Avastin safety issues being addressed by physician community

RIO GRANDE, Puerto Rico — A growing concern over potential ocular and systemic safety issues of intravitreal bevacizumab has led to an online registry to track adverse events, Andrew Moshfeghi, MD, told attendees of the Masters of the American Society of Retina Specialists meeting. To date, 68 centers have supplied information to the registry, which is headed by Anne Fung, MD, Dr. Moshfeghi said. It includes information on 4,869 patients who have undergone 6,584 injections.

“What we’ve seen so far with adverse events are two cases of endophthalmitis, three retinal detachments and 11 abrasions,” he said.

With intravenous Avastin (bevacizumab, Genentech) for the treatment of metastatic colorectal cancer in conjunction with 5-FU chemotherapy, systemic adverse events have included a rise in blood pressure and stroke.

Dr. Moshfeghi also recommends keeping the diluted Avastin for a maximum of 2 weeks. He advised physicians to tell retinal patients there is a reported increased risk of arterial thromboembolic events (including stroke) when relatively large doses of Avastin are given intravenously with traditional chemotherapy to patients with end-stage colorectal cancer every 2 weeks, but that it is not known what risk, if any, is associated with intravitreal delivery of minute quantities of Avastin in relatively healthy patients every 4 to 8 weeks.

"If a patient has a stroke 2 to 4 weeks after being injected with intravitreal Avastin, then [most studies would consider the event as possibly/probably] drug related," he said. However, this informal survey of retinal physicians captured data for all systemic adverse events and asked the respondent to then characterize the time-frame of the adverse event, so there was no pre-specified time-frame in which an adverse-event was considered "related."