Latanoprost Without Benzalkonium Chloride Fails to Achieve Noninferiority Status

dripping eye drops during consultation with an ophthalmologist
dripping eye drops during consultation with an ophthalmologist
Despite its failure to achieve noninferiority status, latanoprost without BAK may still be a safe alternative to latanoprost with BAK in treating patients with open-angle glaucoma or ocular hypertension.

Latanoprost without benzalkonium chloride (BAK) failed to achieve noninferiority status vs latanoprost without BAK for lowering intraocular pressure (IOP) among patients with open-angle glaucoma (OAG) or ocular hypertension (OHT), according to findings published in Eye & Contact Lens.

Researchers recruited 578 patients with OAG or OHT who had an unmedicated IOP of 22 mm Hg or higher and less than 5 mm Hg difference between eyes. The team randomized participants in a 1:1 ratio to receive a single daily eyedrop of latanoprost without BAK (n=289) or latanoprost with BAK (n=289) over 12 weeks. They measured IOP at baseline and at follow-up visits occurring at 7, 28, 56, and 84 days, obtaining a total of 3 measurements (8 AM, 10 AM, and 4 PM) during each session. Investigators established IOP as the primary efficacy endpoint, and assessed the noninferiority of latanoprost without BAK based on 3 criteria: the 95% confidence interval of the least squares mean difference between treatments included 0 mm Hg at all 12 time points, the upper limit of the 95% CI was less than 1.5 mm Hg at all 12 time points, and the upper limit of the 95% CI was less than 1.0 mm Hg for 7 of the 12 time points. 

Both patient groups achieved substantial and clinically meaningful IOP reduction from baseline, and those in the latanoprost without BAK group experienced a reduction of approximately 6-7 mm Hg IOP reduction from baseline at all time points. However, latanoprost without BAK failed to achieve noninferiority status according to the predetermined standards. Ultimately, the 95% CI of the mean difference in IOP reduction from baseline included 0 mm Hg for only 7 of 12 required time points, and the upper limit of the 95% CI was less than 1.0 mm Hg for 4 of 7 required time points.

In a subgroup analysis, latanoprost without BAK was less effective in lowering IOP among patients with a baseline IOP of 29-35 mmHg compared with those with an IOP of 22-28 mmHg. It failed to meet any of the 3 noninferiority criteria for the high IOP group and met only 1 criterion for the low IOP group.

“Although noninferiority was not established, the substantial decrease in IOP, tolerability profile, and potential long-term risks associated with BAK exposure encourage the use of latanoprost 0.005% without BAK as a safe alternative to latanoprost 0.005% solution with BAK for the management of patients with OAG or OHT,” according to the researchers.

This study may have been limited by its short washout period which could have allowed confounding due to previous medications. 

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures. .

Reference

Wirta D, Malhotra R, Peace J, et al. Noninferiority Study Comparing Latanoprost 0.005% Without Versus With Benzalkonium Chloride in Open-Angle Glaucoma or Ocular Hypertension. Eye Cont Lens. 2022;48(4):149-154. doi:10.1097/ICL.0000000000000860