From: Designs for clinical trials with time-to-event outcomes based on stopping guidelines for lack of benefit
Stage (i)
Outcome
α i
ω i
δ i
e i
t i
1
FFS
0.5
0.95
1.00
113
3.0
2
0.25
0.92
213
4.4
3
0.1
0.89
331
5.8
4
OS
0.025
0.9
0.84
403
8.0
Overall
0.017
0.84*
0.012
0.83**