Peruzzi D, Gavazza A, Mesiti G, Lubas G, Scarselli E, Conforti A, Bendtsen C, Ciliberto G, La Monica N, Aurisicchio L. A vaccine targeting telomerase enhances survival of dogs affected by B-cell lymphoma. Mol Ther. 2010 Aug;18(8):1559-67. doi: 10.1038/mt.2010.104. Epub 2010 Jun 8. PMID: 20531395; PMCID: PMC2927056.

Canine cancers occur at rates comparable to those seen in humans and exhibit striking similarities to human malignancies, including histological features, tumor genetics, biological behavior, and response to conventional therapies. Similar to human cancers, the telomerase reverse transcriptase (TERT) activity in dogs is primarily restricted to tumor tissues and absent in most normal tissues, making dog TERT (dTERT) a promising target for translational cancer immunotherapy.

This study assessed the immunogenic potential of a cancer vaccine based on adenovirus serotype 6 (Ad6) and DNA electroporation (DNA-EP) to elicit immune responses against dTERT in dogs diagnosed with malignant lymphoma (ML). The vaccine was administered in combination with a standard chemotherapy regimen (cyclophosphamide, vincristine, prednisone, or COP). Remarkably, dTERT-specific immune responses were observed in 93% of treated dogs (13 out of 14), with the responses being long-lasting, detectable over time, and free of autoimmunity or other side effects.

Importantly, the survival time of dogs receiving the combined vaccine and chemotherapy significantly exceeded that of historical controls treated with chemotherapy alone (over 97.8 weeks versus 37 weeks, P = 0.001). These findings demonstrate that the Ad6/DNA-EP-based cancer vaccine effectively overcomes immune tolerance, induces durable immune responses, and substantially prolongs survival in canine ML patients. This approach holds great promise for further exploration in human clinical trials.