Capnia, a Palo Alto, Calif., company that delivers carbon dioxide through a patient's nose to treat things like migraines and rhinitis, has raised $16.3 million of a potential $19 million third round of funding. Backers include existing investors Vivo Ventures, Asset Management and Teknoinvest, as well as individuals including chief executive Ernest Mario, according to VentureWire, which first reported the news. The company said the money will help the company finish the second phase of trials for its product.

The company had previously raised more than $20 million.