Back in February this year, Aldeyra Therapeutics Inc (NASDAQ:ALDX) announced that it had completed enrollment ahead of schedule in a phase II trial of its lead development asset, ADX-102. The trial is a phase IIb study, set up to investigate the safety and efficacy of the drug in a target indication of allergic conjunctivitis and it's specifically aimed at patients that are nonresponsive or unable to tolerate the current standard of care therapy in the space.As we'll get to shortly, this is a pretty big subgroup of the total patient population, which is also pretty big. For a company with a market capitalization the size of that of Aldeyra, a little over $78 million at last count, a regulatory green light in this indication would be a game changer.This isn’t the company's only ADX-102 program (the mechanism of action (MOA) for the drug makes it widely applicable to a range of indications of this type) but it is the one that serves up the nearest term catalyst.As our regulars know already, we like to make sure readers are aware of these catalysts before they hit press.With this in mind, here's what we're looking out for from Aldeyra, when we're looking out for it and what the catalyst might mean for the company's share price near term.So, as readers have probably guessed, the catalyst is data from the above-mentioned phase IIb trial. The study was initially slated to complete during the third quarter of this year, but with the early enrollment completion, this trial completion came forward.The trial is now set to wrap up this month and data should follow before the end of June.If the data is positive (i.e. if it suggests efficacy in the target indication) then there's a good chance we’ll see a mid to high double digit run in Aldeyra's market capitalization before the start of third quarter 2017.The key to this run is in the MOA of the drug and its application to the target indication. For those not familiar with allergic conjunctivitis, it's a condition in which allergens cause red, watery, itchy eyes in patients. Think of it as hay fever, but worse. Current over the counter SOCs include things like antihistamines and other anti-allergens. As many as 60% of patients don’t respond to OTC therapy, however, and seek prescription medication. The current SOC in the prescription side of the indication is steroids – generally eye drop administration steroids. These work by reducing inflammation but they can also cause intraocular pressure as a side effect, as well as induce a host of other nasty tolerability issues. In many patients, they just don’t work.Here's where ADX-102 comes in.It's designed to reduce inflammation through the trapping of what's called aldehyde – an inflammatory agent. It does this, however, while concurrently avoiding inducing intraocular pressure. This basically overcomes the tolerability issues associated with steroid treatment, meaning the drug could become SOC in the group of patients that have difficulty with the latter, or that don't respond to it at first use.So herein lies our thesis.The company is going to put out data from the phase IIb trial this month. It's a double blind study testing two strengths against placebo, and against a primary endpoint of a reduction in ocular itching. Secondary endpoints are ocular redness, tearing and eyelid swelling.We're looking for a stat sig improvement in the two active arms over the placebo arm, and we'd love to see the improvement come out in line with concentration (in other words, we'd like to see the stronger dose, a 0.5% concentration, result in a more significant improvement over placebo).If the data falls in line with this outcome, and we see a clean safety profile, the stock is going to run.Here's the trial protocol for anyone looking to brush up on the details ahead of the release.Catalyst date: anytime between now and end June.We will be updating our subscribers as soon as we know more. For the latest updates on ALDX, sign up below!Disclosure: We have no position in ALDX and have not been compensated for this article.