What happened

Shares of Insys Therapeutics (NASDAQ:INSY) rose 11% in June, according to data provided by S&P Global Market Intelligence. While the biotech is most famous for its opioid painkiller Subsys as well as Syndros, which is based on a compound in marijuana, it was clinical trial data from a new product that has investors excited.

So what

In the clinical trial, Insys' epinephrine nasal spray had similar bioavailability as intramuscular injection with Mylan's (NASDAQ:MYL) EpiPen, which also delivers epinephrine to treat anaphylaxis after exposure to something the patient is extremely allergic to.

The data was only from an early-stage study in 60 patients, but since both drugs use the same active ingredient, the key question was whether Insys could deliver the drug through the nose safely; once the drug is in the bloodstream, the efficacy of epinephrine should be similar.

Insys didn't release any quantitative data from the trial, so investors will have to wait for the results to be presented at a medical conference or published in a peer-reviewed journal to see how "similar" the two delivery methods really are.

Boy sticking his hand out refusing a bowl of peanuts

Image source: Getty Images.

Now what

Insys will have to test the drug in another trial, but the pathway to approval seems fairly de-risked at this point, assuming regulators agree with Insys' assessment that the drugs have similar bioavailability.

The bigger question is whether customers will want to use a nasal product. Normally a nasal spray would be preferred to an injection, especially in children, but the use of epinephrine isn't an everyday or even weekly occurrence. In a best-case scenario, a patient avoids the allergen and uses the product rarely. When the drug does need to be used, it's an urgent situation, and you can imagine parents preferring to be able to inject a child -- as much as it might hurt -- rather than having to navigate sticking a medication up the child's nose.

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