Phase I Study of Intraperitoneal Administration of Paclitaxel Combined with S-1 Plus Cisplatin for Gastric Cancer with Peritoneal Metastasis

Preclinical toxicological assessment of amido-bridged nucleic acid-modified antisense oligonucleotides targeting synaptotagmin XIII for intra-abdominal treatment of peritoneal metastasis of gastric cancer

BACKGROUND

Peritoneal metastasis of gastric cancer is closely associated with dismal prognosis. In previous preclinical proof-of-concept studies, an amido-bridged nucleic acid (AmNA)-modified antisense oligonucleotide (ASO), designated ASO-4733 that targets the gene encoding synaptotagmin XIII (SYT13), inhibited cellular functions required for the formation of peritoneal metastasis of gastric cancer cells. ASO-4733 achieved therapeutic effects when intra-abdominally administered to mouse xenograft models. Here, we conducted an analysis of Syt13-deficient mice to determine the pharmacokinetics and toxicity of intra-abdominal administration of ASO-4733.

METHODS

The effects of Syt13-deficiency in mice were determined. Good Laboratory Practice toxicity tests and the toxicokinetics of intra-abdominal administration of ASO-4733 were conducted in cynomolgus monkeys and rats. The pharmacokinetics of ASO-4733 administered intravenously or intra-abdominally to rats were investigated.

RESULTS

Syt13-deficient mice exhibited normal reproduction, organ functions, and motor functions. Weekly intra-abdominal administration of ASO-4733 (125 mg/kg), corresponding to a 50-fold increase of the estimated clinical dose for 4 weeks, was well tolerated by cynomolgus monkeys. In rats, off-target toxicity (not attributable to hybridization) was observed after weekly intra-abdominal administration of ASO-4733. Blood concentrations of ASO-4733 were lower and rose more slowly after intra-abdominal administration compared with intravenous administration.

CONCLUSIONS

The preclinical profile of intra-abdominal administration of ASO-4733 demonstrated its suitability for entry into clinical trials of patients with peritoneal metastasis of gastric cancer.

Phase II Study of Intraperitoneal Administration of Paclitaxel Combined with S-1 and Cisplatin for Gastric Cancer with Peritoneal Metastasis

BACKGROUND

Intraperitoneal chemotherapy is promising for gastric cancer with peritoneal metastasis. Although a phase III study failed to show a statistically significant superiority of intraperitoneal paclitaxel combined with S-1 and intravenous paclitaxel, the sensitivity analysis suggested clinical efficacy. Thus, attempts to combine intraperitoneal paclitaxel with other systemic therapies with higher efficacy have been warranted. We sought to explore the efficacy of intraperitoneal paclitaxel with S-1 and cisplatin.

PATIENTS AND METHODS

Gastric cancer patients with peritoneal metastasis were enrolled in the phase II trial. In addition to the established S-1 and cisplatin regimen every 5 weeks, intraperitoneal paclitaxel was administered on days 1, 8, and 22 at a dose of 20 mg/m2. The primary endpoint was overall survival rate at 1 year after treatment initiation. Secondary endpoints were progression-free survival and toxicity.

RESULTS

Fifty-three patients were enrolled and fully evaluated for efficacy and toxicity. The 1-year overall survival rate was 73.6% (95% confidence interval 59.5-83.4%), and the primary endpoint was met. The median survival time was 19.4 months (95% confidence interval, 16.1-24.6 months). The 1-year progression-free survival rate was 49.6% (95% confidence interval, 34.6-62.9%). The incidences of grade 3/4 hematological and non-hematological toxicities were 43% and 47%, respectively. The frequent grade 3/4 toxicities included neutropenia (25%), anemia (30%), diarrhea (13%), and anorexia (17%). Intraperitoneal catheter and implanted port-related complications were observed in four patients. There was one treatment-related death.

CONCLUSIONS

Intraperitoneal paclitaxel combined with S-1 and cisplatin is well tolerated and active in gastric cancer patients with peritoneal metastasis.

Feasibility and Safety of Laparoscopic D2 Gastrectomy in Combination with Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC) in Patients with Gastric Cancer at High Risk of Recurrence-The PIPAC-OPC4 Study

BACKGROUND

Patients with gastric adenocarcinoma (GAC) are at high risk of peritoneal recurrence despite perioperative chemotherapy and radical resection. This study evaluated feasibility and safety of laparoscopic D2 gastrectomy in combination with pressurized intraperitoneal aerosol chemotherapy (PIPAC).

METHODS

This was a prospective, controlled bi-institutional study in patients with GAC at high risk of recurrence treated with PIPAC with cisplatin and doxorubicin (PIPAC C/D) after laparoscopic D2 gastrectomy. High risk was defined as a poorly cohesive subtype with predominance of signet-ring cells, clinical stage ≥ T3 and/or ≥ N2, or positive peritoneal cytology. Peritoneal lavage fluid was collected before and after resection. Cisplatin (10.5 mg/m²) and doxorubicin (2.1 mg/m²) were aerosolized after anastomosis (flow 0.5-0.8 ml/s, maximum pressure 300 PSI). Treatment was feasible and safe if ≤ 20% had Dindo-Clavien ≥ 3b surgical complications or CTCAE ≥ 4 medical adverse events within 30 days. Secondary outcomes were length of stay (LOS), peritoneal lavage cytology, and completion of postoperative systemic chemotherapy.

RESULTS

Twenty-one patients were treated with a D2 gastrectomy and PIPAC C/D. The median age was 61 years (range 24-76), there were eleven female patients, and 20 patients had preoperative chemotherapy. There was no mortality. Two patients had grade 3b complications that were potentially related to PIPAC C/D (one anastomotic leakage, and one late duodenal blow-out). One patient had severe neutropenia, and nine patients had moderate pain. The LOS was 6 days (4-26). One patient had positive peritoneal lavage cytology before resection, and none were positive after. Fifteen patients had postoperative chemotherapy.

CONCLUSIONS

Laparoscopic D2 gastrectomy in combination with PIPAC C/D is feasible and safe.

Intraperitoneal Chemotherapy for Unresectable Peritoneal Surface Malignancies

Malignancies of the peritoneal cavity are associated with a dismal prognosis. Systemic chemotherapy is the gold standard for patients with unresectable peritoneal disease, but its intraperitoneal effect is hampered by the peritoneal-plasma barrier. Intraperitoneal chemotherapy, which is administered repeatedly into the peritoneal cavity through a peritoneal implanted port, could provide a novel treatment modality for this patient population. This review provides a systematic overview of intraperitoneal used drugs, the performed clinical studies so far, and the complications of the peritoneal implemental ports. Several anticancer drugs have been studied for intraperitoneal application, with the taxanes paclitaxel and docetaxel as the most commonly used drug. Repeated intraperitoneal chemotherapy, mostly in combination with systemic chemotherapy, has shown promising results in Phase I and Phase II studies for several tumor types, such as gastric cancer, ovarian cancer, colorectal cancer, and pancreatic cancer. Two Phase III studies for intraperitoneal chemotherapy in gastric cancer have been performed so far, but the results regarding the superiority over standard systemic chemotherapy alone, are contradictory. Pressurized intraperitoneal administration, known as PIPAC, is an alternative way of administering intraperitoneal chemotherapy, and the first prospective studies have shown a tolerable safety profile. Although intraperitoneal chemotherapy might be a standard treatment option for patients with unresectable peritoneal disease, more Phase II and Phase III studies focusing on tolerability profiles, survival rates, and quality of life are warranted in order to establish optimal treatment schedules and to establish a potential role for intraperitoneal chemotherapy in the approach to unresectable peritoneal disease.

Intraperitoneal therapy for gastric cancer peritoneal carcinomatosis

INTRODUCTION

Gastric adenocarcinoma (GAC) is one of the most aggressive malignancies worldwide and has a poor prognosis. Multidisciplinary therapies are used in its treatment, but the prognosis for GAC patients with peritoneal metastases (PM) remains poor and there is no effective established approach.

AREAS COVERED

This review summarizes the results of recent clinical studies and recent advances in the management, including surgery, chemotherapy, targeted therapy, and immunotherapy. In this review, keywords were searched in combination with 'peritoneal carcinomatosis' and 'gastric cancer' in PubMed, and then studies that evaluated peritoneal carcinomatosis associated with gastric cancer were identified through reading them. Several studies were quoted at second hand. Despite recent advances in therapeutic approaches such as systemic chemotherapy, immunotherapy, intraperitoneal chemotherapy, debulking surgery, thermal hyperthermic intraperitoneal chemotherapy, pressurized intraperitoneal aerosol chemotherapy, immunotherapy, and best supportive therapy, further studies are necessary. This review also summarizes molecular biology of GAC patients with PM.

EXPERT OPINION

Each modality is advancing and some have shown therapeutic effects, but none have become standard treatments that exhibit remarkable effects. To improve the prognosis of GAC patients with PM, large-scale clinical trials and further basic research are required.

Amido-Bridged Nucleic Acid-Modified Antisense Oligonucleotides Targeting SYT13 to Treat Peritoneal Metastasis of Gastric Cancer

Patients with peritoneal metastasis of gastric cancer have dismal prognosis, mainly because of inefficient systemic delivery of drugs to peritoneal tumors. We aimed to develop an intraperitoneal treatment strategy using amido-bridged nucleic acid (AmNA)-modified antisense oligonucleotides (ASOs) targeting synaptotagmin XIII (SYT13) and to identify the function of SYT13 in gastric cancer cells. We screened 71 candidate oligonucleotide sequences according to SYT13-knockdown efficacy, in vitro activity, and off-target effects. We evaluated the effects of SYT13 knockdown on cellular functions and signaling pathways, as well as the effects of intraperitoneal administration to mice of AmNA-modified anti-SYT13 ASOs. We selected the ASOs (designated hSYT13-4378 and hSYT13-4733) with the highest knockdown efficiencies and lowest off-target effects and determined their abilities to inhibit cellular functions associated with the metastatic potential of gastric cancer cells. We found that SYT13 interfered with focal adhesion kinase (FAK)-mediated intracellular signals. Intraperitoneal administration of hSYT13-4378 and hSYT13-4733 in a mouse xenograft model of metastasis inhibited the formation of peritoneal nodules and significantly increased survival. Reversible, dose- and sequence-dependent liver damage was induced by ASO treatment without causing abnormal morphological and histological changes in the brain. Intra-abdominal administration of AmNA-modified anti-SYT13 ASOs represents a promising strategy for treating peritoneal metastasis of gastric cancer.