EXEL confirmed long time ago the total alpha to spend in COMET-1 is 0.05.
They have never said how they allocated it, though I would have to say I never detected any sense that they would be surprised if the trial went to the full analysis.
FWIW, here is what I've worked up over the years (at BSR and ABV) on COMET-1.
COMET-1 enrollment pattern
May “initiated trial” 280 international sites targeted.
July to December 2012 = 60 patients
February 2013: “50% of trial sites are activated”
May 2013: “Most COMET trial sites are activated”
January to September 2013 = 900 patients
“960 patients enrolled in 14 months”
Statistical assumptions
1*=OS
N=960
Randomized 2:1
Study arm 9.0 month OS assumption (cabozantinib monotherapy)
Control arm 7.0 month OS assumption (prednisone monotherapy)
90% power at HR=0.75, p=0.05
One interim analysis, originally disclosed as 387 patients (later as “2/3rds of total events”)
Final analysis confirmed at 578 events
Other
The 7-month baseline assumption was derived from the COU-AA-301 trial of abiraterone (Zytiga) and represents the duration of treatment on the Zytiga arm between the end of treatment (median time on drug) and death (median overall survival).
There is no SPA.
The trial was initiated May 30, 2013, but management said they enrolled the 960 patients in 14 months.
I expect the trial was enrolled mostly ex-US, particularly in Europe.
Hope everyone is doing well, been a long time since I dropped by.
David
Views are my own. May have a position in stocks I discuss. Not a solicitation to buy or an offer to sell. On Twitter @AlpineBV_Miller
