This week, I learned about a new clinical trial for a drug that shows promise in the treatment of wet macular degeneration (AMD) in patients who have not responded to treatment with either Avastin or Lucentis, the two drug interventions most commonly used at present.
The drug is called iSONEP™ and it has been created by Lpath, a San Diego, California-based pharmaceutical corporation. iSONEP™ is the ocular version of Sphingomab™, which is Lpath’s anti-angiogenic drug for the treatment of cancer. (See below for an explanation of “anti-angiogenic”.)
The clinical trial, entitled Efficacy and Safety Study of iSONEP with and without Lucentis/Avastin to Treat Age-Related Macular Degeneration (AMD), is a Phase II clinical trial that commenced in September 2011 and is still recruiting patients.
Here is more information about the iSONEP™ clinical trial:
iSONEP™ has completed a Phase I clinical trial in wet AMD patients. iSONEP met its primary endpoint of being well tolerated in all 15 patients at dosage levels ranging from 0.2 mg. to 1.8 mg. per intravitreal [i.e., within the eye] injection. No drug-related serious adverse events were reported in any of the patients.
In the Phase II trial, Lpath plans to dose 160 subjects who have not responded completely to Lucentis or Avastin. Effects/Endpoints that will be studied include change in visual acuity, change in retinal thickness, and change in lesion [i.e., the part of the retina that is bleeding] size.
About blood vessel growth and anti-angiogenic drugs
Angiogenesis is a term that describes the growth of new blood vessels and plays a critical role in the normal development of body organs and tissue. Sometimes, however, excessive and abnormal blood vessel development can occur in diseases such as cancer (tumor growth) and AMD (retinal and macular bleeding).
Substances that stop the growth of these excessive blood vessels are called anti-angiogenic (anti=against; angio=vessel; genic=development), and anti-neovascular (anti=against; neo=new; vascular=blood vessels).
The focus of current anti-angiogenic drug treatments for wet AMD is to reduce the level of a particular protein (vascular endothelial growth factor, or VEGF) that stimulates abnormal blood vessel growth in the retina and macula; thus, these drugs are classified as anti-VEGF treatments. The anti-VEGF drugs used at present (Lucentis and Avastin) are administered by injection directly into the eye after the eye’s surface has been numbed.
About Clinical Trials
Most clinical trials are designated as Phase I, II, or III, based on the questions the study is seeking to answer:
- In Phase I clinical trials, researchers test a new drug or treatment in a small group of people (20-80) for the first time to evaluate its safety, determine a safe and effective dosage range, and identify possible side effects.
- In Phase II clinical trials, the study drug or treatment is given to a larger group of people (100-300) to determine if it is effective and to further evaluate its safety.
- In Phase III studies, the study drug or treatment is given to even larger groups of people (1,000-3,000) to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
- In Phase IV studies, after the Food and Drug Administration (FDA) has approved the drug, continuing studies will determine additional information, such as the drug’s risks, side effects, benefits, and optimal use.
Thus, iSONEP™ must undergo additional testing, via Phase III clinical trials, before definitive results regarding its safety and efficacy can be determined. VisionAware will provide updates on this important research as they become available.