Biomira's Theratope Cancer Vaccine

Biomira has reported the results of a Phase II study of its therapeutic cancer vaccine, Theratope, which suggest that the product may be an effective adjunctive therapy for metastatic breast cancer. The data also shows that its activity can be increased by the administration, prior to Theratope, of low-dose, intravenous cyclophosphamide.

A total of 48 women were enrolled into the study, which was conducted at Cross Cancer Institute in Edmonton, Canada, and Guy's Hospital in London, UK. 24 patients were given the vaccine along with a pretreatment of low-dose (300mg/m2) intravenous cyclophosphamide. At this dose, which is much lower than that which would be used in a chemotherapy regimen, cyclophosphamide is thought to act as a biomodulating agent, says Biomira. In addition, 12 patients were randomized to low-dose oral cyclophosphamide, and 12 patients received no cyclophosphamide pretreatment.

The women on the iv cyclophosphamide plus Theratope schedule have a projected median survival of 19.7 months, compared to 12.6 months with the other two groups (a combined result; there was no significant difference between oral and no cyclophosphamide). Projected values for median survival have been given because of the better-than-expected survival in this seriously-ill group of patients.