Fleming's Phase II Procedure
案例：
Since Phase I studies indicate that the experimental regimen is somewhat more toxic than the standard, in phase II clinical trial, it is decided to set p0=0.2 and pA=0.4, the maximum 25 patients accrual in 2 stages (Nmax=25, Numstage=2). A one-sided significance level test (α =0.05) with 80% power (β=0.2), the number of patients to accrue in stage 1 is 15 (n1=15) and in the last stage (stage 2), 25 patients are tested (n2=10). The acceptance points and rejection points in stage 1 is 3 and 7 respectively (a1=3, r1=7), it means that if the number of treatment response in stage 1 is less than or equal to 3, then stop the study and reject the alternative hypothesis
, if the number of treatment response in stage 1 is greater
than or equal to 7, then stop the study and reject the null hypothesis
, if the number of treatment response in stage 1 is greater
than 3 and less than 7, then continue to stage 2 to recruit 10 more patients.
The acceptance points and rejection points in stage 2 is 8 and 9 respectively
(a2=8, r2=9), it means that if the number of treatment
response in stage 2 is less than or equal to 8, then stop the study and reject
the alternative hypothesis
, if the number of treatment response in stage 2 is greater
than or equal to 9, then stop the study and reject the null hypothesis
.
Fleming (1982) Biometrics 38: 143-151