Biotech Values

[DewDiligence]

Re: Xarelto’s superiority claim or lack thereof

I watched the live webcast from AHA this morning when Forbes’ Langreth questioned the presenters at the session for late-breaking results, which formed the basis of the article you posted.

The argument by Dr. Hylek dismissing the per-protocol analysis (which showed Xarelto superiority to warfarin) because of Xarelto’s relatively short half-life is a red herring, IMO. I thought Dr. Califf refuted Dr. Hylek’s argument during the Q&A session by noting that the “in treatment” period used for the PP analysis included two days beyond a patient’s last dose and also included time when a patient was taken off drug for surgery.

The Xarelto claim of superiority in the PP analysis should IMO be dismissed for a much simpler reason: that ITT analysis is the preferred yardstick for results in a superiority test. (In a non-inferiority test, on the other hand, PP analysis is preferred for reasons that have previously been discussed on this board, e.g. in #msg-42490033.)

Whether the lack of a superiority claim for Xarelto relative to warfarin in the FDA label will hinder Xarelto’s commercial success is harder to say. My guess is that it will make some difference, but not a lot.

Comments?