Anti-VEGF Shot Improves Sight for Diabetes Patients

The study "provides evidence for the longer-term use of bevacizumab in the treatment of persistent diabetic macular edema," they wrote.

Laser therapy has been the mainstay of treatment for diabetic macular edema (DME) for the past three decades. While the technique reduces the risk of visual loss, it may not be quite as good at improving visual acuity, the researchers said.

That's why clinicians have been using VEGF inhibitors off-label for the condition, and several trials have investigated their efficacy. The two most commonly used are bevacizumab (Avastin) and ranibizumab (Lucentis).

Ranibizumab is approved for age-related macular degeneration; bevacizumab has long been approved for various cancer indications. Both drugs are manufactured by Genentech, but ranibizumab injections can run $1,950 each while bevacizumab costs only $50 per shot.

The Centers for Medicare and Medicaid Services recently held a meeting to discuss whether the drug class should be covered for diabetic macular edema.

Hykin and colleagues conducted the BOLT study in 80 patients with center-involving diabetic macular edema that persisted despite previous laser therapy. They compared 1.25 mcg bevacizumab injections with further laser therapy. One-year results showed that patients had greater improvements in visual acuity with the injections than with laser photocoagulation.

The researchers found that those results persisted at 2 years, with mean visual acuity still higher in the bevacizumab arm (64.4 versus 54.8, 20/50 versus 20/80). These patients also had a mean gain of 8.6 letters compared with a mean loss of 0.5 letters for those who had laser surgery.

About half (49%) gained 10 or more letters, and 32% gained at least 15 letters with bevacizumab, compared with 7% and 4% of laser therapy patients (P=0.001 and P=0.004, respectively).

The mean reduction in central macular thickness was 146 ěm with VEGF therapy versus 118 ěm in laser surgery, although there wasn't a significant between-group reduction, the researchers reported.

Patients had a median of 13 bevacizumab injections compared with a median of four laser treatments. During the second year, however, the mean was just four injections, "implying that visual improvement and stable macular thickness can be maintained in the longer term with a reduced injection frequency of probably 6 to 12 weeks." They added that it's possible that a 4-week injection cycle may provide even better visual acuity gains.

There were 27 ocular adverse events with bevacizumab, which were largely related to the injection, compared with seven adverse events in the laser therapy group. There were six systemic serious adverse events with the VEGF inhibitor compared with four in the laser group, but the researchers noted that their study wasn't large enough "to make definitive safety statements." However, they said there were no cases of endophthalmitis and no unusual complications related to the injection.

Hykin and colleagues concluded that the results are in line with several other trials of VEGF inhibitors in diabetic macular edema, and that cost will likely be an important factor in deciding between bevacizumab and ranibizumab therapy.

Practice Pearls:

• Point out that the study indicates that improvements in visual acuity seen with bevacizumab at 1 year were maintained over the second year.
• This is a report of 2-year outcomes of a prospective, randomized, controlled trial that evaluated intravitreous bevacizumab or additional laser therapy in the management of diabetic macular edema.

Source: http://www.diabetesincontrol.com/index.php?option=com_content&view=article&id=12615&catid=53&Itemid=8, Rajendram R, et al "A two-year prospective randomized controlled trial of intravitreal bevacizumab or laser therapy (BOLT) in the management of diabetic macular edema" Arch Ophthalmol 2012; DOI: 10.1001/archophthalmol.2012.393.