New class of glaucoma drug shows clinical promise

Growing clinical experience with Rho kinase (ROCK) inhibitors suggests this new class of drugs may soon have an important place in the treatment of glaucoma, reported Hidenobu Tanihara MD, professor of ophthalmology, Kumamoto University, Kyushu, Japan, at the World Ophthalmology Congress in Tokyo.

ROCK inhibitors are the first class of drug to target the trabecular meshwork directly. ROCK inhibitors appear to enhance aqueous drainage by acting on the actin cytoskeleton and cellular motility in the trabecular meshwork, Schlemm’s canal and in ciliary muscle. The new class of drug may lower IOP by decreasing resistance to aqueous outflow by cellular relaxation in the trabecular meshwork, he noted.

The drugs, which also have the potential advantage of being administered in eye drop form, are in Phase II and Phase III clinical trials. Dr Tanihara reviewed his own recent work with one agent, K-115, which is now in Phase III studies. He reported that the drug produced significant, dose dependent reductions in IOP in eyes with glaucoma and ocular hypertension. The effects were additive when combined with current prostaglandin agents. The new drug produced tolerable side effects mostly limited to transient hyperaemia. The drug will soon be submitted for approval on the Japanese market, he noted.