Mann steps down as CEO of inhaled insulin maker MannKind Corp.

Alfred Mann, the billionaire entrepreneur and inventor behind several successful medical device companies, is stepping down as chief executive of MannKind Corp., a Valencia maker of inhaled insulin.

Mann, 89, the founder and chief financial backer of MannKind, intends to continue working as the company’s executive chairman. He said in a news release that “the timing is right for me to step back from CEO.”

Mann will be replaced by Hakan Edstrom, the company’s president and a board member since 2001, MannKind said Monday in a news release.

“I am extremely proud of all that has come to fruition at MannKind,” Mann said. “Together with my colleagues, we have built a truly unique biopharmaceutical company with an incredibly bright future.”

The leadership transition comes as French pharmaceutical company Sanofi prepares to begin selling MannKind’s inhaled insulin drug, Afrezza, this year.

MannKind spent more than a decade developing and testing Afrezza, which was approved in June by the Food and Drug Administration.

In August, Sanofi acquired the rights to market and distribute Afrezza, in a deal that could pay MannKind as much as $925 million.

MannKind shares fell 27 cents, or 5%, to $5.49 in Monday trading.

Keith Markey, an analyst with Griffin Securities, said in a research report that he expects a “smooth transition” of leadership at MannKind. He said he expects Sanofi to announce soon that it will begin selling Afrezza in February.

“MannKind is running three shifts at its Connecticut manufacturing plant to build inventory in anticipation of the rollout,” Markey said. “Separately, we learned that Sanofi will hold meetings in late January to prepare its sales team for the official launch.”

Twitter: @spfeifer22