Aflibercept effects mild in patients not responding to ranibizumab

By Laird Harrison

Nice, France-Switching from ranibizumab to aflibercept may allow some patients to extend the time between treatments for neovascular age-related macular degeneration (AMD), researchers say.

“About one third of lesions showed an increased duration of treatment effects,” said Katja Hatz, MD, head of medical retina and research at Vista Klinik, Binningen, Switzerland who presented the finding at the European Society of Retina Specialists 15th EURETINA Congress.

Visual acuity remained unchanged in the patients said Dr. Hatz, probably because they were being treated with ranibizumab on a strict 4-week schedule before switching.

Some research has suggested superiority for aflibercept compared to ranibizumab in certain categories of patient, but few prospective trials have examined the results in patients who switch from one therapy to the other.

So Dr. Hatz and her colleagues followed 33 patients after being pre-treated with intravitreal ranibizumab on a treat-and-extend regimen who could not be extended to 4-week intervals after at least 2 attempts.

They gave the first aflibercept injection 4 weeks after the last ranibizumab injection. They followed up with further aflibercept treatments according to a treat-and-extend approach, starting with a 4 weeks interval, then attempting to extend in 2-week-steps.

Twenty-nine patients were available for follow-up after 24 weeks for the efficiency analysis and all were included in the safety analysis.

After switching to aflibercept, 24.1% of patients were able to increase their maximum recurrence-free treatment interval to 6 weeks and another 10.4% increased to 8 weeks. The remainder stayed stuck at 4 weeks. The mean maximum recurrence-free treatment interval at 24 weeks was approximately 5 weeks.

The best-corrected visual acuity score remained stable.

The patients’ mean lesion size did not change significantly, either. But their central retinal thickness, pigment epithelial detachment, area of leakage and mean maximum pigment epithelial detachment horizontal diameter were significantly reduced.

Two patients experienced a pseudoendophthalmitis following an aflibercept injection. And one patient on a 4-week aflibercept treatment schedule had an extensive macular hemorrhage.

In the question and answer period that followed Dr. Hatz’s presentation, Mitchell, MD, PhD, from the University of Sydney, called it a “very interesting study.”

He wanted to know about what percentage of patients on ranibizumab were unable to extend from a 4- to a 6-week treatment interval. Dr. Hatz responded that it was about 20%.

Dr. Mitchell then asked if there were any characteristics that distinguished these patients from others.

They all had pigment epithelial detachment, Dr. Hatz said.