FDA calls for assessment of Sanofi, Regeneron's alirocumab; Regeneron's shares fall

Sanofi revealed Friday in a regulatory filing that the FDA requested that the company and partner Regeneron Pharmaceuticals assess the potential neurocognitive adverse effects of their experimental PCSK9 inhibitor alirocumab. Shares of Regeneron declined as much as 10 percent on the news.

Specifically, Sanofi said that the regulator directed the drugmakers to determine whether any neurocognitive adverse events occurred in any trials of their global development programme for the therapy, particularly in longer-term studies. Additionally, the agency is also asking the companies to determine the feasibility of incorporating new tests to identify potential cognitive events "into at least a subset of patients" in their ongoing late-stage studies.

Sanofi remarked that neither company knows how the FDA became aware of potential neurocognitive safety signals associated with PCSK9 inhibitors or whether the events are associated with PCSK9 inhibitors as monotherapy or in combination with statins or other cholesterol-lowering therapy. Sanofi added that the drugmakers do not know of any neurocognitive safety signal associated with alirocumab.

Commenting on the news, Deutsche Bank analyst Robyn Karnauskas said that Regeneron indicated that it has not observed any neurocognitive signals in its late-stage programme of alirocumab. "We note that the FDA had previously been concerned with neurocognitive effects of statins as well," commented Karnauskas, adding "however, some new studies have not found any link between memory loss and the use of statins."

Other drugmakers such as Amgen, Alnylam Pharmaceuticals, Eli Lilly, Pfizer and Roche also have experimental PCSK9 inhibitors under development.

To read more Top Story articles, click here.