It's a bit broader than that - Orphan protects against competition from the "same" drug unless it can be proven to be clinically superior. "Same" here does not actually mean same - it's been interpreted to mean broadly similar in chemical structure. Same active moiety is one definition. Rebif was approved, despite Avonex's orphan drug designation, based on a "clinical superiority" argument.
In Incyte's case, the drugs are different, so you and AF are correct that there is no protection based on Orphan.