Successful endoscopic management of a persistent bronchobiliary fistula with Histoacryl®/Lipiodol® mixture

Introduction A bronchobiliary fistula (BBF) following liver directed therapy (resection/ablation) is a rare complication in which an abnormal communication between the biliary tract and bronchial tree is formed. This case report describes the successful management of a persistent BBF following multiple liver wedge resections and microwave ablation in a patient with a metastatic neuroendocrine tumour of the terminal ileum. Case history A 69-year-old man presented with unexplained weight loss and was subsequently diagnosed with a neuroendocrine tumour of the terminal ileum and liver metastasis. Following elective right hemicolectomy and multiple bilobar liver wedge resections combined with liver microwave ablation, he developed an early bile leak. A month later, a right subphrenic collection was identified and four months following surgery, biloptysis was noted. Numerous attempts with endoscopic retrograde biliary drainage (ERBD) failed to achieve sufficient drainage. The patient was treated successfully with endoscopic injection of a mixture of Histoacryl® glue (B Braun, Sheffield, UK) and Lipiodol® (Guerbet, Solihull, UK). There was no evidence of the BBF one year following intervention. Conclusions This novel approach for persistent BBF management using endoscopic Histoacryl® glue embolisation of the fistula tract should be considered either as an adjunct to ERBD or when biliary tract decompression by drainage and/or sphincterotomy fails, prior to proceeding with surgical interventions.

Tumour diameter is not reliable for management of non-secreting pancreatic neuroendocrine tumours

Small non-functioning pancreatic NETs (pNETs) ≤2 cm can pose a management dilemma in terms of surveillance or resection. There is evidence to suggest that a surveillance approach can be considered since there are no significant radiological changes observed in lesions during long-term follow-up. However, other studies have suggested loco-regional spread can be present in ≤2 cm pNETs. The aim of this study was to characterise the prevalence of malignant features and identify any useful predictive variables in a surgically resected cohort of pNETs. 418 patients with pNETs were identified from 5 NET centres. Of these 227 were included for main analysis of tumour characteristics. Mean age of patients was 57 years, 47% were female. The median follow-up was 48.2 months. Malignant features were identified in 38% of ≤2 cm pNETs. ROC analysis showed that the current cut-off of 20 mm had a sensitivity of 84% for malignancy. The rate of malignant features is in keeping with other surgical series and challenges the belief that small pNETs have a low malignant potential. This study does not support a 20 mm size cut-off as being a solitary safe parameter to exclude malignancy in pNETs.

The Effect of Recipient Body Mass Index and Its Extremes on Survival and Graft Vascular and Biliary Complications After Liver Transplantation: A Single Center Retrospective Study

BACKGROUND This is the largest UK-based study on the effect of recipient body mass index (BMI) and its extremes (BMI <18.5 and BMI ≥35 kg/m²) on liver transplant (LT) outcomes. Its purpose was to analyze the BMI effect on post-LT mortality, graft loss, primary non-function (PNF), and graft vascular and biliary complications. MATERIAL AND METHODS Data were retrieved from a single-center LT database of 2,115 consecutive patients receiving first LT during period February 2004 to September 2015. Survivals were compared across the BMI groups; the effects of recipient BMI on survival, PNF, and graft vascular and biliary complications were analyzed via regression. RESULTS Autoimmune disease and nonalcoholic steatohepatitis were prevalent among underweight and morbidly obese adults, respectively. Graft survival was similar across BMI classes at 30 days and in 1, 2, 5, and 10 years (p=0.75) and on obese versus non-obese (p=0.33). BMI <35 kg/m² versus BMI ≥35 kg/m² mean graft survival was similar (p=0.84). BMI <18.5 kg/m² recipients tended to have inferior mean graft and patient survivals; however, the difference was non-significant (p=0.09 and p=0.1 respectively). BMI <18.5 kg/m² recipients were at higher risk of hepatic artery thrombosis (HR, 1.73, 95% CI 1.73-3, p<0.05). Adult underweight status was an independent HAT risk factor (HR 3, 95% CI 1-8.6, p=0.046). BMI class did not affect ischemic cholangiopathy risk (p=0.84). However, the overall biliary complication risk increased by 3% for every 1 kg/m² BMI rise. CONCLUSIONS Post-LT survival is independent of recipient BMI. Underweight status is linked to higher HAT risk. Biliary complication risk increases with rising recipient BMI. After appropriate recipient selection, recipient BMI extremes are not a contraindication for LT.

Abstract 3221: Kevetrin induces p53-dependent and independent cell cycle arrest and apoptosis in ovarian cancer cell lines representing heterogeneous histologies

Ovarian cancer (OC) is a molecularly and histologically heterogeneous disease; however, standard treatment is the same for all subtypes. High-grade serous OC initially responds to chemotherapy; however, low-grade serous and clear cell OC are relatively chemoresistant. Limited treatment options are available upon recurrence. p53 mutations are found in over 90% of high-grade serous OC. Low-grade serous OC harbor wild type p53, but contain other mutations. During later stages of OC, tumors are a heterogeneous population of mutant cells; thus, development of a novel drug that addresses these molecular differences is highly desirable. Previously, we showed that Kevetrin stabilized wild type p53 and induced transcriptional targets in human lung carcinoma. We sought to validate Kevetrin as a potential treatment for OC with varied p53 status. Endometrioid carcinoma (A2780, wt p53), atypical non-serous clear cell (SKOV-3, deleted p53), and high-grade serous (OVCAR-3, mutant p53) OC cell lines were treated with Kevetrin. Kevetrin induced apoptosis in all three OC cell lines, as assayed by cleavage of PARP and caspase-3. Studies showed significant increases in p53 and p21 protein levels in A2780 cells in 24 to 48 hours; however, in OVCAR-3, Kevetrin downregulated oncogenic mutant p53. RNA levels of p53 and p21 were quantified by qRT-PCR 8 to 72 hours after treatment. No significant changes were observed in p53 mRNA, whereas an increase in p21 mRNA was observed in all three cell lines. In A2780, Kevetrin also induced levels of PUMA in a dose-dependent manner. To establish that Kevetrin mediates increased p21 expression requiring p53 in A2780 cells, p53 was depleted by siRNA. p53 depletion reduced p21 expression, as assayed by FACS, indicating p53 directs p21 expression in a dose-dependent manner after Kevetrin treatment. In an in vivo xenograft study in immunocompromised nude mice bearing established A2780 tumors, Kevetrin treatment inhibited tumor growth at well-tolerated doses. The mode of action in vivo also showed enhanced expression of p21 in tumor tissue, indicating p53 pathway activation in A2780 tumors. In contrast, in SKOV-3 cells and xenografts, a p53 independent increase in p21 expression was observed. In OVCAR-3 cells,Kevetrin altered the expression of three microRNAs (miRNA-27a, miRNA-1274b, miRNA-25), that are known to be dysregulated in OC, in a time-dependent manner. To gain further insight into the mechanism of action in cells with diverse p53 status, RNA-Seq is being performed in the three cell lines and tumor tissue from mice before and after Kevetrin exposure. In summary, Kevetrin has promise as an effective therapeutic agent for endometrioid, non-serous clear cell, and high-grade serous OC, with molecularly diverse p53 status. A Phase 1 clinical study was completed and a Phase 2 clinical study in ovarian cancer is scheduled to begin January 2017.

Citation Format: Ashok Kumar, David P. Brennan, Karima Chafai-Fadela, Sylvia A. Holden, Siya Ram, Geoffrey I. Shapiro, Krishna Menon. Kevetrin induces p53-dependent and independent cell cycle arrest and apoptosis in ovarian cancer cell lines representing heterogeneous histologies [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 3221. doi:10.1158/1538-7445.AM2017-3221

Developing a donation after cardiac death risk index for adult and pediatric liver transplantation

AIM

To identify objective predictive factors for donor after cardiac death (DCD) graft loss and using those factors, develop a donor recipient stratification risk predictive model that could be used to calculate a DCD risk index (DCD-RI) to help in prospective decision making on organ use.

METHODS

The model included objective data from a single institute DCD database (2005-2013, n = 261). Univariate survival analysis was followed by adjusted Cox-regressional hazard model. Covariates selected via univariate regression were added to the model via forward selection, significance level P = 0.3. The warm ischemic threshold was clinically set at 30 min. Points were given to each predictor in proportion to their hazard ratio. Using this model, the DCD-RI was calculated. The cohort was stratified to predict graft loss risk and respective graft survival calculated.

RESULTS

DCD graft survival predictors were primary indication for transplant (P = 0.066), retransplantation (P = 0.176), MELD > 25 (P = 0.05), cold ischemia > 10 h (P = 0.292) and donor hepatectomy time > 60 min (P = 0.028). According to the calculated DCD-RI score three risk classes could be defined of low (DCD-RI < 1), standard (DCD-RI 2-4) and high risk (DCD-RI > 5) with a 5 years graft survival of 86%, 78% and 34%, respectively.

CONCLUSION

The DCD-RI score independently predicted graft loss (P < 0.001) and the DCD-RI class predicted graft survival (P < 0.001).

Role of public standards in the safety and efficacy of biologic medicines

In this report, we emphasize the importance of public monographs with reference materials, coupled with careful process and change control and attention to GMPs, as a means of advancing access to good quality, safe, and effective medicines, with emphasis on available and incoming biologic medicines. With adequate control of articles covered by a monograph, these public standards can form the basis for a global public quality platform that covers reference products, non-interchangeable reference products, biosimilars, and interchangeable biosimilars. Working collaboratively with all stakeholders, new approaches allow these public standards to emerge nationally and globally in a timely way. Yet, there are increasing limitations in the availability of public standards for biologic medicines, which may reverse many decades of progress. Solutions are considered in this report.

Etanidazole as a modulator of combined modality therapy in the rat 9l-gliosarcoma

The use of chemotherapy has led to improved treatment outcome for some pediatric patients with medulloblastoma. We have used a pre-radiation chemotherapy regimen consisting of vincristine and CDDP. The 9L gliosarcoma implanted intracranially and subcutaneously in the same animals was used as a preclinical model system to assess the efficacy of treatment combinations including: vincristine, CDDP, cyclo-phosphamide, etanidazole and radiation. The experimental endpoints were percent increase-in-lifespan, tumor growth delay and tumor cell survival. Both the tumor growth delay and percent increase-in-lifespan improved as the number of agents included in the chemotherapy regimen increased. so that the chemotherapy regimen including all four agents (ETA/VIN/CDDP/CTX) resulted in the greatest tumor growth delay (23.6 +/- 1.5 days) and the greatest increase-in-lifespan (35.8%). When radiation (20 Gray, single dose) was added to the treatment regimens the combinations of ETA/CTX/X-ray and ETA/VIN/CDDP/CTX/X-ray resulted in equivalent tumor growth delays (25.2 +/- 1.3 days and 25.8 +/- 1.7 days, respectively), while the greatest increase-in-lifespan (39.1%) was obtained with the five agent combination. The response of the 9L gliosarcoma to CDDP and cyclophosphamide over a dosage range was very similar to that of the murine FSaII fibrosarcoma. Our results indicate that etanidazole may be an effective chemosensitizer of combination chemotherapy and combined modality treatment regimens for brain tumors.

Decreased tumor oxygenation after cyclophosphamide, reoxygenation and therapeutic enhancement with a perflubron emulsion carbogen breathing

Oxygen profiles of the rat mammary 13672 carcinoma were determined using a pO2 histograph prior to treatment and 24 h and 48 h after i.p. administration of a single dose of cyclophosphamide (300 mg/kg). The tumors were severely hypoxic at 24 h post the administration of cyclophosphamide. There was little increase in oxygenation of the tumors at 48 h post therapy compared with 24 h post therapy indicating that reoxygenation after cyclophosphamide was occurring very slowly in this tumor. Carbogen breathing improved the oxygenation of the tumors under each of the conditions studied. Administration of the perflubron emulsion (8 ml/kg) produced little or no change in the oxygenation of the tumors under normal air breathing conditions. However, the addition of carbogen breathing to administration of the perflubron emulsion increased the oxygenation of the tumors to levels equal to or greater than carbogen breathing at the mean/median pO2's. Perhaps most significantly, administration of the perflubron emulsion with carbogen breathing increased the oxygenation of the most hypoxic regions of the tumors but carbogen breathing alone did not. The growth delay of the Lewis lung carcinoma increased with increasing dose.of the perflubron emulsion along with cyclophosphamide (3 x 150 mg/kg) and carbogen breathing (6 h). This combination treatment was most effective when the cyclophosphamide was prepared in the perflubron emulsion. The number of lung metastases decreased in a manner parallel with increased efficacy of the treatment toward the primary tumor.

Abstract 4470: Kevetrin™, a novel small molecule, activates p53, enhances expression of p21, induces cell cycle arrest and apoptosis in a human cancer cell line

We have previously shown that Kevetrin, a small molecule currently under development, has potent antitumor activity in human multi-drug resistant carcinoma xenograft models while being well tolerated. To investigate the mechanism of action for its potent antitumor activity, we assessed Kevetrin's effect on apoptosis, cell cycle progression, including underlying molecular mechanisms.

Here we report that Kevetrin strongly induced cell cycle arrest and apoptosis in a human lung adenocarcinoma cell line (A549) using the TUNEL assay and FACS analysis; similar results were observed using a human breast carcinoma cell line (MDA-MB-231). Treatment of A549 cells with 400 µM of Kevetrin for 48 hours resulted in G2/M phase cell cycle arrest that was associated with a marked decline in levels of G2/M regulatory proteins, including CDK1 and cdc25B, and increased expression of Wee1. Further, Kevetrin-mediated growth inhibition of A549 correlated with apoptosis induction that was characterized by cleavage of procaspase-3 and poly (ADP-ribose) polymerase (PARP).

The p53 tumor suppressor is a well characterized transcription factor controlling cell growth and apoptosis during times of cellular stress. The tumor suppressor p53 inhibits tumor growth primarily through its ability to induce apoptosis. In cancer development, the resistance of cells to apoptosis is one of the crucial steps. The reactivation of p53 in tumor cells should trigger massive apoptosis and eliminate the tumor. Interestingly, Kevetrin treatment caused enhanced activated p53 levels in A549 cells. Activation of p53 can lead to cell cycle arrest and apoptosis. Western blotting revealed a concentration dependent increase in phosphorylation of p53 at serine 15. The phosphorylation of p53 at serine 15 leads to reduced interaction between p53 and its negative regulator, the oncoprotein MDM2. We also found that Kevetrin increased expression of p53 target genes such as p21 (Waf1). The tumor suppressor protein p21 (Waf1) acts as inhibitor of cell cycle progression. Finally, we also found that p53 induced apoptosis by inducing the expression of PUMA.

Our study shows that Kevetrin activates p53 functions in tumor cells. Thus Kevetrin is a strong candidate as an anticancer drug that targets p53. Based on our studies we plan to initiate a Phase I clinical trial in 2011.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4470. doi:10.1158/1538-7445.AM2011-4470

Abstract LB-283: Novel small molecule has potent antitumor activity in drug-resistant human carcinoma xenograft models

We have previously shown that Kevetrin, a novel molecule currently under development, was effective in reducing tumor growth in human multi-drug resistant lung cancer xenograft models while being well tolerated. In this study, we expanded our tests to include other tumor types: colon and breast. Three of the models have been shown to be multi-drug resistant: HCT-15 colon carcinoma have an overexpression of p-glycoprotein that acts as a membrane efflux pump (Iwahashi 1991, Mickley 1989), MDA-MB-435s carcinoma cells have highly active c-Abl and Arg kinases and overexpress Heat Shock Protein 27 which inhibits apoptosis thereby contributing to drug resistance (2006 Srinivasan, 2008 Shi), and A549 lung carcinoma have the K-ras mutation and overexpress STAT3 and Nrf2; mutations associated with resistance to standard chemotherapy (Akudela 2004, Mahaffey 2009, Homma 2009, Kim 2009). To demonstrate a dose response effect, in the multi-drug resistant A549 lung tumor model, nude mice bearing established tumors were treated with either 50, 100, or 200 mg/kg Kevetrin intraperitoneally (IP) every other day for 3 doses or 200 mg/kg every other day for 3 doses followed by a second cycle 10 days later. Kevetrin delayed median tumor growth in a dose dependent manner where 50, 100, and 200 mg/kg produced tumor growth delays (TGDs) of 0%, 6%, and 21%, respectively, relative to controls. When given in 2 cycles at 200 mg/kg, a significantly greater TGD of 35% was achieved. In the HCT-15 multi-drug resistant colon tumor model, nude mice bearing established tumors were treated with either 200 mg/kg Kevetrin IP every other day for 3 doses or 22 mg/kg paclitaxel intravenously (IV) daily for 4 doses. Paclitaxel had no anti-tumor activity, whereas Kevetrin produced a significant TGD of 16 days (43%) relative to controls. In a non drug-resistant colon tumor model, HT-29, Kevetrin produced a similar TGD of 18 days (49%) while 20 mg/kg 5-fluorouracil (5-FU) IP given daily for 5 doses produced a TGD of 9 days (24%).

In the MDA-MB-435s drug resistant tumor model, nude mice bearing established tumors were treated as above. Paclitaxel had no significant anti-tumor activity (1% TGD), whereas Kevetrin produced a significant TGD of 20 days (65%). In a non drug-resistant breast tumor model, MDA-MB-231, Kevetrin produced a TGD of 26 days (90%), and paclitaxel produced a significant TGD of 18 days (62%).

These results demonstrate that Kevetrin exerted potent anti-tumor activity against three different tumor types, e.g., lung, breast, colon, including those that have multi-drug resistant phenotypes at doses and schedules that were well-tolerated as suggested by &lt;5% weight loss during treatments. Therefore, these studies suggest that Kevetrin has promising potential for the treatment of tumors that have become resistant to standard chemotherapy. Based on our studies we plan to initiate a Phase I clinical trial in solid tumors in 2010.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-283.