A pharmaceutical company said Thursday it has begun selling a new leukemia drug, the fourth new cancer agent since 1983 and the third leukemia drug in 10 years to gain federal approval.

Novantrone mitoxantrone hydrochloride is to be used in combination with other agents for treating adults with acute nonlymphocytic leukemia, Lederle Laboratories said in a statement.The disease strikes about 8,000 Americans a year, the statement said. The drug apparently disrupts the functioning of genetic material in cancer cells, the company said.

Novantrone was approved by the Food and Drug Administration in 1987, but the agency's official rating of the drug indicates it represents little or no advantage over other treatments.

The other three new cancer drugs approved in the past five years are etoposide for testicular cancer, approved in 1983; leuprolide acetate for advanced prostate cancer, 1985; and interferon, approved in 1986 to fight hairy cell leukemia, said Dr. John Johnson of the FDA.

Lederle is a division of American Cyanamid Co.