Eye Drop Under Development for Cataract Delay, Prevention

An ophthalmic solution in its early stages of investigation showed a trend of delaying or preventing the progression of cataracts. The topical solution, identified only as C-KAD (Chakshu Research, Inc., Los Gatos, California), is intended to reduce or reverse the signs of cataract formation. Phase I/II US Food and Drug Administration (FDA) clinical trials are complete, and results indicate a trend toward improved vision in patients with early signs of cataract.

"In the initial, fairly large clinical study, C-KAD showed a trend toward improved vision in individuals with early to moderate, but not advanced, cataracts," said Peter J. McDonnell, MD, in a telephone interview with CRST Europe. Dr. McDonnell, of Johns Hopkins University, is the chairman of the Chakshu Research, Inc. scientific advisory board. A larger study will be needed to demonstrate statistically significant efficacy.

According to a Chakshu Research news release, the drug is designed to prevent damage to the eye by inhibiting reactions that cause oxidative stress, which is the generally accepted cause of cataract. The formula, according to the company, works by breaking up age-forming lipid and protein aggregates to reduce haze and improve visual clarity. A permeation enhancer allows the formula to penetrate into the eye, reaching the lens and vitreous. If approved by the FDA, C-KAD would represent the first safe and noninvasive treatment for vision loss associated with cataracts.

"As a physician, I can say that it would be nice to have treatments for people whose cataract is either not severe enough to need surgery or who have a health problem that precludes them from surgery," Dr. McDonnell said, adding that C-KAD "is targeted at the group of individuals who are experiencing the onset of cataractous symptoms."

Candidates for the drug will include younger, active patients who are first noticing deterioration in their quality of vision. Often, these patients will still have 20/20 vision while reading an eye chart but complain of loss of contrast sensitivity.

"The idea is that if these patients are already starting to experience symptoms, presumably they are likely to get worse relatively quickly," Dr. McDonnell said. "In many people, this drug would delay or avoid the need for cataract surgery by providing them with very good functional vision for much longer than they would have otherwise."

The phase I/II clinical trial included 111 patients from academic centers including Johns Hopkins University, Harvard University, and the University of Utah. Inclusion criteria were as follows: aged 50 years or older, early cataract in both eyes, mild-to-moderate impairment of vision, otherwise healthy eyes, and otherwise good health. Patients had an average starting vision of 20/23 and were prescribed four drops of C-KAD daily for the treatment of their symptoms. Follow-up exams spanned 4 months after initial treatment.

In a subgroup analysis, results showed that C-KAD was a safe treatment that helped patients lower intraocular pressure and gain lines of BCVA. According to the company, 43% of patients in a group of patients who achieved the best results with the drug, a two-line improvement in BCVA was seen.

FDA approval, Dr. McDonnell said, hinges upon results from planned pivotal clinical studies. A larger patient population is needed to show a statistically significant improvement of vision in patients with cataracts. An approval would mean a positive change in the treatment of cataracts, predicted good news considering the shortage of ophthalmologists in the next decade.

"Otherwise, it is going to be a challenge for us—with the graying of our population—to continue doing business as usual. The approval of a treatment to improve vision in cataract patients would reduce the burden of cataract," Dr. McDonnell said. While other over-the-counter products make such claims, he said, C-KAD is the only drug "that we are aware of going through the rigorous FDA approval process to substantiate their claims and which will be prescribed by physicians."

According to statistics from the National Eye Institute, many patients die within 5 to 10 years after cataract surgery. Delaying the progression of cataract for a decade with a treatment such as C-KAD has the potential to decrease the number of cataract surgeries by as much as half, Dr. McDonnell said. "This would have a dramatically positive impact on the spiraling costs of health care. Also, with a projected 30% shortage of ophthalmologists and expanding needs to treat other diseases like age-related macular degeneration and diabetic retinopathy, reducing the need for cataract surgery may help ophthalmologists meet the eye care needs of our society."

Although results to date are promising, Dr. McDonnell hastened to add that no treatments have been approved yet.

"There is no guarantee that results of such trials will be positive. From my perspective, however, it is an enormous hope to treat patients with cataracts that are not yet severe enough to require surgery. It is a big opportunity to positively impact the functioning of many older patients who nowadays lead active lifestyles. I think whatever company can come up with a successful product will be rewarded."

Peter J. McDonnell, MD, is the Director and William Holland Wilmer Professor of Ophthalmology at the Wilmer Eye Institute, the Johns Hopkins University School of Medicine, Baltimore. Dr. McDonnell states that he receives reimbursement as the chairman of the Chakshu Research Inc. scientific advisory board. He may be reached at pmcdonn1@jhmi.edu.