Researchers found that ranibizumab (Lucentis) may slow the progression of diabetic retinopathy….
Michael Ip, MD, of the University of Wisconsin in Madison, and colleagues reported during an oral session at the American Academy of Ophthalmology meeting that, in the 3-year data from the RIDE and RISE trials, visual acuity improved more for patients taking either of two doses of ranibizumab than for those who had sham injections for 2 years before crossing over to the drug.
"There’s strong evidence that ranibizumab is effective at reducing diabetic retinopathy severity," Ip said during the presentation.
Lucentis currently is approved for wet age-related macular degeneration (AMD), retinal vein occlusion (RVO), and diabetic macular edema (DME).
The primary endpoint of the RIDE and RISE trials was change in best-corrected visual acuity at 2 years in patients with diabetic macular edema, and then patients continued in an open-label extension phase for an additional year.
Patients were randomized to one of three groups: 257 patients received a sham injection, 250 had ranibizumab 0.3 mg, and 252 received ranibizumab 0.5 mg. Placebo patients were switched to ranibizumab 0.5 mg in the third year.
In their secondary analysis, Ip and colleagues looked at patients with diabetic retinopathy, a less severe form of DME, conducting 7-field color fundus photography to assess changes from baseline on the ETDRS Severity Scale. They also looked at changes in clinical events, including vitreous hemorrhage and the need for pan-retinal photocoagulation.
Ip said 2-year results showed that ranibizumab prevented further worsening of diabetic retinopathy and actually improved the condition in most patients.
Through 3 years, the researchers found that the mean change in best-corrected visual acuity was maintained for both drug groups (+12.4 for 0.5 mg, +11.2 for 0.3 mg versus +2.5 with placebo), and began to improve in the placebo group once its members were switched to the drug, rising to +4.5 letters at the end of the third year.
But Ip and colleagues also found that significantly more patients in the sham group that crossed over to ranibizumab progressed to proliferative diabetic retinopathy than in either group that was on the drug from the beginning.
Although the progression curves flattened for the crossover group, the gap still remained wide, suggesting that the "delay in ranibizumab therapy results in a reduction in the change to improve diabetic retinopathy severity level," Ip said.
Though preliminary, the data "provide strong evidence that ranibizumab is effective in reducing the severity of diabetic retinopathy," he said, adding that further trials are needed to look at this outcome. He also called for other work to develop and investigate a sustained delivery device that can minimize the number of injections needed.
In the meantime, clinicians should consider using the drug alone or in combination with laser therapy to have an impact on the severity of diabetic retinopathy, Ip said.
The question remains as to whether monthly injections over the entire 3 years will be necessary to sustain improvements in diabetic retinopathy and whether it’s permanent when the patient comes off the drug.
- Intravitreal ranibizumab, currently approved for wet age-related macular degeneration, retinal vein occlusion, and diabetic macular edema, appears to prevent further worsening of diabetic retinopathy and actually improves the condition in some patients, a study found.
- This study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.
Ip MS, et al "Effects of intravitreal ranibizumab on diabetic retinopathy severity: 36-month data from RISE and RIDE trials" AAO 2012; Abstract PA054.