US biotechnology company Genentech Inc is delaying a plan that would make it harder to repackage its Avastin cancer drug as an inexpensive treatment for eye disease.
Earlier this month, Genentech said it would ban purchases of Avastin by independent compounding pharmacies, which divide vials of the medicine to make a low-cost substitute for the company's Lucentis drug for eye disease. Lucentis is chemically similar to Avastin and is approved as a treatment for wet, age-related macular degeneration, the leading cause of blindness among the elderly.
Genentech posted a letter on its Web site on Monday, saying it would delay the start of the ban to January 1 from November 30. Genentech acted after senior executives met with the American Academy of Ophthalmology and American Society of Retina Specialists. The change will allow physicians time to develop transition plans, the company said.
Genentech also said it would reinstate its supply of Avastin to compounding pharmacies if the US Food and Drug Administration authorised the company to do so. FDA spokesman Christopher Kelly said in an October statement that the agency did not ask Genentech to stop distributing Avastin to compounding pharmacies and that it has not taken action to limit the off-label use of Avastin.
"The agency is concerned about the manipulation of sterile products because of the increased risk of product contamination," Kelly said at the time. He was not immediately available for comment on Wednesday.
Avastin has been widely used in the United States and Europe as an off-label treatment for macular degeneration because the cost of a one-month supply for eye use is about 40 to 50 times lower than the $2,000 price for a comparable dose of the newer Lucentis.
"While we can't be certain of the precise effects of any of the differences between Lucentis and Avastin, it is important to emphasise that Lucentis is purposefully different in fundamental ways from Avastin," Genentech on Wednesday in an update to its letter sent earlier this week.
Among other things, Genentech said it reduced the size of the Lucentis molecule by more than 65 percent, to minimise the drug's concentration, and removed certain components of the antibody "to reduce the theoretical possibility of increased inflammation in the eye." Genentech, which is majority owned by Swiss drug maker Roche Holding AG developed Avastin with that company, which has rights to Avastin outside the United States.
California-based Genentech's Lucentis partner is Novartis AG, which has commercial rights to the drug outside the United States. The National Eye Institute and National Institutes of Health are conducting a head-to-head trial comparing Avastin and Lucentis as treatments for macular degeneration.