NEW YORK (Reuters Health) - The benefits of individualized ranibizumab treatment for diabetic macular edema (DME) persist for at least three years, according to results from the RESTORE extension study.
The original RESTORE study showed that ranibizumab alone or combined with laser provided superior visual acuity gains when compared with laser monotherapy over 12 months in patients with visual impairment due to DME.
In the RESTORE extension study, ranibizumab dosing was individualized at the investigators' discretion. Best corrected visual acuity (BCVA) stability and disease progression, monitored monthly, guided treatment.
In a paper online February 3rd in Ophthalmology, Dr. Ursula Schmidt-Erfurth from Medical University Vienna and colleagues reported the results of the complete three-year data on the core and extension studies for 208 patients.
Improvements in BCVA among patients treated with ranibizumab during the core study were generally maintained during months 12 to 36, they found.
Moreover, prior laser monotherapy patients who received ranibizumab during the open-label extension experienced progressive improvements in BCVA, from 2.3 letters at month 12 to 6.0 letters at month 36.
Results followed a similar pattern for central retinal subfield thickness, Early Treatment Diabetic Retinopathy Study severity scores, and Visual Functioning Questionnaire scores.
The average number of ranibizumab injections over the two years of the extension study was similar across the treatment groups (median, 4.0 to 6.0, depending on the group). The most common reason for treatment interruption/discontinuation was disease improvement.
Eight patients (3.3%) experienced ocular serious adverse events in the study eye, and 88 patients (36.7%) had nonocular serious adverse events.
Cataract (11.3%) and eye pain (10.0%) were the most frequent ocular adverse events, and the most common nonocular adverse events were nasopharyngitis, influenza, and hypertension.
"The three-year results of the RESTORE extension study confirmed the favorable efficacy and safety profiles of ranibizumab in the long-term treatment of visual impairment due to DME," the researchers conclude. "This study also demonstrated that individualized treatment was able to consistently maintain visual acuity in the ranibizumab-treated patients."
"Although patients in the prior laser group were finally able to achieve approximately 75% of the benefit seen in the ranibizumab monotherapy group, after receiving ranibizumab in the extension study, this gain was gradual and occurred over the two-year period of the extension," they explained. "Thus, early initiation of ranibizumab therapy may provide prompt and substantial visual acuity gains allowing patients from the working-age population, often challenged by multiple systemic comorbidities, to ease disease management and improve quality of life despite severe and chronic disease."
Dr. David S. Boyer from Retina Vitreous Associates Medical Group, Los Angeles, California recently reviewed anti-VEGF therapy for DME. He told Reuters Health, "Other anti-VEGF drugs have shown similar improvements. The DRCR net (Diabetic Retinopathy Clinical Research Network) is presently doing a head to head study comparing bevacizumab vs. ranibizumab vs. aflibercept. Hopefully the results will help guide us on which drug works better, and to see if PRN treatments will yield comparable results to monthly treatment."
Dr. Boyer said the take-home message of the RESTORE extension study is that "patients may not require as frequent injections but do require careful follow-up to maintain the visual gains."
Novartis Pharma AG, Switzerland sponsored the trial, employed four of the authors, and had various relationships with the other seven authors.
Dr. Schmidt-Erfurth did not respond to a request for comments.
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