INTRAVITREAL IMPLANT

Results of two identical FDA studies conducted by the MEAD study group indicate that the dexamethasone intravitreal implant, Ozurdex® (Allergan), can bring about significant and sustained improvements in vision in patients with diabetic macular oedema (DME), with generally only transient increases in intraocular pressure (IOP), but with a high incidence of cataract in phakic patients, Francesco Bandello MD told attendees at the 14th EURETINA Congress in London.

“In this study, an average of only four to five injections of the 0.7mg or 0.35mg dexamethasone implant over three years provided long-term improvement in vision and macular oedema in patients with DME. The DEX implants met the primary efficacy endpoint for improvement in BCVA. And although development of cataract decreased the benefit of treatment in phakic eyes during the second year of the study, the treatment benefit was restored following cataract extraction,” said Dr Bandello, University Vita Salute, Hospital San Raffaele, Milan, Italy.

The two MEAD studies were identical in design, and involved a total of 1,048 DME patients treated at 131 sites in 22 countries. Selection criteria included vision ranging from 20/50 to 20/200, and a central retinal thickness (CRT) of 300µm or more, determined by optical coherence tomography. The patients were randomised into three groups to receive Ozurdex at a dosage of 0.7mg or 0.35mg, or sham treatment, with repeated injections when indicated, at intervals no shorter than six months.

At a follow-up of three years, 22.2 per cent of patients in the 7.0mg group and 18.4 per cent in 3.5mg group had an improvement of 15 or more letters in best corrected visual acuity (BCVA). That compared to only 12.0 per cent in the sham group (p < 0.018).

In addition, the dexamethasone groups gained an average of 3.5 letters of BCVA, compared to an average gain of only two letters in the sham treatment group. Furthermore, the mean reduction in central retinal thickness was 111.6μm in the 0.7mg group and 107.9μm in the 3.5mg group, compared to only 41.9μm in the sham group (P< 0.001).

Elevations of IOP were fairly mild in most cases where they occurred and were manageable with topical medication in all but three patients, who required trabeculectomy.

“By the end of the study, treatment with the dexamethas-one implant resulted in clinically meaningful improvement in BCVA independent of lens status at baseline. The safety profile of DEX implant was better than the reported safety profile of other intraocular corticosteroids and consistent with previous reports,” Dr Bandello added. Ozurdex was first approved by the US FDA in 2009 for the treatment of macular oedema following branch retinal vein occlusion. Following the release of the MEAD results in late 2014, the FDA extended the approval to include the treatment of DME.

Francesco Bandello: bandello.francesco@hsr.it