A health ministry panel decided Friday to designate the sedative thalidomide as a priority research drug for bone marrow cancer treatment, more than 40 years after it was banned for causing severe birth defects.

Osaka-based Fujimoto Pharmaceutical Corp. filed a request last year for the ministry to designate thalidomide as what is technically known as an "orphan drug."

Under the ministry's definition, an orphan drug is a product used to treat rare but serious diseases that affect fewer than 50,000 patients. Any manufacturer of such a drug receives official backing in research and development, extended market monopoly status and tax breaks.