Tuesday, November 20, 2007

Celebrex Summarized

We've now had a chance to read it.

Not think about it, mind you. Just read it.

Here's the story:

Pfizer moved to prevent plaintiffs' experts from providing the following 6 opinions:

(1) 200 mg/d of Celebrex causes heart attacks and strokes;

(2) 400 mg/d of Celebrex causes heart attacks and strokes;

(3) Celebrex causes heart attacks or strokes more than 3 days after discontinuation;

(4) Celebrex causes strokes;

(5) Celebrex causes strokes after less than 33 months of daily use; and

(6) Celebrex caused any individual plaintiff's heart attack or stroke absent epidemiology evidence that demonstrates a relative risk greater than 2.0.

The opinion has a brief discussion of epidemiology that includes some generally helpful stuff (e.g., epidemiology "can ... be probative of specific causation, but only if the relative risk is greater than 2.0, that is, the product more than doubles the risk of getting the disease" (at 7); and a brief discussion of confidence intervals with no pithy gems (at 9-10)).

As to opinion (1) - Celebrex at 200 mg/d -- the court noted that "there are no randomized controlled trials or meta-analyses of such trials or meta-analyses of observational studies that find an association between Celebrex 200 mg/d and a risk of heart attack or stroke. And most observational studies, indeed, the observational studies that include 97 percent of the reported adverse cv events, also find no statistically significant association. It is thus unsurprising that most of plaintiffs' experts agree that the available evidence at 200 mg/d is inadequate to prove causation." (At 12 (citation omitted)).

As to the two experts who opined that general causation had been established at that dosage, Judge Breyer rejected their opinions in detailed, fairly lengthy discussions. One, Dr. Neil Doherty, "reaches his opinion by first identifying his conclusion -- causation at 200 mg/d -- and then cherry-picking observational studies that support his conclusion and rejecting or ignoring the great weight of the evidence that contradicts his conclusion. Dr. Doherty's opinion does not reflect scientific knowledge, is not derived by the scientific method, and is not 'good science;' it is therefore inadmissible." (At 13). The other, Dr. Marilyn Rymer, "as does Dr. Doherty, ignores the vast majority of the evidence in favor of the few studies that support her conclusion." (At 17).

Then, Judge Breyer considers and rejects plaintiffs' experts' "extrapolation theory" -- that epidemiology from studies of Celebrex at 400 mg/d can be extrapolated to 200 mg/d. (At 19-21). Although another court had permitted extrapolating female data to males, Judge Breyer finds doing so inappropriate for different dosages given the volume of testimony that dose matters. (Id.) Responding to plaintiff's claim that "evidence of harm at 200 mg/d does not exist because Pfizer did not initiate long term randomized trials at such dose," Judge Breyer responds that "[p]laintiffs cite no case ... that suggests that they can satisfy their burden of proof based on lack of evidence; plaintiffs filed these lawsuits and plaintiffs carry the burden of proving today based on currently available scientifically valid evidence that Celebrex can cause heart attacks or strokes at 200 mg/d." (At 20-21).

As to opinions (2) and (4) through (6), the court denied the motion. (At 21-25). For the 400 mg/d dosage, the court found that one "large, long-term, randomized, placebo-controlled, double-blind, multi-center clinical trial" reporting statistically significant results sufficed, even though other studies had inconclusive results. (At 21-22). As to opinion (3) -- whether Celebrex causes heart attacks or strokes more than 3 days after discontinuation -- the plaintiffs offered no expert testimony, so the motion was granted. (At 24).

There will be no slouching towards Thanksgiving for us. We're just too !**!* compulsive.

1 comment:

Anonymous said...

Does anybody know current status of Celebrex case ( as of 12/15/08)