Valencia, CA (Apr. 10)—MannKind suspended discussions with potential partners for the commercialization of its “Technosphere Insulin” product. In a company press release, MannKind cited “the current market sentiment” about inhaled insulins and said it would be “unable to achieve an appropriate valuation for Technosphere Insulin” until Phase III data confirmed its safety and efficacy.

MannKind said a preclinical study in which its Technosphere medicine was administered to rats found no evidence that the drug or the carrier had carcinogenic potential. A separate study of transgenic mice prone to cancer “found no macroscopic indications of carcinogenicity in animals treated with Technosphere Insulin or Technosphere particles for 26 consecutive weeks,” according to the release. The company also stated that its clinical program had shown no higher incidence of lung cancer in patients taking Technosphere Insulin than in the general population.

The day before MannKind’s announcement, Nektar Therapeutics (San Carlos, CA) ended negotiations with potential partners for its inhaled insulin programs. Nektar said its decision resulted from Pfizer's (New York) new analysis of data from its ongoing clinical trials of “Exubera” inhaled insulin. Nektar said it would end spending on its inhaled-insulin programs.

MannKind’s and Nektar’s decisions followed Pfizer’s update to the label for its “Exubera” inhaled insulin. The new label includes a warning with safety information about lung cancer cases observed in Exubera patients. The label states that patients who developed lung cancer had a history of cigarette smoking and that there were too few cases to determine whether the development of lung cancer is related to Exubera. Pfizer announced the label change in an Apr. 9 press release.

During Pfizer’s clinical-trial program, 6 of the 4740 patients who took Exubera developed lung cancer. Only 1 of the 4292 patients not treated with Exubera developed lung cancer. In the press release, Pfizer acknowledged a postmarketing report of lung cancer in one Exubera-treated patient.