What happened

Shares of Clearside Biomedical (NASDAQ:CLSD) are up 17% at 12:45 p.m. EST after the company gave a regulatory update for two of its clinical trials testing its eye drug, CLS-TA, this morning, although today's increase is likely just a continuation of the 32% rise yesterday after releasing positive phase 3 data for the drug in another eye disease.

So what

In the first update, Clearside Biomedical said it enrolled its first patient in the phase 3 TOPAZ trial testing the suprachoroidal administration of CLS-TA in combination with one of Roche's anti-VEGF drugs, Lucentis or Avastin, in patients with macular edema associated with retinal vein occlusion (RVO).

The second update involves a phase 3 trial called SAPPHIRE testing suprachoroidal CLS-TA in combination with Regeneron Pharmaceuticals' (NASDAQ:REGN) anti-VEGF Eyelea in patients with RVO. Based on enrollment, the company now expects data in the fourth quarter of 2018 instead of the first quarter of 2019.

The earlier data from SAPPHIRE isn't likely to help Clearside Biomedical get the drug approved for RVO earlier because it appears to be planning to wait for the TOPAZ data to submit them together to the FDA to get a broad label that will allow suprachoroidal CLS-TA to be used with any anti-VEGF drug, which could be helpful with new anti-VEGF drugs in the works. Nevertheless, the quick enrollment in SAPPHIRE likely means TOPAZ will enroll quickly, and it's a good sign that RVO patients and their doctors are looking for an efficacy boost beyond anti-VEGF drugs, foretelling solid sales if the trials are positive.

Doctor giving an eye exam

Image source: Getty Images.

Finally, yesterday, the company reported data from the phase 3 PEACHTREE trial testing suprachoroidal CLS-TA in patients with macular edema associated with non-infectious uveitis. In the trial, 46.9% of patients receiving suprachoroidal CLS-TA for 24 weeks were able to read an additional 15 letters on an eye chart compared to 15.6% of patients who received placebo. Looking at the absolute values, patients receiving suprachoroidal CLS-TA had a mean improvement of 13.7 letters compared to 2.9 letters for placebo-treated patients. Either way, that's a solid improvement compared to placebo.

Now what

While the updates on TOPAZ and SAPPHIRE are added bonuses, the results from PEACHTREE are clearly what investors should be focused on since they appear to be enough to get suprachoroidal CLS-TA approved to treat patients with macular edema associated with non-infectious uveitis. The company plans to submit the marketing application to the FDA in the fourth quarter, putting a likely approval in 2019.

Brian Orelli and The Motley Fool have no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.