by Dan Roberts
It is important to note at the outset of this report that patients are highly respected across the professional board for their willingness to act as pioneers in the ongoing research. Our participation in clinical trials is greatly appreciated by the researchers.
That having been said, here are latest updates on research in which many of us have played a part. All of these were reported at the annual meeting of the Association for Research in Vision and Ophthalmology (ARVO), May 1-5, 2011, in Fort Lauderdale, Florida.
Results From the Comparison of AMD Treatments Trial (CATT)
For those who are following the recent news about the results of the Comparison of AMD Treatments Trial (CATT), here is a summary of the long-awaited report by the research team to the ARVO meeting in Ft. Lauderdale on May 1, 2011.
1. The report focused on the relative safety and efficacy of Lucentis and Avastin. The research team did not get into other issues, such as cost, availability, etc., since that was not the purpose of the trials.
2. A detailed description of the trial design and methods were well-received by a large audience of researchers and ophthalmologists.
3. The results were presented and well-received. That is, after one year, the two compounds have been found to be extremely similar in their improvement of mean visual acuity and the occurrence of adverse events. For more detail, see Ranibizumab and Bevacizumab for Neovascular Age-Related Macular Degeneration
4. These are top line results, with more detail to come later. Meanwhile, the subjects will continue under observation as the trial proceeds through its second year. Five related trials are also underway in the UK and Europe, all of which deserve watching for potential new findings.
5. The results revealed surprisingly little difference in the efficacy of scheduled injections and the efficacy of injections delivered on an as-needed basis for both drugs.
6. The general consensus of opinion among the doctors using Avastin was that they would continue using the drug off-label. At the same time, they will ensure that patients are fully aware of adverse events (SAE) that have been determined at this time to be neither significant nor insignificant to the end results. No discussions have yet been held with the Centers for Medicare and Medicaid Services (CMS) regarding changes in policy regarding reimbursement for Avastin as a treatment for wet AMD.
7. Questions yet to be answered:
Will more advancing OCT diagnostics detect more fluid after treatment?
Will new genetic findings allow for better predictions, durability of response, and number of injections?
Another report is expected at next year’s ARVO meeting following conclusion of the trials. Meanwhile, it is important that patients discuss their treatment with their doctors for a full understand of the current findings.
ECT with CNTF protein — Neurotech
Encapsulated cell technology (ECT) that releases a protein called ciliary neurotrophic factor (CNTV) for treatment of dry AMD has completed Phase 3 trials with good results. Results from Phase 3 presented to the 2011 ARVO meeting showed continued promise, with CNTV leading to stabilization of vision in subjects starting with good visual acuity of at least 20/63, and lessening of the progression of lesion size in geographic atrophy. More about ECT
Fenretinide — ReVision Therapeutics
Phase 2 trials are completed with a surprising outcome. In addition to expected positive results, researchers have found that the drug also reduces by 2-fold the rate of conversion to neovascularization in patients with geographic atrophy. This means that fenretinide, in addition to slowing the progression of dry AMD, could also become a pre-treatment for wet AMD. More about fenretinide
Lucentis “Super Dose”– Genentech/Roche
The current HARBOR trial has revealed that a higher dose of Lucentis (ranibizumab) for treatment of wet AMD has been found to be more effective in fifty “incomplete responders” over 24 months. “Incomplete responders” are individuals who have shown no appreciable response to the normal treatment. Intravitreal injection with 2.0 mg, however, rather than the current 0.5 mg, led to a significant decrease in retinal thickness (swelling) after the first 3 months, plus a 4-letter gain after 8 weeks. This improvement was maintained up to one year with no serious adverse events.
Microplasmin for vitreal adhesion — Thrombogenics
A single intravitreal injection of a new drug has been shown in Phase 3 trials to relieve adhesion of the vitreous to the inner retinal membrane, thus reducing risk of damage from such conditions as diabetic vitreous hemorrhage and macular hole. It accomplished this by inducing a post vitreous detachment (PVD), eliminating the need for a vitrectomy. More about microplasmin
Geographic atrophy (advanced dry AMD) is four time as common as wet AMD. More advanced imaging techniques is allowing better analysis of types of GA. Some have been found to actually be late onset Stargardt disease or central areolar chroidal dystrophy (CACD). Others may be characterized by a prevalence of reticular drusen, which are being found to be more common that originally thought. Reticular drusen appear as soft drusen in ill-defined networks of broad interlacing ribbons. Knowing the more specific types of GA may help define more precise treatments. (Ref: Special Interest Group Session 334: “Geographic Atrophy in AMD”, ARVO 2011)