Experimental Cancer Therapy for Canines Now Trialed in Pediatric Patients
In the pursuit of a potential breakthrough for osteosarcoma treatment, a vicious bone cancer that afflicts both dogs and children, researchers are finding hope in a groundbreaking strategy. This approach, termed comparative oncology, utilizes naturally occurring cancers in pets, particularly dogs, as models for studying and treating similar human cancers.
At the forefront of this innovative collaboration is biotech company OS Therapies, which launched a veterinary-focused subsidiary, OS Animal Health, in 2025. The company reported significant success from clinical trials of a new drug called OST-HER2 in dogs with osteosarcoma.
OST-HER2 is an immunotherapy drug that targets the human epidermal growth factor receptor 2 (HER2) protein, which is associated with aggressive tumor growth in various cancers. The tool that delivers this genetic payload is a genetically modified version of Listeria monocytogenes, typically linked to food poisoning, but with transformative implications for cancer treatment.
Inside the body, modified Listeria sneaks into immune cells, triggering a potent response against HER2-expressing tumors. In canine trials, the results were encouraging. Not only did the tumors shrink, but the cancer's spread to the lungs, a common and deadly development in osteosarcoma, was slowed significantly.
Encouraged by the positive results from the canine trial, OS Therapies fast-tracked development of OST-HER2 for pediatric use. In January 2025, the company reported positive results from a Phase 2b clinical trial in young people aged 12 to 39 who had undergone surgical removal of metastatic tumors in the lungs. The drug significantly improved 12-month event-free survival compared to historical controls.
If approved by the FDA, OST-HER2 could potentially reshape the standard of care for this difficult-to-treat population. This groundbreaking work in comparative oncology represents a significant step forward in the fight against cancer-one that may ultimately extend lives and offer a gentler, more effective treatment option for children and pets alike.
- The comparative oncology research, a strategy that utilizes pets' naturally occurring cancers, offers hope for the treatment of similar human medical-conditions like osteosarcoma.
- OS Therapies, a pioneering biotech company, has made significant strides in osteosarcoma treatment by developing a new drug called OST-HER2, which targets the HER2 protein associated with aggressive tumor growth.
- The innovation behind OST-HER2 lies in its delivery system, a genetically modified version of Listeria monocytogenes, traditionally known for causing food poisoning, but now transforming the landscape of cancer treatment.
- In canine trials, OST-HER2 showed promising results; not only did it shrink the tumors, but it also significantly slowed the spread of the cancer to the lungs, a common and deadly development in osteosarcoma.
- Inspired by the success in dogs, OS Therapies expedited the development of OST-HER2 for pediatric use and reported positive results in a Phase 2b clinical trial for young people with metastatic tumors in the lungs.
- If the FDA approves OST-HER2, it could revolutionize the standard of care for pediatric osteosarcoma patients, potentially extending lives and offering a more effective and gentler treatment option, benefiting both children and their beloved pets.
