PP02-23: Placebo Response Reduction Training Increases Assay Sensitivity in Clinical Trials on Migraine Treatment

Poster Presenter

Kathryn Evans

Associate Clinical Scientist
WCG Analgesic Solutions
United States

Objectives

To determine if 3 pooled phase III clinical trials on a CGRP antagonist that incorporated placebo reduction training resulted in a reduced placebo response compared to that of the phase II study on a CGRP antagonist that did not incorporate training.

Method

Placebo responders (>50% reduction in migraine headache days) and the difference in migraine days between placebo and CGRP antagonist were calculated across 3 phase III studies. Proportion of placebo responders between phase II and III studies was compared by using chi-squared analysis.

Results

The phase II clinical trial on the CGRP antagonist had 219 subjects and the mean difference in change in migraine headache days between placebo and active drug was 1.2 (SE+/- 0.21, p=0.003). The three pooled phase III studies had 2954 subjects and the mean difference in change in migraine headache days between placebo and active drug was 2.01 (SE+/-0.29, p<0.001). The phase II trial had statistically significantly more placebo responders (45%) than the pooled phase III trials (30%; x2=21.2, p<0.001). Taken together, the reduced placebo response and increased assay sensitivity suggests placebo response reduction training may successfully reduce placebo response and increase the difference between placebo and active drug.

Conclusion

The results indicate placebo response reduction training may reduce placebo response and increase assay sensitivity; thus, training helps to protect study endpoints. These results appear consistent with previous research on placebo response reduction training in chronic low back pain. More research is needed to determine if placebo reduction training is effective across more indications. Authors: Kathryn Evans, Heather Romero, Nathaniel Katz