Treating or preventing degeneration or destruction of articular cartilage and/or subchondral bone in the affected joint of a mammal is accomplished by administering a compound of formula (I), wherein the variables have the meanings given in the present description. A preferred compound of formula (I) is formula (II). This treatment ameliorates, diminishes, actively treats, reverses or prevents any injury, damage or loss of articular cartilage or subchondral bone subsequent to said early stage of said degeneration ##STR00001##