FDA extended the exclusivity period for AstraZeneca’s breast cancer drug Arimidex® by granting a six-month pediatric exclusivity. Yet, the firm says that it will not pursue approval of the drug for use in children.
AstraZeneca will continue to market Arimidex in postmenopausal women until June 2010. The patent was previously due to expire in December 2009.
“Preclinical and clinical data supported the investigation of the therapeutic potential of Arimidex in pediatric conditions that manifest symptoms resulting from increased estrogen production, for example gynecomastia in pubertal boys and precocious puberty in girls with McCune-Albright Syndrome,” states John Patterson, executive director of development.
Based on the trial results, however, Dr. Patterson notes that the company will not seek a approval in either condition. The studies reportedly did not show a positive affect compared with placebo in gynecomastia nor did they find a benefit in treating early puberty.
Arimidex reportedly has a 38.3% share of total prescriptions for hormonal treatments for breast cancer. In the U.S., AstraZeneca reported that sales reached $507 million for the nine months of 2007, up 15% from the same period of 2006.
In 1995, Arimidex was first sanctioned as a therapy for advanced breast cancer in postmenopausal women with disease progression following tamoxifen. About five years later, AstraZeneca expanded the label to include first-line treatment of postmenopausal women with hormone receptor positive or hormone receptor unknown locally advanced or metastatic breast cancer. The latest indication for the drug came in 2002, when the agency approved Arimidex as an adjuvant treatment of postmenopausal women with hormone receptor positive early breast cancer.