Tarsus Closes IPO, Starts Phase IIb/III Trials for Demodex Blepharitis Drop

Late-stage biotech Tarsus Pharmaceuticals raised $88 million in its October NASDAQ debut. In announcing the close of its initial public offering, the company stated that the 6.325 million shares of common stock were priced at $16 per share, including 825,000 shares sold upon full exercise of the underwriters’ option to purchase additional shares of common stock.

Meanwhile, Tarsus plans to seek Food and Drug Administration approval of its lead candidate, TP-03 – which has begun its first pivotal clinical trial – Saturn-1 – for the treatment of Demodex blepharitis. The drug is designed to paralyze and eradicate mites and other parasites of the eyelids through the inhibition of parasite-specific GABA-Cl channels.

“This is a major milestone for Tarsus, and it’s great to be able to further our mission as a company to discover and deliver breakthrough treatments to transform the lives of patients with common and poorly treated diseases, starting with the eye,” said CEO Bobak Azamian, MD, PhD.

IPO proceeds will be used to advance TP-03 and the company’s pipeline in meibomian gland disease, rosacea, and systemic uses such as the prevention of Lyme disease and community spread of malaria. “Lastly,” he said, “we will use these funds to build the team and capabilities we need to support these clinical activities and prepare for our first commercial launch.”

Adding Experience to Leadership Team
Tarsus has already brought on board COO Sesha Neervannan, PhD, and CCO Aziz Mottiwala, each of whom have more than 20 years’ experience in biopharma along with extensive backgrounds in eye care, respectively leading development and commercial efforts for Allergan’s eye care portfolio.

“We have been purposeful in building a leadership team with significant experience in developing and commercializing therapeutic products for ophthalmic conditions,” Dr. Azamian said. “Our management team and board of directors have founded and led several companies in the ophthalmic care space and have been pivotal in the development and commercialization of various leading ophthalmic products.”

If approved, TP-03 would be the first prescription drug for the treatment of Demodex blepharitis, a condition the company estimates to affect as many as 25 million Americans. This figure is based on Tarsus’ internal research indicating approximately 58% of patients at eye-care clinics have collarettes – pathognomonic evidence of Demodex infestation – and a published study estimating that at least 45 million people annually visit eye-care clinics. The company believes blepharitis in general and Demodex blepharitis specifically are significantly underdiagnosed conditions.

Four Trials Down, Two to Go
To date, Tarsus has completed four Phase II trials for TP-03 in Demodex blepharitis – Mars, Jupiter, Io, and Europa – all of which met their endpoints and showed TP-03 to be well tolerated. “We commenced our Phase IIb/III trial, Saturn-1, in September 2020 and intend to commence our Phase III trial, Saturn-2, in 2021, both with primary and secondary endpoints consistent with those of our Europa and Io Phase II trials,” noted Dr. Azamian.

In the Phase IIa Io trial, treatment with TP-03 was effective at achieving the primary and secondary endpoints, respectively, of collarette cure in 72% of participants and mite eradication in 78% of participants at day 42.

In the Phase IIb Europa trial, statistically significant results were achieved for the primary endpoint of collarette cure by 80% of participants on TP-03 compared with 16% on vehicle (p<0.001) at day 42, and the secondary endpoint of mite eradication by 73% of participants on TP-03 compared with 21% on vehicle (p=0.003) at day 42. TP-03 was well tolerated and there were no reports of serious adverse events or treatment discontinuations due to adverse events in either study. Participants in Europa rated the administration of the eye drops as "neither comfortable nor uncomfortable," "comfortable," or "very comfortable" 87% of the time. The Io and Europa trials included adults aged 18 years or older with more than 10 collarettes present on the upper lid and mild-to-severe lid-margin erythema. Participants had at least 1.5 mites per lash on the upper and lower eyelids combined. One drop of the TP-03 treatment was dosed twice per day in each eye for 42 days. Enrolled participants received no treatment for blepharitis symptoms (i.e., lid hygiene) during the study, as well as 14 days prior. Saturn-2 is Tarsus' confirmatory Phase III randomized, controlled, double-blind trial, and its design is similar to that of Saturn-1. It’s expected to enroll approximately 350 Demodex blepharitis patients. "If successful, we expect these trials to support the submission of an NDA [New Drug Application] to the FDA for TP-03 for the treatment of Demodex blepharitis," Dr. Azamian said. Running Trials During a Pandemic
All of the company’s Phase II trials were conducted in Mexico City, with Europa nearing completion when pandemic restrictions went into effect. Dr. Azamian noted that the clinical development team worked diligently with the trial site and participants to ensure the trial was safely completed. The expectation is that Saturn-1, which is being conducted at multiple US sites, will be completed in 2021.

“Our clinical team is working closely with the contract research organization and our clinical sites to monitor COVID-19 levels in each site’s local area and have contingency plans in the event a site is required to shut down,” he said.” We will continue to work closely with our partners to ensure we are prepared and flexible throughout this dynamic time.”