Novel anthranilic acid derivative or salt thereof

An anthranilic acid derivative represented by the general formula (X) [wherein R 1 represents hydrogen or a carboxy-protecting group; R 2 represents optionally substituted phenyl, a heterocyclic group, etc.; R 3 represents optionally substituted phenyl, a monocyclic heterocyclic group, etc.; X 1 represents carbonyl, etc.; X 2 represents optionally substituted alkylene group, a bond, etc.; X 3 represents oxygen, a bond, etc.; and X 4 represents a group represented by the general formula -X 5 -X 6 - or -X 6 -X 5 - (wherein X 5 means oxygen, a bond, etc.; and X 6 means optionally substituted alkylene, a bond, etc.)] or a salt of the derivative. The derivative or salt has the inhibitory activity of MMP-13 production and is hence useful as a therapeutic agent for articular rheumatism, osteoarthritis, cancer, etc.