery.ResultsThe 1Y-PFS was 28.5% [median survival time (MST): 7.4 months], 1Y-OS was 76.6% (MST not reached), 3Y-PFS was 5.5% (MST: 7.4 months), and 3Y-OS was 26.4% (MST: 25.2 months). The mean and median number of cycles of B-mab XELOX was 13.1 and 10.5, respectively. The objective response rate was 28.6%, and the clinical benefit rate was 58.6%. Grade 1 or Grade 2 adverse events occurred in 60 patients (85.7%); however, they all resolved without intervention. A single Grade 4 event (perforation of the primary tumor) occurred in 1 patient (1.4%). RO conversion surgery was performed in 7 patients (10.0%; primary + liver in 2 patients, primary + lung in 1 patient, liver in 3 patients, and primary in 1 patient). These patients received 3 to 10 cycles preoperatively (mean: 7.3; median: 6.5). R0 surgery was achieved in 5 of the 7 patients (71.4%). Postoperative survival ranged from 1 to 26 months (MST: 8 months).ConclusionsThis modified regimen was safe and effective in Japanese patients, and a high quality of life/quality-adjusted life-year was achieved. To further evaluate PFS and OS, more patients are being investigated.     

Inhibition of vascular adhesion protein-1 enhances the anti-tumor effects of immune checkpoint inhibitors

Modulation of the immunosuppressive tumor microenvironment (TME) is essential for enhancing the anti-tumor effects of immune checkpoint inhibitors (ICIs). Adhesion molecules and enzymes such as vascular adhesion protein-1 (VAP-1), which are expressed in some cancers and tumor vascular endothelial cells, may be involved in the generation of an immunosuppressive TME. In this study, the role of VAP-1 in TME was investigated in 2 murine colon cancer models and human cancer cells. Intraperitoneal administration of the VAP-1-specific inhibitor U-V296 inhibited murine tumor growth by enhancing IFN-γ-producing tumor antigen-specific CD8⁺ T cells. U-V296 exhibited significant synergistic anti-tumor effects with ICIs. In the TME of mice treated with U-V296, the expression of genes associated with M2-like macrophages, Th2 cells (Il4, Retnla, and Irf4), angiogenesis (Pecam1), and fibrosis (Acta2, Loxl2) were significantly decreased, and the Th1/Th2 balance was increased. H₂O₂, an enzymatic product of VAP-1, which promoted the production of IL-4 by mouse Th2 and inhibited IFN-γ by mouse Th1 and human tumor-infiltrating lymphocytes, was decreased in tumors and CD31⁺ tumor vascular endothelial cells in the TMEs of mice treated with VAP-1 inhibitor. TCGA database analysis showed that VAP-1 expression was a negative prognostic factor in human cancers, exhibiting a significant positive correlation with IL-4, IL4R, and IL-13 expression and a negative correlation with IFN-γ expression. These results indicated that VAP-1 is involved in the immunosuppressive TMEs through H₂O₂-associated Th2/M2 conditions and may be an attractive target for the development of combination cancer immunotherapy with ICIs.     

KHDRBS3 promotes multi-drug resistance and anchorage-independent growth in colorectal cancer

5-Fluorouracil (5-FU) is one of the most frequently used pharmacological agents in the treatment of colorectal cancer (CRC). Resistance to chemotherapy is a major cause of treatment failure of CRC, and it is a well known fact that cancer stem cells play a significant role in the acquisition of drug resistance. In this study, we focused on the KHDRBS3 gene that encodes KH RNA Binding Domain Containing, Signal Transduction Associated 3. We first clarified the relationship between KHDRBS3 and 5-FU resistance. We then observed higher expression levels of KHDRBS3 in KRAS-mutant organoids and cell lines in comparison with KRAS wild-type organoids and cell lines. Immunohistochemical analysis using CRC cases revealed that the prognosis of KHDRBS3-positive patients was significantly worse compared with that of KHDRBS3-negative patients. Univariate and multivariate Cox proportional hazards analyses showed that KHDRBS3 was an independent prognostic factor in patients with CRC. We determined that KHDRBS3 might play a crucial role in the acquisition of stem cell properties, such as drug resistance and spheroid/organoid formation, by regulating CD44 variant expression and the Wnt signaling pathway. In an immunodeficient mouse model, KHDRBS3-positive cells showed efficient tumor formation and formed metastatic lesions in the lungs. These results indicated that KHDRBS3 plays a crucial role in drug resistance and anchorage-independent growth by maintaining stem cell-like features in CRC cells. KHDRBS3 could be a promising candidate marker for predicting chemotherapeutic effect and prognosis in CRC patients.     

Radioimmunotherapy with an 211At-labeled anti–tissue factor antibody protected by sodium ascorbate

Tissue factor (TF), the trigger protein of the extrinsic blood coagulation cascade, is abundantly expressed in various cancers including gastric cancer. Anti-TF monoclonal antibodies (mAbs) capable of targeting cancers have been successfully applied to armed antibodies such as antibody-drug conjugates (ADCs) and molecular imaging probes. We prepared an anti-TF mAb, clone 1084, labeled with astatine-211 (²¹¹At), as a promising alpha emitter for cancer treatment. Alpha particles are characterized by high linear energy transfer and a range of 50-100 µm in tissue. Therefore, selective and efficient tumor accumulation of alpha emitters results in potent antitumor activities against cancer cells with minor effects on normal cells adjacent to the tumor. Although the ²¹¹At-conjugated clone 1084 (²¹¹At-anti-TF mAb) was disrupted by an ²¹¹At-induced radiochemical reaction, we demonstrated that astatinated anti-TF mAbs eluted in 0.6% or 1.2% sodium ascorbate (SA) solution were protected from antibody denaturation, which contributed to the maintenance of cellular binding activities and cytocidal effects of this immunoconjugate. Although body weight loss was observed in mice administered a 1.2% SA solution, the loss was transient and the radioprotectant seemed to be tolerable in vivo. In a high TF–expressing gastric cancer xenograft model, ²¹¹At-anti-TF mAb in 1.2% SA exerted a significantly greater antitumor effect than nonprotected ²¹¹At-anti-TF mAb. Moreover, the antitumor activities of the protected immunoconjugate in gastric cancer xenograft models were dependent on the level of TF in cancer cells. These findings suggest the clinical availability of the radioprotectant and applicability of clone 1084 to ²¹¹At-radioimmunotherapy.     

Plasma exchange for the patients with dilated cardiomyopathy in children is safe and effective in improving both cardiac function and daily activities

Autoantibodies against cardiac proteins play an important role in the development of dilated cardiomyopathy (DCM). The efficacy and safety of apheresis such as immunoadsorption (IA) or plasma exchange (PE) to remove such antibodies have been reported in adult DCM patients. However, apheresis for pediatric DCM has not been performed because of technical difficulty due to relatively low blood volume and instability of hemodynamics. As we have experiences of preforming apheresis on hemodynamically unstable children, we have preformed ten courses of PE on seven child DCM patients including both patients in chronic and acute phase to assess the safety and efficacy to PE. Under general anesthesia, the patients were administered PE three times during 3 days as 1 course. Simultaneously, continuous hemodiafiltration (CHDF) was performed in series with the PE circuit to stabilize hemodynamic status and to minimize the adverse effects of PE. The changes in LVEF, CTR, mBP, the dosage of furosemide and NYHA were assessed before and after the procedure of PE. There were no severe adverse effects such as systemic bleeding or refractory hypotension due to apheresis. Echocardiography showed that mean baseline LVEF was 24.3?±?7.8%. Mean LVEF significantly increased 1 week after PE to 30.5?±?12.5%. CTR significantly decreased after PE. Mean BP significantly increased 1 month after PE (54.5?±?10.7 to 60.7?±?9.8 mmHg). NYHA improved after PE significantly (NYHA; 3.4?±?1.1 to 2.5?±?1.1). PE is safe and effective in improving both cardiac function and daily activities.     

Anti-tumor effect of inhibition of IL-6 signaling in mucoepidermoid carcinoma

Mucoepidermoid carcinoma (MEC) is the most frequent malignant salivary gland cancer. Response to chemoradiotherapy is modest, and therefore radical surgery remains the standard-of-care. Emerging evidence suggests that Interleukin (IL)-6 signaling correlates with the survival of cancer stem cells and resistance to therapy. Here, we investigated whether inhibition of IL-6 receptor (IL-6R) signaling with tocilizumab (humanized anti-human IL-6R antibody) sensitizes MEC to chemotherapy using human mucoepidermoid carcinoma cell lines (UM-HMC) and correspondent xenograft models. In vitro, we observed that tocilizumab inhibited STAT3 phosphorylation but had no measurable effect in MEC cell viability (UM-HMC-1,-3A,-3B). In contrast, the anti-tumor effect of single agent tocilizumab on MEC xenografts was comparable to paclitaxel or cisplatin. Combination of tocilizumab with cisplatin or paclitaxel enhanced the inhibitory effect of chemotherapy on xenograft growth (P < 0.05), time to failure (P < 0.01), decreased vascular endothelial growth factor (VEGF) expression and tumor microvessel density (P < 0.05) without added systemic toxicities. Notably, tocilizumab decreased the fraction of MEC cancer stem cells (ALDH^highCD44^high) in vitro, and prevented paclitaxel-induced increase in the fraction of cancer stem cells in vivo (P < 0.05). Collectively, these findings demonstrate that tocilizumab enhances the anti-tumor effect of conventional chemotherapy in preclinical models of mucoepidermoid carcinoma, and suggest that patients might benefit from combination therapy with an inhibitor of IL-6R signaling and chemotherapeutic agent such as paclitaxel.     

3D reconstruction and histopathological analyses on murine corporal body

PurposeErectile dysfunction (ED) is one of the increasing diseases with aging society. The basis of ED derived from local penile abnormality is poorly understood because of the complex three‐dimensional (3D) distribution of sinusoids in corpus cavernosum (CC). Understanding the 3D histological structure of penis is thus necessary. Analyses on the status of regulatory signals for such abnormality are also performed.MethodsTo analyze the 3D structure of sinusoid, 3D reconstruction from serial sections of murine CC were performed. Histological analyses between young (2 months old) and aged (14 months old) CC were performed. As for chondrogenic signaling status of aged CC, SOX9 and RBPJK staining was examined.ResultsSinusoids prominently developed in the outer regions of CC adjacent to tunica albuginea. Aged CC samples contained ectopic chondrocytes in such regions. Associating with the appearance of chondrocytes, the expression of SOX9, chondrogenic regulator, was upregulated. The expression of RBPJK, one of the Notch signal regulators, was downregulated in the aged CC.ConclusionsProminent sinusoids distribute in the outer region of CC which may possess important roles for erection. A possibility of ectopic chondrogenesis induced by alteration of SOX9/Notch signaling with aging is indicated.     

Systematic measurement of lineal energy distributions for proton, He and Si ion beams over a wide energy range using a wall-less tissue equivalent proportional counter

The frequency distributions of the lineal energy, y, of 160 MeV proton, 150 MeV/u helium, and 490 MeV/u silicon ion beams were measured using a wall-less tissue equivalent proportional counter (TEPC) with a site size of 0.72 μm. The measured frequency distributions of y as well as the dose-mean values, y(D), agree with the corresponding data calculated using the microdosimetric function of the particle and heavy ion transport code system PHITS. The values of y(D) increase in the range of LET below ~10 keV μm(-1) because of discrete energy deposition by delta rays, while the relation is reversed above ~10 keV μm(-1) as the amount of energy escaping via delta rays increases. These results indicate that care should be taken with the difference between y(D) and LET when estimating the ionization density that usually relates to relative biological effectiveness (RBE) of energetic heavy ions.