|Budget Amount *help
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1995: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1994: ¥1,000,000 (Direct Cost: ¥1,000,000)
The following observations were obtained through a clinical and experimental investigation of Plachitin, produced by combining an cisplatin and biological material chitin, which possesses a property of slowly releasing cisplatin.
First, VX2 tumor was inoculated in the hind limb of rabbits. Plachitin particles (50 micron in diameter, 300mg cisplatin per 1gm of Plachitin) were injected via the femoral artery. A significant growth-inhibition effect was observed in the Plachitin-treated group, compared with the groups treated by cisplatin only, chitin only, and the group not treated at all. The involution of the tumor was observed only in the Plachitin-treated group. It was speculated that the effect of Plachitin was brought about by both embolizing effect and slow release of cisplatin.
Based on the above observations, anticancer effect of Plachitin was investigated in the patients. Plachitin 1gm (cisplatin 300mg) was administered through the hepatic artery in patients with liver tumors. In patient 1 with multiple primary hepatocellular carcinoma, tumor regression of 39% and decrease of alpha-fetoprotein from 1,182ng/ml to 300ng/ml were observed after 2 courses. In patient 2 with cholangiocarcinoma, tumor regression of 84.4% was observed after 3 courses, and in patient 3 with metastatic colon cancer, tumor regression of 77% was observed after 1 course of therapy. The response rate was 66.7% overall. Epigastric pain, nausea, fever, and elevation of liver enzymes were recorded but all were transient.
In order to establish the safety of intraperitoneal administration of Plachitin, 11 patients with peritoneal dissemination of gastrointestinal malignancy were treated. In patients treated by Plachitin, serum level of cisplatin was low throughout the period and no adverse effects were seen.
In conclusion, the antitumor effect and safety of Plachitin were established. Proceeding into the phase 3 study of this material appears feasible.