Ashton needs life saving treatment

Hello my name is Jill and my cat Ashton was recently diagnosed with F.I.P which is Feline Infectious Peritonitis and it is usually fatal for cats.However there is life saving treatment available through this medical called GS-441524 which hasn't gotten FDA approval yet but has cured so many cats.I am desperate to save my best friend,he is my emotional support animal and my everything.I lost his brother earlier this year to brain cancer and I would do anything to not lose him as well.