An FDA advisory panel recommended approval of MannKind Corp.’s lead pipeline drug Afrezza on Tuesday, clearing a major hurdle to bring the Valencia company’s inhalable insulin to market.

Trading halted earlier in the day while the independent advisory panel discussed approval of Afrezza at the Food and Drug Administration in Washington D.C.

During the meeting, MannKind and FDA officials made highly technical presentations that compared Afrezza to traditional diabetic treatments, and examined potential side effects.

The panel voted 13-1 with one abstention to approve Afrezza for Type 1 diabetics, and 14-0 with one abstention for Type 2 diabetics.

While the FDA isn’t required to follow the panel’s recommendation, it rarely contradicts it. An official determination is expected by April 15.

An FDA staff report has worried investors last week. The report, which was presented to the panel of medical experts, highlighted the potential for Afrezza use to increase the chance of developing lung infections and bronchial spasms in certain types of patients. Coughing by some patients during the clinical trials caused them to stop the treatment. Staff also questioned the accuracy of insulin doses in MannKind’s clinical studies.

Alfrezza would be the company’s first drug to market. The company was founded more than a decade ago by billionaire medical device entrepreneur Alfred Mann. Mann has pumped an estimated $900 million of his own money into the company. One estimate puts potential annual sales at $1 billion to $4 billion.

Shares of MannKind, which were unchanged at $4.02 in regular Nasdaq trading Tuesday, soared 111 percent to $8.47 in after-hours trading following news of the panel's decision.