[13] In February 2005, Takeda acquired San Diego, California, based Syrrx, a company specializing in high-throughput X-ray crystallography, for US$270 million.

[15] In April, Takeda acquired Millennium Pharmaceuticals of Cambridge, Massachusetts, a company specializing in cancer drug research, for US$8.8 billion.

[16] The acquisition brought in Velcade, a drug indicated for hematological malignancies, as well as a portfolio of pipeline candidates in the oncology, inflammation, and cardiovascular therapeutic areas.

[23] On November, the U.S. Food and Drug Administration approved Ixazomib developed by Takeda for use in combination with lenalidomide and dexamethasone for the treatment of multiple myeloma after at least one prior therapy.

[28][29] In October, Takeda announced it had sold a portfolio of over-the-counter and prescription medicines in the Middle East and Africa to Swiss pharmaceuticals company Acino International for more than $200 million.

[30][31] In January 2020, Takeda announced a research partnership with the Massachusetts Institute of Technology (MIT) to advance discoveries in artificial intelligence and health.

[32][33][34] In March 2020, Takeda announced that it has entered into an exclusive agreement to divest a portfolio of non-core products in Latin America to Hypera S.A. for a total value of $825 million.

[47] In 2001, TAP's illegal marketing of Lupron resulted in both civil and criminal charges by the U.S. Department of Justice and the Illinois attorney general for federal and state medicare fraud.

[53][54] In November 2019, Takeda entered an agreement to sell its over-the-counter and prescription drugs businesses in Russia, Georgia, Armenia, Azerbaijan, Belarus, Kazakhstan, and Uzbekistan to Stada Arzneimittel for $660 million.

[55] In June 2020, Takeda announced that it was divesting 18 over-the-counter and prescription drugs marketed in the Asia-Pacific region to South Korea's Celltrion in a deal worth $278 million.

In April 2015 Takeda agreed to pay a settlement of $2.37 billion to an estimated 9,000 people who submitted claims alleging that pioglitazone was responsible for giving them bladder cancer.

[60] In 2014, a plaintiff was awarded $9 billion in punitive damages after a federal court found Takeda hid the cancer risks of their diabetes medicine,[61] but the amount was later reduced to $26 million by a judge who deemed the charge excessive.