AbbVie Inc. and Eisai Co. Ltd. said Humira was approved in Japan as a treatment for an autoimmune disease known as pustular psoriasis.

Humira, AbbVie's blockbuster drug, is already approved for nine other indications in the country. Tokyo-based Eisai has the rights to market the drug in Japan.

The approval for a new indication was based on a phase 3 trial in Japanese patients whose conditions did not improve after being treated with conventional medicines, such as etretinate and cyclosporine.

About 70% of the patients showed a reduction in their disease after 16 weeks of treatment in that trial.

Humira treats a range of autoimmune disorders from rheumatoid arthritis to plaque psoriasis and ulcerative colitis.