A Phase 2, Multi-Center Study To Compare The Efficacy And Safety Of A Chemokine CCR2/5 Receptor Antagonist With Ranibizumab In Adults With Diabetic Macular Edema

Proportion of Subjects Gaining 15 ETDRS Letters in BCVA From Baseline at Week 12

Refraction and visual acuity were assessed through the BCVA obtained using the retro illuminated ETDRS charts. Distance visual acuity was expressed as an ETDRS score (number of letters correctly read).

Time frame: Baseline (Day 0) and Week 12

Mean Change From Baseline in Central Subfield Retinal Thickness in the Study Eye at Week 12

A central reading center was used for the evaluation. A photographer or technician pre certified ("study certified") by the Central Reading Center ought to perform all optical coherence tomography (OCT) imaging. Use of a Spectralis or Cirrus OCT was acceptable.

Time frame: Baseline (Day 0) and Week 12

Mean Change From Baseline in The Area of Fluorescein Leakage in the Study Eye at Week 12

Fluorescein Angiography (FA) using certified digital systems was taken by a photographer who had been pre-certified ("study-certified") by the Central Reading Center. They were evaluated by the Central Reading Center.

Time frame: Baseline (Day 0) and Week 12

Mean Change From Baseline in Steps of Diabetic Retinopathy Step (ETDRS Severity Scale) in the Study Eye at Week 12

Stereo color fundus photographs using certified digital systems were taken by a photographer who had been pre-certified ("study certified") by the Central Reading Center. They were evaluated by the Central Reading Center.

Time frame: Baseline (Day 0) and Week 12

Plasma Concentration of PF-04634817 up to Week 12

Time frame: Week 0, Week 4, Week 8, and Week 12