During the past couple of years we have seen major advances in our ability to treat choroidal neovascularization (CNV). Both Avastin (bevacizumab) and Lucentis (ranibizumab) have been more effective than previous treatments. These agents provide broad blockage of isoforms of vasoendothelial growth factor (VEGF). Initial treatment with these agents appears to offer better initial improvement than Macugen (pegaptanib), which offers selective blockage of the VEGF. In addition, Avastin and Lucentis are more effective than photodynamic therapy (PDT), at least when used as monotherapy. The effect of Anecortave Acetate appears to be similar to PDT.
What is unclear at this point is how long patients should receive therapy and the long- term benefit of treatment. These anti-VEGF injections clearly suppress CNV activity—at least while the drug is still present. Some patients may do well with a short series of injections without further recurrence. Unfortunately, recurrent CNV is very common. Many patients require periodic injections to maintain some degree of CNV suppression.
Triple therapy using PDT, a steroid injection, and an anti-VEGF agent may allow some reduction in the number of total injections. Investigations continue into other alternative therapies that may require fewer injections. The VEGF-Trap (Regeneron) utilizes a decoy receptor fusion protein which has a very high affinity for VEGF. Phase III trials are pending. Another promising development is protein tyrosine kinase (PTK) inhibitors. These small molecules may offer broad suppression of CNV. Multiple companies are developing potential drug therapies.
Another exciting development involves RNA interference to inhibit production of VEGF. This eventually results in interference of the mRNA responsible for VEGF production. Phase III trials are underway to evaluate the RNA interference drug bevasiranib through the COBALT trial. This trial allows all patients to receive initial induction therapy using a series of Lucentis injections. Patients are then randomized to receive either continuing monthly injections of Lucentis or injections of bevasiranib every two or three months. It is hoped that this treatment will allow fewer injections. We are an investigative site for this new treatment and are currently offering enrollment for select patients.
We have been pleased to offer our ARMD patients access to promising new and investigational drugs and techniques for both the prevention and treatment of CNV. Eyecare Associates of East Texas has a firm commitment to ARMD clinical research and our patients have benefited from treatment with therapies or drugs that would otherwise be cost-prohibitive or unavailable outside of the context of a clinical trial. As an investigative site for these trials, our patients are able to receive these cutting-edge treatments locally without the need for travel to major metropolitan centers. Over the years we have been pleased to offer our ARMD patients enrollment in trials involving Macugen, PDT, Anecortave Acetate, Lucentis, and various combination therapies, among others.
The past few years of ARMD management have been ever-changing and exciting. Treatment outcomes are most certainly better than they have ever been. Despite these advances we are sure that the best is yet to come.