Opinion Split on AMD Drugs
Ranibizumab, bevacizumab favored in 2006 PAT survey results.
ANDREW E. MATHIS, PhD, MEDICAL EDITOR
Results of the American Society of Retina Specialists (ASRS) 2006 Practices and Trends (PAT) survey of its members indicate that there is not yet a consensus as to the most effective treatment for wet age-related macular degeneration (AMD), though off-label bevacizumab (Avastin, Genentech) and recently approved ranibizumab (Lucentis, Genentech) are the clear leaders over other therapies.
The lack of a head-to-head study comparing the relative safety and efficacy of ranibizumab and bevacizumab surely accounts for the lack of consensus. However, the recent announcement by the National Institutes of Health that it will fund a large-scale, 2-year, head-to-head study of the two Genentech drugs was welcomed by the retina community.
Though the PAT survey was conducted prior to the June 30 FDA approval of ranibizumab, survey results show that, were the drug available at the time of the survey, it would rival bevacizumab and far outrank other interventions in the treatment of AMD.
For instance, in the case of AMD with classic-type lesions, the respondents polled, given a multiple choice of treatments, chose equally (34% each) bevacizumab and ranibizumab. Photodynamic therapy (PDT) with a vascular endothelial growth factor (VEGF) blocking drug (13.5%) and PDT with steroids (11%) followed third and fourth, respectively.
When the same question was asked with the only difference being occult-type membranes rather than classic-type lesions, respondents overwhelmingly (84%) chose bevacizumab and ranibizumab, but again in the same percentage (42% each). Other therapies only received single percentages.
With the FDA's approval of ranibizumab, it is clear that it will be frequently used by retinal physicians for the treatment of AMD, both with classic-type and occult-type lesions. This is even more clear when it is considered that 95% respondents to last year's PAT Survey were treating AMD with either PDT alone or PDT with steroid.
An interesting finding in this year's PAT Survey is how respondents answered the question of how they would want themselves treated for juxtafoveal lesions. In these cases, physicians were far more conservative. While ranibizumab (36%) and bevacizumab (16%) still accounted for a slim majority of the responses, PDT with an anti-VEGF (28.5%) outranked bevacizumab alone, and 11% chose old-style standard laser therapy.
HOW THE PAT SURVEY IS CONDUCTED
This year's results were reported in September at the 24th Annual ASRS Meeting and the 6th Annual European VitreoRetinal Society (EVRS) Meeting in Cannes, France.
The PAT Survey, as its title suggests, measures the professional habits, treatment regimens, and other information about retinal specialists. After a short section to gather basic demographic information (location, practice information, etc.), the survey moves into questions about how the responding physician treats conditions such as AMD, retinal vascular occlusion (RVO), and diabetic retinopathy. The survey also asks which procedures retinal physicians are using to treat these disorders and reports in what numbers these interventions are being used. Necessarily the questions of the survey are dictated to some extent by developments in the field of retinal disease.
The testing environment itself has also changed over the past 7 years, with Internet administration of the survey replacing more structured administrations previously done exclusively on paper. This has allowed the respondents the ability to answer more at their leisure. As the rate of response for the PAT Survey had already grown significantly between 1999 and 2004, one can only assume that Internet administration of the survey had increased the response numbers even more.
The PAT survey "has taken on a life of its own since it began in 1999," said Robert A. Mittra, MD, editor of the survey for ASRS, during a conversation with Retinal Physician. The survey has been "fueled by the retinal community's interest of the latest preferences and trends among their peers," Dr. Mittra said. Noting the survey's impact on the retinal community, Dr. Mittra stated, "It is quoted frequently in scientific lectures and publications and is used to help support legislative efforts such as the successful American Academy of Ophthalmology (AAO) effort to convince Centers for Medicare & Medicaid Services (CMS) to reimburse Avastin."
STEROIDS FOR RVO GAIN GROUND
Other interesting responses to the survey were on the subject of central RVO. For the management of4-month-old RVO with cystoid macular edema (CME), half (50%) of the respondents chose intravitreal steroid as the treatment they would use. Coming in second was treatment with bevacizumab at 38%. Ranibizumab was not offered as a choice here, though "Other" was a choice offered to respondents, and ranibizumab users could have answered thus.
When asked how they would treat 4-month-old branch RVO with CME, the number of respondents who chose bevacizumab dropped to 14%, behind standard grid laser (38%), laser therapy plus intravitreal steroid (29%), and intravitreal steroid alone (16%). These responses on RVO would seem to indicate that a trend toward use of anti-angiogenic drugs similar to that in treatment of AMD has not yet emerged.
REMAINS TO BE SEEN
Of course, these results are merely the tip of the iceberg, and Dr. Mittra reminds Retinal Physician that "there were many more interesting results revealed in the survey that can be viewed on the ASRS Web site (see editor's note)." Dr. Mittra concluded, "The continued success and value of this survey depends on all in the retinal community taking a few minutes to respond to the survey each year."
Editor's note: The results of the ASRS 2006 PAT Survey are available to ASRS members at www.asrs.org.