The invention relates to novel methods and kits for treating or preventing disease through the administration of random copolymers comprising amino acids tyrosine (Y), phenylalanine (F), alanine (A), and lysine (K). The invention also relates to the treatment of autoimmune diseases, such as multiple sclerosis, and to the administration of random copolymers in treatment regimen comprising formulations that are administered at intervals greater than 24 hours, or to sustained release formulations which administer the copolymer over a period greater than 24 hours. The invention further relates to methods for conducting a pharmaceutical business comprising manufacturing, licensing, or distributing kits containing or relating to the formulations or dosing regimens of random copolymer described herein.