A Study to Learn More About How Well 8 Milligram Aflibercept Works and How Safe it is in Chinese Participants With Diabetic Macular Edema

Researchers are looking for a better way to treat people who have diabetic macular edema.

Diabetic macular edema (DME) is a diabetes-related eye disorder. In DME, the macula, which is the central part of the retina at the back of the eye, swells up resulting in vision problems. This happens due to leakage of fluid from damaged blood vessels.

The study treatment, 8 milligram (mg) aflibercept is injected into the eye. It works by blocking a protein called vascular endothelial growth factor (VEGF) which causes abnormal growth and leakage of blood vessels at the back of the eye.

A lower dose of aflibercept (2 mg) is already approved for the treatment of DME. Based on the findings of another study, the higher dose of aflibercept (8 mg) is expected to reduce the frequency of injections required for treating DME while being equally safe and working as well as the lower dose. The higher dose could make it easier to treat DME and improve quality of life for people with DME.

The main purpose of this study is to learn if high-dose (8 mg) aflibercept given every 16 weeks works as well as low-dose (2 mg) aflibercept given every 8 weeks in Chinese participants.

For this, the researchers will compare the change in participants' 'best corrected visual acuity' (BCVA) after 48 weeks of starting the treatment. BCVA is the clearest vision a participant can have with the help of corrective lenses, such as glasses. It will be measured by the number of letters the participant can read on an eye chart. This is known as their Early Treatment Diabetic Retinopathy Study (ETDRS) letter score.

Participants will be randomly (by chance) assigned to one of two treatment groups to receive study treatment as an injection into the eye up to Week 56:

* 2 mg aflibercept every 8 weeks after receiving 5 initial monthly doses
* 8 mg aflibercept every 16 weeks after receiving 3 initial monthly doses

Each participant will be in the study for around 63 weeks with up to 18 visits to the study site. This includes:

* one visit up to 21 days before the treatment starts during which the doctors will confirm that the participant can take part in the study
* 16 visits during which the treatment will be given. Most of these visits will have a gap of 4 weeks except for one visit that will happen a few days after the previous visit
* one visit 4 weeks after the treatment ends

During the study, the doctors and their study team will:

* check the participants' vision and their overall eye health using different eye tests
* check participants' health by performing tests such as blood and urine tests
* ask the participants questions about the disease and study treatment and how these impact their quality of life
* ask the participants what adverse events they are having An adverse event is any medical problem that a participant has during a study. Doctors keep track of all adverse events, irrespective of whether they think they are related to the study treatment.

Access to study treatment after the end of this study is not planned. Participants can switch to available approved treatments for DME.

EYLEA (aflibercept 40 mg/mL solution for injection) at a dosage level of 2 mg administered intravitreally (IVT) is approved in over 100 countries for the treatment of DME. Despite the proven efficacy and safety of EYLEA in patients with DME, there remains an unmet need for alternative therapies that can decrease the burden of DME treatment via a reduction in the required frequency of IVT injections, while improving visual and anatomic outcomes. The overall one and two year results of PHOTON, a global phase 2/3 trial evaluating high dose (HD or 8 mg) aflibercept in participants with center-involved diabetic macular edema (DME), demonstrate the benefit of HD aflibercept for reducing the frequency of injections required for the treatment of DME while providing visual and anatomic outcomes non-inferior to and a safety profile indistinguishable from EYLEA, 2 mg aflibercept, the established standard of care for the treatment of DME. The observed reduction in the number of HD aflibercept injections required for the treatment of DME over 2 years in PHOTON is expected to translate into the benefit of reducing the burden of treatment and, thereby improving the quality of life for DME patients, their caregivers and health care providers. This study aims to investigate the efficacy and safety of HD aflibercept in Chinese participants with DME over 60 weeks with the primary objective of achieving non-inferior best corrected visual acuity (BCVA) with an extended dosing interval (every 16 weeks after 3 initial monthly injections) vs. 2 mg aflibercept (every 8 weeks after 5 initial monthly injections) similar to the results obtained in PHOTON. This study is designed to support the registration of HD aflibercept for the treatment of DME in China.

Primary Objective: The primary objective of the study is to determine if treatment with HD aflibercept at intervals of 16 weeks provides non-inferior best-corrected visual acuity (BCVA) compared to 2 mg aflibercept dosed every 8 weeks in Chinese participants

Secondary Objectives:

* To determine the effect of HD aflibercept vs. 2 mg aflibercept on anatomic and other visual measures of response;
* To evaluate the safety, immunogenicity and pharmacokinetics (PK) of HD aflibercept in Chinese participants.

Primary endpoint:

* Change from baseline in BCVA by ETDRS letter score at Week 48

Secondary endpoints:

* Change from baseline in BCVA by ETDRS letter score at Week 60
* Participants gaining ≥15 letters at Week 48 and Week 60
* Participants achieving an ETDRS letter score of at least 69 (approximate 20/40 Snellen equivalent) at Week 48
* Participants with no IRF and/or no SRF in the center subfield at Week 48
* Change from baseline in central subfield thickness (CST) at Week 48
* Change from baseline in leakage on fluorescein angiography (FA) at Week 48
* Change from baseline in National Eye Institute Visual Function Questionnaire (NEI-VFQ) total score at Week 48
* Occurrence of treatment-emergent adverse events (TEAEs) and serious adverse events (SAEs) through Weeks 48 and 60
* Participants developing a treatment-emergent ADA response or Nabs to aflibercept through EOS at Week 60
* Systemic exposure to aflibercept as assessed by plasma concentrations of free, adjusted bound, and total aflibercept from baseline through Week 48 This study is a phase 3, multi-center, randomized, double-masked, active-controlled study in Chinese participants with DME involving the center of the macula to investigate the efficacy and safety of HD aflibercept versus 2 mg aflibercept.

The primary objective of the study is to determine if treatment with HD aflibercept at 16 week intervals provides non-inferior BCVA compared to 2 mg aflibercept dosed every 8 weeks in Chinese participants.

322 eligible participants randomized in a 1:1 ratio to the following 2 treatment groups:

1. 2q8: 2 mg aflibercept every 8 weeks following 5 initial monthly doses (n=161) and
2. HDq16: HD aflibercept every 16 weeks following 3 initial monthly doses (n=161). The study consists of a screening period, a treatment period, and an end of study (EOS) visit at Week 60. The study duration for a participant is approximately 63 weeks. The EOS is defined as the last visit of the last participant. No study treatment will be administered at the EOS visit at Week 60.

HD aflibercept is the sponsor's study intervention under investigation. The following intervention groups are included in the study:

* 2 mg aflibercept every 8 weeks (2q8)
* 8 mg aflibercept every 16 weeks (HDq16)

Eligibility Criteria:
Key Inclusion Criteria:

* Men or women ≥18 years of age
* Chinese participants with type 1 or type 2 diabetes mellitus and diabetic macular edema (DME) with central involvement defined as CST ≥300 µm (or ≥320 µm on Heidelberg Spectralis) in the study eye as determined by the reading center at the screening visit and confirmed by the site at baseline visit
* BCVA early treatment diabetic retinopathy study (ETDRS) letter score of 78 to 24 (approximate Snellen equivalent of 20/32 to 20/320) in the study eye at the screening and baseline visits with decreased vision determined to be primarily the result of DME
* Women of childbearing potential (WOCBP) or men who are sexually active with partners of childbearing potential must agree to use highly effective contraception prior to the initial dose/start of the first treatment, during the study, and for at least 4 months after the last administration of study intervention.

Key Exclusion Criteria:

* Evidence of macular edema due to any cause other than diabetes mellitus in either eye
* Active proliferative diabetic retinopathy in the study eye
* Panretinal laser photocoagulation (PRP) or macular laser photocoagulation in the study eye within 12 weeks (84 days) of the screening visit
* IVT anti-VEGF treatment (aflibercept, ranibizumab, bevacizumab, conbercept, faricimab, brolucizumab, pegaptanib sodium) in the study eye within 12 weeks (84 days) of the screening visit
* Previous use of topical steroids within 4 weeks (28 days) of the screening visit or of intraocular or periocular corticosteroids in the study eye within 16 weeks (112 days) of the screening visit, or ILUVIEN or OZURDEX IVT implants at any time
* Prior ocular investigational agents (that have not been approved) in either eye (e.g., IVT, suprachoroidal injections, ocular implants, etc.) at any time.
* Previous treatment with an investigational or approved intraocular gene therapy or cell therapy in either eye at any time.