AMAG Pharmaceuticals and Takeda Pharmaceutical Company Limited (Takeda)  have entered into an agreement to mutually terminate the March 2010 licence, development and commercialisation agreement, which granted Takeda exclusive rights to market ferumoxytol in Canada, the European Union (EU) and Switzerland, as well as certain other geographic territories (under the trade name Rienso outside of Canada where the product's trade name is Feraheme).

Under the terms of the termination agreement, AMAG will regain all worldwide development and commercialisation rights for Feraheme/Rienso. Takeda will make a payment to AMAG in connection with the termination and will provide certain transition services to AMAG for up to 180 days after the marketing authorisation transfer in each territory. In addition, both parties will undertake a transfer of the regulatory files for the product in each respective territory, and Takeda will not participate in any future development or commercialization activities.

Takeda has been commercialising Feraheme in Canada and Rienso in the EU for the treatment of iron deficiency anemia (IDA) in patients with chronic kidney disease (CKD). In both of these territories, Takeda has submitted applications to expand the product's current label to include all patients with IDA regardless of underlying cause. AMAG will be assessing various alternative commercialisation strategies for Feraheme in Canada and Rienso in the EU based, in part, on the pending regulatory decisions which are expected in 2015.

Feraheme received marketing approval from the FDA on June 30, 2009 for the treatment of IDA in adult CKD patients and was commercially launched by AMAG in the US shortly thereafter. Ferumoxytol is protected in the US by five issued patents covering the composition and dosage form of the product. Each issued patent is listed in the FDA's Orange Book, the last of which expires in June 2023.

Ferumoxytol received marketing approval in Canada in December 2012, where it has been marketed by Takeda as Feraheme, and in the European Union in June 2013 where it has been marketed by Takeda as Rienso. Ferumoxytol received marketing approval in Switzerland in August 2013.

Feraheme/Rienso is contraindicated in patients with known hypersensitivity to Feraheme/Rienso or any of its components. Serious hypersensitivity reactions, including anaphylactic-type reactions, have been reported in patients receiving Feraheme/Rienso. Serious adverse reactions of clinically significant hypotension have been reported in the post-marketing experience of Feraheme/Rienso.