An OOPs Class is simply a Template for Creating Objects, that encapsulate Data and Behavior.
In Functional Paradigm, the same encapsulation of Data and Behavior can be achieved using a Higher Order Function (HOF) that replaces the OOPs Class. This HOF, would get the Data from outside (to keep it pure) and will return a function (Behavior) that uses Closure to encapsulate the Data within the returned function.
There is a whole section on object construction in the GoF “Design Patterns” book which exists only to get around the limitations of constructors and classes.
See also: Three Different Kinds of Prototypal OO.
The bottom line: Class doesn’t give you any power that isn’t already supplied by factory functions and the prototypal OO built into the language. All you’re doing when you create a class is opting into a less powerfull, less flexible mechanism and a whole lot of pitfalls and pain.