A Study Intravitreal THN391 in Diabetic Macular Oedema Secondary to Non-Proliferative Diabetic Retinopathy.

THN391-OPT-101 is a study assessing safety and preliminary efficacy of THN391 in patients with diabetic macular edema (DME) given as monotherapy.

This is an open label, multiple ascending dose (MAD) study, in which the safety of THN391 will be assessed in escalating doses. This study will enroll a total of approximately 21 participants into 3 sequential dose-escalating cohorts. Participants will receive 3 monthly THN391administrations.

Inclusion Criteria: * Be willing and able to understand the study procedures and the risks involved and provide written informed consent before the first study-related activity * 18 to 80 years of age (inclusive at the time of informed consent). * Diagnosis of Diabetic Macular Edema (DME) * Vision loss in the study eye Exclusion Criteria: * Be pregnant or breastfeeding * Cataract surgery or any other previous ocular surgery in the study eye within 3 months before Screening * Any other condition except for DME that could affect interpretation of study assessments