Avastin versus Lucentis

A recent study from Bashshur and colleagues reported on 60 patients who were treated with Avastin® and then followed for one year. They gave their AMD patients one injection of Avastin 2.5 mg and then followed them monthly with OCTs. The injections were repeated every month until the macula was dry on OCT. If the OCT was dry, the authors didn’t give an injection but asked the patient to return in one month. The treatment paradigm was similar to the PrONTO study except in PrONTO, Lucentis® .5mg was used instead of Avastin and the patient first received three monthly injections followed by additional injections as needed. The other difference was that Bashshur and colleagues would not reinject if the eye showed persistent subretinal or intraretinal fluid after three injections. They believe that these eyes often remain stable. Therefore they would follow them and only reinject if they worsened. In the PrONTO study, any fluid on OCT was an indication for another injection.

I could criticize the paper because there were only 60 patients and nine of them were lost to follow-up. Still it struck me how similar these results were using Avastin to the results of the PrONTO study, (also a small study), which used Lucentis. The authors used 2.5mg of Avastin which is twice the 1.25mg dose usually used successfully in the US. The higher dose may be the reason however that most of their patients had a dry macula one month after the first injection. In my experience, 1.25mg of Avastin often doesn’t result in a dry macula at one month so maybe the higher dose is useful at least for the first dose.

The Comparison of AMD Treatment Trials (CATT) is starting and will be the definitive study comparing Avastin to Lucentis for the treatment of wet AMD. The results of Bashshur and colleagues however predict that at most, we’ll find only a modest difference between the two drugs.

References:

1. Bashshur, ZF AJO 2008;145:249-256.

2. Lalwani GA, Fung AE, Michels S, Dubovy SR, Feuer WJ Jr, Puliafito CA, Rosenfeld PJ. An OCT-Guided Variable-Dosing Regimen With Ranibizumab (Lucentis) in Neovascular AMD: Two Year Results of the PrONTO Study (Poster Session 247. 1834/B694) ARVO Annual Meeting: The Aging Eye. May 6-10 2007, Fort Lauderdale, FL. Available at http://tinyurl.com/yt5fwd. (you will need to enter "Pronto" in the search field and restrict it to "presentation title").