Cancer has always been one of the most feared diagnoses in veterinary and human medicine. Per the AVMA, over half of dogs over the age of ten will develop cancer. Occasionally, pet owners decide against pursuing chemotherapy for their pet due to fear of a decreased quality of life—in humans, chemotherapy has a much greater risk of debilitating side effects, and thus comes with a stigma. 

A recent study published in the Journal of the American Chemical Society has offered a promising alternative to traditional chemotherapy via what has been dubbed the “Trojan Horse” chemotherapy drug delivery system.

The newly developed system— which still has leaps and bounds to go before being offi cially approved for use—is nicknamed so due to the drug delivery system’s amazing ability to disguise chemotherapeutic drugs as fat. A team of researchers at Northwestern University developed a fatty acid with two binding sites, each capable of attaching to chemotherapeutic drugs. The fatty acid was then hidden within human serum albumin, and “tricked” the tumor into allowing the drug inside. Once metabolized by the cancer cells, the drug activated and killed them.

Although still in its early stages, this chemotherapy drug delivery system shows incredible promise in both human and veterinary medicine. The study team at Northwestern University elected to use small animal models: Mice. In these mice models, the system was able to deliver 20 times the typical dose whilst being 17 times safer than previous chemotherapy delivery methods. The drug was able to destroy tumors in bone, pancreatic, and colon cancer.

The study utilized the drug paclitaxel, a drug not typically used in companion animals. Despite this, the methodology of the “Trojan Horse” should allow for this chemotherapy drug to be replaced with another, companion animal friendly, drug.

Although the time frame for when this method will pursue clinical trials is uncertain, it has helped to shine a ray of hope through the storm cloud of cancer treatment. Chemotherapy can be used as a sole treatment for cancer or in combination with radiation therapy and surgery, and does not have the same side effects in animals as it does in humans; animals typically experience lesser side effects due to different doses and combinations. Despite this difference, it would still prove as benefi cial should a safer and more targeted form of chemotherapy administration be implemented, as this could potentially allow for shorter treatment plans and fewer stressful veterinary visits.

References

Northwestern University. “‘Trojan horse’ anticancer drug disguises itself as fat: Promising system delivers chemo drug straight into tumors with fewer side effects.” ScienceDaily. ScienceDaily, 18 July 2019.

WVRC Emergency & Specialty Pet Care. “Chemotherapy for Dogs & Cats.” WVRC. WVRC, n.d.