Monday, November 05, 2007

The Missing Kaplan Meier Curve

With all the buzz this week about the potential approval of prasugrel (Eli Lilly), it was interesting to note that the study published in the New England Journal of Medicine failed to have one important Kaplan Meier Curve: that of overall mortality. Certainly the benefits of the drug were shown for death from cardiovascular causes, nonfatal myocardial infarction [MI], or nonfatal stroke, but this advantage was offset by an increased risk of fatal bleeding. But when one looks at the TOTAL mortality from death by ANY cause (non-fatal MI, non-fatal stroke, or non-CABG-related nonfatal TIMI major bleeding), there were 249 deaths in the prasugrel group and 239 deaths in the clopidogrel group (p=0.43).

The authors looked for the reason why the data were so lackluster in regards to mortality, so they did a multivariate analysis and discovered "high risk" groups: age >=75, body weight <60 kg (135 lbs) or those with higher stroke. Was this study powered to differentiate these end-points in regards to mortality benefit? Of course not. So to make this point retrospectively sounds like data manipulation in the interest of corporate economics, and in the era of an FDA with hypersensitive tentacles to patient safety, the early release of this drug to the market seems suspect.

But then again, certain well-connected people think otherwise.


Addendum 2220 CST 19 Nov 2007: The full plenary session at the AHA 2007 meeting.

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