Deferasirox


Deferasirox, sold under the brand name Exjade among others, is an oral iron chelator. Its main use is to reduce chronic iron overload in patients who are receiving long-term blood transfusions for conditions such as beta-thalassemia and other chronic anemias. It is the first oral medication approved in the United States for this purpose.
It was approved by the U.S.Food and Drug Administration in November 2005.
According to the FDA, kidney failure and cytopenias have been reported in patients receiving deferasirox oral suspension tablets. It is approved in the European Union by the European Medicines Agency for children six years and older for chronic iron overload from repeated blood transfusions.
In July 2020, Teva decided to discontinue deferasirox.

Properties

The half-life of deferasirox is between 8 and 16 hours allowing once a day dosing. Two molecules of deferasirox are capable of binding to 1 atom of iron which are subsequently eliminated by fecal excretion. Its low molecular weight and high lipophilicity allows the drug to be taken orally unlike deferoxamine which has to be administered by IV route. Together with deferiprone, deferasirox seems to be capable of removing iron from cells as well as removing iron from the blood.

Synthesis

Deferasirox can be prepared from simple commercially available starting materials in the following two-step synthetic sequence:
The condensation of salicyloyl chloride with salicylamide under dehydrating reaction conditions results in formation of 2--1,3-benzoxazin-4-one. This intermediate is isolated and reacted with 4-hydrazinobenzoic acid in the presence of base to give 4-benzoic acid.

Risks

Deferasirox was the #2 drug on the list of 'Most frequent suspected drugs in reported patient deaths' compiled by the Institute for Safe Medical Practices in 2009. There were 1320 deaths reported, perhaps explained by an update to the ADE data of Novartis, and a new boxed warning about gastrointestinal haemorrhage as well as kidney and liver failure.