Aflibercept trial highlights significance of baseline characteristics in DME
A trial evaluating the use of aflibercept 8 mg in patients with diabetic macular edema (DME), found that baseline disease severity may have been greater in patients with shortened dosing intervals, particularly with the 8 mg every 16 weeks dosing regimen. The study observed differences in visual acuity, central retinal thickness, and diabetic retinopathy severity between patients with maintained versus shortened dosing intervals.
The PHOTON trial, a 96-week double-masked noninferiority study, involved the randomization of 658 patients with DME. Participants were assigned to receive aflibercept 8 mg every 12 weeks (8q12) or 16 weeks (8q16) after an initial 3 monthly doses, or aflibercept 2 mg every 8 weeks (2q8) after 5 monthly doses. Starting from Week 16, dosing intervals were adjusted if patients receiving aflibercept 8 mg met specific criteria for regimen modification.
Of the patients who completed Week 48, 9.0% (27/300) in the 8q12 group and 10.9% (17/156) in the 8q16 group had their dosing intervals shortened. A comparison of baseline characteristics between patients with maintained versus shortened dosing intervals revealed interesting insights.
The mean baseline best-corrected visual acuity (BCVA) letter score for patients with 8q12 dosing was 63.9 (maintained) versus 59.4 letters (shortened). Similarly, for patients with 8q16 dosing, the mean baseline BCVA letter score was 62.7 (maintained) versus 53.7 letters (shortened). The baseline central retinal thickness showed a difference as well, with 8q12 patients having 444.9 µm (maintained) versus 511.4 µm (shortened), and 8q16 patients having 447.1 µm (maintained) versus 534.8 µm (shortened).
The baseline Diabetic Retinopathy Severity Score indicated that 33.7% of patients with 8q12 and 26.6% of patients with 8q16 had a score of 47 or worse in the group with maintained dosing intervals, compared to 40.7% and 41.2%, respectively, in the group with shortened dosing intervals.
Reference
Marcus DM, et al. Characteristics of Patients Who Did or Did Not Maintain Aflibercept 8-mg Dosing Intervals in the Phase 2/3 PHOTON Trial. Presented at: AAO 2023.
