The present invention relates to an excellent remedial agent for chronic rheumatoid arthritis, comprising an aminostilbazole derivative represented by the following formula [1] or a salt thereof as an active ingredient:

Wherein A represents heteroaryl or an oxide thereof, B represents ethenylene, D represents phenylene, E represents the formula: —N(R)SO₂—G [wherein G represents phenyl, R represents hydrogen, alkyl, or —COR⁰ (R⁰ represents alkyl, alkoxy, aryloxy, 5- to 6-membered heteroaryl, heteroarylmethyl, aminoalkylene or cyclicaminoalkylene) or the like].