When you think of July, visions of fireworks might come to mind. Three biotechs -- and a big partner for one of them -- are especially hoping to see some fireworks next month.

Neurocrine Biosciences (NASDAQ:NBIX), along with partner AbbVie (NYSE:ABBV), Progenics Pharmaceuticals (NASDAQ:PGNX), and Insys Therapeutics (NASDAQ:INSY) await major approval decisions by the U.S. Food and Drug Administration (FDA). Here's what you need to know about the potential catalysts for these biotech stocks.

July 2018 desk calendar

Image source: Getty Images.

1. Neurocrine Biosciences (and AbbVie)

Neurocrine Biosciences originally developed elagolix but licensed the drug to AbbVie seven years ago. The FDA is scheduled to make its approval decision on the drug for treating endometriosis-associated pain in either July or August.

AbbVie submitted the New Drug Application (NDA) for elagolix in early September 2017. The following month, the FDA granted priority review for the NDA, which should have placed an approval decision no later than April 2018. However, the FDA subsequently extended its review period by three months to give it time to review additional information.

Elagolix is also being evaluated in a phase 3 clinical study for treating uterine fibroids. If approved for both indications, the drug is projected to become a blockbuster for AbbVie. However, success for elagolix is arguably even more important to Neurocrine. The smaller biotech stands to receive milestone payments and royalties on sales of the drug. Neurocrine currently only has one approved product on the market, Ingrezza, which treats tardive dyskinesia, a side effect resulting from long-term use of antipsychotic medications. 

2. Progenics Pharmaceuticals

Progenics Pharmaceuticals already has one product on the market, Relistor, which is licensed to Valeant Pharmaceuticals. The small-cap biotech hopes to add another product to the list, with the FDA scheduled to announce its approval decision by July 31 on Azedra, a treatment for rare tumors in and outside of the adrenal glands.

Like elagolix, Azedra initially had an early review date. However, in March, Progenics announced that the FDA extended the review period for three additional months to review additional data submitted by the biotech. The 10% drop for Progenics stock on the day the delay was announced underscores just how important Azedra is for the biotech.

If approved, Azedra is expected to generate peak annual sales of between $200 million and $300 million. Progenics' market cap is only twice the upper end of that range. Should the FDA give a thumbs-up for the drug next month, expect this biotech stock to skyrocket.

3. Insys Therapeutics

Insys Therapeutics is best known for its opioid painkiller Subsys. The biotech also has another approved product, cannabinoid drug Syndros. But Insys pledged in 2017 to file for approval for at least one new drug each year through 2021. The company submitted for FDA approval of buprenorphine in treating acute pain in December 2017. A decision is expected by July 28. 

Unfortunately for Insys, the odds of winning approval appear to be quite small. In May, an FDA advisory committee recommended against approval of the drug. The FDA doesn't have to go along with the advisory committee's recommendation, but it does so around 86% of the time, according to research by consulting firm McKinsey.

A surprise approval by the FDA would likely provide a nice boost to Insys stock, which has fallen around 18% so far in 2018. On the other hand, a rejection by the FDA might not make much of a difference in the biotech's share price because a negative decision is expected based on the advisory committee recommendation.

Most likely to succeed?

Obviously, Insys is the least likely to succeed of the three. But which of these biotechs is most likely to succeed? It depends on how you define success.

I fully expect Neurocrine and AbbVie will win FDA approval for elagolix. And I think the drug will be by far the biggest winner of the three products mentioned. In that sense, Neurocrine and AbbVie are most likely to succeed.

However, an approval for Azedra would mean more to Progenics than an approval of elagolix would mean for Neurocrine, and certainly more than it would mean for AbbVie. Will Azedra secure approval, though? I think the odds are pretty good and wouldn't read too much into the FDA's delay to review additional data. While there's still a reasonable chance that Azedra won't win approval, I think the biggest catalyst for July could benefit Progenics.

Keith Speights owns shares of AbbVie. The Motley Fool owns shares of and recommends Valeant Pharmaceuticals. The Motley Fool has a disclosure policy.