Litigation	12 Months Ended
Dec. 31, 2013
Litigation	19. Litigation On October 10, 2013, October 17, 2013, December 3, 2013 and December 6, 2013, purported shareholder class actions, styled Jimmy Wang v. ARIAD Pharmaceuticals, Inc., et al., James L. Burch v. ARIAD Pharmaceuticals, Inc., et al., Greater Pennsylvania Carpenters’ Pension Fund v. ARIAD Pharmaceuticals, Inc., et al, and Nabil Elmachtoub v. ARIAD Pharmaceuticals, Inc., et al, respectively, were filed in the United States District Court for the District of Massachusetts (the “District Court”), naming the Company and certain of its officers as defendants. The lawsuits allege that the Company made material misrepresentations and/or omissions of material fact regarding clinical and safety data for Iclusig in its public disclosures during the period from December 12, 2011 through October 8, 2013 or October 17, 2013, in violation of Sections 10(b) and 20(a) of the Securities Exchange Act of 1934, as amended, and Rule 10b-5 promulgated thereunder. On January 9, 2014, the District Court consolidated the actions and appointed lead plaintiffs. On February 18, 2014, the lead plaintiffs filed an amended complaint as contemplated by the order of the District Court. The amended complaint extends the class period for the Securities Exchange Act claims through October 30, 2013. In addition, plaintiffs allege that certain of the Company’s officers, present and former directors and certain underwriters made material misrepresentations and/or omissions of material fact regarding clinical and safety data for Iclusig in connection with the Company’s January 24, 2013 follow-on public offering of common stock in violation of Sections 11 and 15 of the Securities Act of 1933, as amended. The plaintiffs seek unspecified monetary damages on behalf of the putative class and an award of costs and expenses, including attorney’s fees. On November 6, 2013, a purported derivative lawsuit, styled Yu Liang v. ARIAD Pharmaceuticals, Inc., et al., was filed in the United States District Court for the District of Massachusetts (the “District Court”), on behalf of the Company naming its directors and certain of its officers as defendants. On December 6, 2013, an additional purported derivative lawsuit, styled Arkady Livitz v. Harvey J. Berger, et al, was filed in the District Court. The lawsuits allege that the Company’s directors and certain of its officers breached their fiduciary duties related to the clinical development and commercialization of Iclusig and by making misrepresentations regarding the safety and commercial marketability of Iclusig. The lawsuits also assert claims for unjust enrichment and corporate waste, and for misappropriation of information and insider trading by the officers named as defendants. On January 23, 2014, the District Court consolidated the actions. On February 3, 2014, plaintiffs designated the Yu Liang complaint as the operative complaint as contemplated by the order of the District Court. The plaintiffs seek unspecified monetary damages, changes in the Company’s corporate governance policies and internal procedures, restitution and disgorgement from the individually named defendants, and an award of costs and expenses, including attorney fees. Additional complaints may be filed against the Company and its directors and officers related to the Company’s disclosures and announcements concerning the safety, marketing and commercial distribution and further clinical development of Iclusig in the United States. The Company believes that these actions are without merit. At this time, no assessment can be made as to the likely outcome of these lawsuits or whether the outcome will be material to the Company. From time to time, the Company may be subject to various claims and legal proceedings. If the potential loss from any claim, asserted or unasserted, or legal proceedings is considered probable and the amount is reasonably estimated, the Company will accrue a liability for the estimated loss.

19. Litigation

On October 10, 2013, October 17, 2013, December 3, 2013 and December 6, 2013, purported shareholder class actions, styled Jimmy Wang v. ARIAD Pharmaceuticals, Inc., et al., James L. Burch v. ARIAD Pharmaceuticals, Inc., et al., Greater Pennsylvania Carpenters’ Pension Fund v. ARIAD Pharmaceuticals, Inc., et al, and Nabil Elmachtoub v. ARIAD Pharmaceuticals, Inc., et al, respectively, were filed in the United States District Court for the District of Massachusetts (the “District Court”), naming the Company and certain of its officers as defendants. The lawsuits allege that the Company made material misrepresentations and/or omissions of material fact regarding clinical and safety data for Iclusig in its public disclosures during the period from December 12, 2011 through October 8, 2013 or October 17, 2013, in violation of Sections 10(b) and 20(a) of the Securities Exchange Act of 1934, as amended, and Rule 10b-5 promulgated thereunder. On January 9, 2014, the District Court consolidated the actions and appointed lead plaintiffs. On February 18, 2014, the lead plaintiffs filed an amended complaint as contemplated by the order of the District Court. The amended complaint extends the class period for the Securities Exchange Act claims through October 30, 2013. In addition, plaintiffs allege that certain of the Company’s officers, present and former directors and certain underwriters made material misrepresentations and/or omissions of material fact regarding clinical and safety data for Iclusig in connection with the Company’s January 24, 2013 follow-on public offering of common stock in violation of Sections 11 and 15 of the Securities Act of 1933, as amended. The plaintiffs seek unspecified monetary damages on behalf of the putative class and an award of costs and expenses, including attorney’s fees.

On November 6, 2013, a purported derivative lawsuit, styled Yu Liang v. ARIAD Pharmaceuticals, Inc., et al., was filed in the United States District Court for the District of Massachusetts (the “District Court”), on behalf of the Company naming its directors and certain of its officers as defendants. On December 6, 2013, an additional purported derivative lawsuit, styled Arkady Livitz v. Harvey J. Berger, et al, was filed in the District Court. The lawsuits allege that the Company’s directors and certain of its officers breached their fiduciary duties related to the clinical development and commercialization of Iclusig and by making misrepresentations regarding the safety and commercial marketability of Iclusig. The lawsuits also assert claims for unjust enrichment and corporate waste, and for misappropriation of information and insider trading by the officers named as defendants. On January 23, 2014, the District Court consolidated the actions. On February 3, 2014, plaintiffs designated the Yu Liang complaint as the operative complaint as contemplated by the order of the District Court. The plaintiffs seek unspecified monetary damages, changes in the Company’s corporate governance policies and internal procedures, restitution and disgorgement from the individually named defendants, and an award of costs and expenses, including attorney fees.

Additional complaints may be filed against the Company and its directors and officers related to the Company’s disclosures and announcements concerning the safety, marketing and commercial distribution and further clinical development of Iclusig in the United States.

The Company believes that these actions are without merit. At this time, no assessment can be made as to the likely outcome of these lawsuits or whether the outcome will be material to the Company.

From time to time, the Company may be subject to various claims and legal proceedings. If the potential loss from any claim, asserted or unasserted, or legal proceedings is considered probable and the amount is reasonably estimated, the Company will accrue a liability for the estimated loss.