Tarsus eyes a new market

Lotilaner is already used to control fleas in animals. Tarsus Pharmaceuticals’ efforts to get it approved in humans took a step forward today with a pivotal trial win for TP-03, a lotilaner eyedrop for Demodex blepharitis. There are currently no therapies for this eye disorder, which is caused by a Demodex mite infestation in the eyelashes. Saturn-1 met its primary endpoint, with TP-03 significantly reducing collarettes, or “eyelash dandruff” – the waste products of these mites – versus placebo. Tarsus plans to file the project in the US next year pending data from a second pivotal study, Saturn-2. Still, questions remain. Tarsus said adverse events were all mild, but a 12% rate of burning/stinging might raise alarm bells. Another question is how big this market really is. Tarsus, which floated last October, reckons there could be as many as 25 million US patients, but this is based on a 1,000-patient study, called Titan. This found that 58% of patients visiting eyecare professionals had collarettes, and Tarsus has extrapolated this to the 45 million visits to eyecare professionals each year. The group, whose stock was up 15% in premarket trading, fell 10% this morning.