Acoltremon Eye Drops for Dry Eye Disease

Acoltremon is a prescription eye drop for dry eye disease. It works in an unusual way: instead of adding moisture to the eye or calming inflammation, it switches on the cold-sensing nerve endings in the clear front surface of the eye, the cornea. Those nerves normally tell the tear glands to keep making a steady, background flow of tears. During its development the medicine was known by the code name AR-15512, and the early papers use that name.

This page covers the cold-receptor science behind the drop, the Nobel Prize connected to that science, what each of the COMET trials found, the burning and stinging reported when the drop goes in, the reports collected since approval, the United States approval and label, and what the published papers say about how it sits among other dry eye medicines. The Dry Eye Disease page describes the condition itself, its causes, how it is diagnosed and its other treatments.

Table of Contents

  1. What Acoltremon Is
  2. How Cold-Sensing Nerves in the Cornea Help Make Tears
  3. The 2021 Nobel Prize for Temperature and Touch Receptors
  4. COMET-1, the Phase 2b Trial
  5. COMET-2 and COMET-3, the Phase 3 Trials
  6. Screens, Reading and Work in the Pooled COMET Data
  7. Burning and Stinging When the Drop Goes In
  8. Reports Collected Since Approval
  9. The United States Approval and the Label
  10. How the Papers Place It Among Other Dry Eye Medicines
  11. What Is Not Yet Known
  12. Key Research Papers
  13. Connections
  14. Featured Videos

What Acoltremon Is

Acoltremon is a small chemical medicine given as an eye drop at a strength of 0.003%. The United States label describes it as an agonist, meaning a switch-on substance, of transient receptor potential melastatin 8 (TRPM8), the main cold receptor on sensory nerves. The label gives its chemical formula as C18H27NO2 and describes the pure substance as a white to pale yellow crystal that does not dissolve in water.

The compound comes from the same chemical family as menthol, the cooling substance in mint. A 2021 chemistry paper describes AR-15512 as having been known earlier as AVX-012 and WS-12, and as “a bioactive compound with menthol-like cooling activity.” The molecule can exist in several mirror-image and near-mirror-image shapes; that paper made the unwanted shapes on purpose so that laboratories could test the medicine and confirm that only the intended shape, called (1R,2S,5R), was present.

The aim of the drop is to raise the eye’s own tear production. Most dry eye treatments either replace tears from outside (artificial tears), slow their evaporation, keep them on the eye longer, or calm inflammation of the eye surface over weeks. Acoltremon instead acts on the nerve signal that tells the tear glands to work. A 2025 summary of the approval describes the result as both more tears and a cooling sensation.

Reviews do not all describe the drug’s action in exactly the same words. Most call it a TRPM8 agonist. A 2026 review of the new drugs approved in 2025 in Europe, the United States and the United Kingdom calls it the first “positive allosteric modulator” of TRPM8, a substance that makes the receptor easier to switch on. The United States label states that the exact way it works in dry eye disease is unknown.

How Cold-Sensing Nerves in the Cornea Help Make Tears

The nerve endings in the cornea include some that sense pain and irritation and others that sense small changes in temperature. Every time the eye is open, a little of the tear film evaporates, and evaporation cools the surface, in the same way that a wet finger feels cold in a breeze. A 2025 review describes how the cold receptor TRPM8 on corneal nerves responds to these small temperature drops, and also to the saltier tears that form as water evaporates. Through a nerve reflex, the signal reaches the tear glands, which then release more of the steady, background tears that keep the eye wet between blinks.

Laboratory and human studies built up this picture step by step:

The animal results come from mice. They explain why scientists expected a cold-receptor switch-on drop to raise tear flow in people; the human tests of acoltremon itself are the COMET trials described below.

A related idea is behind a different medicine. Varenicline nasal spray stimulates a nerve pathway in the nose that also leads to tear production. A 2026 review of nerve-based dry eye treatments describes both varenicline nasal spray and acoltremon as medicines that engage reflex or sensory tear pathways (Zhang 2026). The heat-sensing receptor TRPV1, the receptor for chili pepper, is a separate member of the same family; the capsaicin and TRPV1 animation shows how that one works.

The 2021 Nobel Prize for Temperature and Touch Receptors

The 2021 Nobel Prize in Physiology or Medicine was awarded jointly to David Julius and Ardem Patapoutian for their discoveries of receptors for temperature and touch. Julius’s laboratory had earlier used capsaicin, the hot substance in chili peppers, to find the heat receptor TRPV1. The menthol and cold receptor TRPM8, described by both laboratories in 2002, was a central part of the temperature work. Patapoutian’s laboratory also discovered the Piezo channels that sense touch and pressure.

Acoltremon is one of the first approved medicines built directly on the cold-receptor discovery. The 2025 approval summary describes it as the first TRPM8 agonist approved for dry eye disease (Zhou 2025). The two scientists, and the wider story of these receptors in pain, cold and touch, are covered on the Julius and Patapoutian page, which has a section on menthol and TRPM8.

COMET-1, the Phase 2b Trial

The first larger test in people with dry eye disease was the phase 2b trial called COMET-1, published in 2022. Patients were split into three equal groups: one received a 0.0014% drop, one a 0.003% drop and one an inactive drop with the same base liquid (the “vehicle”), each twice daily for 12 weeks. The 0.003% group had 122 patients.

The trial had two main measures, chosen in advance, both read at day 28: a 0 to 100 score of eye discomfort, and a Schirmer test done after numbing drops. Neither main measure was met: there was no significant difference between the active and inactive groups on either one.

Other measures did move. In the 0.003% group, the Schirmer test done without numbing drops improved on days 1 and 14, staining of the eye surface improved on days 14 and 84, redness improved on day 84, and the Symptom Assessment iN Dry Eye (SANDE) questionnaire score improved on days 14, 28 and 84. Several quality-of-life measures also improved. The most common side effects were burning and stinging when the drop went in. The authors wrote that, although the predefined main measures were not met, the 0.003% drop showed significant improvements in signs, symptoms and quality of life (Wirta 2022). The 0.003% strength and the Schirmer test without numbing were the ones carried into the phase 3 trials.

The Schirmer test is a thin paper strip placed inside the lower eyelid for five minutes; the number of millimeters it wets is a rough measure of watery tear production. Done without numbing drops, it also counts the reflex tears that the eye’s nerves trigger.

COMET-2 and COMET-3, the Phase 3 Trials

The two phase 3 trials were identical in design and were published together in 2026 (Pattar 2026; doi:10.1016/j.ophtha.2025.09.018). Adults aged 30 or older with dry eye disease were enrolled if at least one eye showed both surface staining and a low Schirmer test result after numbing drops (from 2 to under 10 millimeters in five minutes), and if they also scored 50 or more on both an eye discomfort scale and the dryness symptom questionnaire. COMET-2 enrolled 465 patients and COMET-3 enrolled 466. In each trial, half received acoltremon 0.003% and half the vehicle drop, twice daily for 90 days. The label adds that artificial tears were not allowed during the studies, that the average age was 61 (range 30 to 93) and that 74.8% of patients were women.

The main measure was the share of patients whose Schirmer test without numbing drops rose by 10 millimeters or more by day 14. The label gives the average starting Schirmer results as 6.2 millimeters on acoltremon and 5.9 millimeters on vehicle in COMET-2, and 6.8 and 6.4 millimeters in COMET-3.

The difference was statistically significant in both trials (P < 0.0001).

The time course reported in the paper:

Staining of the conjunctiva, the thin membrane covering the white of the eye, was lower on acoltremon at every time point measured. Staining of the cornea and conjunctiva were exploratory measures, not the main tests. Mild burning or stinging when the drop went in was the only eye side effect reported in more than 2.5% of patients. The authors concluded that acoltremon led to consistent, clinically meaningful tear production and reductions in dry eye signs and symptoms compared with vehicle.

The journal that published the trials also ran an editorial on them, titled “Placing the Phase 3 Results in Perspective” (Moshfeghi 2026, doi:10.1016/j.ophtha.2026.01.020). It has no published abstract, so its views are not summarized here.

Screens, Reading and Work in the Pooled COMET Data

A 2026 analysis pooled all three COMET trials (584 patients on acoltremon and 595 on vehicle) to look at everyday tasks that need steady vision. Patients rated, on a 0 to 100 scale, how much dry eye symptoms got in the way of activities such as using electronic devices, and of their work. This analysis was carried out after the trials had finished and was not one of their planned main tests; the authors call the data exploratory.

All of these differences were statistically significant. In the same pooled data, burning or stinging when the drop went in was reported by 50.2% of patients on acoltremon (97.6% of those cases mild) and 3.2% on vehicle (Periman 2026).

Burning and Stinging When the Drop Goes In

The side effect seen in every acoltremon trial is a burning, stinging or painful feeling at the moment the drop goes in. The trial papers and the label report it in these terms:

A short review of the approval states that no serious eye side effects were noted in the trials (Zhou 2025), and the first-approval review describes a low rate of patients stopping treatment (Lee 2025). Because the drug acts on a cold-sensing nerve receptor, a cooling sensation is also part of how it is described (Zhou 2025).

A 2025 pooled analysis of trials of medicines acting on these temperature-sensing receptors (six trials, 884 patients, covering one TRPV1 blocker and the TRPM8 agonist) found no increase in side effects overall compared with vehicle drops (Duan 2025). That analysis grouped two different kinds of medicine together.

Reports Collected Since Approval

After a medicine is approved, doctors, patients and manufacturers can send reports of suspected side effects to the United States Food and Drug Administration (FDA) Adverse Event Reporting System. A 2026 study searched that database from the second quarter of 2025 to the first quarter of 2026 and found 2,667 reported side effects linked to acoltremon (Hu 2026).

Reports of this kind show which problems are being reported more often than expected. They cannot show that the medicine caused them, and they cannot show how often a problem happens. The authors wrote that the findings need to be interpreted cautiously and call for further study.

The United States Approval and the Label

The United States Food and Drug Administration first approved acoltremon on May 28, 2025, for the treatment of the signs and symptoms of dry eye disease (Zhou 2025). A news report in a drug-discovery journal described it as the first approved medicine of its class (Mullard 2025, doi:10.1038/d41573-025-00106-x), and the first-approval review summarizes its development (Lee 2025). The current label is published on DailyMed, the National Library of Medicine’s label service, and gives “Initial U.S. Approval: 2025.”

The label states:

The National Library of Medicine’s breastfeeding database, LactMed, states that there is no information on acoltremon during breastfeeding, that it is poorly absorbed and that amounts reaching breast milk are likely very low. It describes pressing on the tear duct at the inner corner of the eye for 2 to 5 minutes after the drop as a way to reduce the amount absorbed, and states that use of the drop is not a reason to stop breastfeeding (LactMed 2026).

How the Papers Place It Among Other Dry Eye Medicines

No trial has tested acoltremon head to head against another dry eye medicine. The label points out that side-effect rates from the trials of one drug cannot be directly compared with rates from the trials of another drug, because trials are run under widely varying conditions. The papers below are reported as their abstracts describe them.

The one published indirect comparison, with cyclosporine

A 2026 study used a statistical method called a matching-adjusted indirect comparison. It took individual patient data from COMET-2 and COMET-3 and re-weighted them to resemble the published summary data from the trials of cyclosporine 0.05% eye drops, matching on age, race, sex and the numbed Schirmer result. The outcome was the Schirmer result sorted into categories. At day 90, the rise was greater for acoltremon, by 1.62 categories (95% confidence interval 1.42 to 1.83). An exploratory analysis comparing acoltremon at day 14 with cyclosporine at day 90, the earliest time point available for cyclosporine, gave the same 1.62-category difference. The authors state that because the comparison was “unanchored” (it had no shared comparison group), the results may be affected by differences between the trials that could not be measured (Pflugfelder 2026). The paper’s disclosures state that several authors were employees of, or consultants to, the manufacturer.

What the other medicines’ own main trials measured

These trials enrolled different patients, ran for different lengths of time and used different main measures. Recent reviews describe the field as moving toward treatments chosen for the mechanism behind each person’s dry eye, with acoltremon given as an example of a mechanism-specific therapy (Cukurova 2025; Rossi 2026).

What Is Not Yet Known

Decisions about prescription eye medicines belong with a clinician.

Key Research Papers

  1. Pattar GR, Wirta D, Jerkins G, Paauw J, McLaurin EB, Liu A, et al. Acoltremon Ophthalmic Solution 0.003% for Signs and Symptoms of Dry Eye Disease: Results of Phase 3 Pivotal COMET-2 and COMET-3 Studies. Ophthalmology. 2026;133(5):563-574. PubMed PMID: 41038456
  2. Wirta DL, Senchyna M, Lewis AE, Evans DG, McLaurin EB, Ousler GW, et al. A randomized, vehicle-controlled, Phase 2b study of two concentrations of the TRPM8 receptor agonist AR-15512 in the treatment of dry eye disease (COMET-1). Ocul Surf. 2022;26:166-173. PubMed PMID: 35970431
  3. Periman LM, Lappin CJ, McDonald MB, Coats J, Pattar GR, Okoro T, et al. Improvement in Visual-Tasking Daily Living Activities and Work Productivity in Patients with Dry Eye Disease: Integrated Analysis of COMET Studies. Ophthalmol Ther. 2026;15(9):3025-3039. PubMed PMID: 42470519
  4. Pflugfelder S, Okoro T, Ainslie-Garcia M, Haltner A, Prentiss EK, Salvo-Halloran EM, et al. Matching-adjusted indirect comparison of acoltremon ophthalmic solution 0.003% and cyclosporine 0.05% ophthalmic emulsion for increased tear production in patients with dry eye disease. J Comp Eff Res. 2026;15(6):e260032. PubMed PMID: 42132429
  5. Hu X, Yu C, Huang Y. Disproportionality analyses of acoltremon: a real-world safety assessment based on the the FDA adverse event reporting system database. Front Med (Lausanne). 2026;13:1906740. PubMed PMID: 42625667
  6. Lee A. Acoltremon: First Approval. Drugs. 2025;85(10):1307-1310. PubMed PMID: 40736647
  7. Zhou Y, Zhang W, Sun F. Acoltremon: The first TRPM8 agonist approved for the treatment of dry eye disease. Drug Discov Ther. 2025;19(3):210-211. PubMed PMID: 40571589
  8. Papapetropoulos A, Topouzis S, Alexander SPH, Cortese-Krott MM, Helyes Z, Martemyanov K, et al. Novel drugs approved by the EMA, the FDA and the MHRA in 2025: A year in review. Br J Pharmacol. 2026;183(9):1779-1813. PubMed PMID: 41771767
  9. Gallar J, Pflugfelder S, Galor A, Gupta PK, Hamrah P. Corneal sensory nerve regulation of tear production through stimulation of transient receptor potential melastatin 8 (TRPM8) channel: A potential new approach for treating dry eye disease. Ocul Surf. 2025;38:142-154. PubMed PMID: 40685077
  10. Parra A, Madrid R, Echevarria D, del Olmo S, Morenilla-Palao C, Acosta MC, et al. Ocular surface wetness is regulated by TRPM8-dependent cold thermoreceptors of the cornea. Nat Med. 2010;16(12):1396-9. PubMed PMID: 21076394
  11. McKemy DD, Neuhausser WM, Julius D. Identification of a cold receptor reveals a general role for TRP channels in thermosensation. Nature. 2002;416(6876):52-8. PubMed PMID: 11882888
  12. Peier AM, Moqrich A, Hergarden AC, Reeve AJ, Andersson DA, Story GM, et al. A TRP channel that senses cold stimuli and menthol. Cell. 2002;108(5):705-15. PubMed PMID: 11893340
  13. Bautista DM, Siemens J, Glazer JM, Tsuruda PR, Basbaum AI, Stucky CL, et al. The menthol receptor TRPM8 is the principal detector of environmental cold. Nature. 2007;448(7150):204-8. PubMed PMID: 17538622
  14. Vieth R, Griffiths C, Rapson LM. Acute Tear Secretion Response to Menthol Delivered as a Vapor to the Eye: A Placebo-Controlled, Double-Blind, Randomized Clinical Trial. Pharmaceutics. 2026;18(8):910. PubMed PMID: 42654027
  15. Rodríguez-Arévalo S, Pujol E, Abás S, Galdeano C, Escolano C, Vázquez S. Synthesis, Characterization and HPLC Analysis of the (1S,2S,5R)-Diastereomer and the Enantiomer of the Clinical Candidate AR-15512. Molecules. 2021;26(4):906. PubMed PMID: 33572112
  16. Duan X, Ju M, Liu X, Hu J. Efficacy and safety of transient receptor potential channel modulators for dry eye: A systematic review and meta-analysis. Cont Lens Anterior Eye. 2025;48(3):102347. PubMed PMID: 39753447
  17. Zhang J, Li Z. The neuro-immune-epithelial axis in dry eye: From pathogenic crosstalk to neuromodulatory therapies. Exp Eye Res. 2026;270:111133. PubMed PMID: 42320871
  18. Forestier MG, Nassar Badillo J, Oliver AL. Ophthalmic Treatments and Evolving Management of Sjögren's Disease: An Overview. J Clin Med. 2026;15(18):7272. PubMed PMID: 42796043
  19. Sall K, Stevenson OD, Mundorf TK, Reis BL. Two multicenter, randomized studies of the efficacy and safety of cyclosporine ophthalmic emulsion in moderate to severe dry eye disease. CsA Phase 3 Study Group. Ophthalmology. 2000;107(4):631-9. PubMed PMID: 10768324
  20. Holland EJ, Luchs J, Karpecki PM, Nichols KK, Jackson MA, Sall K, et al. Lifitegrast for the Treatment of Dry Eye Disease: Results of a Phase III, Randomized, Double-Masked, Placebo-Controlled Trial (OPUS-3). Ophthalmology. 2017;124(1):53-60. PubMed PMID: 28079022
  21. Tauber J, Berdy GJ, Wirta DL, Krösser S, Vittitow JL. NOV03 for Dry Eye Disease Associated with Meibomian Gland Dysfunction: Results of the Randomized Phase 3 GOBI Study. Ophthalmology. 2023;130(5):516-524. PubMed PMID: 36574848
  22. Fahmy AM, Harthan JS, Evans DG, Greiner JV, Tauber J, Sheppard JD, et al. Perfluorohexyloctane ophthalmic solution for dry eye disease: pooled analysis of two phase 3 clinical trials. Front Ophthalmol (Lausanne). 2024;4:1452422. PubMed PMID: 39564145
  23. Wirta D, Vollmer P, Paauw J, Chiu KH, Henry E, Striffler K, et al. Efficacy and Safety of OC-01 (Varenicline Solution) Nasal Spray on Signs and Symptoms of Dry Eye Disease: The ONSET-2 Phase 3 Randomized Trial. Ophthalmology. 2022;129(4):379-387. PubMed PMID: 34767866
  24. Cukurova F, Coco G, Lixi F, Giannaccare G. Current and emerging pharmacological treatment options for patients with dry eye disease. Expert Rev Clin Pharmacol. 2025;18(7):485-501. PubMed PMID: 40751370
  25. Rossi C, Borselli M, Lucisano A, Coco G, Busin LML, Scorcia V, et al. Developments in the therapeutic landscape for dry eye. Expert Opin Pharmacother. 2026;27(2):83-95. PubMed PMID: 41697150
  26. Acoltremon. In: Drugs and Lactation Database (LactMed). Bethesda (MD): National Institute of Child Health and Human Development; 2006-. PubMed PMID: 41730067

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