Lucentis is reported to stabilize vision in about 95 percent of patients and actually improve vision in up to 40 percent. But before Lucentis hit the market, retina specialists began using Avastin off-label, and it was quickly and broadly adopted as a first-line therapy for AMD. The few published studies on treatment of AMD with Avastin--trials that did not compare the drug with other AMD treatments--coupled with results in clinical practice have been so encouraging that Medicare usually covers the cost despite the lack of formal approval. And price is at the crux of this debate: Lucentis costs $2,000 per injection while Avastin is about $50. Moreover, patients must undergo a series of injections with both drugs. Although Medicare pays in either case, patients who lack insurance or have high co-payments can realize huge savings with Avastin. Not surprisingly, many physicians prefer to stock the less-expensive drug. And Genentech, which makes Avastin and Lucentis, has had little financial incentive to conduct additional clinical trials to gain FDA approval of Avastin to treat wet AMD.

"Avastin is one of the most commonly used drugs worldwide for the treatment of wet AMD," says Daniel F. Martin, M.D., chairman of the Cole Eye Institute at the Cleveland Clinic and head of a new study that will compare the two drugs directly. "We have a responsibility to understand the long-term visual and safety results associated with Avastin and to understand how these results compare to Lucentis." Funded by the National Eye Institute, a division of the National Institutes of Health, the study is currently enrolling participants at 43 centers around the country. Results are expected in 2011. (For more information, go to http://clinicaltrials.gov/show/NCT00593450.)