Aerie shares crushed after glaucoma therapy flops in PhIII

Two months ago Aerie Pharmaceuticals CEO Vicente Anido was boasting to Reuters that his late-stage therapy for glaucoma, Rhopressa, was on track to an approval with a clear shot at earning $1 billion a year. On Thursday evening, he was forced to mount a defense of the drug after conceding defeat in a key Phase III study and watching shares plunge more than 70% in a rout.

Aerie ($AERI) set a low bar for itself, going after evidence of noninferiority of its once-daily therapy with twice-daily timolol, a beta blocker, in lowering intraocular pressure (IOP). There were signs of a drop in efficacy during the trial and a third of the patients in the Rhopressa arm suffered from red eye--a condition that was widely viewed as a potential stumbling block for the biotech.

Aerie quickly circled its wagons around its lead drug, highlighting evidence of success in the study, claiming that a slight revision of the trial would have allowed for success and maintaining that it still believes strongly in the treatment. The biotech also noted tellingly that it has $179 million in the bank to weather the storm.

Reuters' recent analysis points to Inotek as Aerie's closest rival in the clinic with an eye drop named trabodenoson that should wrap Phase III in 2017. Both drugs aim to treat glaucoma through the trabecular network which keeps the eye drained. And they're out to compete with prostaglandins currently marketed by Alcon (Travatan) and Allergan (Lumigan), which was recently bought out by Actavis ($ACT).

Aerie has a follow-up glaucoma treatment in development called Roclatan which delivered positive data in a Phase IIb study last summer. Roclatan, though, is simply a combination of Rhopressa (AR-13324) and latanoprost, a popular glaucoma drug sold as Xalatan by Pfizer ($PFE), which brings in more than $1 billion a year.

Aerie's second Phase III for Rhopressa is expected to report out in the third quarter with a separate safety-only study in the works as well.

"We are obviously disappointed that we missed the primary endpoint for Rocket 1," Anido said in a statement. "We expected Rhopressa to demonstrate better performance based on the results we saw in the previous Phase IIb studies. However, if we had set the high end of the baseline range just one mmHg less, we would have demonstrated non-inferiority compared to timolol at all nine measured time points and numerical superiority at the majority of time points. We believe Rhopressa shows great promise at IOPs where the majority of patients are represented. Also, we believe the meaningful decrease in the number of patients that experienced efficacy loss at the lower baseline IOPs supports the potential benefit of the Rhopressa on episcleral venous pressure."

- here's the release