Table 5.

Required number of primary endpoint events

	HR = 0.50	HR = 0.55	HR = 0.60	HR = 0.65	HR = 0.70	HR = 0.75
80% power	65	88	120	169	247	379
85% power	75	100	138	194	282	434
90% power	87	118	161	226	330	508

Calculations performed using nQuery 7.0 and assume a 0.05 type I error rate (two-sided) with 1:1 randomization