Clinical Trials

Since 2005, a group of scientists and clinicians from around the world have identified and are studying hundreds of persons with MacTel Type 2. Progress has been made to find ways to help prevent the condition from developing and to find potential treatment(s) but more work is needed. Special scientists (geneticists) are working to understand if this disorder is inherited (passed down from your parents) and basic scientists are working to understand what happens to the eye tissue inside a MacTel eye.

The purpose of this study is to identify persons with MacTel Type 2, and their affected family members to create a Registry of persons with MacTel Type 2. This Registry will be used to study participants with MacTel Type 2 now and may be used in the future to identify persons to be in a study that may help find a way to prevent or treat this eye condition. We also wish to keep in contact with persons who have told by their MacTel doctor that they have MacTel Type 2.

In this document, the word “affected” means that it has been confirmed that you have MacTel Type 2. These persons may also be referred to as “Probands” when they are the first person in the family to be diagnosed with the disorder.

“Unaffected” means that at this time, there is no evidence of MacTel Type 2.

Brief Summary:

This study is a phase 3, randomized, multi-center study to evaluate the efficacy and safety of the Renexus® implants in participants with macular telangiectasia type 2.

The purpose of this study is to compare the effects, good or bad, of ranibizumab when it is delivered by an ocular (eye) implant (also known as the Port Delivery System with ranibizumab, or PDS) versus ranibizumab delivered by injections into the eye as treatment for your DME. The ocular implant releases ranibizumab continuously (without stopping) over a long period of time into the back of your eye, and it can be refilled with fresh ranibizumab by your study doctor. Because the implant continuously releases ranibizumab over time, you may not need additional eye injections to treat your DME. This study will help determine whether ranibizumab delivered continuously through an ocular implant is similar in effectiveness to ranibizumab injections into the eye for treating patients with DME.

DME, a long-lasting condition, is the most common cause of vision loss among people with diabetes and causes problems in vision such as blurred or wavy vision and colors that appear to be washed out. It is caused by damage to blood vessels in the retina (the light-sensitive layer at the back of the eye) that causes the vessels to leak blood or fluid into the macula (the most sensitive and central part of the retina that gives you sharp vision). DME causes the macula to swell, leading to blurred or wavy vision. A protein called vascular endothelial growth factor (VEGF) is involved in the development and leakiness of damaged blood vessels, which leak blood or fluid in the macula in patients with DME.

Ranibizumab is a medicine that blocks VEGF, which in turn slows the growth of and leakage from the damaged blood vessels in your eye. In this study, you will either get ranibizumab delivered by the ocular implant with refills every 6 months, which will release ranibizumab continuously over time into the back of your eye, or you will receive monthly injections of ranibizumab into your eye at a dose of 0.5 mg.

Ranibizumab, given by regular injections into your eye at a dose of 0.3 mg in the U.S. and 0.5 mg in Europe, is approved for the treatment of DME. The Food and Drug Administration (FDA) has not approved a 0.5 mg monthly dose for DME in the U.S. The two doses have been shown in clinical studies to have similar safety and effectiveness results.

For subjects receiving the ocular implant, the ranibizumab given as a dose of 2 mg in the implant and refilled every 6 months is considered an experimental study drug that will only be given to subjects in this research study. However, the active ingredient, ranibizumab, is the same as that in the approved product.

The ocular implant is an experimental device, which means the FDA has not approved it to be implanted in the eye for the treatment of DME. The implant is slightly bigger than a grain of rice (see Figure 1 and Figure 2). The ocular implant is covered by the conjunctiva – the thin, clear skin covering the eye and is usually not visible to others because it is hidden by the upper eyelid.