Table 4:

Sample size estimates^a

% Inactive Patients in Placebo Group	% Decrease in Mean Lesion Volume of Active Patients	Absolute % Increase in Inactive Patientsb
		0%	10%	20%	30%	40%	50%
10	0	–	–	–	435	225	124
	10	518	309	204	139	86	65
	20	128	101	82	65	47	38
	30	56	50	43	35	30	27
	40	31	28	24	22	21	19
	50	20	19	18	17	16	16
40	0	–	–	–	–	–	580
	10	470	369	315	251	199	153
	20	121	115	94	83	75	66
	30	49	44	44	40	37	36
	40	25	24	23	24	21	20
	50	15	15	15	15	14	15

^aNumber of patients per treatment arm necessary to perform parallel-group-designed trials with a statistical power of 80%, to detect treatment effects ranging from 0% to 50% increase in inactive patients and a 0%–50% reduction in mean enhancing-lesion volume in active patients.

^b– Indicates percentage increase of patients developing no/zero enhancing lesions during follow-up.