TAT-10: Locoregional alpha-radioimmunotherapy against peritoneal metastasis of gastric cancer

Kanazawa, Japan (UroToday.com) Patients with peritoneal metastasis of gastric cancer (PMGC) have an extremely poor prognosis as no effective therapeutics have been established. Gastric cancer overexpresses HER2 about 20% of the time. Trastuzumab is a humanized anti-HER2 monoclonal antibody so we investigate At211-trastuzumab in mice models using N87 xenografts for treatment of PMGC.

Biodistribution results showed that intraperineal administration was more effective than intravenous injection. The maximum tumor uptake with intraperitoneal administration was over 60 percent injected dose per gram (%ID/g) compared to about 18%ID/g with intravenous injection. A single dose of At211- trastuzumab (1 MBq) was sufficient to completely eradicate GC xenografts in two of six treated mice by inducing DNA double strand breaks,  and reduce the tumor burden of three other mice.

No significant side effects such as weight loss, leucocytopenia, or damage to liver or kidney function were observed. 

These results offer promise for At21-trastuzumab as a treatment option for HER2+ PMGC.

Presented By: Huizi Keiko Li from Graduate School of Medical and Pharmaceutical Sciences, Chiba University, Japan and Radiation and Cancer Biology Team, NIRS, QST, Japan

Written By: William Carithers, Lawrence Berkeley National Laboratory

at the 10th International Symposium on Targeted Alpha Therapy (TAT-10)  May 31 - June 1, 2017 - Kanazawa, Japan.