Jankowski RJ, et al. - In female subjects with predominant stress urinary incontinence, researchers investigated the safety and effectiveness of autologous muscle derived cells for urinary sphincter repair (AMDC-USR) via a randomized, double-blind, multicenter trial examining intra-sphincteric injection of 150 × 106 AMDC-USR vs placebo in this female population. With no product-related serious adverse events or discontinuations due to adverse events, AMDC-USR was safe and well-tolerated. Using the composite primary outcome, interim analysis revealed an unexpectedly high placebo response rate (90%) which prevented assessment of treatment effect as designed and thus enrollment was halted at 61% of planned subjects. In post hoc analyses, more stringent endpoints lowered placebo response rates and revealed a possible treatment effect.