MannKind shares plummet as FDA delays Afrezza, calling for more trials

Shares of US drugmaker MannKind (Nasdaq: MNKD) plunged nearly 50% to $5.21 on Wednesday, after the company revealed that US approval of its inhalation powder for hyperglycemia, Afrezza, could not be approved at this time.

The US Food & Drug Administration issued a complete response letter regarding the New Drug Application for Afrezza (insulin human [rDNA origin]) Inhalation Powder for the treatment of adult patients with type 1 and type 2 diabetes for the control of hyperglycemia.

The principal issue raised by the FDA concerned the usage of in vitro performance data and clinical pharmacology data to bridge MannKind's next-generation inhaler to the phase 3 trials conducted using its MedTone inhaler. The agency has requested that MannKind conduct two clinical trials with the next-generation inhaler (one in patients with type 1 diabetes and one in those with type 2 disease), with at least one trial including a treatment group using the MedTone inhaler in order to obtain a head-to-head comparison of the data for the two devices. In the complete response letter, the FDA stated that, after an adequate titration of study medication, there should be at least 12 weeks of relatively stable insulin dosing at the end of the treatment period.