Cancer cases rise for inhaled-insulin patients
Pfizer Inc. reported an increase of lung cancer among patients who used its discontinued inhaled insulin Exubera, another setback for developers of needle-free diabetes treatments.
MannKind Corp., maker of a similar product that hasn't reached the market, fell 60 percent in Nasdaq trading after Pfizer's disclosure. Nektar Therapeutics Inc., which developed Exubera with Pfizer, fell 25 percent after the cancer findings led it to cancel its search for a new partner.
Exubera was the first inhaled insulin, approved in January 2006, and Pfizer gave up selling the product in October because its cost and unwieldy design made it unpopular with patients. Eli Lilly & Co., Novo Nordisk A/S, and Alkermes Inc. also abandoned experimental inhaled insulin this year, all but ending the industry's investment of more than $4 billion and a dozen years.
"Concern over cancer will not be limited to Exubera solely," William Tanner, an analyst with Leerink Swann & Co. in New York, wrote in a research report yesterday. "We no longer think there will be a major market for inhaled insulin" because of the cancer risk and because other forms of insulin have become more convenient, he said.
Pfizer said yesterday it updated Exubera's prescribing information to include a cancer warning after a review of clinical trial data found there were six cases of lung cancer among 4,740 patients using the drug, compared with one of 4,292 who did not take the drug. All cases were in former cigarette smokers. The lung cancer cases were twice the number as when Pfizer won regulatory approval for Exubera in January 2006, though too few cases to prove a link, Pfizer said.
Pfizer said it will make the device available for an unspecified period while patients switch to other forms of insulin. There were 2,438 prescriptions written for Exubera in February, according to research firm Wolters Kluwers.
When Pfizer scrapped Exubera last year, it returned the rights to the drug's developer, Nektar Therapeutics. In a statement yesterday, Nektar, of San Carlos, Calif., said it ended negotiations with potential partners for the product.
MannKind has lost 84 percent of its value in the past 12 months as bigger drug makers quit inhaled insulin. The company said last month it plans to file an application late this year for US clearance of its Technosphere insulin inhaler. The product is in the third and final round of human tests needed to support marketing approval. Three analysts downgraded MannKind yesterday.
Calls to Mannkind officials weren't returned yesterday. Nektar will now focus on other products, chief executive officer Howard Robin said.
