Did you search with the manufacturer directly? They often have their own coupon plans and if you don't find that, search the manufacturer and income assistance or something along those lines, they might have a general way to help.

There's also Mark Cuban's http://costplusdrugs.com though they're limited in what they offer.

Sam's Club, Costco, and Walmart can have cheaper prices and some places are cheaper if you pay cash instead of insurance

This website might help: https://medicineassistancetool.org/