GTC Biotherapeutics (fka GTCB)

[DewDiligence]

How likely is the U.S. ATryn trial to succeed?

[Reposted from msg #4576 with typographical corrections.]


Success is likely, IMO, for several reasons:

1. The unmet medical need for ATryn in the U.S. is much greater than in Europe because there is only one approved plasma-derived antithrombin product (Thrombate from Talecris) and its supply is small and unreliable (#msg-20966468). By comparison, Europe has a reliable source of plasma-derived antithrombin from several manufacturers.

2. Compared to the phase-3 trial that got ATryn approved in Europe, the U.S. phase-3 trial includes more than twice as many patients treated with ATryn and it has a control arm (#msg-5609005).

3. Forty-five percent (14/31) of the patients in the ATryn arm of the U.S. phase-3 trial are already known to have been treated successfully because they are the same 14 patients who comprised the data set that led to ATryn approval in the EU. This is like a baseball player stepping up to home plate with a count of two balls and no strikes!