MannKind (NASDAQ:MNKD) faced three big hurdles going into 2013. Now, the company has cleared one of them: MannKind announced results from phase 3 studies of its inhaled insulin, Afrezza, Wednesday morning. Here are the highlights of those results -- and what they might mean as the company attempts to leap over the two remaining hurdles.

A giant leap
To get technical, MannKind just leaped two hurdles, as there were two phase 3 clinical studies. One study related to type 1, diabetes while the other involved type 2 diabetes.

In the type 1 diabetes study, 518 patients on basal-bolus insulin therapy were divided into three groups. The first group continued on subcutaneous insulin aspart in combination with a basal insulin. The second group switched to Afrezza using MannKind's next-generation Dreamboat inhaler in combination with basal insulin. The third group switched to Afrezza using the older MedTone inhaler along with basal insulin.

There weren't any significant pulmonary-function differences between the group using the Dreamboat inhaler and the group using the MedTone inhaler. This finding will help MannKind make the case that previous data showing a positive pulmonary safety profile with the MedTone inhaler should apply for the Dreamboat inhaler as well.

The type 1 diabetes study results showed that the Afrezza group using the Dreamboat inhaler showed A1C level decreases comparable to insulin aspart. Patients taking Afrezza also experienced significantly less hypoglycemia and significant decreases in fasting blood glucose levels than did patients taking insulin aspart.

In the type 2 diabetes study, patients taking Afrezza in combination with metformin with or without another oral medication experienced significant reductions in A1C levels compared to patients taking only oral therapy. Over a 24-week period, the A1C level for patients in the study's Afrezza group saw mean A1C level reduction of 0.82%. The mean A1C level for patients taking only oral medication dropped 0.42%.

Both studies also found that Afrezza was generally well-tolerated. Were there any negatives in these phase 3 results? Yes, there was one negative -- but it was totally expected.

The type 2 diabetes study found that slightly more than two-thirds of the patients taking Afrezza plus metformin experienced hypoglycemia (low blood sugar). Only 30.1% of patients taking oral therapy alone had hypoglycemia. However, there wasn't a statistically significant difference between the groups in incidence of severe hypoglycemia.

Two hurdles to go
MannKind will still analyze the clinical results more, but the next big hurdle is to obtain regulatory approval for Afrezza. The company has previously stated that it plans to resubmit the New Drug Application for Afrezza in October. Given positive findings from both studies, I expect that MannKind will finally get that long-hoped-for approval sometime in 2014.

The biggest hurdle of all, though, is to successfully commercialize Afrezza. MannKind will have to win where others have failed miserably.

Pfizer (NYSE:PFE) lost nearly $3 billion in its attempt to market Exubera, the inhaled insulin developed by Nektar Therapeutics (NASDAQ:NKTR). Eli Lilly (NYSE:LLY) halted its inhaled-insulin development program in 2008 before it even reached the market.

There are plenty of reasons why this time will be different for MannKind, though. Afrezza -- and, more importantly, the Dreamboat inhaler -- seem likely to overcome the hurdles that tripped up Pfizer. However, MannKind won't be able to succeed all by itself; it needs a partner to bring Afrezza to market.

Al Mann, MannKind's founder and CEO, has mentioned that the company has been in discussions with potential partners. Those talks are likely to kick into high gear now that the clinical study results have been announced.

Pfizer and Lilly could both be reasonable fits and might even be among those companies to which Al Mann alluded. I think Sanofi (NYSE:SNY) could be in the mix as well. The French drugmaker is a leader with its insulin products, and Afrezza could be a nice addition to its portfolio. For that matter, an acquisition of MannKind might even be more tempting to Sanofi than a partnership on Afrezza.

All this is speculation for now, of course. We'll probably find out in the next few months which partner (or acquirer) will step forward. MannKind's easy jump over the clinical-study hurdle, though, makes it much more likely to successfully make the next couple of jumps.

Fool contributor Keith Speights has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not 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.