buy doxycycline for dogs 13 Other potential FDA- approved alternatives for ankylosing spondylitis include the interleukin- 17A inhibitors secukinumab given intravenously 10 mg kg at weeks 0, 2, and 4, followed by 150 mg or 75 mg subcutaneously every 4 weeks starting at week 8 and ixekizumab 80 mg subcutaneously every 2 or 4 weeks, each of which significantly reduces the signs of ankylosing spondylitis.