Tarsus Pharmaceuticals, Inc., a commercial stage biopharmaceutical company, focuses on the development and commercialization of therapeutics, starting with eye care.
The company launched XDEMVY (lotilaner ophthalmic solution) 0.25% for the treatment of Demodex blepharitis in August 2023, after receiving U.S. Food and Drug Administration (FDA) approval in July 2023.
XDEMVY targets and eradicates the root cause of Demodex blepharitis — Demodex mite infestation. The active pharmaceutical ingredie...
Tarsus Pharmaceuticals, Inc., a commercial stage biopharmaceutical company, focuses on the development and commercialization of therapeutics, starting with eye care.
The company launched XDEMVY (lotilaner ophthalmic solution) 0.25% for the treatment of Demodex blepharitis in August 2023, after receiving U.S. Food and Drug Administration (FDA) approval in July 2023.
XDEMVY targets and eradicates the root cause of Demodex blepharitis — Demodex mite infestation. The active pharmaceutical ingredient (API) of XDEMVY, lotilaner, paralyzes and eradicates mites and other parasites through the inhibition of parasite-specific gamma-aminobutyric acid-gated chloride (GABA-Cl) channels, with no GABA-Cl inhibition in humans.
As of December 31, 2024, the company has completed seven clinical trials that include a Phase 3 trial (the Saturn-2 trial), a Phase 2b/3 trial (the Saturn-1 trial), four Phase 2 trials, and a Phase 1 trial (the Hyperion trial) for XDEMVY in Demodex blepharitis, all of which met their primary, secondary, and/or certain exploratory endpoints, with the drug generally safe and well tolerated throughout each trial. The company has also completed, and/or has ongoing clinical trials for the potential treatment of Demodex blepharitis in patients with Meibomian Gland Disease (MGD), including a Phase 2a clinical trial (the Ersa trial) that evaluated XDEMVY for the treatment of MGD in patients with Demodex blepharitis, and a pilot clinical trial that evaluated an XDEMVY vehicle for the potential treatment of MGD in patients with Demodex mites (the Rhea trial), TP-04 for the potential treatment of Ocular Rosacea, and TP-05 for potential Lyme disease prophylaxis, among others.
The company intends to further advance its pipeline with the lotilaner API to address several diseases in human medicine, including eye care and infectious disease prevention. The company is investigating the development of its product candidates to address targeted diseases with high unmet medical needs, which include TP-04, a novel ophthalmic gel formulation of lotilaner for the potential treatment of Ocular Rosacea, and TP-05, a novel investigational oral formulation of lotilaner for potential Lyme disease prophylaxis and community malaria reduction.
TP-03 Demodex blepharitis in patients with Meibomian Gland Disease (MGD)
In August 2022, the company announced the enrollment of its first patient in the Ersa trial. In December 2023, the company announced positive topline results from the Ersa trial evaluating XDEMVY administered twice daily (BID) or three times a day (TID) for six weeks and twelve weeks. XDEMVY demonstrated statistically significant and clinically meaningful improvements compared to baseline in two objective measures of the disease: the presence and quality of liquid secretion as measured by the Meibomian Gland Secretion Score; and the number of glands secreting normal or clear liquid.
Given the positive results of these trials, and the FDA’s feedback that these patients are already included in XDEMVY’s label for the treatment of Demodex blepharitis, the company is moving forward with sharing this data with eye care providers (ECPs) to further educate them on the disease and the potential benefits of treating these patients with XDEMVY.
TP-04 for the Potential Treatment of Ocular Rosacea
The company is exploring the therapeutic potential of TP-04 as a novel topical ophthalmic gel formulation of lotilaner for the treatment of Ocular Rosacea, a chronic eyelid disease characterized by redness, flushing, and inflammation of the eyelid margin, visible blood vessels, and surrounding peri-ocular skin.
TP-04 is designed to eradicate Demodex mites, a potential root cause of Ocular Rosacea. In March 2023, the company announced positive topline results from the Phase 1 Galatea trial (the Galatea Phase 1 trial) and initiated a Phase 2a trial (the Galatea trial) for the potential treatment of rosacea. The Galatea trial was a multicenter, randomized, vehicle-controlled trial evaluating the safety, tolerability, and efficacy of TP-04. In February 2024, the company announced positive topline results from the Galatea trial, which demonstrated statistically significant improvements (p<0.05) in inflammatory lesions and Investigator's Global Assessment (IGA) score (change in baseline and success rate) compared to vehicle at Week 12. After review of this data with the FDA and Key Opinion Leaders (KOLs), the company decided to pursue the development of TP-04 for the potential treatment of Ocular Rosacea. In January 2025, the company announced plans to initiate a Phase 2 trial in the second half of 2025 for the potential treatment of Ocular Rosacea.
TP-05 for the Potential Prevention of Lyme Disease
The company is exploring the therapeutic potential of TP-05 as an oral, systematic prophylactic for Lyme disease designed to eradicate the tick before it can transmit the Borrelia burgdorferi infection that causes Lyme disease.
In December 2022, the company announced positive topline results from the completed Phase 1 Callisto trial (the Callisto trial) and enrollment of the first patient in the Phase 2a clinical trial (the Carpo trial). The Carpo trial was designed to evaluate TP-05 for the potential prevention of Lyme disease in humans. The Carpo trial was a randomized, double-blind, placebo-controlled trial that evaluated the efficacy of TP-05 in killing lab-grown, non-disease-carrying ticks after they have attached to the skin of healthy volunteers, as well as confirm the safety, tolerability, and blood concentration of TP-05. Sterile, non-pathogenic nymphal ticks were placed on the skin of healthy human volunteers at two separate instances (one day prior to dosing and 30 days after dosing).
In February 2024, the company announced positive topline results from the Carpo trial, which demonstrated a statistically significant benefit in killing ticks compared to vehicle (p < 0.0001). Specifically, after the Day 1 tick challenge, mean tick mortality was 97.0% (± 1.4 standard error, SE) and 92.0% (± 6.3 SE) for the high and low doses of TP-05, respectively, compared to only 5.0% (± 2.5 SE) for placebo. Similarly, at the 30-day challenge, mean tick mortality at 24 hours after placement was 89.0% (± 11.1 SE) and 91.0% (± 6.1 SE) for the high and low doses of TP-05, respectively, compared to only 9.0% (± 8.0 SE) for placebo (p<0.001).
In December 2024, the company met with the FDA about its Lyme disease program. The FDA agreed to its proposed approach for a Phase 2b clinical trial, which plans to include several hundred subjects. Additionally, the FDA confirmed that a Phase 3 clinical study would require a disease prevention field study that would likely require the enrollment of thousands of patients.
Strategy
The company’s key strategies are to continue to accelerate the launch trajectory of its first marketed product, XDEMVY; continue to pursue a potentially transformative opportunity in ocular rosacea; continue to advance and expand its pipeline, bringing novel products utilizing lotilaner to unmet needs across human medicine, including Lyme disease prophylaxis; evaluate and strategically enter collaborations to maximize the potential of its pipeline and the scope of its eye care product offerings; and continue innovating and planning for growth.
Commercial Strategy for Demodex Blepharitis
In August 2023, the company launched XDEMVY in the U.S. with a specialty sales force, social and digital media, and ECP education campaigns targeting prescribing ophthalmologists and optometrists.
During 2024, the company continued to work with KOLs and various associations to increase Demodex blepharitis awareness and education, highlighting prevalence, impact, and simplicity of diagnosis of Demodex blepharitis. The company’s goal is to continue to educate ECPs about the prevalence of Demodex blepharitis, simplicity and efficiency of diagnosis, and the positive profile of XDEMVY. Consistent with its goal to educate ECPs, the company expanded its sales force by approximately 50 new representatives and leaders in 2024. In addition to educating ECPs, the company activated its first Direct-to-Consumer (DTC) campaign in streaming television in the fourth quarter of 2024 that leverages creative and memorable visuals to illustrate the damaging impact of the disease, with the goal of supporting patients in their journey and encouraging them to consult with ECPs to see whether XDEMVY is right for them.
In 2024, the first full year XDEMVY was available on the market, XDEMVY generated $180.1 million in net product sales, with more than 163,000 bottles dispensed to patients, and the company secured broad commercial and Medicare coverage. The success of XDEMVY was built on a very core set of fundamentals and a reflection of the company’s strategic approach to an unwavering focus on evidence generation, education, ease of access, and execution.
Blepharitis
The company has conducted epidemiology and market research on the prevalence of blepharitis and potential adoption of XDEMVY. The company’s research indicates approximately 58% of patients presenting to ECP offices have collarettes and, based on the Gao et al. 2005 study (the Gao study), all patients with collarettes were also found to have Demodex mites. In addition, the company’s market research suggests the potential for a high level of adoption of XDEMVY.
The company's Approach: Treating Demodex Mites, a Root Cause of Disease
To address these limitations and high unmet need for effectively treating Demodex blepharitis, the company developed and is in the process of commercializing XDEMVY, which is the definitive standard of care for the treatment of Demodex blepharitis. XDEMVY is a novel therapeutic based on the drug lotilaner, which is designed to paralyze and eradicate mites and other parasites through the inhibition of parasite-specific GABA-Cl channels. XDEMVY met all endpoints in its clinical trials and was generally well tolerated throughout each of these trials. As a result, XDEMVY was approved by the FDA in July 2023 for the treatment of Demodex blepharitis, and the company began commercializing XDEMVY in August 2023.
Clinical Development Program
As of December 31, 2024, the company has completed seven clinical trials that include one Phase 3 trial, one Phase 2b/3 trial, four Phase 2 trials, and one Phase 1 trial for XDEMVY in Demodex blepharitis, all of which met primary, secondary, and/or certain exploratory endpoints, while demonstrating XDEMVY was well tolerated. These pivotal trial results (Phase 2b/3 and Phase 3) supported the FDA approval of XDEMVY in July 2023.
The company has also completed, and/or has ongoing clinical trials for the potential treatment of Demodex blepharitis in patients with MGD, including the Ersa trial involving XDEMVY and the Rhea trial involving an XDEMVY vehicle; TP-04 for the potential treatment of Ocular Rosacea; and TP-05 for potential Lyme disease prophylaxis, among others.
The Saturn-2 Trial
In May 2021, the company initiated the Saturn-2 trial, a randomized, controlled, multicenter, double-masked trial studying the safety and efficacy of XDEMVY for the treatment of Demodex blepharitis. The Saturn-2 trial was similar in design and size to the Saturn-1 trial, which met the primary and all secondary endpoints. The Saturn-2 trial's primary endpoint was the proportion of patients achieving collarette cure, defined as zero to two collarettes per lid. Secondary endpoints included the eradication of Demodex mites and the proportion of patients achieving a cure based on a composite of collarette cure and erythema cure (eyelid redness). A statistically significant outcome for primary efficacy endpoints is typically one of the requirements for FDA approval of a product. A statistically significant outcome indicates that the probability of the outcome occurring at random is less than the pre-established allowed error level, frequently set at 0.05 (or 1 in 20).
In May 2022, the company announced positive topline results of the Saturn-2 trial, its second XDEMVY pivotal trial. The Saturn-2 trial enrolled 412 adults having, among other things, more than ten collarettes per lid and at least mild lid erythema. All pre-specified primary and secondary endpoints were met, XDEMVY was well tolerated, and improvement in lids (reduction of collarettes to no more than two collarettes per upper lid) was demonstrated in 55% of patients treated with XDEMVY.
The Saturn-1 Trial
In September 2020, the company commenced the Saturn-1 trial, a randomized, controlled, multicenter, double-masked Phase 2b/3 trial that evaluated the safety and efficacy of XDEMVY in adults with Demodex blepharitis. The Saturn-1 trial enrolled 421 adult patients having more than ten collarettes on the upper lid and at least mild erythema of the upper eyelid margin. Each patient had at least 1.5 mites per lash on the upper and lower eyelids combined. One drop of XDEMVY was self-administered twice per day in each eye for six weeks. Enrolled patients received no treatment for blepharitis symptoms (i.e., lid hygiene) during the trial or 14 days prior to enrollment. The primary endpoint was complete collarette cure (grade zero defined as zero to two collarettes per lid) and the secondary endpoints included complete mite eradication (mite density of zero mites per lash) and composite cure (the presence of zero to two collarettes on the upper eyelid and the absence of erythema (redness)).
In June 2021, the company announced positive results of the Saturn-1 trial. The pre-specified primary and secondary endpoints were met, and improvement in lids (reduction of collarettes to no more than two collarettes per upper lid) was demonstrated in 44% of patients treated with XDEMVY.
In July 2021, the company presented additional data from the Saturn-1 trial at the American Society of Cataract and Refractive Surgery 2021 Annual Meeting, demonstrating high treatment response rates and reinforcing the potential of XDEMVY to be the standard of care for Demodex blepharitis patients.
The company also announced results from an additional Saturn-1 trial safety analysis, which reinforced XDEMVY’s positive profile, revealing that XDEMVY had no clinically significant adverse effect on multiple safety measures, including Corrected Distance Visual Acuity (CDVA), corneal staining, and intraocular pressure (IOP), and no significant findings from slit lamp biomicroscopy or fundus exam in the study. In addition, no impact to endothelial cell density (ECD) was demonstrated in a subset of 21 patients. ECD was further evaluated as part of the Saturn-2 trial plan and also demonstrated no impact.
Phase 2 Clinical Trials
The company completed four Phase 2 clinical trials for XDEMVY, along with one additional ex vivo study, which included its Mars, Jupiter, Io, and Europa clinical trials. Key efficacy endpoints for its Mars and Jupiter clinical trials included collarette grade and mite density, and key efficacy endpoints for its Io and Europa clinical trials included collarette cure rate based on collarette grade, which the company refers to herein as collarette cure rate, and mite eradication rate. The primary, secondary, and/or certain exploratory endpoints were met, as applicable, in such trials, and showed statistically significant cure and eradication rates in Io and Europa. XDEMVY was generally well tolerated throughout these trials.
To address this unmet need in the rosacea market, the company is developing lotilaner as a topical sterile ophthalmic product, TP-04. TP-04 is designed to be active after topical administration with no systemic activity. Lotilaner’s mechanism of targeting and killing Demodex mites has been established through the company’s preclinical study and clinical trials evaluating XDEMVY in Demodex blepharitis.
The company has completed the initial preclinical studies and a Phase 1 trial for TP-04 and has selected a topical ophthalmic formulation for early clinical studies. The company intends to leverage systemic preclinical data from its XDEMVY program, such as embryofetal development studies, genotoxicity studies, and safety pharmacology studies, and augment it with the dermal toxicology studies. In March 2023, the company initiated the Galatea trial evaluating TP-04, a novel gel formulation of lotilaner, for the treatment of rosacea. In February 2024, the company announced positive topline results from the Galatea trial, which demonstrated statistically significant improvements (p<0.05) in inflammatory lesions and IGA score (change in baseline and success rate) compared to vehicle at Week 12. TP-04 was generally well tolerated.
After review of this data with the FDA and KOLs, the company decided to pursue the development of TP-04 for the potential treatment of Ocular Rosacea. In January 2025, the company announced plans to initiate a Phase 2 study in the second half of 2025 for the potential treatment of Ocular Rosacea.
Since Borrelia is usually transferred during the second or third day following a tick bite, the company’s approach is to eradicate the tick before it can transmit the bacteria. To do this, the company is developing TP-05 as an oral tablet formulation of lotilaner. The company is targeting potentially at least 30 days of prophylactic protection against Lyme disease with a simple oral regimen of TP-05. Given that lotilaner was developed specifically, in part, to eradicate ticks with systemic administration to domesticated animals such as dogs or cats, the pharmacology of lotilaner for Lyme disease prophylaxis is well understood.
In December 2022, the company announced positive topline results from the Phase 1 Callisto trial for TP-05, a novel, oral, non-vaccine therapeutic for the potential prevention of Lyme disease. The Callisto trial was a randomized, double-blind, single and multiple-ascending dose trial that evaluated the safety, tolerability, and pharmacokinetics (PK) of TP-05 in healthy subjects. Results from the trial showed that TP-05 was well tolerated, with no dose-related or drug-related serious adverse events. PK data from the trial demonstrated rapid absorption and an extended half-life of TP-05 that potentially supports a convenient oral regimen, reinforcing its potential as a rapid onset, prophylactic therapy for Lyme disease. Additionally, exploratory ex-vivo tick kill modeling that utilized serum from TP-05 treated subjects demonstrated potent, rapid killing of adult and nymph ticks. In December 2022, the company also announced the initiation of the Phase 2a Carpo trial, evaluating TP-05 for the potential prevention of Lyme disease in humans. The Carpo trial is a randomized, double-blind, placebo-controlled trial that evaluated the efficacy of TP-05 in killing lab-grown, non-disease carrying ticks after they have attached to the skin of healthy volunteers, as well as confirming the safety, tolerability, and blood concentration of TP-05. In February 2024, the company announced positive topline results from the Carpo trial.
In December 2024, the company met with the FDA regarding its Lyme disease program. The FDA agreed to its proposed approach for a Phase 2b clinical trial, which plans to include several hundred subjects. Additionally, the FDA confirmed that a Phase 3 clinical study would require a disease prevention field study that would likely require the enrollment of thousands of patients.
Chemistry, Manufacturing and Controls (CMC)
The company relies, and expects to continue to rely, on contract manufacturing organizations (CMOs) to manufacture and supply its preclinical and clinical materials to be used during the development of its product candidates. The company has assembled a team of employees and consultants to oversee its technical quality and CMOs.
Although the company has relied on a single supplier for both non-clinical and clinical supply for lotilaner under cGMP protocols, and a single CMO to manufacture XDEMVY and perform analytical testing services, the company has identified and is in the process of qualifying an additional manufacturer to provide lotilaner and drug product manufacturing and analytical testing services. The company has suppliers for TP-04 topical formulation for Ocular Rosacea and TP-05 oral formulation for its Phase 1/2 trials.
The company’s third-party service providers, its third-party supply chain providers, their facilities, and XDEMVY used in its clinical trials or for commercial sale are required to be in compliance with the requirements of cGMP. The cGMP regulations govern manufacturing processes and procedures, including requirements relating to organization of personnel, buildings and facilities, equipment, control of components and packaging containers and closures, production and process controls, packaging and labeling controls, holding and distribution, laboratory controls, records and reports, and returned or salvaged products. Product candidates used in late-stage clinical trials must be manufactured in accordance with cGMP requirements, and manufacturing specifications and processes must satisfy FDA or other authorities’ requirements before any product is approved and before the company can manufacture commercial products. The company’s third-party manufacturers are also subject to periodic inspections of facilities by the FDA and other authorities, including procedures and operations used in the testing and manufacture of XDEMVY to assess compliance with applicable regulations. The company’s failure, or the failure of its third-party providers and supply chain providers, to comply with such statutory and regulatory requirements could subject it to possible legal or regulatory action, including clinical holds, fines, injunctions, civil penalties, delays, suspension or withdrawal of approvals, license revocation, suspension of production, warning letters, the seizure or recall of products, operating restrictions, and criminal prosecutions. Any of these actions could have a material impact on commercial supplies of XDEMVY, clinical supplies of TP-03, or the company’s other product candidates. Contract manufacturers at times encounter difficulties involving production yields, quality control, and quality assurance, as well as shortages of qualified personnel.
Sales and Marketing
The company launched XDEMVY in the U.S. in August 2023. In 2024, XDEMVY generated $180.1 million in net product sales driven by the following: more than 163,000 bottles dispensed to patients; more than 15,000 ECPs prescribed XDEMVY; broad commercial, Medicare, and Medicaid reimbursement extended to more than 90% of covered lives, as of February 25, 2025; and gross to net discounts of approximately 45%.
There are approximately 25 million people in the U.S. who suffer from Demodex blepharitis; however, the company is initially targeting the approximately 9 million people who are proactively seeking treatment for Demodex blepharitis or seeking treatment for complementary eye conditions or treatments.
As of December 31, 2024, the company has observed increased adoption and utilization in the additional Demodex blepharitis patient segments noted, which was further validated by its latest market research detailing that even at this early stage in the launch, approximately 40% of ECPs surveyed are already prescribing XDEMVY across each of these additional patient segments. Over 90% of the ECPs indicated they plan to increase utilization across these segments.
Outside the U.S., the company intends to further develop commercialization strategies for TP-03. In March 2021, the company entered into the China Out-License with LianBio Ophthalmology Limited (LianBio), granting exclusive commercial rights of TP-03 for the treatment of Demodex blepharitis and MGD within the China Territory. In March 2024, the company executed an agreement with GrandPharma and LianBio to transition these rights to GrandPharma. The company is also exploring development and commercialization opportunities in other markets, including Europe and Japan.
Intellectual Property
The patents and applications in the company’s portfolio can be categorized as related to XDEMVY, TP-03, TP-04, TP-05, or future pipeline product candidates and alternative technologies. Some of the company’s issued patents and patent applications are exclusively licensed to it in therapeutic fields of use from Elanco.
As of December 31, 2024, the material licensed-in portfolio includes approximately 38 issued patents and approximately 17 pending patent applications from Elanco. These patents and patent applications relate to lotilaner and are issued or pending in, for example, the U.S., Argentina, Australia, Brazil, Canada, Chile, China, Columbia, several European territories, India, Japan, South Korea, Mexico, New Zealand, the Russian Federation, South Africa, and Taiwan. The issued patents include composition of matter claims. The estimated natural expiration dates of the issued material in-licensed patents are approximately 2029 or 2030, with a potential extension until 2032.
Approximately 76 of the company’s owned material patents and pending patent applications include treatment and composition of matter claims that relate to XDEMVY or TP-03 with respect to its lead indication (e.g., isoxazoline parasiticides for the treatment of Demodex blepharitis), as well as other conditions. These pending material patent applications include applications in the U.S., Australia, Brazil, Canada, China, several European territories, Hong Kong, Israel, India, Japan, South Korea, Mexico, New Zealand, the Russian Federation, and South Africa. The company has a total of 38 material XDEMVY or TP-03-related issued patents worldwide. The estimated natural expiration dates of these issued patents are in 2038, and if additional patents issue on the material XDEMVY or TP-03-related pending applications, the estimated natural expiration dates are between approximately 2038 and 2040.
The company also protects its brand through trademark rights. As of December 31, 2024, the company owns approximately 7 trademark registrations in the U.S., approximately 3 pending trademark applications in the U.S., approximately 34 trademark registrations in foreign countries, and approximately 50 pending trademark applications in foreign countries. To supplement the protection of its brand, the company also owns at least 6 registered internet domain names.
License Agreements
Elanco In-License Agreement for Skin and Eye Diseases or Conditions in Humans
In January 2019, the company entered into an agreement with Elanco granting it exclusive, worldwide, sublicensable license rights to certain intellectual property for the development, marketing, and commercialization of lotilaner for the treatment, palliation, prevention, or cure of any eye or skin disease or condition in humans (as amended and restated in June 2022, the Eye and Derm Elanco Agreement). The company utilizes the intellectual property licensed under the Eye and Derm Elanco Agreement in its TP-03 and TP-04 product candidates. The company is permitted to have certain third parties manufacture lotilaner for it and, upon Elanco's consent, additional third parties.
Elanco In-License Agreement for All Other Diseases or Conditions in Humans
In September 2020, the company entered into a license agreement with Elanco (the All Human Uses Elanco Agreement) granting it an exclusive, worldwide, sublicensable license to certain intellectual property for the development, marketing, and commercialization of lotilaner for all applications in humans other than the treatment, palliation, prevention, or cure of any eye or skin disease or condition. The company utilizes the intellectual property licensed under the All Human Uses Elanco Agreement in its TP-05 product candidates. The company is permitted to have certain third parties manufacture lotilaner for it and, upon Elanco's consent, additional third parties.
GrandPharma Agreement
In March 2021, the company entered into the China Out-License with LianBio (the China Out-License) for its exclusive development and commercialization rights of TP-03 (lotilaner ophthalmic solution) 0.25% in The People's Republic of China, Macau, Hong Kong, and Taiwan (the China Territory) for the treatment of Demodex blepharitis and MGD.
In February 2024, LianBio announced its plan to wind down its operations. In March 2024, the company executed an agreement assigning the China Out-License from LianBio to GrandPharma (the Novation Agreement), and LianBio made a one-time payment (the Termination Payment) to the company in April 2024.
Government Regulation
In the U.S., the company is subject to extensive regulation by the U.S. Food and Drug Administration (FDA), which regulates drugs under the Federal Food, Drug, and Cosmetic Act (the FDCA) and its implementing regulations.
The company’s product candidates are considered small molecule drugs and must be approved by the FDA through the NDA process before they may be legally marketed in the U.S.
The company relies, and expects to continue to rely, on third parties for the production of clinical and commercial quantities of its products in accordance with current good manufacturing practice (cGMP) regulations.
History
Tarsus Pharmaceuticals, Inc. was founded in 2016. The company was incorporated under the laws of the state of Delaware in 2016.
