News & Events
Recent News and Events
In ongoing research, Dr. Jeffrey Phillips has been working to identify new treatments for a devastating form of cancer in horses. Dr. Phillips leads a collaborative research group that is studying a new treatment for equine melanoma. Melanomas are among the most common tumors noted in horses comprising ~15% of all skin tumors. These tumors occur in all breeds and colors of horses but are most commonly seen in grey horses, reaching incidence rates as high as 80% in older animals. Because many horses present for treatment of their tumors with locally advanced, non-resectable tumors, effective non-surgical therapies are clearly needed to improve survival in these patients. Ideally, these therapies would include drugs that have not only local but also systemic activity to either treat or prevent disease spread. Therapies that target tumor-specific “factors” have the potential to not only treat but to potentially prevent the development of tyrosinase-expressing tumors.
The goal of this Morris Animal Foundation (D12EQ-037) funded project is to evaluate a new type of vaccine to treat horses with melanoma. This vaccine has been previously reported to be effective in treating melanoma in dogs. To accomplish our goal we proposed a study wherein the vaccine was used in gradually escalating doses in horses that had been diagnosed with melanoma. Horses are then evaluated for effective response to vaccine, immunologic response, and side effects. Effective response to vaccine would be determined based on changes in the tumor. Immunologic response would be evaluated using serum antibody titers and measures of cell-mediated response.
To date, we have accrued and treated the first two cohorts of patients for this project. These horses have been closely monitored for side effects and evidence of beneficial response. Virtually every horse has demonstrated substantial improvement following treatment. In some cases, benefit has been seen as early as two weeks after initiation. We are moving forward with the recruitment of additional cases and expect to be able demonstrate that the vaccine is safe and effective for the treatment of equine melanoma.
Anti-tumor cellular infiltrate in treated horses. (Image provided by Dr. John Biggerstaff, co-investigator).
A melanoma in a grey horse both before and after therapy with marked improvement noted.