Macugen Advisory Committee To Discuss Concomitant Use With Visudyne
This article was originally published in The Pink Sheet Daily
Executive Summary
FDA's Dermatologic and Ophthalmic Drugs Advisory Committee will discuss concomitant use of Pfizer/Eyetech's Macugen and Novartis/QLT's Visudyne (verteporfin) at an Aug. 27 meeting
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FDA's Dermatologic and Ophthalmic Drugs Advisory Committee will discuss concomitant use of Pfizer/Eyetech's Macugen and Novartis/QLT's Visudyne (verteporfin) at an Aug. 27 meeting. The committee is meeting to consider Pfizer/Eyetech's NDA for Macugen (pegaptanib) for the treatment of neovasuclar or "wet" age-related muscular degeneration (AMD). 1 FDA briefing materials indicate the agency is asking the committee to consider: "Has the concomitant use of PDT therapy with pegaptanib been explored sufficiently?" and, "Are there concerns with using this product concomitantly with PDT therapy?" Photodynamic therapy (PDT) with verteporfin is currently the only approved treatment for AMD, with an indication limited to patients with the predominantly classic form of the disease. Macugen efficacy claims are based on two prospective, multi-center, randomized, double-masked, controlled trials with broad entry criteria for vision, lesion size and angiographic subtype. I.V. injections of pegaptanib (.3 mg, 1 mg, or 3 mg) or sham injections were administered every six weeks for 48 weeks with a follow-up period to 54 weeks, totaling a maximum of nine injections. Doctors were permitted to administer PDT in the indicated patient population based on their clinical judgment, but patients were not randomized to receive PDT. Therefore, an "inherent bias limits the interpretation of efficacy with and without it," Pfizer/Eyetech's briefing documents state. The 2 sponsors' briefing documents state there was low usage of PDT during the study overall and "no evidence that PDT usage influenced the efficacy of pegaptanib." The primary efficacy endpoint for the trials was the proportion of responders, defined as patients avoiding a 15-letter loss of visual acuity (3 (Also see "Pfizer/Eyetech's Macugen Safety To Be Discussed By FDA Advisory Cmte." - Pink Sheet, 25 Aug, 2004.)). The sponsors' data also indicate a higher rate of ocular adverse reactions, including eye pain, punctuate keratitis and vitreous floaters, with concomitant PDT use. - Andrew Shelton |