U.S. regulators have requested more information on an inhaled insulin device being developed by MannKind Corp, sending the company's shares down 24.7 percent.
MannKind said on Monday that it had received a so-called complete response letter from the Food and Drug Administration, which has been considering whether to approve the product, a whistle-sized device designed to treat diabetes.
The agency asked for additional information about data designed to support the clinical utility of the device, known as Afrezza, and information about how comparable the commercial version of the product is to the version used in clinical trials.
"The fact that the FDA wants more data supporting clinical utility is not good for Afrezza," said Jon LeCroy, an analyst at Hapoalim Securities. "We have always questioned the need for a new inhaled insulin and it looks as if the FDA may have similar questions."
The FDA did not request an additional clinical trial, nor did it cite any safety concerns. But it did ask for updated safety data. The agency also requested changes to the proposed labeling of the cartridges, foil pouches and cartons used in the device.
Alfred Mann, the company's chief executive, said in an interview that he considers the FDA's letter "overall very positive.
"The good news is that although they can always change their minds, they have said they do not require any new trials and have not raised any safety concerns," he said.
Still, in answer to a question, he said that even though the FDA has not requested a new clinical trial, it could do so if the company did not provide satisfactory information.
Valencia, California-based MannKind said it would request a meeting with the FDA to discuss the matter.
Afrezza, previously known as Afresa, is designed to deliver a more effective rapid-acting insulin than injectable products such as Eli Lilly & Co's Humalog and Novo Nordisk's NovoLog.
A few years ago, an inhaled insulin developed by Pfizer Inc failed spectacularly, casting a shadow over such products.
Pfizer's Exubera, approved in 2006, was expected to generate annual sales of $2 billion. But the inhaler was big and bulky and patients were put off by the need for periodic lung function tests. In the first nine months of 2007, Exubera generated sales of just $12 million.
Lilly and Novo Nordisk, which were also developing inhaled insulin, dropped their products too.
MannKind has been kept afloat with the help of its founder, CEO Mann, who has poured millions of dollars of his own money into the company.
Mann, who owns roughly 46 percent of MannKind's shares, is one of the world's richest men. He built his fortune as an entrepreneur who helped develop solar cells, cardiac pacemakers, insulin pumps and implantable technology designed to restore hearing and sight.
Mann is convinced that Afrezza can have the same revolutionary impact on the treatment of diabetes as cardiac pacemakers had on the treatment of heart disease.
MannKind, which has scheduled a conference call on Tuesday morning to discuss the FDA's requests, said it had not planned to launch a commercial version of the device in its current form.
It had hoped to follow up with a supplemental new drug application (NDA) to market a next-generation version of the device.
"We will discuss with the FDA whether it is appropriate to use what would otherwise have been a supplemental NDA submission, which we had planned to make during the second quarter of this year, to address the agency's requests," Mann said in a statement. "If this approach is acceptable, we believe that this regulatory action will not have a significant impact on the timing of the commercial launch of Afrezza."
MannKind shares fell $2.59, or 24.7 percent, to close at $7.89 on Nasdaq. Earlier in the day they fell as low as $6.56. (Reporting by Toni Clarke; editing by John Wallace, Gary Hill)