Fighting Brain Tumors

by Morgan Solomon

 Image: UGA College of Veterinary Medicine

Image: UGA College of Veterinary Medicine

For the past few years the University of Georgia College of Veterinary Medicine has been working hard to establish a cure that will fight brain tumors in canines and that has significant potential to eventually help humans. Dr. Simon Platt is leading this research where they have created the concept of “magic bullet” implants.

When fighting brain cancers, it is a difficult approach because most cancers cannot be removed surgically, and chemotherapy drugs are not able to reach the tumor due to the blood brain barrier (BBB). According to their research, the BBB blocks 100 percent of large molecules and 98 percent of small molecules from entering the brain—this is true for both canines and humans.

In order to work around the BBB, Dr. Platt and his team have created these implants. The implants are polymeric microcylinders made up off PLGA, a plastic used in absorbable sutures that is biocompatible and non-toxic to the brain. These microcylinders have been created in a way that makes it possible for them to be implanted through stereotactic implantation, which means the procedure is minimally-invasive. The polymer of the microcylinders can be adjusted so whatever drug it contains is delivered over a specific period of time prescribed by the researchers.

The significance of these microcylinders is the fact that they can be placed directly into the cancerous tissue within the brain. This action allows doctors to sidestep the BBB completely, and a high dosage of chemotherapy is delivered into the cancer. Another positive of this approach is that there is not any risk of the side effects associated with high doses of chemotherapy delivered orally or intravenously, such as myelosuppression or gastrointestinal upset.

Glioma is a type of tumor that occurs in the brain and spinal cord; this type of cancer is common in both dogs and humans. Temozolamide (TMZ) is an Federal Drug Administration approved chemotherapy drug used to treated gliomas in humans, and it has also been proven to be safe in dogs with lymphatic cancer. However, there is not a significant amount of research to prove that TMZ is effective in fighting brain tumors in dogs. Dr. Platt and his team plan to study the effectiveness of implanting PLGA microcylinders infused with TMZ and gadolinium in dogs with gliomas. The team’s preliminary studies have proven that these microcylinders containing TMZ and gadolinium are well-tolerated in healthy dogs.

They are now in a pilot clinical trial where they have successfully treated six dogs with this approach. Once this trial is completed, they hope to launch a nationwide clinical trial that will test this therapy in many different institutions.

When asked about the significance of this project, Dr. Platt, the owner of a 7-year-old German Wirehaired Pointer, responded with three things he finds most important regarding this research. First, the project offers a potential treatment for dogs whose owners may not have the resources to pursue any treatment. Second, in the future this could be a part of standard brain tumor treatment in dogs, which means this represents something that could have a major impact on the quality of life for many affected dogs. Finally, the potential that the success of this work could impact the treatment of humans with similar brain tumors is immense, and it is incredible to think that it is a distinct possibility. According to Dr. Platt this research could become part of regular treatment protocol for dogs within five years if successful. The commencement of human clinical trials will most likely follow a similar time line.

In order to help with the progress of this research, there is a Georgia Funder page with a goal of raising $50,000. This funding will support the study by taking care of the financial cost of this treatment for five dogs including MRIs, surgery, bloodwork, hospital stays and more. If you want to contribute, you can find the page by visiting www.dar.uga.edu and searching “canine brain tumors” so you can help Dr. Platt and his team get closer to curing brain cancer in dogs, and maybe one day in humans.