There are several steps you can take to protect  your film’s concept during the developmental phase. It is extremely important to safeguard your ideas before they’re fully developed. To do so you may want to consider making all persons who are privy to your idea sign non-disclosure agreements, as requiring them to sign a binding legal document outlining their confidentiality requirements can prevent leaks. 

Additionally, limiting the amount of people you inform about your concept can limit the possibilities of leaks. Make sure that your concept is copyrighted and that all records of your ideas are documented.