Elanco Animal Health, a Division of Eli Lilly and Company, in collaboration with Michigan State University (MSU), Oklahoma State University (OSU), and Louisiana State University (LSU) recently completed a study of horses afflicted with equine Cushing’s disease also known as pituitary pars intermedia dysfunction (ECD/PPID) to document the efficacy and safety of pergolide in support of FDA approval.
Veterinary prescribed off-label use of pergolide in horses with ECD/PPID has been documented in the literature for nearly twenty years in 25 global, scientific publications. An FDA-approved pergolide product for horses afflicted with ECD will assure the access to and the uniformity and quality of a pergolide therapy for horses in the United States.
Equine Cushing’s disease— also known as pituitary pars intermedia dysfunction, or PPID—is one of the more common diseases ohorses older than 15 years of age. In horses with PPID, the middle lobe of the pituitary gland becomes enlarged over time and results in overproduction of hormones. The most classic symptom of PPID is a long, curly hair coat that does not shed properly.
Other symptoms include excessive drinking and urination, laminitis, lethargy, excessive sweating, muscle mass loss, and repeated infections (such as sole abscesses, tooth root infections, and sinusitis.
For more than 20 years, pergolide was the drug of choice for treatment of PPID and resulted in significant improvement to the horse’s quality of life.
However, pergolide, which was an FDA-approved medication for people with Parkinson’s disease, had never been officially approved for veterinary applications and had to be used off label.
FDA approval of the product for veterinary use was needed to ensure access to and the uniformity and quality of a pergolide therapy for horses. A clinical trial was needed, and the VTH was one of the study sites.
The study included about 120 horses enrolled across the U.S. Dr. Hal Schott, a specialist in equine internal medicine, headed thestudy at MSU. The results proved to be quite favorable and the data have now been submitted to the FDA.
Approval of pergolide for treatment of PPID is anticipated in early 2011.
As part of the study, Schott, along with radiologists Drs. Tony Pease and Jennifer Kinns, also performed some CT and MRI imaging of the horses and found an enlarged pituitary, which they expected.
“We found the CT and MRI images were similar, but the anatomical detail could be seen much better on MRI than CT,” says Pease.
In a small number of horses that had CT imaging performed before treatment with pergolide, the size of the pituitary gland remained unchanged, despite marked improvement in the clinical signs of PPID.
“This was the first study to assess changes in pituitary gland size after treatment with pergolide,” says Schott, “and although these imaging modalities are not necessary to diagnose PPID, they may prove useful in the evaluation of future additional treatment options for this disease. “
Schott extends thanks to all the referring veterinarians and clients who enrolled horses in the study. “Without them, these sorts of advancement in veterinary medicine are simply not possible,” he says.