Rostaporfin (Miravant Medical Technologies).
Pharmacia Corp, under license from Miravant Medical Technologies (formerly PDT Inc), is developing rostaporfin (SnET2, Purlytin), a light-activated cytotoxic drug developed as part of Miravant's PhotoPoint photodynamic therapy (PDT) program, for the potential treatment of wet age-related macular degeneration (AMD) [180314]. In January 2002, results of phase III trials indicated that rostaporfin had not met the primary efficacy endpoint for the wet form of AMD. At this time, a full review of the data was to be undertaken, and decisions about future development of the drug were to be made after additional analyses had been completed [435577]. The original licensing agreements included the development of rostaporfin for several ophthalmology, oncology and urology indications [289078], and for dermatological applications including certain skin cancers [267521]. However, in August 1998, Miravant reported that it no longer intended to pursue cutaneous metastatic breast cancer (CMBC), in order to focus on AMD [439372], [439384]. Also in 1998, studies in basal cell carcinoma and AIDS-related Kaposi's sarcoma were discontinued because of business considerations [439372]. Rostaporfin is activated by red light with a wavelength of 664 nm. It is injected into the patient, where it distributes and selectively binds to plasma lipoproteins, which are produced in high concentrations by hyperproliferating cells such as cancer cells. After 24 h, the targeted cells are stimulated by red light to activate the compound. This triggers the formation of toxic free radical species that destroy the cells without affecting the surrounding normal tissue [85236]. In January 2002, Credit Suisse First Boston estimated sales for Pharmacia of 40 million US dollars in 2003 and 80 million US dollars in 2004 [436118], while in the same month, Argus Research predicted peak annual sales for Pharmacia of less than 250 million US dollars[436279].
Hunt
David W C
DW
QLT Inc, 887 Great Northern Way, Vancouver, British Columbia, V5T 4T5, Canada. dhunt@qltinc.com