The New England Journal of Medicine have just published online the results of the Comparison of Age-related macular degeneration treatment trial (CATT) comparing the efficacy of FDA approved ranibizumab (Lucentis) to off-label bevacizumab (Avastin); a trial that has important commercial importance given the comparative costs of an intravitreal injection of around $1950 (Lucentis) vs. $50 (Avastin).
Key Study Results
Based on 1208 patients randomly assigned in the single-blind noninferiority trial, primary outcome was mean change in visual acuity between baseline and 1 year. This was equivalent between the two drugs.
Bevacizumab administered monthly was equivalent to ranibizumab administered monthly, with 8.0 and 8.5 letters gained, respectively.
Secondary outcome measures included the incidence of ocular and systemic side effects, the results show some similarities and differences:
Rates of death, myocardial infarction and stroke were similar for patients receiving either bevacizumab or ranibizumab (P>0.20).
The proportion of patients with serious adverse events (primarily hospitalization) was higher with bevacizumab than with ranibizumab (24.1% vs 19%)
The conclusion of the study is that:
At 1 year, bevacizumab and ranibizumab had equivalent effects on visual acuity when administered to the same schedule”
However, here is the potential ‘get out’ for Genentech:
Differences in rates of serious adverse events require further study.
The investigators note that the difference in serious adverse events may be due to:
“chance, imbalances in baseline health status that were not included in the medical history or multivariate models, or a true difference in risk.”
i.e. they don’t know.
What the results from the CATT study mean is that Avastin and Lucentis are similar, but different. That is not a surprising result given that they originate from the same anti-VEGF monoclonal antibody. However, they are not identical.
Clearly, if I were a patient, the additional 5% risk of serious adverse events would have to be weighed against the cost benefits. For those who are uninsured or unable to afford Lucentis, receiving Avastin may be an informed decision worth taking. As the investigators note:
One of the many factors that contribute to the selection of a drug for a patient is cost. A single dose of ranibizumab costs 40 times as much as a single dose of bevacizumab. This cost differential has important economic implications when extrapolated to the more than 250,000 patients who are treated for neovascular AMD annually in the United States.
I look forward to hearing the animated discussion of these results at the ARVO annual meeting in Fort Lauderdale on Sunday.
The CATT Research Group (2011). Ranibizumab and Bevacizumab for Neovascular Age-Related Macular Degeneration New England Journal of Medicine DOI: 10.1056/NEJMoa1102673