MannKind's (NASDAQ:MNKD) PDUFA date is Sunday, so it's very likely we could hear on Friday whether the Food and Drug Administration will approve its inhaled insulin Afrezza.

This isn't the first time the drug-device has been up for approval. The company changed the device portion of Afrezza before the last review, which led the FDA to request more clinical trials. MannKind ran the trials, which both came back positive.

If approved, Afrezza will compete with injected mealtime insulins from Eli Lilly (NYSE:LLY) and Novo Nordisk (NYSE:NVO). One of the clinical trials showed that Afrezza was non-inferior -- clinical-trial lingo for the same or better -- to Novo Nordisk's Novolog.

Slam-dunk approval, then?

Not so fast.

While the FDA advisory committee recommended the agency approve the drug, the agency has the final say and doesn't always follow the panel's advice. Considering that the FDA's briefing documents sent to the committee trended toward the negative side, an approval isn't a foregone conclusion.

Watch the following video for more thoughts on the potential approval of MannKind's Afrezza from senior biotech specialist Brian Orelli and health-care analyst David Williamson.

Brian OrelliDavid Williamson, and The Motley Fool have no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.