Genentech has informed doctors about a number of reported cases of eye inflammation linked to off-label use of its cancer drug Avastin.

The US biotechnology giant has issued “important safety information” regarding off-label intravitreal use of Avastin (bevacizumab), along with partner Roche, it is aware of 36 reports of intraocular adverse events, 32 of which involve serious inflammatory reactions, all originating in Canada. Roche noted that as of November 26, there were 25 spontaneously reported Canadian cases reported of eye inflammation, endophthalmitis, blurred vision and floaters.

The issue is connected specifically to off-label use of Avastin for age-related macular degeneration, a far cheaper alternative to Genentech/Novartis’ Lucentis (ranibuzumab), which is approved for that particular condition. Genentech had said in October 2007 that Avastin would no longer be supplied to independent compounding pharmacies that divide vials so that ophthalmologists can use it in an unapproved way to treat AMD, though a deal with doctors was struck later.

Nevertheless, Genentech has again stressed that only Lucentis is approved for AMD and the authorities at Health Canada say that investigations are underway.