148 Current Alzheimer Research, 2009, Vol. 6, No. 2 Vellas et al. Table 1. Patient Disposition and Demographics by Treatment and Response Group Antibody Responder Placebo-treated Patients enrolled in original Phase 2a Study 201 (n) Who died in Study 201(n [%]) Patients or caregivers not contacted for participation in Study 251 (n [%]) Known dead (n [%]) Status unknown (n [%]) Patients or caregivers contacted for participation in Study 251 (n [%]) Dead, caregiver did not agree to participate (n [%]) Alive, did not agree to participate (n [%]) Dead, caregiver agreed to participate (n [%]) Alive, agreed to participate (n [%]) Total participation in Study 251, alive or dead (n [%]) Mean time to follow up in Study 251 from baseline in original Phase 2a Study 201 ± SD (years) Mean time to follow up in Study 251 from end of original Phase 2a Study 201 ± SD (years) Mean age ± SD (years), start of Study 251 Phase 2a Study 201 baseline mean MMSE ± SD, (n) ApoE4 carriers, n (%) 59 1 (1.7) 19 (32.2) 5 (8.5) 14 (23.7) 39 (66.1) 6 (10.2) 8 (13.6) 1 (1.7) 24 (40.7) 25 (42.4) 4.63 ± 0.12 3.66 ± 0.14 74.9 ± 7.32 21.0 ± 3.3 (24) 20 (80.0) 72 2 (2.8) 22 (30.6) 3 (4.2) 19 (26.4) 48 (66.7) 3 (4.2) 15 (20.8) 1 (1.4) 29 (40.3) 30 (41.7) 4.61 ± 0.10 3.63 ± 0.14 73.7 ± 8.65 19.8 ± 2.8 (29) 17 (56.7) Note: The denominators for patient disposition percentages are the numbers of patients enrolled in the original Phase 2a Study 201. The denominators for ApoE4 carrier percentages are the total numbers participating in Study 251, alive or dead. (96.0%). After approximately 4.6 years of follow up, anti- body responders demonstrated a 25.0% lower decline in ac- tivities of daily living as determined by the DAD compared with placebo-treated patients (mean change ± SD of -56.34 ± 28.45 for placebo vs -42.28 ± 30.88 for antibody responders, p=0.015). Dependence Scale Caregivers provided Dependence Scale ratings for 28/30 placebo-treated patients (93.3%) and 24/25 antibody re- sponders (96.0%). Antibody responders demonstrated a 17.6% lower mean score in caregiver dependence compared with placebo-treated patients (mean score ± SD of 10.2 ± 2.6 for placebo vs 8.4 ± 3.4 for antibody responders, p=0.033). CDR-SOB CDR-SOB ratings were obtained for 24/30 placebo- treated patients (80.0%) and 22/25 antibody responders (88.0%). Similar to the DAD and Dependence Scale, anti- body responders from the phase 2a study showed 20.2% less decline on the CDR-SOB scale compared with placebo, al- though this difference was not statistically significant (mean change ± SD of 7.63 ± 4.48 for placebo vs 6.09 ± 4.75 for antibody responders, p=0.185). Cognitive Function NTB The NTB as well as the other cognitive instruments were only administered in follow up to those patients who were available for testing and capable of being tested on these instruments. At the time of the follow-up study, the NTB was attainable in only 10/30 placebo-treated patients (33.3%) and 13/25 antibody responders (52.0%). No significant dif- ferences were observed in the change from baseline for the overall NTB 9-component z-score between antibody re- sponders and placebo-treated patients (mean change ± SD of -0.751 ± 0.560 for placebo vs -0.597 ± 0.626 for antibody responders, p=0.440). Of the NTB z-score components, the Rey Auditory Verbal Learning Test – Delayed Recall com- ponent showed reduced decline among antibody responders (mean change ± SD of -1.096 ± 1.165 for placebo vs 0.114 ± 1.138 for antibody responders, p=0.046). MMSE and ADAS-Cog An MMSE was attainable in 18/30 placebo-treated pa- tients (60.0%) and 20/25 antibody responders (80.0%). No significant differences were observed between antibody re- sponders compared with placebo-treated patients after 4.6 years of follow up (mean change ± SD of -8.3 ± 5.8 for pla- cebo vs -8.0 ± 7.8 for antibody responders, p=0.719). The ADAS-Cog was attainable in 11/30 placebo-treated patients (36.7%) and 16/25 antibody responders (64.0%). No significant differences in ADAS-Cog score were observed between placebo-treated patients and antibody responders after approximately 4.6 years of follow up (mean change ± SD of 14.4 ± 14.2 for placebo vs 14.3 ± 14.0 for antibody responders, p=0.616).