UPDATE 3-US FDA: Data inconclusive on Sanofi insulin risks

* Regulators continue study of possible cancer risk

* U.S. FDA started probing Lantus safety in 2009

* Drug is one of company’s top products
(Adds details on drug; updates shares)

By Lisa Richwine

WASHINGTON, Jan 12 (BestGrowthStock) – U.S. regulators are
continuing to probe whether a Sanofi-Aventis (SASY.PA: )(SNY.N: )
diabetes treatment raises cancer risk after determining that
data from four studies was inconclusive.

The FDA had announced in July 2009 that it was reviewing
studies suggesting an increased risk of cancer associated with
Sanofi’s long-acting insulin called Lantus, one of the
company’s top-selling products.

In an update released on Wednesday, the agency said it had
completed a review of four published studies and found evidence
of cancer risk was “inconclusive due to methodological
limitations.”

The agency also looked at a five-year randomized trial
comparing Lantus to another type of insulin in patients with
Type 2 diabetes. That study did not support a higher rate of
cancer with Lantus but also had limitations, the FDA said.

“At this time, FDA has not concluded that Lantus increases
the risk of cancer. Our review is ongoing,” the agency said in
a statement on its website.

Patients should not stop taking Lantus unless told to do so
by a doctor, the FDA said.

Lantus is one of Sanofi’s top products. Sales of the drug
are projected to hit $6.2 billion in 2014, according to Thomson
Reuters consensus estimates.

Concerns about a possible link between Lantus and cancer
have hit Sanofi shares in the past. The French company is
particularly reliant on Lantus because it faces a wave of
patent expirations on other blockbuster medicines. That big
patent “cliff” is a key reason behind Sanofi’s hostile bid for
biotech company Genzyme Corp (GENZ.O: ) as it hunts additional
sources of revenue.

The FDA said cancer cases were being studied in an ongoing
Sanofi trial of Lantus called Origin. A preliminary review did
not show evidence of a higher cancer risk, the FDA said.
Results from the trial are expected at the end of 2011.

Sanofi plans three other studies to evaluate the cancer
issue with results expected by the end of June, the FDA said.

The agency also is considering use of a Department of
Veterans Affairs patient database to shed light on the
concern.

Shares of Sanofi-Aventis rose 4.9 percent to close at
$33.71 on the New York Stock Exchange.

The FDA posted the notice on http://bit.ly/hVDraB.

(Reporting by Lisa Richwine; Editing by Bernard Orr and
Richard Chang)