Calviri, a biotechnology company focused on developing cancer vaccines, has commenced a clinical trial to evaluate its investigational immunotherapy vaccine in canines diagnosed with early-stage hemangiosarcoma (HSA). The study, titled Scout Out Canine Hemangiosarcoma (SOCH), will investigate whether the vaccine can prolong the lives of dogs with stage 1 or stage 2 tumors when administered alongside standard treatments such as surgery and chemotherapy.
The core objective of the vaccine is to stimulate the immune system, enabling it to identify and eliminate cancer cells. While personalized cancer vaccines combined with checkpoint inhibitor immunotherapy have shown promise in humans, Calviri noted that creating such customized vaccines for dogs, tailored to specific mutations in tumor DNA, can be impractical and cost-prohibitive.
Novel Neoantigen Approach
Calviri has adopted an innovative approach by utilizing neoantigens derived from tumor RNA variants. These neoantigens, originating from RNA errors, are shared across various patients and tumor types. This discovery allows Calviri to produce "off-the-shelf" vaccines suitable for treating a broader range of tumors. A previous clinical trial evaluated a preventative cancer vaccine based on similar neoantigens in dogs.
Targeting Early-Stage Tumors
The current vaccine distinguishes itself from other cancer vaccines, which are typically employed in treating advanced-stage tumors in both humans and dogs. The SOCH trial is designed to target early-stage tumors, with the goal of enhancing survival rates by intervening when the tumors are smaller and less advanced.
"HSA is very aggressive. If this vaccine approach proves effective for HSA, there is a good chance it will work for other tumors," said Douglas Thamm, VMD, director of clinical research at Colorado State University's (CSU) Flint Animal Cancer Center, and lead of the trial at CSU.
Hemangiosarcoma in Dogs
HSA is a prevalent cancer in dogs, particularly affecting breeds such as golden retrievers, German shepherds, labrador retrievers, boxers, pit bulls, and dogs with thin hair coats like Greyhounds, beagles, and dalmatians. HSA commonly originates in the spleen and can metastasize to other areas of the body.
HSA tumors are characterized by abnormal blood cells and fragile blood vessels that are invasive and prone to rupture. Ruptured tumors can cause bleeding into body cavities, leading to various clinical symptoms. Even with early detection, the life expectancy for dogs diagnosed with HSA typically ranges from 5 to 11 months.
Standard Treatment and Trial Design
Standard treatment protocols involve surgical removal of the cancerous spleen and chemotherapy. Additional treatments may include anti-bleeding medications, bioactive extracts from mushrooms, anti-arrhythmic drugs, blood transfusions, and procedures to remove fluid from around the heart or in the chest or abdomen.
"HSA is a devastating diagnosis for dogs. We are hopeful that this unique vaccine will improve the prognosis," stated David Vail, DVM, MS, DACVIM (oncology), and clinical principal investigator for the study.
The trial will enroll dogs at academic veterinary oncology institutions at the University of Wisconsin, Colorado State University, and the University of California-Davis. Participants will be randomly assigned to either a group receiving a placebo vaccine or a group receiving the investigational vaccine. Both groups will receive standard care, including surgery and chemotherapy, in addition to their assigned vaccine. The study is expected to last two years, with a target enrollment of up to 80 dogs.
Sami Al-Nadaf, DVM, trial director at UC-Davis Veterinary Medicine, has invited interested veterinarians and dog owners to contact oncclinicaltrials@vetmed.wisc.edu for more information.
Funding for the trial is provided by Calviri and a donation from David MacNeil in memory of his golden retriever Scout.
