Tarsus nabs key data in hunt to repurpose dog drug as cure for eye parasite
Eight months after their $101 million IPO, Tarsus Pharmaceuticals say they’ve cleared the first of two trials needed to prove to their FDA that their repurposed dog drug can successfully banish mites from patients’ eyes.
The California biotech announced Monday that, in a Phase II/III study, 81% of patients with the common eye infestation Demodex blepharitis achieved a “clinically meaningful” cure of infestation-induced lesions after taking the drug, called TP-03. That compared to 23% of patients on placebo. And, on the secondary endpoint, 68% of patients saw their mites eradicated entirely — compared to 18% on placebo.
If the data hold up in a Phase III trial expected to read out next year, the company will apply for FDA approval. They estimate that between 9 million and 25 million Americans suffer from the disease, which can trigger damaging inflammation and irritation around the eyelid.
“Millions of people are living with Demodex blepharitis, and we know from recent research that these patients are suffering daily,” CEO Bobak Azamian said in a statement. “We believe the results from our Saturn-1 trial mark an important moment in Demodex blepharitis research, showing the potential of TP-03 to target the underlying cause of this disease and potentially become the standard of care for patients and clinicians.”
The company’s lead drug is a version of a common veterinary drug lotilaner, often used to prevent tick and flea infestations in dogs. Tarsus sub-licensed the molecule from pet health giant Elanco in 2019 and reformulated it: Rather than a chewy, beef-flavored tablet, the molecule would come in clear (presumably flavorless) eye drops.
The Saturn-1 trial is their fifth to test lotilaner on Demodex blepharitis. The study enrolled 421 patients who had more than 10 collarettes — waxy lesions near the eye that are a hallmark of the disease — and mild reddening. In addition to the endpoints on collarettes and mite eradication, 68% of patients saw both their collarette and redness diminish strongly. Just over 13% saw both vanish entirely.
The most common side effect was pain, burning or stinging at the administration site; 11.8% of patients reported it.
The company is also developing an oral form of the drug for Lyme disease and malaria.