Shares of MannKind Corp. rose Thursday after the Valencia biotech said a new study indicates its inhaled insulin product didn’t cause adverse lung effects.

The Valencia company, which plans to submit its Afresa inhaler for U.S. Food and Drug Administration approval early next year, said the drug met primary endpoints in its last two human trials.

Two years of tests on more than 2,000 people with type 1 or type 2 diabetes showed “no adverse effects on patients’ lungs,” MannKind said in a statement, adding it would release details of the study by mid-month.

The second study met its goal of showing Afresa regulated meal-time blood sugar levels more quickly than the injected insulin it was compared with.

MannKind’s shares have plummeted since Pfizer and other drug makers abandoned competing products on safety concerns, including the irritating effect their powdered insulin might have on patients’ lungs. MannKind has maintained its inhaled insulin has a different composition and is less likely to irritate.

MannKind, which has no products on the market, expects Afresa sales can top $1 billion a year.

MannKind shares were up 19 cents, or 6.7 percent, to $3.11 in Nasdaq morning trading after jumping 13 percent in pre-market trading.