Conditions: Diabetic Retinopathy
Keywords: Diabetic Macular Edema Diabetic Retinopathy Rapamycin Sirolimus Diabetes
Allocation: NA | Intervention model: SINGLE_GROUP
Enrollment: 5
Healthy volunteers: no

Brief summary:
Objective: Diabetic macular edema (DME) is a frequent manifestation of diabetic retinopathy, a leading cause of blindness in the United States. The only proven treatment for DME is laser photocoagulation. Sirolimus has been shown to inhibit the production, signaling and activity of many growth factors relevant to the development of diabetic retinopathy. Therefore, this study will investigate the safety and efficacy of multiple sirolimus injections in patients with DME.

Study Population: Eligibility criteria include central macular thickening \> 260 microns and visual acuity 20/32 or worse in one or both eyes.

Design: Five participants will be enrolled into this open-label pilot study. After receiving a 20 μL (440 μg) subconjunctival injection in the study eye at baseline and Month 2, the participants will be re-evaluated every two months for at least one year for possible additional injections. During follow-up, participants will not undergo re-injection if they show significant clinical improvement or treatment success, defined as no intraretinal fluid or cysts present on optical coherence tomography (OCT) OR 100% reduction in excess retinal thickness over 260 microns on OCT OR no leakage on fluorescein angiography (FA). Beginning at Month 4, participants will be assessed for treatment failure, defined as loss of 15 or more letters of vision compared to baseline at two consecutive visits OR a 50% or greater increase in total retinal thickness as measured by OCT at two consecutive visits. Individual participants deemed treatment failures will continue receiving sirolimus injections, but will be allowed to receive focal laser therapy for any amenable leaking microaneurysms at Month 4. Beginning at Month 6, focal laser therapy will be permitted for both treatment failures and participants who do not meet the criteria of a treatment success. Participants will have the option of continuing treatment until a common termination date of one year.

Outcome Measures: The primary outcome is the change in visual acuity in the study eye at six months compared to baseline. Secondary outcomes include changes in visual acuity in the study eye at one year as compared with baseline, changes in retinal thickness as measured by OCT and changes in fluid leakage in the macula as demonstrated by FA at six months, one year and throughout the study period in the study and fellow eyes. Safety outcomes include number and severity of systemic and ocular toxicities, adverse events and infections, and the number of participants withdrawn from study therapy.

Detailed description:

Arms:
arm 1: The study eye was treated with sirolimus.

Interventions: intervention 1: Sirolimus
Intervention descriptions: intervention 1: 20 μL (440 μg) of sirolimus were injected at baseline, Month 2, and every 2 months thereafter if re-treatment criteria were satisfied.

Protocol document: