2015 may be noted as a year of emergence for sustained-release drug delivery therapies for dry eye and glaucoma, according to Jonathan H. Talamo, MD, Boston.
Cornea specialists have always appreciated the need to treat dry eye, “but it’s now becoming more and more appreciated and the importance of underlying dry eye and drying is so ubiquitous,” said Ernest W. Kornmehl, MD, Brookline, MA.
Sjögren's syndrome occurs in 11% of dry eye patients and in the past, specialists relied on the standard anti-RNP antibody tests like SS-A (Ro) and SS-B (La) to detect Sjögren's. “The Sjö test (Nicox, Paris) is much more specific and sensitive,” he said. “It has very high sensitivity and specificity. The new bio markers they're evaluating [are] salivary protein 1, carbonic anhydrase and parotid secretory protein. That is really a much quicker and more sensitive way of diagnosing Sjögren's.” The Sjo test will have a great effect on a patient’s life since often the disease is not diagnosed for years, leaving the patient with increasingly poor vision and increasing frustration.
Dr. Talamo said 2015 was also the year where diagnostics and new therapies started to gain traction. Drug therapy that “gets at the root cause of dry eye when it is inflammatory in nature” will continue to be a primary target for researchers.
“Steroids work short-term, as rescue or induction therapy for dry eye, and we’ve had cyclosporine 0.05% (Restasis, Allergan) on the market for 10 years, but not all cases are inflammatory,” Dr. Talamo said. “We may see some approvals for rescue therapy in the near future, either with topical drop delivery or punctal plug delivery.”
Most importantly, he said, is that “we're at the threshold of seeing a second major anti-inflammatory drop approved for dry eye with lifitegrast (Shire).” Shire expects to launch the drug in 2016 after U.S. regulatory approval.
While not yet submitted for regulatory approval—and likely still years away from it—P-321 (Parion Sciences), a specific and potent inhibitor of ENaC, produced a concentration-dependent increase in tear output that persists with a long duration of action in normal mice and rats. Furthermore, P-321 significantly increases tear output and improves corneal staining in dry eye models.
Corneal specialists “have always appreciated the need to treat dry eye. We can't treat [the] allergy unless the underlying dry eye has been treated,” Dr. Kornmehl said.
The past year has seen a sustained-release dexamethasone intracanalicular depot (Dextenza, Ocular Therapeutix) enter its first phase III allergic conjunctivitis clinical trial, a phase II study for inflammatory dry eye disease, and phase III studies for postoperative inflammation and pain. Dextenza achieved 1-unit difference from vehicle in ocular itching, which has previously been the FDA standard for approval of therapies in this disease.
Peter Hersh, MD
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Dr. Hersh has financial interest with Addition Technology, Avedro Inc., and Synergeyes Inc.