Why "Adverse Event" Source Documents Matter, In Discovery Of Incretin Mimetics Litigation

Incretin mimetics, like Merck's Januvia^® (sitagliptin), and those made and sold by several other manufacturers, are the subject of some consolidated federal MDL action in Southern California.

We've begun tracking this narrative, as of relatively recently. [Backgrounder of two weeks ago, there.]

The plaintiffs are angling to get the origial source documents (AERs), or copies of them -- of the hundreds of adverse event reports -- from Merck and the others. The plaintiffs need them they say to establish causation, as to their claims (increased risk of pancreatitis and possibly, risks of some kinds of cancers). Put succinctly, a summary of the document may look ordinary, while the source itself may reveal patterns not apparent in the very same summaries. So, here is a bit of the plaintiffs' latest motion, and argument -- for discovery and production of the source files:

. . . .Source files are important for many reasons. They show what actually happened with an adverse event. It is not uncommon for MedWatch summaries to mischaracterize or misstate important aspects of an event. For instance, a manufacturer’s MedWatch summary may say an event was not causally related to its drug, when the source documents (e.g., medical records) show the doctors felt the event was caused by the drug. The only way to tell if the MedWatch forms given to the FDA accurately characterize an adverse event is to review the source files for that event. . . .

Source files also show whether pancreatic cancers were properly reported to the FDA. There are reasons to believe such cancers were not correctly reported, and were underreported. . . .

These questions can only be answered by reviewing the source documents for each pancreatic cancer adverse event. Source files also show whether pancreatic cancers were properly reported to the FDA. . . .

Source files can also show whether "safety signals" have been generated. FDA guidance notes that even one "well-documented" adverse event can be a safety signal. Source files can provide the detailed documentation for those signals. . . . Signal detection leads directly to the assessment of causal association. . . .

Finally, source documents are also necessarily part of Defendants’ preemption defense. To establish that defense, Defendants must prove by "clear evidence" that the FDA would reject any [additional warnings] that fully explained the basis for the proposed warning. . . .

We will keep you posted, but remember, these are the plaintiffs' arguments. Merck would say all the info the plaintiffs need is already available in a summarized fashion, at MedWatch. Have a peaceful and productive start to the week!