The present invention relates to a microsomal prostaglandin E synthases-1 (“mPGES-1”) inhibitor for the treatment of osteoarthritis pain in a subject. For example, the present invention relates to a method of treating moderate osteoarthritis pain in a subject in need thereof by orally administering to the subject a substituted triazolone compound as a mPGES-1 inhibitor. The present invention also relates to pharmaceutical compositions comprising the mPGES-1 inhibitor, and to processes for preparing such pharmaceutical compositions.
