Clinical Trial Shows Promise for Dogs with Aggressive Malignant Melanoma

Veterinary comparative oncology researchers are exploring a new immunotherapy option for patients with aggressive malignant melanoma. The University of Illinois Veterinary Teaching Hospital team includes members of the Cancer Center at Illinois (CCIL).

In a clinical trial sponsored by Ankyra Therapeutics, researchers injected pet dogs who have naturally occurring melanoma with a cytokine, a protein that activates the immune system. High levels of cytokines in the bloodstream can cause toxicity, so to avoid this problem the cytokine, called Interleukin 12, is anchored to aluminum hydroxide. Aluminum hydroxide has been used for almost 100 years as a vaccine adjuvant. Given the physical properties of aluminum hydroxide, anchored interleukin 12 is retained locally at high concentrations within the sites of tumor injection. The goal is to elicit an immune response strong enough to shrink the tumor and alert the immune system to fight cancers found in other areas of the body. The strategy is similar to the study discussed in a recent article, but the current technology using aluminum hydroxide as a cytokine anchor can be used effectively in any solid tumor regardless of the protein components within different tumor types.

“We have recruited and treated 14 dogs in this clinical trial. Many of these dogs have tolerated the therapy very well. Excitingly, there are dogs that are showing robust positive responses,” said Dr. Timothy M. Fan, a professor of veterinary oncology and CCIL Associate Director for Translational Research and Development.

The technology used in this clinical trial has now been approved to start phase one human clinical trials. The first human cancer patients are expected to be enrolled and treated at Massachusetts General Hospital and other sites before the end of 2023.

“We hope that the studies we did in dogs will be very important in recognizing what aspects we need to look for in people,” said Fan.

Researchers plan to continue their study with another cohort of canines who will receive an optimal dose of anchored cytokine in combination with checkpoint inhibitors, another type of immunotherapy. It is expected that the greatest anticancer activities will be achievable through rational combination of multiple immunotherapy strategies.

For more information about clinical trials at the Veterinary Teaching Hospital, click here.