Sunday, October 25, 2009

Risk of stroke with Lucentis vs. Avastin

In the February 2009 issue of Ophthalmology, a meta-analysis was reported in a letter to the editor pointing out some risks associated with intravitreal injection of ranibizumab (Lucentis). The letter looked at pooled data from the MARINA, ANCHOR and FOCUS studies which were done to determine effectiveness and adverse effects of Lucentis. The authors of the letter point out that when pooling all the data, the ranibizumab group had a 2.2% incidence of stroke, whereas the control group had a 0.7% incidence of stroke. They conclude that the risk of stroke rises as a result of ranibizumab treatment. When they look at the incidence of myocaridal infarction (MI), the ranibizumab group had a 1.9% incidence whereas the control group had a 3.0% incidence. They did not "conclude" that intravitreal injection was protective for MI, but the incidence is lower in the group receiving the drug vs. the control group.

Since the letter was published, there has been some discussion regarding the implications of this meta-analysis for those of us using Avastin. At the current time the feeling is that this data cannot be extrapolated to Avastin, in part because Avastin is a larger molecule (the entire globulin, vs. the immune arms as with ranibizumab). This molecular characteristic is felt to result in less egress of Avastin into the systemic circulation, and it is to this characteristic that the longer-acting effect of Avastin has been attributed. There is currently an NIH sponsored head-to-head clinical trial comparing Lucentis and Avastin underway. The results are due in 2012. The study is ongoing, and the fact that it has not been stopped is some solace to those of us who prefer Avastin that the study has not to date shown that Avastin is either hugely inferior or has significantly higher side-effects that Lucentis.

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