BOSTON (Reuters) – MannKind Corp said on Wednesday that U.S. regulators have rejected Afrezza, its experimental device to treat diabetes, and will require two new clinical trials before approving the product.
MannKind's shares fell 7.3 percent to $9.11 before being halted pending the news.
Afrezza is a whistle-sized inhaler that 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.
The device is the small company's most advanced product. MannKind's founder and biggest shareholder is Alfred Mann, 85, an entrepreneur who has pumped roughly $925 million of his personal fortune into the company to keep it afloat.
As of December 31, roughly 28 percent of the company's regularly traded shares -- or 21.5 million -- were held "short" by investors betting the stock would fall.