Study Shows Drug Effective and Safe in Deterring Demodex Blepharitis

Demodex is an underdiagnosed cause of blepharitis and, in some cases, ocular surface inflammation and corneal neovascularization. For these reasons, treatments are needed to keep the troublesome mite at bay. Treatments have included manual removal of collarettes, lid scrubs with tea tree oil (TTO)-containing shampoos, TTO-containing lid cleaning products, or okra-based products. The latest addition to our treatment arsenal is lotilaner ophthalmic solution 0.25% (Xdemvy, Tarsus).

Demodex, shown here, face a new foe.

Here, I provide an overview of a study that played a pivotal role in the FDA approval of Xdemvy, and the study’s value to corneal specialists.


The study, “Lotilaner ophthalmic solution, 0.25%, for the treatment of Demodex blepharitis: results of a prospective, randomized, vehicle-controlled, double-masked, pivotal trial (Saturn-1)” was a phase 2b/3 clinical trial that evaluated the safety and efficacy of lotilaner ophthalmic solution, 0.25%.1 This is an antiparasitic agent that paralyzes and eradicates Demodex by selectively inhibiting parasite-specific gamma-aminobutyric chloride channels.

The study was comprised of 413 participants: 209 in the treatment group and 204 in the control group, with slightly more women in each group (58% and 56%, respectively). Each group used their assigned treatment bilaterally, b.i.d. for 43 days, and were assessed at days 8, 15, 22, and 43.

At day 43, 81.3% in the treatment group achieved a collarette grade of 0 or 1 in the upper eyelid, versus 23.0% in the control group (P<0.0001). Additionally, the mean erythema grade, which was 1.5 at baseline in both groups, decreased to grade 0 or cure in 19.1% in the treatment group versus 6.9% in the control group (P = 0.0001). Further, the composite cure, grade 0 for collarettes and erythema, was significantly higher in the treatment group versus the vehicle group (13.9% versus 1.0%, P<0.0001).

The incidence of ocular treatment-emergent events was relatively equal in both the treatment and control groups (19.8% versus 21.5%). No other clinically significant ad-verse effects were recorded on multiple safety measures, including corrected distance acuity, corneal staining, or endothelial cell density.


In an observational study, approximately 58% of patients had collarettes present, suggesting that as many as 25 million US adults may have Demodex blepharitis.2 What’s more, the symptomatic and psychosocial impact of Demodex are common complaints of patients and should not be dismissed.3

The eradication of mites in the study group, as well as the significant reduction of eyelid erythema after 43 days shows the efficacy of lotilaner 0.25% and confirms the results of the previous Europa and Io studies.4,5 CP


  1. Yeu E, Wirta DL, Karpecki P, Baba SN, Holdbrook M; Saturn I Study Group. Lotilaner ophthalmic solution, 0.25%, for the treatment of Demodex blepharitis: results of a prospective, randomized, vehicle-controlled, double-masked, pivotal trial (Saturn-1). Cornea. 2023;42(4):435-443.
  2. Trattler W, Karpecki P, Rapoport Y, et al. The prevalence of Demodex blepharitis in US eye care clinic patients as determined by collarettes: a pathognomonic sign. Clin Ophthalmol. 2022;16:1152-1164.
  3. Yeu E, Holdbrook MJ, Baba SN, et al. Psychosocial impact of demodex blepharitis. Invest Ophthalmol Vis Sci. 2021;62:1261-1261.
  4. Gonzalez-Salinas R, Yeu E, Holdbrook M, et al. Collarette elimination and demodex mite eradication with topical lotilaner ophthalmic solution, 0.25. J Ocular Pharmacol Ther. 2021;37(8):479-484.
  5. Gonzalez-Salinas R, Karpecki P, Yeu E, et al. Safety and efficacy of lotilaner ophthalmic solution, 0.25%, for the treatment of blepharitis due to demodex infestation: a randomized, controlled, double-masked clinical trial. Cont Lens Anterior Eye. 2022;45(4):101492.