Genentech said its acute macular degeneration (AMD) treatment Lucentis maintained vision in study subjects and improved it in up to a third of patients.
The data may not bode well for wet AMD treatment Macugen, which already is marketed by Pfizer and Eyetech. Like Lucentis, Macugen (pegaptanib) is an angiogenesis inhibitor designed to selectively block a protein that underlies AMD. Patients taking Macugen have shown maintenance effects but not the kind of visual gains evident in the Lucentis trial.
The results from the Phase III trial show Lucentis (ranibizumab) met its primary endpoint of maintaining vision in patients with the wet form of AMD after one year. Ninety-five percent of Lucentis-treated patients lost fewer than 15 letters, compared with 62 percent getting the sham injection.
In a secondary endpoint, patients taking Lucentis for a year could read on average seven more letters off an eye chart than patients taking placebo, who lost an average of 10.5 letters. That translates into a 17-letter mean change in visual acuity from trial start between the groups.
In May Genentech said some of the 716 subjects in the trial improved their vision, but the biotech firm didn't reveal how many or the extent of improvement. The new data answer those questions.
Up to 34 percent of patients taking Lucentis for a year improved vision by 15 letters or more compared to about 5 percent in the placebo cohort.
Also, nearly 40 percent of subjects in the Lucentis cohort achieved a visual acuity score of 20/40 or better after a year compared to 11 percent in the control group.
At an earlier analyst briefing, an ophthalmologist speaking on behalf of Eyetech said one cannot directly compare new trial results to older data. There is no substitute for a head-to-head trial between drugs, he said. The company instead sought to emphasize Macugen's favorable safety profile and tolerance by patients.
In addition to Macugen, Novartis and QLT market the wet AMD drug Visudyne, which must be injected intravenously rather than in the eye. Two other firms, Allergan and Pharmacopeia, recently announced an agreement to research compounds for AMD.
Meanwhile, Genentech says it applied for fast-track designation this month and, if received, will begin submitting data to the FDA on a rolling basis by year end. Results of a second Phase III trial are expected later this year.
Genentech is developing Lucentis with Novartis' ophthalmic unit, which has marketing rights outside North America.