Could This Combination Immunotherapy Help Dogs Beat Osteosarcoma (and other aggressive cancers)?

A new clinical trial, sponsored by Ardent Animal Health, is now enrolling dogs diagnosed with osteosarcoma across multiple U.S. locations. The study is testing a combination treatment that brings together two immune-modulating drugs: an autologous cancer vaccine (made from the dog’s own tumor) and a novel immune checkpoint inhibitor drug. 

If successful, this approach could lead to a safe, effective, and widely accessible treatment for aggressive cancers in dogs, offering hope beyond the current standard of care.

Watch the video here.

Map of the Clinical Trial Sites

Episode Highlights:

[00:05:00] Overview of the immune system’s role in cancer progression

[00:06:50] How mutations and neoantigens arise from inflammation

[00:09:30] How the immune system recognizes cancer: dendritic cells & killer T-cells

[00:13:20] How tumors use immune checkpoints to evade detection

[00:18:45] CD200 checkpoint inhibitor: new mechanism being tested in trial

[00:21:00] How CD200 blocks cytokine release and suppresses the immune system

[00:23:15] How the Ardent trial’s checkpoint inhibitor (CD200-ARL) aims to reverse this

[00:31:00] Disease-free interval with standard of care for canine osteosarcoma is ~6 months

[00:34:20] General Info about the Vaccine (Ardent’s Autologous Immunotherapy) 

[00:36:10] Internal survival data: Hemangiosarcoma median survival = 181 days

[00:38:20] Vaccine is currently not commercially available — only via clinical trial

[00:40:00] CD200-ARL boosts dendritic cell activity and may downregulate PD-1

[00:41:30] Clinical success in glioma: adding CD200 doubled survival

[00:44:10] Protocol for checkpoint inhibitor and vaccine administration

[00:55:00] Trial sites: 16+ clinics across the U.S.

[00:56:30] Comparison of CD200 peptide vs PD-1/CTLA-4 antibody inhibitors

[00:59:30] Booster shots are possible if enough vaccine is prepared

[01:01:00] Potential cost advantage of peptide therapy vs monoclonal antibodies

[01:02:30] Trial may finish enrollment by Spring 2026

Key Quotes:

"Our internal data shows dogs with hemangiosarcoma treated with vaccine alone survived over 180 days without chemo." 

“The median survival time in this (previous study) group (getting CD200-ARL immune checkpoint inhibitor) was actually over a year, which is pretty unheard of in glioma in dogs.”

"The peptide checkpoint inhibitor and autologous vaccine combo may provide an affordable and chemotherapy-free treatment option."

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Check out other articles and videos

• Finding better, less toxic cancer treatments for dogs with a new genomic test?

• A New Trial is Enrolling Dogs with Hemangiosarcoma

• New Canine Cancer Screening Tests

Questions? Email us at info@ccralliance, and we'll get back to you as soon as we can!

Canine Cancer Alliance is a non-profit organization supporting research for canine cancer cures.

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Always seek guidance from your veterinarian with any questions regarding your pet’s health and medical condition.