Galena Biopharma has reported clinical biomarker data from its Phase I/II trial of NeuVax (nelipepimut-S or E75) that demonstrates a consistent reduction of circulating tumor cells (CTCs) in breast cancer vaccinated patients.
According to the data, the vaccine-treated patients were expected to show a decrease in CTCs when compared to control patients, and NeuVax boosters are expected to provide long-term benefit from the return of CTC.
Galena president and CEO Dr Mark Ahn said approximately a quarter of resectable node-positive breast cancer patients will relapse within three years, despite having no evidence of disease following surgery and radiation treatment.
"The data presented today shows that treatment with NeuVax reduces CTCs and therefore may prevent growth of future micrometastasis, lending support to the idea of using the woman's immune system to prevent relapse of her breast cancer," Ahn said.
A minimum of two CTC measurements from blood samples of 26 NeuVax patients were made during the vaccine treatment, using the CellSearch system (Veridex).
The decreased CTCs during the treatment period, subsequent increase in patients' E75-specific CD8+ cytotoxic T-lymphocytes and a raise in their delayed type hypersensitivity (DTH) reactions were observed in 16/26 NeuVax treated patients.
No cancer recurrence case was observed in any of the patients during the follow-up period, which lasted for five years.
CTCs are cells that have isolated from the primary breast tumour, circulate in the bloodstream and might lead to metastases in different tissues.
Increased presence of CTCs is linked to high chances of a cancer recurrence leading to poor disease-free survival and overall survival, signifying a dormancy of isolated micrometastases.