Golimumab/Simponi is denied by insurance — what to do?

I’ve been on Simponi for about a year for PIC (after being on Humira and developing antibodies to that). The Simponi is working so far, but my new Aetna medicare advantage insurance plan is denying any refills, after 3 appeals. They say it’s “off label” which is true, but FDA has not approved anything else that works for me. So now I have no medication. Any advice on how to deal with this? Simponi is so expensive out of pocket. Hire a lawyer? Switching out of Medicare Advantage to a traditional Part D plan? Thank you for any advice you can provide.