Early sales of MannKind Corp.'s new inhaled insulin drug were less than expected, and the Valencia company's stock skidded to near a one-year low.
French pharmaceutical company Sanofi, which is marketing the drug, Afrezza, in a partnership with MannKind, said first-quarter U.S. sales came in at about $1.1 million.
MannKind is expected to discuss its first-quarter results next week.
Maxim Jacobs, an analyst with Edison Investment Research in London, said in a research note that the Afrezza sales number was "terribly disappointing considering the size of the market."
Sanofi said in a statement that it expects Afrezza sales to build slowly. The company said it plans to launch a direct-to-consumer marketing campaign this year.
"The initial rollout of Afrezza is targeted and focused on building awareness behind the product and appropriate usage," the company said. "Because of requirements imposed by the FDA for starting patients on this therapy and the necessary time to gain market access, it will take time for Afrezza to demonstrate its potential."
Matt Pfeffer, MannKind's chief financial officer, said in an email that the slow start for Afrezza was not a surprise.
"There are well known and understood reasons for this, which we are in the process of correcting," he said. "The first quarter was also only a partial quarter. ... The second quarter will be much more telling, as will the third. What we need to see is the trend."
MannKind shares were down 29 cents, or 6.3%, to $4.29 on Thursday.
The Food and Drug Administration approved Afrezza last summer as an alternative to other diabetes therapies.
MannKind later reached an agreement with Sanofi to market the drug. The French firm began selling Afrezza in the United States in February.