Placebo Reduction Strategies

Increases in the placebo response rate of patients in CNS clinical trials is a trend which has resulted in increased difficulty in being able to conduct a meaningful trial of a compound.  The diagram below illustrates that a 40% placebo response results in only 10% (1 in 10) of the patients being informative.

Patient Responds to:
Placebo –
Drugs +
Placebo –
Drugs –
Placebo +
Drugs +
Informative Not Informative Not Informative
10% 50% 40%

Application of placebo reduction strategies, like the Sequential Parallel Comparison Design, can reduce the placebo response to a level where 1 in 4 of the patients become informative.

Patients’ Response Type:
Placebo –
Drugs +
Placebo –
Drugs –
Placebo +
Drugs +
Application of Placebo Response Reduction Strategies
Informative Not Informative Not Informative
10%
25%
50% 40%
25%