You probably have already looked into this, but just in case, my hospital helped me get a grant from PSI. It's a company that helps cover high prescription costs.
https://www.patientservicesinc.org/
Also, I know it depends on the insurance company, but my Soliris treatments were classified under my Major Medical instead of Prescription because I received them at the hospital. That alone really helped.
Then the PSI helped cover the remainder.
I read a few articles in 2011 siting it as the most expensive drug in the world at the time, also.