expected percentage of patients remaining in hematologic remission at 2 years 
in the historical control group is about 45%. To detect an increased survival 
at 2 years of 20% (with a =0.05 and /9=0.20) approximately 50 patients 
achieving CR and receiving intensification therapy will be needed. Thus we 
plan to continue enrolling patient on this protocol for up to 4 years. 
To assure that patients do not receive inferior treatment, this study will also 
be analyzed in a sequential fashion and stopped if the relapse rate in the first 
year exceeds 25%. The following table will be used (assumes a test of 
significance at the nominal level a =.05): 
Stop if number of "successes" (b) 
Number of patients (a) is less than 
6-7 
3 
8 
4 
9 - 10 
5 
11 - 12 
6 
13 
7 
14 - 15 
8 
16 
9 
17- 18 
10 
19 
11 
20 
12 
(a) "Number of patients" considered is the number of patients undergoing 
transplantation except those patients on the protocol still in CR less 
than one year post transplant. 
(b) "Success" is defined here as a complete remission lasting for at least 
one year post transplant. 
"Stopping" does not necessarily imply that the study is to be permanently 
discontinued but only that a careful investigation of factors leading to the 
exercise of the stopping rule will be made by all co-investigators of the 
protocol. 
Monitoring of the study will be done quarterly by the biostatistical co- 
investigator (Dr. Schell). 
[518] 
Recombinant DNA Research, Volume 14 
