) --U.S. regulators approved

Ariad Pharmaceuticals'


leukemia drug ponatinib Friday, more than three months earlier than expected.

Ariad will sell the drug under the brand name Iclusig to treat adults with chronic myeloid leukemia (CML) and Philadelphia chromosome positive acute lymphoblastic leukemia (Ph+ ALL) -- rare blood and bone marrow diseases.

"The approval of Iclusig is important because it provides a treatment option to patients with CML who are not responding to other drugs, particularly those with the T315I mutation who have had few therapeutic options," said FDA cancer drug chief Richard Pazdur.

Ariad shares were down 43 cents to $23.44 in Friday trading. Investors widely expected Iclusig's approval although the FDA's decision comes well before the March 27, 2013 approval decision date.

Both CLL and Ph+ ALL cause excessive and unregulated production of white blood cells by the bone marrow due to a genetic abnormality that produces excessive quantities of a protein known as BCR-ABL.

In 2001,


(NVS) - Get Report

Gleevec was approved as one of the first "targeted" drugs capable of repairing the genetic error in CML and ALL patients. Gleevec became a multi-billion dollar blockbuster drug for Novartis, which went on to develop and market a successor drug, Tasigna.

Bristol-Myers Squibb

(BMY) - Get Report

markets a similar drug known as Sprycel.

The FDA approved Iclusig to treat patients with leukemia that is resistant or intolerant to these currently approved drugs.

-- Reported by Adam Feuerstein in Boston.

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