The drug met all primary and secondary endpoints in the Osprey and Apteryx studies with an excellent safety and tolerability.
In a major development for glaucoma treatment, Qlaris Bio (Massachusetts, United States) announced positive topline results from two U.S. Phase II clinical trials evaluating QLS-111 in primary open-angle glaucoma (POAG) and ocular hypertension (OHT).
The trials, named Osprey and Apteryx, met all primary and secondary endpoints, demonstrating significant intraocular pressure (IOP) reduction and a strong safety profile.
QLS-111’s first-in-class mechanism of action reduces IOP by targeting episcleral venous pressure (EVP).
“The QLS-111 Phase II data are quite promising and indicative of an innovative therapy,” said renowned glaucoma specialist Prof. Ike Ahmed, director of the Alan S. Crandall Center for Glaucoma Innovation at the Moran Eye Center, University of Utah.
The Apteryx study also showed positive results when the drug is used both in conjunction with latanoprost and as a standalone therapy.
“Along with its attractive safety profile, the potential of QLS-111 to surpass the additive efficacy of other glaucoma medications when used with latanoprost means patients can remain on a drug that can achieve better IOP control,” said Prof. Ahmed.
“The robust results of the Osprey and Apteryx trials give me confidence that our patients may soon have an important new treatment option that targets this clear unmet need.”
Glaucoma expert Dr. Shan Lin talks about QLS-11’s and its potential in glaucoma treatment.
The findings were presented at the Glaucoma 360 New Horizons Forum 2025 on February 7 in San Francisco, California.
So why is QLS-111 different?
Qlaris believes that QLS-111’s EVP-targeting mechanism of action sets it apart. Most glaucoma treatments work by reducing the production of aqueous humor or improving its outflow, but QLS-111’s EVP-based strategy is a first in targeting this key factor in IOP.
By lowering EVP, the drug could have the potential to provide a more complete solution for patients, especially those who don’t achieve sufficient IOP control with other treatments, especially given trial data on QLS-111’s synergistic effects with latanoprost.
“This substantial additive effect demonstrates the potential to significantly benefit patients who do not achieve IOP lowering goals with current therapies,” said Dr. Barbara Wirostko, chief medical officer at Qlaris Bio. “Additionally, we believe the promising tolerability profile of QLS-111 will further enhance the value to our patients by driving improved treatment compliance and adherence.”
Dr. Shan Lin explains QLS-11’s mechanism of action.
Breaking down the data: what the trials revealed
QLS-111 is a novel topical formulation using Qlaris Bio’s ATP-sensitive potassium channel modulation to relax the vascular and vascular-like tissues beyond the trabecular meshwork, reducing distal outflow resistance and EVP. The drug has been tested in two clinical trials in the U.S.
The Osprey trial (NCT06016972) focused on evaluating QLS-111’s safety, tolerability, and IOP-lowering efficacy in 62 adult patients with POAG or OHT. Results showed that the 0.015% QLS-111 dose, administered once daily in the evening (QPM), led to the greatest IOP reduction—averaging 3.7 mmHg from a baseline of 23.0 mmHg.
The Apteryx trial (NCT06249152) examined QLS-111’s effectiveness when used alongside latanoprost, a common glaucoma treatment. This study, conducted in 32 patients aged 12 and older, found that adding QLS-111 (0.015%) to latanoprost led to an additional 3.2 mmHg reduction in IOP with QPM dosing and 3.6 mmHg with BID (twice-daily) dosing.
The safety profile of QLS-111 is also something to celebrate. Across both trials, there were no serious adverse events, and no significant hyperemia (eye redness) was observed—even when QLS-111 was used alongside latanoprost.
For now, the results from these Phase II trials suggest that QLS-111 may offer a promising option for glaucoma and ocular hypertension treatment. It’s certainly one to watch in the coming months!
