Phase I dose-escalation study of endoscopic intratumoral injection of OBP-301 (Telomelysin) with radiotherapy in oesophageal cancer patients unfit for standard treatments.

PURPOSE: OBP-301 (Telomelysin) is an attenuated type-5 adenovirus that contains the human telomerase reverse transcriptase promoter to regulate viral replication. OBP-301 sensitises human cancer cells to ionising radiation by inhibiting DNA repair, and radiation enhances coxsackievirus and adenovirus receptor-mediated OBP-301 infection on the contrary. We assessed OBP-301 with radiotherapy in oesophageal cancer patients unfit for standard chemoradiation treatments. METHODS: A phase I dose-escalation study of OBP-301 with radiotherapy was conducted in 13 histologically confirmed oesophageal cancer patients deemed unfit to undergo surgery or chemotherapy. Study treatment consisted of OBP-301 administration by intratumoural needle injection using a flexible endoscope on days 1, 18 and 32. Radiotherapy was administered concurrently over 6 weeks, beginning on day 4, to a total of 60 Gy. RESULTS: Of the 13 patients, 7, 3 and 3 patients were treated with 1010, 1011 and 1012 virus particles, respectively. Study group comprised 10 males and 3 females, with a median age of 82 years (range, 53-91 years). All patients developed a transient, self-limited lymphopenia. Distribution studies revealed transient virus shedding in the plasma. Eight patients had local complete response (CR); all of them exhibited no pathologically viable malignant cells in biopsy specimens, and 3 patients had a partial response. The objective response rate was 91.7%. The clinical CR rate was 83.3% in stage I and 60.0% in stage II/III. Histopathological examination revealed massive infiltration of CD8+ cells and increased PD-L1 expression. CONCLUSION: Multiple courses of endoscopic intratumoural OBP-301 injection with radiotherapy are feasible and provide clinical benefits in patients with oesophageal cancer unfit for standard treatments.

Oncolytic Virus-Mediated Targeting of the ERK Signaling Pathway Inhibits Invasive Propensity in Human Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC) cells have an exceptional ability to invade nerves through pronounced crosstalk between nerves and cancer cells; however, the mechanism of PDAC cell invasion remains to be elucidated. Here, we demonstrate the therapeutic potential of telomerase-specific oncolytic adenoviruses, OBP-301 and tumor suppressor p53-armed OBP-702, against human PDAC cells. Highly invasive PDAC cells exhibited higher levels of phosphorylated extracellular signal-regulated kinases 1 and 2 (ERK1/2) expression independent of KRAS expression; ERK1/2 inhibitor or small interfering RNA (siRNA) treatment significantly reduced the migration and invasion of PDAC cells, suggesting that the ERK signaling pathway is associated with the invasiveness of PDAC cells. OBP-702 infection suppressed ERK signaling and inhibited PDAC cell migration and invasion more efficiently than OBP-301. OBP-702 also effectively inhibited PDAC cell invasion even when invasiveness was enhanced by administration of motility stimulators, such as nerve and neurosecretory factors. Moreover, noninvasive whole-body imaging analyses showed that OBP-702 significantly suppressed tumor growth in an orthotopic PDAC xenograft model, although both viruses were equally effective against subcutaneous tumors, suggesting that OBP-702 can influence the orthotopic tumor microenvironment. Our data suggest that oncolytic virus-mediated disruption of ERK signaling is a promising antitumor strategy for attenuating the invasiveness of PDAC cells.

Prone-position thoracoscopic resection of posterior mediastinal lymph node metastasis from rectal cancer.

Mediastinal lymph node metastasis from colorectal cancer is rare, and barely any reports have described resection of this pathology. We report herein a successful thoracoscopic resection of mediastinal lymph node metastasis in a prone position. A 65-year-old man presented with posterior mediastinal lymph node metastasis after resection of the primary rectal cancer and metachronous hepatic metastasis. Metastatic lymph nodes were resected completely using thoracoscopic surgery in the prone position, which provided advantages of minimal invasiveness, good surgical field, and reduced ergonomic burden on the surgeon. Thoracoscopic resection in the prone position was thought to have the potential to become the standard procedure of posterior mediastinal tumors.

[A case of advanced hepatocellular carcinoma with portal vein invasion successfully treated by sorafenib].

A 73-year-old man was followed up for HCV-associated chronic hepatitis and hepatocellular carcinoma (HCC), developed in segment 8 of the liver. Radiofrequency ablation (P-RFA) was used to treat the tumor in June 2004. Afterwards, the patient underwent repetitive transcatheter arterial chemoembolization (TACE) against recurrent tumors 5 times. An abdominal computed tomogram (CT) showed an infiltrative mass in the left liver with tumor thrombus invading into the umbilical portion. Transarterial infusion (TAI) therapy of cisplatin (CDDP) was performed 2 times, in January and June of 2010. The size of the main tumor was decreased according to CT, and tumor marker levels such as AFP and PIVKA-II also decreased, but tumor thrombus of the portal vein developed into the main trunk (Vp4). We started therapy with sorafenib in July, 2010. Two months later, an abdominal CT revelaed further reduction of the main tumor and a shrunken tumor thrombus of the portal vein back to the left lobe. The therapeutic effect of sorafenib against HCC with tumor thrombus of the portal vein continued for 9 months.