Intraperitoneal administration of radiolabelled monoclonal antibody pemtumomab (Yttrium-90-HMFG1) in gastric cancer

Abstract

Aim

To evaluate the feasibility of treatment method (intraperitoneal administration of radiolabelled monoclonal antibody) for patients with gastric cancer.

Method

A total of 15 eligible patients, with histologically proven adenocarcinoma of the stomach or gastro-oesophageal junction, who had undergone resection to remove the primary tumour mass, were enrolled in the study. Eight patients were treated with the study drug and 7 of patients were enrolled into the standard care control arm.

Materials and Results

Mean blood radioactivity peaked between 36 and 48 hours, with a mean peak value of approximately 15% ID. Data previously reported on intraperitoneal Y-HMFG1 treatment of patients with ovarian cancer show peak values of 25 – 35% ID seen at 48 hour post-injection. The present results require confirmation in a large population of gastric cancer patients, but suggest that the transfer of radioactivity into the blood pool is decreased compared with the ovarian cancer patients.

Conclusions

A HAMA response was detected in all patients after treatment, and there is some suggestion that is follows a bi-phasic pattern. If as hypothesised, a HAMA response provides a boost to the immune system, leading to a potential longer term benefit, then the HAMA response seen in this study following pemtumomab treatment is encouraging.