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Biotech / Medical : Abgenix, Inc. (ABGX) -- Ignore unavailable to you. Want to Upgrade?


To: keokalani'nui who wrote (518)11/4/2005 9:20:49 PM
From: Miljenko Zuanic  Respond to of 590
 
Wilder,

GS guy got things wrong, imo.

75% is number of the pts in BSC group that crossed over to P.

My view: at week-8 60% on P progressed (40% response rate as SD and PR, best response rate) while min. 90% of BSC pts progressed (95% confidence interval for 33% difference in PFT at any measured point was reached). Now, because they got PFS average of 46% imply that for remaining 10% BSC and 40% P arm pts rate of progression was much slower for P than for BSC, up to at last (I guess) 20 weeks. It boils down, because BSC is no longer good comparator (most likely that 10% pts progressed very quickly after week-8), how did 40% of P arm fired after week-8? Here is true medical benefit, like 6 and 12 month survival, quality of life, other medications,...

Overall, P data for third line pts may look good if there is substantial benefit for more than 10% of the pts (those with PR).

AMGN/ABGX CC did not answered clearly on this because they were comparing P data with something that has no chance in this setting, So, even 10% P survival in 6 months will generate more than 50% reduction in progression rate at this time-point. Without K-M. curve we are blind.

For instance Tarceva has great K.-M. curve relative to BSC, still market penetration isn't much greater that for Irresa before T is introduced to market (so far). Further, P will compete with C for the same pts.

Miljenko



To: keokalani'nui who wrote (518)11/4/2005 9:41:38 PM
From: Miljenko Zuanic  Read Replies (1) | Respond to of 590
 
One more thing,

For very good reason Mike King (from CC, Thanks J.S.) asked for FDA guidance and concern when PFS is surrogate end-point, randomized and blind study. In this trial type (non-blind) pts on BSC want to be “declared progressive” as soon as possible, as they may still have chance in cross over arm. So, without clear survival benefit at 6 and 12 months (single P arm), they may not get full approval, only s.p.H.

Miljenko