The early days of letrozole

The year 2007 marks the 10th anniversary of the approval of letrozole (Femara®) in the United States, while 2006 marked not only the 10-year milestone of letrozole’s approval in Europe but also the 25th anniversary of Novartis’s (then Ciba-Geigy [1970–1996]) dedication to the aromatase inhibitor (AI) program. It began with the introduction of the first-generation AI aminoglutethimide (Orimeten®) in 1981, progressed to the marketing of the steroidal AI formestane (Lentaron®), development of the second-generation AI fadrozole (Afema®), and finally led to letrozole, the most recent third-generation agent. This long track record in the development of AIs is unique in the pharmaceutical industry.