Not all marketing is TV ads or sales jobs to doctors.
In this hypothetical case, marketing $$ were spent to discover that existing late state melanoma treatments were lacking in some important respect (efficacy, side effects, cost...), and that there was a sufficient market to continue the expensive process of developing a potential treatment.
In this hypothetical case, marketing $$ were spent to discover that existing late state melanoma treatments were lacking in some important respect (efficacy, side effects, cost...), and that there was a sufficient market to continue the expensive process of developing a potential treatment.