NEW YORK (Reuters Health) – Bevacizumab improved visual acuity and central subfield thickness (CST) in a retrospective analysis of diabetic macular edema patients.
“Use of bevacizumab, the cheapest of the three vascular endothelial growth factor (VEGF) inhibitors, for retinal diseases…varies among countries, according to drug regulatory processes, reimbursement policies and its availability,” Dr. Sanjeep Bhandari of the US National Eye Institute in Bethesda told Reuters Health by email.
“Our study provides evidence that bevacizumab treatment in eyes with diabetic macular edema in routine clinical practice yielded visual outcomes similar to those reported in observational studies of ranibizumab and aflibercept,” said Dr. Bhandari, who was who was at the University of Sydney, Australia when the research was conducted. “Its effect in reducing macular thickness, however, was inferior to those of aflibercept and ranibizumab.”
As reported in Eye, Dr. Bhandari and colleagues analyzed one-year treatment outcomes of 298 eyes of 220 patients with diabetic macular edema (mean age, 62; 46% women) who received at least two 1.25 mg injections of bevacizumab between 2013- 2018.
The mean visual acuity at one year was three letters better than a mean of 68 letters at study entry.
Nearly a quarter of eyes achieved visual acuity of at least 20/40. Eyes presenting with that vision at baseline tended to maintain it during the observation period; those presenting with worse vision gained a mean of nine letters.
CST improved by 29 micrometers, from a mean of 402 at study entry.
Eyes that completed one year of follow-up received a median of seven bevacizumab injections. About 20% of eyes started on bevacizumab were changed to either another VEGF inhibitor or a steroid (triamcinolone). Although macular thickness was reduced further, the switch to either ranibizumab or aflibercept did not lead to functional improvement.
However, eyes that subsequently received triamcinolone had vision improvement as well as a reduction in macular thickness.
Approximately 10% of eyes dropped out over 12 months, even though their mean visual acuity had improved by seven letters from the initial visit.
The authors state, “Bevacizumab is a reasonable option for the treatment of (diabetic macular edema) when cost, convenience and availability pose an issue.”
Dr. Bhandari noted, “Third-party payors in many countries reimburse the approved drugs (e.g., aflibercept and ranibizumab). Clinicians may be reluctant to use an off-label drug (bevacizumab) when registered drugs are available.”
Dr. Dean Eliott, Director of the Retina Service at Mass Eye and Ear and Co-Director, Diabetic Eye Disease Center of Excellence at Harvard Medical School in Boston agreed that bevacizumab “is an effective treatment option for diabetic macular edema in real-world clinical practice.”
“Compared to other observational studies, the visual gains in the present study were relatively low,” he told Reuters Health by email. “However, the higher vision at study entry may partly account for the lower gains, due to a ceiling effect.”
“The final vision at one year in the present study was similar to that of the bevacizumab group in the DRCR.net Protocol T study, suggesting that bevacizumab is beneficial at least when vision is good,” he said. “This study does not provide evidence that bevacizumab achieves similar outcomes as ranibizumab or aflibercept when presenting vision is poor.”
The DRCR.net Protocol T study (https://bit.ly/3d1Bj2X) “reported that bevacizumab was less effective than either ranibizumab or aflibercept at reducing macular thickness at one year,” he said. “The present study showed even less reduction in macular thickness, which was probably due to fewer treatments given – a median of seven injections in this study versus 10 in the DRCR.net Protocol T study.”
“For the treatment of diabetic macular edema, retina specialists should be able to choose among the available VEGF inhibitors, and this includes the FDA-approved medications as well as bevacizumab,” he concluded. “There are a variety of factors that determine which agent may be best for an individual patient.”
SOURCE: https://go.nature.com/31YodgC Eye, online March 25, 2021
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