Analysis of FDA side-effect reports flags Sanofi, Celgene meds

When new drugs roll out, they meet the general population for the first time. Patients are no longer hand-picked as they are in clinical trials. And that often translates into a flurry of side-effect reports to the FDA. Last year's crop of new drugs is no exception.

More than 57,000 adverse event reports were filed with the FDA last year, and more than 16,000 of those involved drugs approved over the last two years, according to some number-crunching done by AdverseEvents, a California-based data-analysis company.

Using reports obtained from the FDA through a Freedom of Information Act request, the company identified and evaluated side-effects data. AdverseEvents then ranked drugs with the highest adverse-event risks and highlighted a few meds it predicts will see action by the agency, in a new white paper, "Expediting Drug Safety Using FOIA." It's worth noting that these adverse event reports don't prove that a drug actually caused the side effect flagged for the FDA, but high numbers of them often spur the agency to investigate.

Results? Tecfidera (dimethyl fumarate), the new multiple sclerosis drug from Biogen Idec ($BIIB), was the subject of more than 7,000 side-effect reports, but after sifting those reports, AdverseEvents puts it on the low end of the risk table. At the high end is Pomalyst (pomalidomide), the multiple myeloma treatment from Celgene ($CELG); with 1,004 "primary cases" last year, the drug ranked second, by the company's RxScore, at 71 on a 1-100 range.

But it was Sanofi's ($SNY) new MS drug, Aubagio (terifluonomide) that AdverseEvents pegged for probable safety-related action from the FDA. With 1,792 primary cases, Aubagio scored at just 48 on that 100-point scale, but the data-crunchers saw a high rate of reporting on side effects not currently listed on Aubagio's FDA-approved label. Those include muscular weakness and spasms, vertigo, and memory impairment.

"We believe these reports will lead to an FDA action or alert that could significantly alter prescribing behavior and revenue potential for this medication," the company said in the white paper.

The company also saw red flags in reports of diarrhea among patients using Vascepa (icosapent), the Amarin ($AMRN) blood-lipid pill derived from fish oil. Signifor (pasireotide), the Novartis ($NVS) Cushing's disease treatment, was flagged for reports of urinary tract infections, while Korlym (mifepristone), another Cushing's disease drug, from Corcept Therapeutics, saw a worrisome number of reports of weight reduction, the company said.

Some of the flagged drugs already carry serious warnings for various side effects. When new signals pop up and the FDA chooses to investigate, the agency probes the side-effect reports more carefully. Red flags in the adverse-events database don't always translate to an FDA investigation, much less stepped-up warnings. But keeping an eye on the numbers is what we do.

- get access to the white paper

Special Reports: Top 15 Drug Launch Superstars - Tecfidera | New FDA approvals of 2013 - Pomalyst - Tecfidera

Editor's note: The white paper link was updated and title corrected to read, "Expediting Drug Safety Using FOIA."