Biotech Values

[DewDiligence]

Re: GTCB / U.S. approval timeline for ATryn

[Dew’s timeline from #22027: enrollment complete in late 2006; treatment and follow-up complete in mid 2007; BLA submission in late 2007, approval in 2008.]

>Why does treatment and follow-up take so long? Is it a case say, in pregnancies, that they must wait until the babies come to term, etc?<

No (lol), but six months or slightly more for treatment and follow-up is not that long.

Much of the follow-up work pertains to the “prospective historical” control arm, in which investigators will find and analyze historical cases of hereditary AT deficiency that match the ATryn arm in patient and procedure characteristics. While doing this, the investigators will remain blinded to the outcomes in the selected control cases (hence the use of the “prospective” adjective).

The ATryn arm of this study ought to be relatively straightforward, but the control arm requires considerable care to satisfy the FDA that this is a bona fide controlled study.

The original timeline for the U.S. ATryn program that was presented at the 2005 annual meeting (showing approval by the end of 2007) was too aggressive, as is evidenced by Dr. Cox’s RedHerring interview. My own timeline (at the top of this message) does have some slack built in, but I think adding slack is reasonable in a trial that has a tricky design and very large commercial importance for the company.