Sirolimus for Advanced Age-Related Macular Degeneration

Objective: Age-related macular degeneration (AMD), the leading cause of blindness in people over age 65 in the United States, is a heterogeneous clinical entity in which retinal degeneration occurs predominantly in the macula in the context of aging and leads to impairment of central visual acuity. AMD occurs in two general forms, one of which involves choroidal neovascularization (CNV) with subsequent formation of a disciform scar. This is often referred to as the neovascular or wet form. A second form, the subject of this study, is termed dry or atrophic macular degeneration and involves a constellation of clinical features that can include drusen, pigment clumping and/or retinal pigment epithelium (RPE) dropout and geographic atrophy (GA). GA can begin as a thinning of the RPE with involvement of the underlying choriocapillaris and subsequently lead to an atrophic change in the macula. Inflammation may play a role in the pathogenesis of GA. Sirolimus inhibits the production, signaling and activity of many inflammatory factors relevant to the development of GA. Therefore, the objective of this study is to investigate the safety and possible efficacy of serial sirolimus intravitreal injections in participants with bilateral GA.

Study Population: Six participants with bilateral GA associated with AMD will be enrolled. Initially, 10 participants with bilateral GA associated with AMD were to be enrolled. However, only six will be enrolled, as sirolimus intravitreal injections will no longer be administered to participants.

Design: In this single-center, prospective, controlled, unmasked, Phase I/II study, one eye of eligible participants was initially randomized to investigational product (intravitreal sirolimus) while the fellow eye was observed. Participants initially received a 20 μL (440 μg) intravitreal injection sirolimus in the study eye at baseline and every two months thereafter unless contraindicated. As of September 2012, sirolimus intravitreal injections were no longer administered to participants. Both the study and fellow eyes will be observed every two months until the study terminates. The study will not terminate until all participants have been followed through Month 12.

Outcome Measures: The primary outcome is the rate of change in area of GA based on masked grading by an external Reading Center of fundus photographs in the study eye and fellow eye at Month 12 compared to baseline. Secondary outcomes will include changes in best-corrected visual acuity (BCVA), changes in drusen area based on masked digital grading of fundus photography, absolute and relative changes in area of GA measured using fundus photography and autofluorescence imaging, and development of exudative AMD measured using optical coherence tomography (OCT). Safety outcomes will include the number and severity of adverse events (AEs). Ocular safety outcomes will be indicated by changes in visual acuity, ocular surface changes, intraocular inflammation and any other ocular changes not consistent with the natural progression of GA.

Inclusion criteria

• 56 or older
• Must understand and sign the protocol's informed consent document
• Must have at least ½ disc area (approximately 1 mm^2) of GA compatible with AMD present in each eye

GA is defined as one or more well-defined and often circular patches of partial or complete depigmentation of the RPE, typically with exposure of underlying choroidal blood vessels. Even if much of the RPE appears to be preserved and large choroidal vessels are not visible, a round patch of RPE partial depigmentation may be classified as early GA. The GA in each eye must be able to be photographed in their entirety, and it must not be contiguous with any areas of peripapillary atrophy, which can complicate area measurements

• Must have at least one large druse (greater than or equal to 125 μm) in each eye
• Must not have any evidence or history of exudative disease related to AMD in either eye as determined by a recent fluorescein angiogram performed within 4 months of study enrollment
• Must have a steady fixation in both eyes in the foveal or parafoveal area and media clear enough for good quality photographs
• Must have visual acuity of 20/400 or better in each eye
• Female participants of childbearing potential and male participants able to father children must have (or have a partner who has) had a hysterectomy or vasectomy, be completely abstinent from intercourse, or agree to practice two acceptable methods of contraception throughout the course of the study and four months after their last study injection. Acceptable methods of contraception include:

• hormonal contraception (i.e., birth control pills, injected hormones, dermal patch or vaginal ring),
• intrauterine device,
• barrier methods (diaphragm, condom) with spermicide, or
• surgical sterilization (hysterectomy or tubal ligation).

Exclusion criteria

• Actively receiving study therapy in another investigational study
• Unable to comply with study procedures or follow-up visits
• Evidence of an ocular disease other than AMD in either eye that may confound the outcome of the study (e.g., diabetic retinopathy with 10 or more hemorrhages or microaneurysms, uveitis, pseudovitelliform macular degeneration moderate/severe myopia)
• Has any of the following: a) a history of macular laser, b) a history of photodynamic therapy (PDT), c) received an intravitreal injection of anti-vascular endothelial growth factor (VEGF) agent for wet/exudative AMD at any point, or d) received an intravitreal injection of any other agent (not an anti-VEGF agent) within four months prior to study enrollment

Participants currently taking or who have previously taken AREDS vitamin supplementation are not excluded.

• Has had a vitrectomy
• Expected to need ocular surgery during the course of the trial
• Has undergone lens removal in the last three months or yttrium aluminum- garnet (YAG) laser capsulotomy within the last month
• On chemotherapy
• On immunosuppressive medication
• On ocular or systemic medications known to be toxic to the lens, retina or optic nerve
• History of ocular herpes simplex virus (HSV)
• Has a condition that, in the opinion of the investigator, would preclude participation in the study (e.g., unstable medical status including blood pressure and glycemic control)
• Has a history of cancer (other than a non-melanoma skin cancer) diagnosed within the past five years
• Has laboratory values outside normal limits and considered clinically significant by the investigator
• Is currently taking one of the following drugs: amprenavir, atazanavir, clarithromycin, darunavir, delavirdine, erythromycin, fluconazole (at doses of 200mg or greater), fluvoxamine, indinavir, itraconazole, ketoconazole, nefazodone, nelfinavir, posaconazole, quinupristin, ritonavir, saquinavir, telithromycin, troleandomycin, verapamil or voriconazole
• Female participant is pregnant or breast-feeding.