Comfort, efficacy combine in glaucoma medication

Research finds Combigan reduces IOP in a range of patients while minimizing discomfort

Some ophthalmologists struggling to improve compliance in glaucoma patients found an unexpected degree of efficacy and comfort in a recent post-marketing study.
A prospective, multicenter, open-label study of Combigan (brimonidine tartrate/timolol maleate, Allergan, Irvine, Calif.) found it lowered IOP among treatment-naive patients, patients who switched glaucoma medications, and those who used it to supplement their existing medications. Additionally, both patients and their physicians generally found it was well tolerated and comfortable.
The research was presented as a poster at the 2009 World Glaucoma Congress in Boston and titled “Evaluating the Efficacy, Tolerability and Safety of Brimonidine 0.2%/Timolol 0.5% Ophthalmic Solution.”
Those findings could have a big impact for physicians treating a disease with notorious compliance problems.
“Tolerability of medications is very important [in glaucoma]; it’s one of the major factors that affects compliance,” said Carlos Buznego, M.D., voluntary assistant professor of ophthalmology, Bascom Palmer Eye Institute, Miller School of Medicine, University of Miami, Miami. “We have a disease state that is one of the worst for full compliance in that it’s an asymptomatic disease with the potential for vision loss.”
The overall efficacy of Combigan included a mean IOP reduction among all patient types from 21 mm Hg to 16.3 mm Hg, or more than 20%. The biggest reduction was among treatment-naive patients, who achieved a mean 9.3 mm Hg reduction from a baseline of 25.5 mm Hg at two months.
Dr. Buznego highlighted the statistically significant improvement and good reductions of IOP in all three patient groups. Specifically, the results ran counter to the expectation Combigan would provide less IOP reduction in patients where it replaced another glaucoma drug.
“The study seems to show that Combigan was better than the prior medications they were on,” Dr. Buznego said.
The efficacy also matched the high tolerability the drug achieved. Nearly 97% of patients rated Combigan as “good,” “very good,” or “excellent” by the second month. More than 55% of patients also rated their overall satisfaction and ocular comfort as better than with previous medications.
That comfort likely stemmed from Combigan’s reduced incidence of adverse events. For instance, 25% of patients reported fewer incidents of burning and stinging, compared to reports on previous medications. Fewer incidents of red eyes and blurred vision were also reported.
Although the mean IOP reduction was important, Dr. Buznego said patient satisfaction is “where the rubber meets that road” in determining glaucoma medication usefulness.
“That’s one of those things that was a little surprising to me” in the study, he said.
Others also credited the overall combination of the comfort and efficacy with the improved clinical results.
“The large [20%] drop tells us that the drug worked and some of this may have been due to improved compliance,” said E. Randy Craven, M.D., associate clinical professor, Department of Ophthalmology, University of Colorado School of Medicine, Aurora, Colo.
Common adverse events the researchers identified included ocular hyperemia (2.5%), ocular burning (2.3%), oral dryness (1.5%), and blurred vision (1.3%).
Other important findings for Dr. Craven include the broad efficacy of the drug across patient groups and when combined with other IOP-lowering medications.
Ehsan Sadri, M.D., Newport Beach, Calif., one of the authors of the study, said that although a decrease in pressure was expected, the large extent of the IOP reduction among all three patient groups was surprising.
Also noteworthy to the study author was that patients who were between 22 and 28 mm Hg had slightly better outcomes compared with other pressure ranges.
“That suggests that the higher the IOP, the greater the reduction; this is significant for our other patients,” Dr. Sadri said.
The medication performed well in the view of the treating physicians. The IOPs of nearly 95% of participating patients were judged to be at least “somewhat controlled” by the investigating physician. Additionally, 90% of physicians rated their patients’ acceptability and tolerability of the drug as at least “good.”
The future research will flesh out the findings. Dr. Craven said the one-year IOP-control data from the Phase III clinical trial was the critical point at that time, as the one-year results with this post-marketing group will be.

Editors’ note: The Combigan study was supported by Allergan (Irvine, Calif.). Dr. Buznego has financial interests with Alcon (Fort Worth, Texas) and Allergan. Dr. Craven has financial interests with Allergan and Merck (Whitehouse Station, N.J.).

Contact information

Buznego: cbuz@comcast.net
Craven: ercraven@yahoo.com
Sadri: esadrii@gmail.com