Biotech Values

[DewDiligence]

Phase-3 vs phase-2:

[This is a repost of an old message on the BIOM board that is germane to many development-stage biotech companies including, of course, GENR.]

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Why phase 3 fails to match phase 2:
by: DewDiligence
09/22/02 02:20 pm
Msg: 104714 of 161130

One reason that phase-3 trials frequently fail to live up to the promise of phase-2 results is an effect I call “Program-survival bias.”

Bad phase-2 trials generally result in clinical programs being canceled (no phase 3), while good phase 2 trials result in continuation to phase 3. Hence the phase-2 data for programs which proceed to phase 3 will have a positive bias, which implies that phase-3 data should on average be weaker than the corresponding phase-2 data.

Although I’ve not seem any formal study of this effect, intuitively, it seems clear to me that it must be a significant factor.
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