Shares of Insmed more than doubled on Tuesday after the drug maker said a new inhaled antibiotic showed promise for treating a rare lung disease, and it announced plans to sell $250 million shares to the public.

The stock jumped to $26.99 on Tuesday from just over $12.

The company said its Alis medication had a successful trial and showed significant improvement for patients.

The company said in a statement that it would use the proceeds of its offering to fund ongoing and future clinical development of Alis and move forward with its effort to obtain regulatory approvals so it could begin selling the medication. Goldman Sachs and Leerink Partners are handing the stock sale, with Evercore Partners and Stifel, Nicolaus & Co. also pitching in.