In 2011, MannKind Corp. was forced to run around the track again to get approval for its inhalable insulin. But since then, it keeps clearing its hurdles.

The Valencia drug maker announced Aug. 14 that two late-stage trials of its Afrezza inhaler proved the drug to be effective – indicating to investors that long-awaited approval from the Food and Drug Administration could be on the way.

The day of the announcement, shares spiked as much as 27 percent before settling down. It closed up 73 cents, or 11 percent, on Aug. 14 to $7.59.

“You get a sense that we’re finally coming to a head,” said Graig Suvannavejh, an analyst who follows MannKind at MLV & Co. in New York. “Both trials show that it works.”

The Afrezza inhaler dispenses a powdered form of fast-acting insulin and is used by diabetics to control blood-sugar levels that can jump up after meals. One of the trials found Afrezza, coupled with generic drug metformin, to be better in reducing long-term blood sugar levels than oral treatments with type-2 diabetics.

MannKind, founded by billionaire Alfred Mann, is hoping it can upend existing injected treatments.

The inhaler was first submitted to the FDA for approval in 2010. The agency delayed the green light, however, because a larger inhaler was used in trials than the one MannKind intended to bring to market. So the company was sent back to the drawing board to test the product again with the smaller inhaler, setting the schedule back significantly.

Now, the most recent trials pave the way for a new application to the FDA this year, with approval widely expected to be announced next year. Suvannavejh said that he expects the drug to go on the market in the second half of next year.

But questions persist as to the drug’s marketability. One obstacle: The trials found patients gained a pound or so of weight while using the inhaler. That and other concerns were raised by analysts in a call after the close of the markets Aug. 14. That helped bring about a sharp sell-off of MannKind shares the next day. The stock tumbled 13 percent to close at $6.64 on Aug. 15.

Suvannavejh said the sell-off also resulted from investors taking profits, since the stock had tripled in value since the start of the year.

Now, attention is focused on which company MannKind will choose as a partner to bring Afrezza to market. MannKind has enlisted New York investment bank Greenhill & Co. to help find that partner.

Sauvannavejh sees that as another indication of confidence.

“The fact that they hired Greenhill is a very positive sign,” he said.