Supplementary Online Content Curtis C, Gamez JE, Singh U, et al. Phase 3 trial of flutemetamol labeled with radioactive fluorine 18 imaging and neuritic plaque density. JAMA Neurol. Published online January 26, 2015. doi:10.1001/jamaneurol.2014.4144. efigure 1. Disposition of Subjects. efigure 2. Receiver Operating Characteristic Curves for Flutemetamol PET Without and With CT. efigure 3. Examples of Flutemetamol PET for True Positive and True Negative Cases. efigure 4. Examples of Flutemetamol PET for the False Positive and False Negative Cases Not Near the CERAD Cutoff. etable 1. Characteristics of Subjects with Image Interpretations Discordant and Concordant with Post-mortem SOT. etable 2. Summary of Treatment-Emergent Adverse Events by System Organ Class and Preferred Term etable 3. Distribution of Neuritic Plaque Pathology. etable 4. By-Reader Sensitivity and Specificity for Flutemetamol, Florbetapir and Florbetaben. This supplementary material has been provided by the authors to give readers additional information about their work.
efigure 1. Disposition of Subjects Consented and screened n = 203 Excluded patients n = 23 Withdrawal by family/legal rep. = 1 Screen failure = 21 Agitated, unable to scan = 1 Received Fultemetamol F 18 Injection (Safety Analysis Set) n= 180 Did not complete study n = 4 Lost to follow-up = 1 Death = 1 a Protocol violation = 1 Agitated, unable to scan = 1 Completed study (Full Analysis Set) n = 176 Subjects who did not die = 107 Died during study n = 69 Brain was not evaluable = 1 Post-mortem Analysis Set n = 68 a This death appears as a discontinuation because of the way it was reported on the case report form. This subject s brain was not autopsied.
efigure 2. Receiver Operating Characteristic Curves for Flutemetamol PET Without and With CT Flutemetamol without CT (blue line with diamonds) area under the curve is 0.90; with CT (red line with squares) is 0.93. The AUC was constructed using each reader s results.
efigure 3. Examples of Flutemetamol PET for True Positive and True Negative Cases True Positive - PET True Negative - PET efigure 4. Examples of Flutemetamol PET for the False Positive and False Negative Cases Not Near the CERAD Cutoff False Positive - PET False Negative PET False Positive CT False Negative - CT
The False Positive case and False Negative case displayed are the false cases that did not exhibit borderline pathology (See Figure 1 in manuscript). Patient summaries for the False Positive and False Negative cases that did not have borderline pathology False Positive: 85 year old white woman with a medical history that included dementia. Her PET images were assessed as positive by 4 readers and negative by the fifth reader; her PET/CT images were assessed as positive by all 5 readers. The subject died 192 days after the [ 18 F]flutemetamol PET scanning. According to the SoT, the subject s brain was normal for neuritic plaques. Neuropathological assessment indicated that she had a low probability of AD, with no vasculopathy or tauopathies, but she had findings consistent with a synucleinopathy (dementia with Lewy bodies). Further review of this case revealed marked atrophy of the frontal, temporal, parietal, and cingulate. Moderate diffuse plaques were observed in the association cortices with no evidence of CAA. In summary, this was a normal case by SoT, which detects only neuritic plaques, but with a moderate diffuse plaque load, which might account for the flutemetamol signal. It is worth noting that 4 out of 5 readers rated this image as positive and with CT available, 5 out of 5 readers rated the [ 18 F]flutemetamol uptake as positive. A recent update of the National Institute on Aging Reagan Institute histopathology criteria for AD includes assessment of diffuse plaques in subcortical regions. Numerous diffuse plaques seen in the thalamus and midbrain in this case are consistent with Thal Phase 4 (A2) and intermediate likelihood of AD by these new criteria. False Negative: 87 year old white man with a medical history that included restless leg syndrome, unsteady gait, apathy, peripheral artery disease, coronary artery bypass graft surgery, high blood pressure, hypothyroidism, and a melanoma of the left leg treated with radiation. His PET images were assessed as negative by 3 blinded readers and positive by the remaining 2; his PET/CT images were assessed as positive by all 5 readers. The subject died 22 days after [ 18 F]flutemetamol PET scanning. According to the SoT, the subject s brain was abnormal for neuritic plaques. Neuropathological assessment indicated he had an intermediate probability of AD, with no vasculopathy, tauopathies, or synucleinopathy. Further review of this case revealed mild atrophy in the frontal cortex and cingulate. Neuritic plaques were observed in moderate amounts in the neocortex of all lobes. Diffuse plaques were present but less common. CAA was not evident. In summary, this was a clearly abnormal case with respect to the SoT, so image interpretation may have been confounded by atrophy in key assessment areas. In this case, the anatomic images were of benefit. AD=Alzheimer s disease; CAA=cerebral amyloid angiopathy; CT=computed tomography; FN=false negative; FP=false positive; PET=positron emission tomography; SoT=standard of truth; TN=true negative; TP=true positive
etable 1. Characteristics of Subjects with Image Interpretations Discordant and Concordant with Post-mortem SOT Characteristic False Negatives a (n = 6) False Positives a (n = 2) Concordant b (n = 43) Age (mean, years) 78.2 86.0 82.0 % Female 16.7% 100.0% 53.5% % White 100.0% 50.0% 93.0% % Not Hispanic or Latino 83.3% 50.0% 67.4% Weight (mean, kg) 62.98 53.9 61.96 Body Mass Index (mean, kg/m 2 ) 22.93 22.89 22.92 % With Reported Baseline Clinical Diagnosis 0% 20.9% AD 33.3% 0% 51.2% Other dementing disorder 0% 100% 27.9% No history of cognitive impairment 66.7% 0% 20.9% % Using AD Medication(s) 0% 0% 39.5% % With indicated plaque density post mortem None 0% 0% 14.3% Sparse 16.7% 50% 14.3% Moderate 83.3% 50% 31.0% Frequent 0% 0% 40.5% % With NIA-RI AD likelihood Normal 0% 0% 16.7% Low 66.7% 100% 11.9% Intermediate 33.3% 0% 9.5% High 0% 0% 61.9% a By majority image interpretation. b By all readers. Abbreviations: AD, Alzheimer s disease; NIA-RI, National Institute on Aging - Reagan Institute.
etable 2. Summary of Treatment-Emergent Adverse Events by System Organ Class and Preferred Term System Organ Class Preferred Term a Safety Analysis Set (N = 180) n (%) Number (%) of subjects with any treatment-emergent AE 9 (5) 95% exact binomial confidence interval for the treatment-emergent 2%, 9% AE rate Blood and lymphatic system disorders Anemia Cardiac disorders Atrial fibrillation Gastrointestinal disorders Vomiting General disorders and administration site conditions Pyrexia Infections and infestations Clostridial infection Nervous system disorders Senile dementia Psychiatric disorders Mental status changes Respiratory, thoracic, and mediastinal disorders Rhonchi Vascular disorders 2 (1) Flushing 2 (1) Abbreviation: AE, adverse event. Subjects reporting more than one event in a category were counted only once for that category. A treatment-emergent adverse event was an AE that began (or a pre-existing AE that worsened) between the start of Flutemetamol 18 Injection administration and 24 hours post injection. a Medical Dictionary for Regulatory Activities (MedDRA) version 13.1.
etable 3. Distribution of Neuritic Plaque Pathology Drug None Sparse Moderate Frequent Total a Reference Florbetapir 15 (25%) 5 (8%) 9 (15%) 30 (51%) 59 Clark, 2012 9 Flutemetamol 12 (18%) 14 (21%) 22 (33%) 19 (28%) 67 GE067-007 data Florbetaben 13 (16%) 17 (21%) 21 (26%) 82 Neuraceq US 31 (38%) Package Insert 30 a One flutemetamol brain did not have a CERAD neuritic plaque assessment.
etable 4. By-Reader Sensitivity and Specificity for Flutemetamol, Florbetapir and Florbetaben PET Agent Amylo id+ Amyl oid- Tot al Flutemet amol 43 25 68 Amyloi d Prevale nce 63% Read er TP TN FN FP Sensitiv ity Specific ity 1 35 22 8 3 81% 88% 42 25 67 2 37 23 5 2 88% 92% 43 25 68 3 40 11 3 14 93% 44% 42 25 67 4 39 20 3 5 93% 80% 43 25 68 5 38 23 5 2 88% 92% Florbeta 63% ben 52 30 82 1 50 25 2 5 96% 83% 52 30 82 2 51 23 1 7 98% 77% 52 30 82 3 51 24 1 6 98% 80% Florbeta 66% pir 39 20 59 1 36 19 3 1 92% 95% 39 20 59 2 37 19 2 1 95% 95% 39 20 59 3 34 19 5 1 87% 95% 39 20 59 4 36 20 3 0 92% 100% 39 20 59 5 27 18 12 2 69% 90% Abbreviations: FN, false negative; FP, false positive; PET, positron emission tomography; ROC-AUC, receiver operating characteristic area under the curve; TN, true negative; TP, true positive. RO C- AU C 0.9 0 0.9 0 0.8 5