Tarsus Pharmaceuticals is a commercial-stage biopharmaceutical company focused on eye care. Its sole commercial product, XDEMVY (lotilaner ophthalmic solution 0.25%), is the first and only FDA-approved treatment for Demodex blepharitis, a chronic eyelid disease caused by Demodex mite infestations. XDEMVY works by delivering lotilaner, an anti-parasitic molecule, directly to the eyelid to paralyze and eradicate the mites. The six-week, twice-daily treatment eliminates the root cause of the disease rather than managing symptoms. Tarsus sells XDEMVY through a specialty sales force targeting roughly 15,000 ophthalmologists and optometrists, supplemented by DTC advertising. Revenue is recognized when bottles ship to distributors. The primary volume driver is new prescriptions, though retreatment is expected to grow over time, as roughly 40% of patients in clinical trials showed mite recurrence within a year. Gross-to-net discounts run approximately 44-45%, though gross margins are approximately 93% given the low manufacturing cost of a small molecule ophthalmic solution. Key costs include the sales force, annual DTC spend of $70-80M, and royalties to Elanco for the lotilaner license. Beyond XDEMVY, Tarsus is developing additional lotilaner-based therapies, including TP-04, a topical gel targeting ocular rosacea (Phase 2 initiated December 2025), and TP-05, an oral tablet for Lyme disease prophylaxis (Phase 2 planned for Q2 2026). Tarsus is also pursuing international approvals for XDEMVY in Europe, Japan, and China.