A Study to Evaluate ASP8232 in Reducing Central Retinal Thickness in Subjects With Diabetic Macular Edema (DME)

Inclusion Criteria:

- Subject must have a documented diagnosis of type 1 or type 2 diabetes mellitus and a
glycosylated hemoglobin A1c (HbA1c) of ≤ 12.0% at Screening

- Subject has definite retinal thickening due to diffuse diabetic macular edema (DME)
involving the central macula based on evaluating investigator's clinical evaluation
and demonstrated by spectral domain-optical coherence tomography (SD-OCT)

- Subject has central subfield thickness (CST) of at least 375 μm by SD-OCT with
presence of intraretinal and/or subretinal fluid at screening visit and at the
randomization visit

- Subject has early treatment diabetic retinopathy study (ETDRS) best corrected visual
acuity (BCVA) letter score ≤ 73 (Snellen 20/40) and ≥ 24 (Snellen 20/320) at screening
visit

Exclusion Criteria:

- Subject's study eye has macular edema considered to be due to a cause other than DME

- Subject's study eye has a decrease in BCVA due to causes other than DME that is likely
to be decreasing BCVA by 3 lines or more

- Subject's study eye has significant macular ischemia as shown on angiography

- Subject's study eye has any other ocular disease that may cause substantial reduction
in BCVA

- Subject has active peri-ocular or ocular infection

- Subject's study eye has a history of non-infectious uveitis

- Subject's study eye has high myopia (-8 diopter or more correction)

- Subject's study eye has a history of prior pars plana vitrectomy

- Subject's study eye has a history of any ocular surgery within 3 months prior to Day 1

- Subject's study eye has a history of YAG capsulotomy within 3 months prior to Day 1

- Subject's study eye has a history of panretinal scatter photocoagulation (PRP) or
focal laser within 3 months prior to Day 1 or anticipated need for PRP during the
course of the study through the Week 12 visit

- Subject's study eye has a history of prior IVT, subtenon, or periocular, non-sustained
release, steroid therapy within 3 months prior to Day 1

- Subject's study eye has a history of intravitreal sustained release dexamethasone
therapy within 6 months prior to Day 1.

- Subject's study eye has a history of intravitreal sustained release fluocinolone
within 3 years prior to Day 1.

- Subject's study eye has a history of prior treatment for DME with IVT anti-vascular
endothelial growth factor (VEGF) treatment within 8 weeks prior to Day 1

- Subject has a history of prior treatment with any other (than previously listed)
approved treatment which is not labeled for DME within 1 year prior to Day 1

- Subject's study eye has high-risk proliferative diabetic retinopathy (PDR)

- Subject has uncontrolled glaucoma

- Subject has media clarity, papillary constriction (i.e., senile miosis), or subject
lacks cooperation that would interfere with any study procedures, evaluations or
interpretation of data