STATISTICAL ANALYSES All the analysis were performed on an intention-to-treat basis. Primary outcomes are LOGPAD change in pain severity and whether a patient was a responder (pain score dropped ≥2 points or ≥30%). Because there was no statistical difference in these two outcomes among the 4 placebo groups, all placebo patients were combined (Comb PL) in the subsequent analyses. Primary analytic tool was mixed model for repeated measures (MMRM), assuming autoregressive covariance structure (LOGPAD pain and Brief Pain Inventory - BPI interferences), and Generalized Estimating Equation (GEE) model for categorical outcomes (Response rates and Patient Global Impression of Change - PGIC). The main objective was to assess whether the changes in outcome from baseline or the response rates were the same across the study phases, while adjusting for baseline values and time effect. Least square means were contrasted. Interaction between time and study phases were also tested to see if the treatment effect is a function of time. Fisher's exact tests or ANOVA (Kruskal-Wallis) tests were performed for cross-sectional group comparison, including baseline.