The name "Derby Pie" is a registered trademark of Kern's Kitchen, which registered the name in 1968. The company uses the name in the form "DERBY-PIE®" in official literature and advertisements. Kern's Kitchen diligently guards the trademark and secret recipe, which is known only to a small group of Kern family members and a single Kern's Kitchen employee (who actually mixes the recipe today). The company has filed several lawsuits over the years to protect its commercial rights. Because of this, others who make similar pies have had to alter their recipes slightly and/or use a different name (such as "Pegasus Pie", a reference to the Pegasus Parade at the Kentucky Derby Festival and May Day Pie, in reference to the First Saturday in May, the day of the Kentucky Derby).
This is all I could find on it Nancy, so its not much help Larry