Topical Interferon Gamma-1b for Central Serous Chorioretinopathy

Objective: Central serous chorioretinopathy (CSC) is a retinal disorder characterized by an accumulation of serous fluid under the retina thought to be due to excessive choroidal hyperpermeability. The retinal pigment epithelium (RPE) plays a critical role in removing fluid from the subretinal space. This RPE "pump" is believed to be a key player in the reabsorption of subretinal fluid and maintenance of retinal attachment. Fluid transport assays have examined whether interferon gamma induces changes in fluid transport across human fetal RPE monolayers and showed an increase in fluid absorption from the retinal to the choroidal side of the tissue. An in vivo rodent model of retinal detachment has been used to measure the effect of interferon gamma on re-absorption following retinal detachment and showed that the addition of interferon gamma to the anterior eye surface caused a significant, rapid decrease in retinal detachment volume in the first hour of observation. This pilot study will investigate the safety, tolerability and potential efficacy of serial ocular instillations of topical interferon gamma-1b for classic CSC.

Study Population: Five participants with subretinal fluid due to classic CSC will initially be enrolled. However, up to an additional two participants may be enrolled in order to obtain the five participants to be included in the analysis if any participants withdraw from the study.

Design: In this Phase I/II, non-randomized, prospective, uncontrolled, dose-escalation, single-center pilot study, a series of ocular instillations of topical interferon gamma-1b will be administered in the study eye over a two-week period. If the fluid re-accumulates or increases, participants will be eligible for re-challenging with topical interferon gamma-1b in the study eye at Week 4. Participants will be followed for one year. Participants may be eligible for additional re-challenges after the initial eight week study period ends if their fluid re-accumulates or increases further.

Outcome Measures: The primary outcome measure related to the safety and tolerability of serial ocular instillations of topical interferon gamma-1b will be assessed by the number and severity of adverse events (AEs) related to the investigational product and the number of withdrawals. Secondary efficacy outcomes include changes in best-corrected visual acuity (BCVA), central retinal thickness and maximum lesion volume as measured on optical coherence tomography (OCT), leakage as observed on fluorescein angiograms (FA), autofluorescence patterns as observed on fundus autofluorescence (FAF) imaging and mean macular sensitivity as assessed by microperimetry.

• INCLUSION CRITERIA:
• Participant must be 18 years of age or older.
• Participant must understand and sign the protocol s informed consent document.
• Female participant of childbearing potential (see Appendix 1 for definition) must not be pregnant or breast-feeding, must have a negative pregnancy test at screening and must be willing to undergo pregnancy tests at scheduled study visits.
• Female participant must be post-menopausal (see Appendix 1), must have had a hysterectomy, have a partner with a vasectomy, be completely abstinent from intercourse or must agree to practice two reliable methods of contraception throughout the course of the study and for six weeks after administration of investigational product. 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 (tubal ligation).

Exclusion criteria

• Participant is actively receiving an investigational medication in another research trial that may have unknown effects on CSC as determined by the investigator.
• Participant has evidence of ocular disease other than CSC in the study eye that may confound the outcome of the study (e.g., neovascular age-related macular degeneration).
• Participant has evidence of choroidal neovascularization (CNV) in the study eye.
• Participant is expected to need ocular surgery in the study eye during the eight weeks of the study.
• Participant is expected to need focal laser treatment or photodynamic therapy (PDT) in the study eye during the eight weeks of the study.
• Participant is on medications that enhance RPE pumping of fluid (e.g., acetazolamide).
• Participant is on steroid medication (oral (e.g., prednisone), topical (e.g., hydrocortisone cream) or inhaled (e.g., fluticasone inhaler)).
• Participant has a systemic condition that, in the opinion of the investigator, would preclude participation in the study (e.g., Hypertension not controlled with medications or active infection requiring treatment).
• Participant is allergic to fluorescein dye.
• Participant has multiple sclerosis (MS), as interferon gamma may cause MS exacerbations.
• Participant is on anti-cortisol or anti-androgen medications (e.g., finasteride or mifepristone), as there is some data suggesting that these medications may reduce CSC fluid.