Quinazolinones and pyrido[3,4-d]pyrimidin-4-ones as orally active and specific matrix metalloproteinase-13 inhibitors for the treatment of osteoarthritis

Quinazolinones 8 and pyrido[3,4-d]pyrimidin-4-ones 9 as orally active and specific matrix metalloproteinase-13 inhibitors were discovered for the treatment of osteoarthritis. Starting from a high-through-put screening (HTS) hit thizolopyrimidin-dione 7, we obtained two chemotypes, 8 and 9, using computer-aided drug design (CADD) and methodical structure-activity relationship (SAR) studies. They occupy the unique S₁′-specificity pocket and do not bind to the Zn²⁺ ion. Some pyrido[3,4-d]pyrimidin-4-ones, such as 10a, possess favorable absorption, distribution, metabolism, and elimination (ADME) and safety profiles. 10a effectively prevents cartilage damage in rabbit animal models of osteoarthritis without inducing musculoskeletal side effects when given at extremely high doses to rats.