 Preliminary results from LFAN and LFBC showed semagacestat did not slow disease progression and was associated with worsening of clinical measures of cognition and the ability to perform activities of daily living. Study drug was stopped in all studies. Studies LFAN, LFBC and LFBF have been amended to continue collecting safety data, including cognitive scores, for at least seven months. The CT-Registry will reflect results of analyses from the original protocol in addition to those from the amended protocol. Very few participants from LFBC rolled over into LFBF N 9. Due to insufficient sample size, the data for LFBC participants who rolled into LFBF were not analyzed. 