Glaucoma Clinical Trials
Chat Highlights
July 20, 2011

On Wednesday, July 20, 2011, Dr. Michael Pro, a glaucoma specialist at Wills, and the glaucoma chat group discussed "Glaucoma Clinical Trials".

Moderator: Tonight's topic is “Glaucoma Clinical Trials”.

P: What is a clinical trial?

Dr. Pro: A clinical trial is a study designed to answer a specific question in medicine. Modern trials are strongly monitored with patient safety in mind. There are still many practices in medicine that are based on assumption and habit. A good trial might question those assumptions and they form the basis of evidence-based medicine. That means making treatment decisions based on the outcome of studies and trials.

P: Where are clinical glaucoma trials held?

Dr. Pro: They can be held in both private practices and academic medical centers. Large trials involve many sites and may be very expensive to run. Trials can be either government-sponsored, privately funded, or industry funded.

P: What are the benefits/risks to the subject in the clinical trial?

Dr. Pro: It depends on what's being studied. Let's start by looking at medical trials. Usually there is little immediate benefit to the patient for being involved in a drug development study. Many compounds are studied in FDA monitored and industry-sponsored trials. Promising compounds for glaucoma may be tested in glaucoma patients. However, the patient may not be aware that he or she is being treated with a new drug versus a control drug and once the trial is over the patient may go back to the medicines that were being used before.

The data from the study is analyzed and eventually a new drug may be brought to market. For his or her troubles, the patient may have some small financial benefit (depending on the study and site) and the knowledge that he or she may be helping to develop a new medication.
In a surgical device trial, the patient may benefit from a new device that is superior to surgical treatments that are currently available.

P: What is the difference between a blind and double blind trial?

Dr. Pro: A single blinded trial means that the patient is not aware of the medicine or treatment that is being used in the study. For instance, in a drug study, drug X is a new compound and drug Y is an existing drop. Patients are randomized to receive either drug X or Y, and the bottles look the same to the patient and they aren't told what they are getting.

Double blinded means that the doctors in the study are also ignorant of the treatment being offered (only the study coordinators know). Blinding and double blinding are done to try to eliminate bias in studies.

For instance, a doctor may know that drug Y is Latanoprost. He or she may know that Latanoprost is a great drop and may bias his or her evaluation in favor of Latanoprost versus drug X.

P: How many clinical glaucoma trials take place each year?

Dr. Pro: This is a good question. Including device studies, I think there may be 10-20 studies per year. I don't really know the exact number of drug or device studies, but there are numerous small studies involving smaller patient numbers. For instance, at this year's ARVO (Association for Research and Vision in Ophthalmology) meeting there must have been over 200 posters on various subjects.

P: What clinical trials are being performed at Wills?

Moderator: This following will you take you to article about trials at Wills Glaucoma Research Center.
http://willsglaucoma.org/searchlight/vol20no1.htm#3

Dr. Pro: Right now we are looking at various topics. There are on-going studies about functional impairment in glaucoma patients. There is also a new study about a novel material to be used in glaucoma trabeculectomy surgery. Furthermore, there are studies about using Avastin in bleb needling, studies about using an intraocular steroid during glaucoma surgery, and many others.

P: Is there a “perfect” candidate to participate in glaucoma clinical trials?

Dr. Pro: Well, some studies do need a lot of follow-up. So, we do see more retired patients in our drug or observational studies. Beyond that, I notice that many of the folks involved are motivated to help science and feel that they are advancing the field of glaucoma (which they are!)P: Does a participant continue to work with his/her glaucoma specialist while participating in a trial?

Dr. Pro: Yes.

P: Are there any trials currently with people who have borderline high IO pressure even though they had an iridotomy in order to see if there is something else or something better to do for such folks (like me)?

Dr. Pro: Not that I know of. There are some studies about the utility of laser iridotomy in various conditions, notably pigment dispersion and pigmentary glaucoma. Peripheral Iridotomy (PI) was not helpful in patients with pigmentary glaucoma and elevated IOP, but we still don't know if PI is helpful to prevent glaucoma in patients with pigment dispersion syndrome and normal IOP

P: I know that Copaxone is currently used by humans for Multiple Sclerosis, but have clinical trials for its use in glaucoma (by protecting retinal ganglion cells) yet gone beyond animal studies? Also, what is the story with Memantine, which I think has been in clinical trials for a while?

Dr. Pro: There are no glaucoma trials with Copaxone. Maybe the company is scared away by the results of the Memantine study.
That was a very large and expensive study by Allergan. The idea was to study the benefit of the Alzheimer's drug in glaucoma neuro-protection. It was a rigorous study, but did not show a benefit and unfortunately no papers have come from that study yet. We hope to see papers even from unsuccessful studies because looking at the data can still yield some insights.

P: Does a participant need to be near the study center to participate?

Dr. Pro: Yes.

P: Is there a directory or resource to find out where these clinical trials are offered?

Dr. Pro: Yes, one can look at the website clinicaltrials.gov.

P: Is there a place to see summaries of completed clinical trials?

Dr. Pro: You might want to evaluate the website that I listed above. Also, journals publish papers that come from completed trials.

P: What are the phases of clinical trials?

Dr. Pro: Phase I is drug discovery and animal studies. Phase II are preliminary human studies and may involve healthy subjects. Bloodwork is usually involved and side effects are carefully listed. Phase III involves promising compounds on individuals with glaucoma (for a glaucoma trial). After a drug completes Phase III, the FDA carefully evaluates the data. Approved drugs can be brought to market by the pharmaceutical company. Phase IV is a study on an approved drug for a new indication.

P: Of all the clinical glaucoma trials, which has yielded the most useful information in the treatment of glaucoma?

Dr. Pro: The large NIH funded studies which ended over 10 years ago. Those were AGIS, CIGTS, and OHTS. They each answered different questions.
AGIS helped to define the benefit of maintaining a lower IOP. CIGTS showed that drops may be as beneficial as surgery in many patients. OHTS helped define risk factors to develop glaucoma in patients with an elevated IOP.

P: How is the safety of the participants protected in clinical glaucoma trials?

Dr. Pro: The protection starts before the study begins. Any study must be approved by an institutional review board (IRB). The IRB is composed of physicians, lawyers, clergy, and others. The IRB evaluates patient safety. Once approved by the IRB, the study coordinator and principal investigator are responsible for patient safety. Drug and device trials are also overseen by industry.

Moderator: Thank you Dr. Pro. That is all the questions for the evening.

Dr. Pro: You are all welcome. Great questions everyone!

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