Combination Therapy a One-Two Punch to KO Aggressive Brain Cancer

A recent research investigation revealed that the combination of radiotherapy and a virus designed to target cancer cells proved to be more successful in treating a challenging and fatal type of brain tumor compared to the individual use of either therapy.

The National Brain Tumor Society reports that glioblastoma (GB) constitutes slightly more than half, specifically 50.1%, of all primary malignant brain tumors. It is considered one of the most lethal and hard-to-treat cancers. The survival rate for GB stands at a mere 6.9%, and individuals diagnosed with this form of cancer typically have an average lifespan of only eight months.

Combining Aggressive Radiotherapy with Oncolytic Virus Therapy for Glioblastoma Treatment

Due to the aggressive nature of glioblastoma (GB), its treatment requires a similarly aggressive approach. Radiotherapy is typically the primary treatment option, particularly when the tumor is inoperable. However, it often fails to target invasive cancer cells effectively. As a result, oncolytic virus (OV) therapy has emerged as a form of immunotherapy that utilizes viruses to infect and eliminate cancer cells, while also triggering an immune response against the tumor. One example of such an oncolytic virus is the vaccinia virus (VACV), a large, double-stranded DNA virus that was originally used for smallpox vaccination but has shown promising anti-tumor properties.

Researchers from the University of Alberta in Canada conducted a recent study to assess the efficacy of combining radiotherapy and oncolytic virus (OV) therapy in the treatment of glioblastoma (GB).

“The effectiveness of individual cancer therapies is often limited due to the heterogeneous nature of tumors caused by high mutation rates. Therefore, combining multiple therapies offers the greatest potential for success,” explained Mary Hitt, the corresponding author of the study.

Enhanced Therapeutic Outcomes

The researchers conducted experiments on mice with glioblastoma (GB) tumors to investigate the effects of simultaneous treatment with high-dose radiation and a genetically modified form of vaccinia virus (VACV). They also evaluated the outcomes of using each treatment independently. The results demonstrated that mice receiving both treatments experienced significantly improved therapeutic results compared to those receiving only one treatment.

Mice treated solely with radiation exhibited a 20% tumor clearance rate, while the cure rate for mice treated solely with VACV was 15%. However, an impressive 67% of mice treated with both therapies successfully cleared their GB tumors. Furthermore, when fresh cancer cells were reintroduced to some of the cured mice, 62% of the mice receiving the combination treatment demonstrated resistance or rejection of the new cancer growth.

Quinn Storozynsky, the lead author of the study, expressed astonishment at the remarkable impact of the combination therapy surpassing the efficacy of each individual treatment.

Empowering the Immune System

According to the researchers, their findings indicate that combination therapy effectively leverages the body’s immune system to combat the immune suppression commonly observed in glioblastoma (GB).

Harnessing the immune system to locate and eliminate cancer cells is an incredible approach, as stated by Storozynsky, utilizing the evolutionarily conserved response to carry out the task.

The researchers propose further studies to explore the optimal effects of different radiation doses in combination with VACV or other oncolytic virus (OV) therapies. They also suggest testing the effectiveness of an immune checkpoint inhibitor, an immunotherapeutic agent that stimulates an anti-tumor response in the immune cells of the body.

Currently, in the United States, only one OV therapy, a modified herpes simplex virus (HSV), has been approved by the FDA for certain melanoma patients. A few other countries have approved three additional oncolytic viruses. The researchers are hopeful for the approval of more OV therapies in the future but acknowledge the time-consuming process of confirming their safety and effectiveness through clinical trials.

Hitt mentioned, “It’s a slow process of confirming the safety and effectiveness through clinical trials, but I think it’s just a matter of time.”

Read The Original Article On New Atlas.

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