The company's shares initially rose as much as 10.6
percent before falling back amid conflicting opinions from analysts
on how the FDA will likely rule. The shares were down 3.3 percent at
$5.03 in early afternoon trading.
The reviewers issued their report ahead of a meeting on Tuesday of
outside advisers to the FDA, who will discuss clinical trial data
and advise on whether the product, Afrezza, should be approved. The
FDA is not obliged to follow the advice of its advisory panels but
typically does so.
Afrezza is a whistle-sized inhaler designed to deliver more
effective, rapid-acting insulin than injectable products offered by
Eli Lilly and Co and Denmark's Novo Nordisk.
In early 2011, the FDA rejected Afrezza and asked for two more
clinical trials, one for Type 1 diabetes and one for the more common
Type II form of the disease. The FDA wanted MannKind to prove that a
second-generation version of the device, known as the Dreamboat, was
equivalent to a first-generation inhaler known as MedTone.
The FDA staff raised questions about dosing, missing data,
bronchospasms, or constriction of the air passages of the lung, and
Afrezza's effect on lung function, but raised no major new safety
"There do not appear to be any patterns suggesting a difference in
safety between the two devices in regards to serious adverse
events," the review found.
Craig Suvannavejh, an analyst at MLV & Co said the document revealed
"no smoking guns."
"Based on our quick read thus far, we come away positively and see
no major issues that would derail a positive outcome," he said in a
By contrast, Simos Simeonidis, an analyst at Cowen and Company, said
the documents "don't paint a rosy picture." He said the drug is
unlikely to win approval for Type 1 diabetes and that winning
approval for Type 2 is "a stretch."
The FDA review found that the Dreamboat inhaler was effective in
lowering HbA1c, a measure of blood sugar, compared with a placebo in
patients with Type 2 diabetes. The results appeared less robust in
patients with Type 1 disease.
"Chances for a positive panel and approval in Type 2 appear better
than Type 1, but a lot of questions around efficacy remain,"
Patients with diabetes do not produce enough insulin or are unable
to use insulin effectively. As a result, excess glucose builds up in
the blood. Symptoms include increased thirst, hunger, fatigue,
weight loss and infections. Uncontrolled, it can lead to kidney
failure, blindness, heart disease and stroke.
[to top of second column]
Inhaled insulin has a checkered history. In 2006, the FDA
approved Exubera, an inhaled insulin device made by Pfizer Inc that
had been expected to generate annual sales of $2 billion. But the
inhaler was bulky and patients were put off by the need for periodic
lung function tests. Pfizer abandoned the product after sales failed
to take off.
Lilly and Novo Nordisk also dropped their inhaled insulin products.
Subsequently, clinical trials revealed a possible, though unproven,
link between Exubera and lung cancer.
The FDA's review of Afrezza found four cases of lung cancer during
the development program. In two of the cases, the patients had a
prior history of heavy tobacco use. The other two did not, but Dr.
Lee Pai-Scherf, who is with the FDA's oncology products division,
examined the data and said "the available characteristics are
consistent with what would be expected in this population."
Pai-Scherf added, however, that "the current available evidence does
not allow a meaningful analysis" regarding the risk of lung cancer
in patients exposed to Afrezza because of small numbers and other
Cory Kasimov, an analyst at J.P. Morgan, said these seemingly
unresolved issues may require more data, but said that could
potentially be obtained after the drug has been approved.
"Overall, the documents are somewhat more benign than many
anticipated," he said. "However, there will be some potentially
tenuous discussion topics on Tuesday."
(Reporting by Toni Clarke; editing by Doina Chiacu, Peter Galloway
and Jonathan Oatis)
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