Cyclosporin Implant to Treat Uveitis

Overview

This study will evaluate the safety and effectiveness of a sustained-release cyclosporin implant to treat uveitis, a sight-threatening eye inflammation caused by an immune system abnormality. Previous studies in humans have shown that, taken by mouth, the drug cyclosporin is effective in treating chronic uveitis. Uveitis may require long-term treatment with potent immune-suppressing drugs, such as cyclosporin, cyclophosphamide, methotrexate, azathioprine or steroids. Taken systemically (by mouth or injection), however, these drugs can do serious damage to the kidneys, liver or lungs, and can raise blood pressure and lower blood cell counts. Because of this, some patients cannot or will not use these medicines. This small pilot study will evaluate the safety, and to some extent effectiveness, of cyclosporin delivered directly into the eye, to try to prevent harmful side effects. In animal studies, sustained-release cyclosporin implants did not cause the severe side effects seen with systemic use of the drug. Some animals developed opacity of the lens and slowed retinal responses, both of which reversed when the drug was stopped. Earlier animal studies of cyclosporin injected directly into the eye reduced inflammation that had been produced experimentally. Patients with uveitis who have active inflammation and poor vision are eligible to participate in this study. Patients will be randomly assigned to one of two treatment groups. One group will receive a 1-mg implant that releases 0.8 micrograms of drug each day; the second group will receive a 2-mg implant that delivers 1.4 micrograms of drug a day. Before surgery, patients will have a medical history, basic physical examination, and complete eye examination, including special tests called electroretinogram and fluorescein angiography. An electroretinogram measures the electrical responses generated in the retina in the back of the eye. Fluorescein angiography uses a special camera to photograph the retina, showing the condition of the blood vessels in the eye. The surgical procedure to place the implant takes about 1.5 hours and may be done under either local or general anesthesia. Patients will stay in the hospital overnight. After discharge from the hospital, they will return for follow-up visits 1 and 2 weeks after surgery, then once a month for 6 months, and then every 3 months until the implant is depleted of drug or removed. During these follow-up visits, eye examinations will be repeated to evaluate the effects of the implant on the eye. Repeat blood tests will measure the amount of cyclosporin in the blood and the drug's effect on the kidneys. When the implant runs out of drug (between 2 and 3 years), it may be removed or left in place.

Sight threatening uveitis may require long term use of systemic immunosuppressants. In some patients, aggressive systemic immunosuppressive therapy fails to control inflammation and can lead to serious side effects. Oral Cyclosporin A (CsA) has been shown in several human trials to be effective in treating chronic uveitis. This pilot study will assess the safety, and to some extent efficacy, of a novel intraocular CsA release implant in patients with active inflammation and poor visual acuity in one eye despite immunosuppressant therapy. Patients will be randomly assigned to receive in one eye a 1 or 2 mg CsA implant releasing at either 0.8 microgram per day or 1.4 microgram per day respectively. The main purpose of the study is to assess the safety of the CsA implant. Secondary outcomes will include a change from baseline in the ocular inflammation, visual acuity, and the need for concomitant anti-inflammatory medications.