Issues in applying multi-arm multi-stage methodology to a clinical trial in prostate cancer: the MRC STAMPEDE trial

Table 3 Impact of variable factors on STAMPEDE target accrual and duration

	Median		Arms accruing at stage				Total		Differences in
Pts/yr	Median FFS (m)	Median OS (m)	1	2	3	4	Pts	Time (m)	Total pts	Time (m)
Reference
500	24	48	6	6	6	6	3411	82	0	0
Impact of accrual rate
350	24	48	6	6	6	6	2960	102	-451	20
500	24	48	6	6	6	6	3411	82	0	0
750	24	48	6	6	6	6	4046	65	635	-17
Impact of FFS event rates
500	18	36	6	6	6	6	3040	73	-371	-9
500	24	48	6	6	6	6	3411	82	0	0
500	30	60	6	6	6	6	3743	90	332	8
Impact of OS event rates
500	24	48	6	6	6	6	3411	82	0	0
500	24	60	6	6	6	6	3743	90	332	8
Impact of dropping arms
500	24	48	6	6	6	6	3411	82	0	0
500	24	48	6	6	6	2	3190	77	-221	-5
500	24	48	6	6	2	2	2983	72	-428	-10
500	24	48	6	2	2	2	2738	66	-673	-16
500	24	48	6	5	4	3	3133	75	-278	-7

Difference = difference from reference scenario, FFS = failure-free survival, OS = overall survival, Pts = patients, M = months. This does not include the Pilot stage for safety, concentrating only the particular issues relating to the application of the MAMS activity and efficacy stages

ISSN: 1745-6215