Engineered phages eradicated tumors in 44 percent of vaccinated mice but not in the rest

Researchers genetically engineered a phage that normally infects E. coli to bind to proteins on tumor cells and deliver instructions for a malaria-specific antigen. The approach redirected immunity from a prior malaria vaccine to attack the tumors.

Amin Hajitou at Imperial College London and colleagues tested the method in 60 mice with tumors just beneath the skin. Fifteen mice received the malaria vaccine followed by six tail-vein injections of the engineered phages over two weeks. The remaining mice served as controls, with groups receiving no intervention, the vaccine alone, or the phages alone.

In 44 percent of the treated mice, the tumors were eradicated and had not returned one year later. Other treated mice lived longer than the control groups, which showed no survival benefit. “The phage acts like a targeted delivery vehicle,” Hajitou said.

David Withers at the University of Oxford noted that the systemic administration improves on current oncolytic virus approaches that require direct injection into tumors. The study appears in the journal Biomaterials. The team is in talks with the MHRA about an early-stage human trial planned to begin next year.

Adjusting the antigen instructions could allow the method to work with vaccines against flu or covid-19, Hajitou said.