A Phase 2 Clinical Trial on the Use of Cibinetide for the Treatment of Diabetic Macular Edema

Purpose: Evaluating the effects of cibinetide in diabetic macular edema (DME). Methods: Phase 2 trial. Naïve patients with >400 µm central retinal thickness (CRT) DME in one/both eyes were recruited (May 2016–April 2017) at the Belfast Health and Social Care Trust. The study eye was that with best vision and lowest CRT. Patients self-administered cibinetide 4 mg/day subcutaneously for 12 weeks. Primary and secondary outcomes: mean change from baseline to week 12 in best corrected visual acuity (BCVA), CRT, central retinal sensitivity, tear production, patient-reported outcomes, adverse events and antibodies to cibinetide. Descriptive statistics were used; exploratory analyses focused on non-study eyes, diabetic control, serum cytokines and albuminuria. Results: Nine patients were recruited; eight completed the study. There was no improvement in mean change baseline-week 12 in BCVA (−2.9 + 5.0), CRT (10 + 94.6 microns), central retinal sensitivity (−0.53 + 1.9 dB) or tear production (−0.13 + 7.7 mm), but there was an improvement in National Eye Institute Visual Function Questionnaire (NEI VFQ-25) composite scores (2.7 + 3.1). Some participants experienced improvements in CRT, tear production, diabetic control and albuminuria. No serious adverse events/reactions or anti-cibinetide antibodies were seen. Conclusions: The cibinetide 12-week course was safe. Improvements in NEI VFQ-25 scores, CRT, tear production, diabetic control and albuminuria, observed in some participants, warrant further investigation. Trial Registration: EudraCT number: 2015-001940-12. ISRCTN16962255—registration date 25.06.15.