SUBGROUP ANALYSIS

Regardless of the baseline visual acuity, patients with diabetic macular oedema (DME) appear to have better functional and anatomic outcomes with intravitreal aflibercept (EYLEA®, Regeneron Pharmaceuticals) than they do with laser photocoagulation, and those with the worst baseline vision seem to have the greatest functional and anatomical improvements with the anti-VEGF agent, according the results of the VIVID and VISTA Phase III studies, said Edoardo Midena MD, PhD, University of Padua, Italy.

In a paper he presented at the 14th EURETINA Congress in London, Dr Midena described the findings of a subgroup analysis he and his associates conducted of the two similarly-designed studies that compared the safety and efficacy of intravitreal aflibercept and macular laser photocoagulation in the treatment of DME with central involvement.

The purpose of the subgroup analysis was to evaluate the impact of baseline visual acuity on visual outcomes and changes in central retinal thickness in DME patients receiving aflibercept.

The two studies involved a total of 865 patients, 404 in the VIVID study, conducted in the US, and 461 in the VISTA study, conducted in Europe and Japan.

In both studies patients were randomised to receive intravitreal aflibercept 2.0mg every four weeks (2q4) plus sham laser, intravitreal aflibercept 2.0mg every eight weeks (2q8) after five initial monthly doses plus sham laser, or laser photocoagulation plus sham intravitreal treatment.

The subanalysis showed that among patients receiving aflibercept there was a trend towards an inverse correlation between baseline best corrected visual acuity (BCVA) and the amount of improvement in BCVA during treatment.

In contrast, the changes in BCVA with laser treatment appeared to bear no relation to baseline BCVA and the results with laser were inferior to those achieved with aflibercept in all baseline BCVA subgroups. In the VIVID trial, the mean changes in BCVA from baseline to week 52 for the 2q4, and 2q8 intravitreal aflibercept regimen groups were gains of 15.3 and 20.6 letters respectively, among those with baseline BCVA of less than 40 letters, gains of 12.0 and 10.2 letters respectively among those with baseline visual acuity between 40 and 55 letters, and gains of 11.6 and 11.5 letters respectively among those with baseline visual acuity between 55 and 65 letters.

The reductions in central retinal thickness followed a similar pattern, Dr Midena noted. That is, central retinal thickness in the 2q4 and 2q8 intravitreal aflibercept regimen groups was reduced by 423.3 microns and –355.3 microns respectively, among those with baseline visual acuity of less than 40 letters, but by only 135.7 microns and 132.6 microns among those with a baseline BCVA greater than 65 letters.

The visual and anatomic results of the VIVID and VISTA studies were virtually identical for all baseline visual acuity subgroups, Dr Midena noted. Laser compared poorly with intravitreal aflibercept in both studies, achieving mean gains of BCVA no greater than 2.8 letters and mean reductions in central retinal thickness no greater than 145.9 microns.

Edoardo Midena: edoardo.midena@unipd.it