Cancerous tumors in rats, dogs and humans were shown to shrink after being injected with an altered form of bacteria. The results were seen in a recent study out of Johns Hopkins Medicine, which used a modified version of the Clostridium novyi (C. novyi-NT) bacterium.
The anti-tumor response was “strong and precisely targeted,” according to researchers.
The study used three different models – rats, pet dogs and one human. The bacteria used, which is found naturally in soil, thrives in environments where oxygen is poor. Researchers say this made it particularly attractive in fighting the oxygen deficient cells found in tumors that don’t respond well to radiation and chemotherapy.
For the first part of the study, rats were implanted with aggressive brain tumors known as gliomas. When treated with the bacterium, the tumors shrank. The treatment was also found to extend the rats’ lifespans.
Researchers tried the approach once more – this time in 16 pet dogs suffering from naturally occurring tumors. The subjects were treated with the direct-tumor injection. Six of the dogs experienced an anti-tumor response within three weeks. What’s more is that three of these six showed a complete eradication of their tumors, while the other three showed significant tumor shrinkage.
“We treated a human patient with a similar approach,” said Dr. Verena Staedtke, a neuro-oncology fellow at Johns Hopkins. “Similar to the studies we’d done before, the tumor shrank, allowing the patient to gain some functionality in her arm.”
The human patient had been suffering from a metastatic tumor in her arm. After treatment, the tumor significantly reduced. However, she did experience a strong inflammatory response and abscess formation.
Researchers say the results are still very tentative. The next step is to expand the clinical trial.
“It’s not something we would consider for all patients, but it might be an especially good treatment for patients that have locally advanced disease,” said Staedtke.
By Marianne Hayes