A patient is injected with a cancer-killing virus treatment for the first time

How does the treatment work? 

The technology aims to use the body's immune system to counter tumors. However, the presence of the tumor is an obvious sign that the immune system has failed to recognize the threat. So, researchers aim to use a virus that will produce fragments that can flag cancerous cells to the immune system.

To do this, the researchers modify a virus, in this case, a poxvirus, and then use it to infect the patient. Once inside the host cell, the modified virus replicates and then blasts open the host cell to release thousands of new viral particles that then go and attach themselves to the cancerous cells. These attachments serve as a flag for the host's immune system to attack the cancerous cells. 

The treatment being used in this trial has been developed by the Australian company, Imugene and is called CF-33-hNIS or Vaxinia. The drug has shown to be effective in shrinking colon, lung, breast, ovarian, and pancreatic tumors in laboratory tests and in animal models, the press release claims. 

The hNIS in the drug stands for human Sodium Iodide transporter, a protein that the researchers will use to image and monitor viral replication as well as damage to the cancerous cells by using radioactive iodine Science Alert reported. 

What will the trial entail? 

The Phase 1 trial is aimed at determining that the drug is safe and will be administered to 100 volunteers across ten sites in the U.S. and Australia. The volunteers will be cancer patients with metastatic or advanced solid tumors who have had at least two prior lines of cancer treatments. The experimental drug, Vaxinia, will either be injected intravenously or directly into the tumors, the press release said. 

While all volunteers will receive the drug, once the safety of the drug has been demonstrated, certain individuals will also receive the pembrolizumab, an immunotherapy that has also been documented to improve the immune system's capability to fight tumors. 

"Interestingly, the same characteristics that eventually make cancer cells resistant to chemotherapy or radiation treatment actually enhance the success of oncolytic viruses," said Yuman Fong, a key developer of the genetically modified virus. "We are hoping to harness the promise of virology and immunotherapy for the treatment of a wide variety of deadly cancers."

The trial is being undertaken under the U.S. Food and Drug Administration (USFDA)'s investigational new drug (IND) process and was authorized in December 2021. Patient recruitment is still ongoing and is expected to take two years to complete.