Analysts have swooped in on the Franco-German firm after its blockbuster diabetes drug Lantus (insulin glargine) was linked to cancer in the journal Diabetologia. Though the association is not conclusive, cautious analysts have drastically lowered their forecasts for the drug; Societe Generale is expecting zero growth for 2009 while Morgan Stanley has cut its revenue predictions by more than half according to industry reports. Sanofi-Aventis’ guidance for Lantus sales in 2012 is 5 billion euros.

In an attempt to ameliorate the situation, Sanofi-Aventis yesterday held a conference call for analysts and investors in which it stated the firm had found no increase in cancer risk for the diabetes drug. However, Sanofi-Aventis CEO Chris Viehbacher said, "we want to take the scientific high road” to find the answers, perhaps by collaborating with other research groups rather than by conducting a prospective trial that could take too long to throw up the requisite information.

Viehbacher added that the Diabetologia papers had “significant limitations” – a sentiment echoed by the European Medicines Agency, which in a statement yesterday pointed to a number of inconsistencies in the results. “On the basis of the currently available data, a relationship between insulin glargine and cancer cannot be confirmed nor excluded,” the agency noted. “However, the concerns raised by the four studies require further in-depth evaluation.” It has charged its scientific advisory committee, the CHMP, with performing a detailed assessment of the studies’ results.