Table 2.

Operating Characteristics of the direct assignment option design vs. a Balanced randomized design based on 6000 simulations, and assuming stage I analysis at 50% accrual

	Response Rate Ratio (treatment versus control)	α= 0.10		α= 0.20
		Balanced Randomized Design	Design with Direct Assignment Option	Balanced Randomized Design	Design with Direct Assignment Option
Power (%)	2.00	80.6	79.3	79.3	78.0
	2.25	90.5	89.0	88.0	86.3
	2.50	96.5	95.5	94.5	93.2
	3.00	99.7	99.3	99.0	98.7
Type I Error Rate (%)	-	10.4	11.5	19.7	21.8

[1-β = 0.80; Response rate in the control arm = 0.20, Total planned sample size: 101 (α = 0.10); 65 (α =0.20)]