Aerie Pharmaceuticals Inc (NASDAQ:AERI) shares shot up 50% on the news that the FDA has agreed to the company’s proposed change in the primary endpoint range of its second phase III registration study, Rocket 2, on its lead candidate Rhopressa.

Aerie Pharma said that it will narrow down Rocket 2’s primary endpoint range to include patients with baseline intraocular pressures (IOP) ranging from more than 20 mmHg to less than 25 mmHg (previous range: more than 20 mmHg to less than 27 mmHg). The former range will now represent a secondary endpoint for the study.

We remind investors that in Apr 2015 Aerie Pharma announced efficacy data from the first registration study, Rocket 1, on Rhopressa. Although the study failed to meet the primary efficacy endpoint of non-inferiority of once-daily Rhopressa in lowering IOP compared to twice-daily timolol, Rhopressa successfully showed non-inferiority in comparison to timolol in patients with IOP below 26 mmHg at all nine measured time points.

Aerie Pharma also said that the FDA will allow it to use a hierarchical statistical approach to evaluate whether the study is adequately powered at the revised range of the primary endpoint. Three-month efficacy results from the study should be out by the end of the third quarter of 2015.

Originally, three phase III registration studies had been planned for Rhopressa – Rocket 1 (a 90-day efficacy trial), Rocket 2 (a 12-month safety trial with 90-day interim efficacy readout) and Rocket 3 (a safety-only study). Rocket 3 is currently being conducted in Canada. However, Aerie Pharma intends to start a new phase III registration study (Rocket 4) on Rhopressa in the third quarter of 2015. The company plans to file for the approval for Rhopressa in the U.S. in the second half of 2016.

Meanwhile, the company is preparing to initiate the first phase III registration study (Mercury 1) on Roclatan for the treatment of glaucoma in the third quarter of 2015.

Our Take

Following the FDA’s agreement, the revised primary endpoint of Rocket 2 will lie in the same range in which Rhopressa demonstrated success in Rocket 1. Notably, the Baltimore Eye Survey estimates show that nearly 80% of newly diagnosed glaucoma patients have unmedicated baseline IOPs below 26 mmHg. We expect investor focus to remain on updates from the Rocket 2 study. Positive results from the study should be a major boost for the company. If developed successfully and approved for commercialization, Rhopressa stands the chance of gaining a large market share.

Aerie Pharma currently carries a Zacks Rank #4 (Sell).

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