New Bacterial Therapy Destroys Cancer Without Immune System

A research team led by Professor Eijiro Miyako at the Japan Advanced Institute of Science and Technology, in collaboration with Daiichi Sankyo Co., Ltd. and the University of Tsukuba, has developed a novel cancer treatment that operates without relying on the immune system.

This new therapy utilizes a unique microbial partnership known as AUN, which consists of two naturally occurring bacterial species: Proteus mirabilis, referred to as A-gyo, and the photosynthetic bacterium Rhodopseudomonas palustris, termed UN-gyo.

Historically, bacterial cancer therapy traces back to 1868, when German physician Busch noted that a patient infected with bacteria experienced remission. In 1893, Dr. William Coley furthered this concept by creating bacterial-based treatments, leading to modern immunotherapies like checkpoint inhibitors and CAR-T cell therapies.

However, these therapies depend heavily on an intact immune system, which can be compromised by treatments like chemotherapy and radiotherapy, often rendering them ineffective for many patients. The AUN therapy addresses this limitation by effectively destroying cancer cells even when immune function is impaired.

AUN demonstrates remarkable compatibility with the human body, presenting minimal side effects. One significant advantage is its ability to suppress cytokine release syndrome, a potentially serious immune reaction.

The mechanism of action for AUN involves several coordinated strategies, including targeting and destroying tumor blood vessels and cancer cells, and a structural transformation in A-gyo that enhances its tumor-killing efficacy.

The bacterial ratio within the tumor environment shifts from an initial mix of about 3% A-gyo to 97% UN-gyo, ultimately achieving an approximate 99% to 1% ratio, maximizing therapeutic effectiveness. UN-gyo activates beneficially only in the presence of A-gyo, acting as a regulator that enhances precision in killing cancer cells while reducing harmful bacterial activity.

This synergy embodies the Japanese concept of AUN, symbolizing balance and harmony. Professor Miyako stated that preparations are underway to launch a startup aimed at advancing this technology, with hopes to initiate clinical trials within six years.

This promising new method could represent a significant advancement in cancer therapy, particularly for patients whose immune systems are weakened, marking a pivotal moment in the evolution of bacteria-based cancer treatments, as published in Nature Biomedical Engineering.