One is a financial assistance program
that helps you with the cost of your copay - for example, my copay was $90, and they helped me out with $40 of it. When I had problems affording the $50, I talked to my neurologist, who helped me with a complete financial assistance program that would allow me to get it for free.
However, Aetna is a complicated mess. I have to get all my medication through their Specialty Pharmacy, not their mail-order pharmacy, which is confusing.