ARIAD Pharmaceuticals, Inc. was an American oncology company founded in 1991 and headquartered in Cambridge, Massachusetts. On February 16, 2017, Takeda announced it had completed its acquisition of Ariad.

On December 14, 2012 the FDA approved Ariad Pharmaceutical's leukemia drug Iclusig for patients with all forms of chronic myeloid leukemia (CML) or Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) who are resistant or unable to tolerate other tyrosine kinase therapies on the market. The drug was temporarily withdrawn from the market in November 2013 "because of the risk of life-threatening blood clots and severe narrowing of blood vessels". This suspension was partially lifted on December 20, 2013 with ponatinib being issued revised prescribing information, a new "black box warning" and a "Risk Evaluation and Mitigation Strategy" in place to better evaluate the risks and benefits of using the drug.

Ariad also has brigatinib, a lung cancer drug which has completed its registration trial in ALK fusion driven non-small cell lung cancer as of June 2016.

In January 2017, Takeda announced it would acquire Ariad for $5.2 billion, expanding the company's oncology and hematology divisions. The acquisition was completed on February 16, 2017.

Ariad is engaged in the discovery, development, and commercialization of medicines for cancer patients. It offers Iclusig (ponatinib), a tyrosine kinase inhibitor for the treatment of adult patients with chronic myeloid leukemia (CML), and Philadelphia chromosome-positive acute lymphoblastic leukemia in the United States and Europe. Various investigator-sponsored trials are ongoing in several indications, including first line and second line CML, acute lymphoblastic leukemia (BCR-ABL), acute myeloid leukemia (FLT3 inhibitor), non-small cell lung cancer (RET, FGFR), advanced biliary cancer With FGFR2 fusions and other cancers with activating mutations involving the following Genes: FGFR1, FGFR2, FGFR3, FGFR4, RET, and KIT.

In addition, its product pipeline consists of Brigatinib, an investigational inhibitor of anaplastic lymphoma kinase for treating advanced solid tumors comprising non-small cell lung cancer. This drug reported results of its registration trial at ASCO, June 6, 2016, with encouraging results; AP32788, an inhibitor of solid tumors with EGFR and HER2 activating mutation, which began phase I testing in the second quarter of 2016; and Ridaforolimus, an investigational mTOR inhibitor for various types of cancers. The company sells and markets Iclusig through specialty pharmacies and specialty distributors in the United States. It has collaboration and license agreement with Medinol Ltd. and ICON Medical Corp. to develop and commercialize stents and other medical devices to deliver ridaforolimus.

On February 21, 2014 Ariad Pharmaceuticals announced the appointment of Sarissa Capital's Alexander J. Denner, Ph.D. to a two-year term on the company's Board of Directors. Previously, Denner served as a senior managing director at Carl Icahn's Icahn Capital and is currently Ariad's second-largest shareholder. On January 10, 2016, Ariad announced that Denner had become the chairman of the board, replacing Harvey Berger. Shortly thereafter, the company announced the termination of its shareholder's rights plan (the "poison pill.")

In July 2015, the company announced it was due to receive up to $200 million through a royalty financing deal with PDL BioPharma on future sales of ponatinib.

In 2016, the company was ranked #3 on the Deloitte Fast 500 North America list.