Over 200 publications, including the composite endpoints regulators now recognize. We publish our methodology in the open so reviewers meet it before your submission does.
Alzheimer's Association International Conference (AAIC) · 2024:Poster Tue-17 · Hendrix, Dickson et al.
Companies recently identified clinical study sites engaging in fraudulent practices, reducing success in Alzheimer's disease (AD) clinical trials. Successful trials are reliable…
When the sample size a conventional design demands is larger than the trial you can run, a Global Statistical Test lets the clinical-endpoint hypotheses be tested anyway. The paper sets out when GST applies, how it is pre-specified, and how it has been received in review.
14 publications
Sorted newest first
2026 · The Journal of Prevention of Alzheimer's Disease
Hendrix, Suzanne · Mallinckrodt, Craig
Background: Soluble amyloid β1–42 (Aβ42) signals via the α7 nicotinic acetylcholine receptor to hyperphosphorylate tau in Alzheimer's disease (AD). Simufilam disrupts this pathogenic signaling by binding filamin A and disrupts its linkages with inflammatory receptors to reduce neuroinflammation. We assessed simufilam in two Phase 3 clinical trials in mild-to-moderate AD. Methods: Participants were age 50–87 with Stage 4 or 5 CE, a mini-mental state exam (MMSE) ≥16 and ≤27 and a Clinical Dementia Rating Global Score (CDR-GS) of 0.5, 1 or 2. The criterion supporting AD pathology was plasma phosphorylated (p)-tau181 or prior amyloid PET. RETHINK randomized participants to simufilam 100 mg or placebo for 52 weeks. REFOCUS evaluated simufilam 50 and 100 mg versus placebo for 76 weeks. Co-primary endpoints were change from baseline on ADAS-Cog12 and ADCS-ADL. Sub-studies assessed exploratory plasma biomarkers and, in REFOCUS only, CSF and imaging biomarkers. Results: Both trials failed to meet co-primary, secondary or exploratory biomarker endpoints. REFOCUS was terminated early, with 22% of participants still active in the trial. In the predefined mild subgroup in REFOCUS, simufilam was associated with slower cognitive decline than placebo through Week 64 (p = 0.019). This finding disappeared at Week 76 with 45% missing data and did not replicate in RETHINK. Favorable nominal exploratory post-hoc findings amongst participants with the highest half of screening plasma p-tau181 levels occurred in RETHINK but not REFOCUS. The plasma p-tau181 entry criterion did not reliably exclude amyloid PET negativity in the sub-study. Conclusions: Simufilam did not meet co-primary or secondary endpoints in these Phase 3 trials. Simufilam was safe and well tolerated. Trials registered at clinicaltrials.gov: NCT04994483 and NCT05026177
2025 · Alzheimer's & Dementia
Duncan, Garrett · Dickson, Samuel · Johnson, Sam · Dayley, Caleb · Hendrix, Suzanne · Mallinckrodt, Craig
INTRODUCTION: The importance of biomarkers as a primary outcome or as supportive evidence of clinical effect is rising as the field shifts toward disease-modifying treatments and earlier intervention, because they have lower variability and can indicate disease progression earlier than clinical outcomes. This study assessed the performance of plasma pTau 181 and 217 as a predictive biomarker and potential primary endpoint in early-phase Alzheimer’s disease (AD) trials. METHODS: Summary data from recent monoclonal antibody (mAb) trials including plasma pTau 181 and 217 were analyzed to evaluate associations between plasma pTau 181/217 and clinical outcomes. The suitability of plasma pTau 181/217 as a surrogate endpoint for internal decision making was assessed using Prentice criteria. Simulations were conducted to explore the statistical power of using plasma pTau 181/217 as a primary outcome in dose-escalation, proof-of-concept (POC) trial designs. Additional criteria for biomarker validation were applied to simulated data. RESULTS: A strong group-level correlation (r = 0.781) was observed between treatment effects on plasma pTau 181/217 and Clinical Dementia Rating scale – Sum of Boxes (CDR-SB). Mean change in plasma pTau 181/217 significantly predicted mean change in CDR-SB (p = 0.013). The treatment effect on pTau 181/217 was ∼2.6 times greater than on CDR-SB. Prentice Criteria 1, 2, and 4 were met or reasonably met; Criterion 3 is not applicable in the POC setting. CONCLUSION: Plasma pTau 181/217 at 6 months shows future promise to reasonably likely predict clinical benefit for drugs that reduce pTau 181/217 levels, supporting its use as a primary endpoint in early-phase trials. With effect sizes similar to those seen with donanemab, adequately powered trials may require as few as 100 participants. Such trials should include prespecified analyses to evaluate individual-level Prentice criteria, and pTau 181/217 results can be used to predict potential Phase 3 clinical outcomes.
2024 · J Prev Alzheimers Dis
Dickson, Samuel · Brownlee, Allison · Haaland, Benjamin · Mallinckrodt, Craig · Hendrix, Suzanne
Assessment of meaningfulness in randomized clinical trials (RCTs) in Alzheimer's disease (AD) is challenging, particularly in early disease. Converting clinical outcomes to disease progression time allows assessment of treatment effects using a metric that is understandable and meaningful: time. We demonstrate time savings assessments using meta time component tests (TCTs) in the LipiDiDiet multinutrient RCT. Dietary patterns are important for dementia prevention, likely due to individual cumulative nutrient effects. LipiDiDiet used a multinutrient (Fortasyn Connect) formulation in patients with prodromal AD, benefitting cognition (5-item composite NTB, effect 0.089), cognition and function (CDR-SB, -0.605), and slowing hippocampal atrophy (0.122 cm3). Meaningfulness of point differences is unclear. However, a combination TCT showed 9-month disease time savings at 24 months (38% slowing of disease time): 9.0, 10.5, and 7.2 months for NTB, CDR-SB, and hippocampal volume, underscoring the value of TCTs in AD RCTs and the need for continued validation of this approach.
2024 · Front Neurol
Nicodemus-Johnson, Jessie · Hendrix, Suzanne
Background: Alzheimer's Disease (AD) is a multifactorial, progressive neurodegenerative disease that disrupts synaptic and neuronal activity and network oscillations. It is characterized by neuronal loss, brain atrophy and a decline in cognitive and functional abilities. Cognito's Evoked Gamma Therapy System provides an innovative approach for AD by inducing EEG-verified gamma oscillations through sensory stimulation. Prior research has shown promising disease-modifying effects in experimental AD models. The present study (NCT03556280: OVERTURE) evaluated the feasibly, safety and efficacy of evoked gamma oscillation treatment using Cognito's medical device (CogTx-001) in participants with mild to moderate AD. Methods: The present study was a randomized, double blind, sham-controlled, 6-months clinical trial in participants with mild to moderate AD. The trial enrolled 76 participants, aged 50 or older, who met the clinical criteria for AD with baseline MMSE scores between 14 and 26. Participants were randomly assigned 2:1 to receive self-administered daily, one-hour, therapy, evoking EEG-verified gamma oscillations or sham treatment. The CogTx-001 device was use at home with the help of a care partner, over 6 months. The primary outcome measures were safety, evaluated by physical and neurological exams and monthly assessments of adverse events (AEs) and MRI, and tolerability, measured by device use. Although the trial was not statistically powered to evaluate potential efficacy outcomes, primary and secondary clinical outcome measures included several cognitive and functional endpoints. Results: Total AEs were similar between groups, there were no unexpected serious treatment related AEs, and no serious treatment-emergent AEs that led to study discontinuation. MRI did not show Amyloid-Related Imaging Abnormalities (ARIA) in any study participant. High adherence rates (85-90%) were observed in sham and treatment participants. There was no statistical separation between active and sham arm participants in primary outcome measure of MADCOMS or secondary outcome measure of CDR-SB or ADAS-Cog14. However, some secondary outcome measures including ADCS-ADL, MMSE, and MRI whole brain volume demonstrated reduced progression in active compared to sham treated participants, that achieved nominal significance. Conclusion: Our results demonstrate that 1-h daily treatment with Cognito's Evoked Gamma Therapy System (CogTx-001) was safe and well-tolerated and demonstrated potential clinical benefits in mild to moderate AD. Clinical Trial Registration: www.ClinicalTrials.gov, identifier: NCT03556280.
2022 · Neurology
Nicodemus-Johnson, Jessie · Hendrix, Suzanne
Objective: To evaluate the safety, tolerability, adherence, and efficacy of 40Hz sensory stimulation therapy in subjects with Alzheimer’s disease (AD). Background: 40Hz gamma sensory stimulation diminishes AD pathology, neurodegeneration, and brain atrophy, synaptic and learning dysfunctions in transgenic mice carrying AD-related human pathological genes (Adaikkan & Tsai, 2020). These results initiated the development and validation of non-invasive, gamma sensory stimulation as a potential therapeutic for AD treatment. Design/Methods: Participants on AD spectrum were randomized to receive daily, one-hour, EEG-calibrated, noninvasive audio-visual stimulation, or sham stimulation in a 6-month clinical trial (Overture trial; NCT03556280) using Cognito Therapeutics medical device. Both safety (MRI, physical and neurological exams), and efficacy (AD cognitive and functional instruments, volumetric MRI) were assessed. Results: A total of 135 subjects were screened, 74 were randomized, and 53 completed the trial. The rate of AEs during the trial were roughly equivalent between groups. There were no unexpected serious treatment adverse events. Over the 6-month treatment period, changes in ADCS-ADL scores were significantly better in the treatment group compared to sham, indicating a 78% slowing in functional decline (P<0.0003). Similarly, the treatment group demonstrated a statistically significant 83% (p<0.013) reduction in cognitive decline, shown by changes in MMSE scores. The outcomes of MADCOMs, ADAS-cog14 and CDR-sb were not statistically different between groups. Quantitative MRI analysis revealed that whole brain volume loss in the treatment group demonstrated a significant, 72% reduction in brain atrophy (p<0.01) compared to sham group. Reduced lateral ventricle enlargement and diminished loss in cortical thickness in the occipital cortex have been also observed. MRI data demonstrated absence of ARIA in all subjects. Conclusions: Long-term, daily, self-administered, home-use of gamma sensory stimulation is both safe and well tolerated in AD subjects. Patients given gamma stimulation therapy maintained cognitive and functional abilities. Gamma sensory stimulation reduced brain atrophy, indicating potential disease-modifying effects in AD.
2022 · Alzheimer's & Dementia
Dickson, Samuel · Nicodemus-Johnson, Jessie · Knowlton, Newman · Hennessey, Sean · Hendrix, Suzanne
2020 · Alzheimer's & Dementia
Background The AMBAR study enrolled 496 mild-to-moderate Alzheimer’s disease (AD) patients from Spain and US centers, 347 of which were randomized [1:1:1:1] to three treatment arms of plasma exchange (PE) with different doses of albumin with or without intravenous immunoglobulin (IVIG) or placebo (sham PE) arm. PE treatment showed slow cognitive and functional decline in AD patients, with variable significance in outcome (primary: ADCS-ADL, ADAS-Cog; secondary: CDR-Sb, ADCS-CGIC), baseline disease severity, and treatment arm (low-albumin; low-albumin+IVIG, high-albumin+IVIG, and all three combined). The percentage of patient dropouts ranged from 20% in the placebo to 34.9% in the low-albumin+IVIG group. In this analysis we investigated the effect of possible biases due to discontinuations and baseline imbalances, and assessed the consistency across outcomes. Method The impact of discontinuations was determined by least squares mean estimates from the Mixed Model for Repeated Measures (MMRM) analysis using the z-score carried forward analysis (zLOCF). The overall impact of the treatment on the disease was determined by a global statistical test which combined with equal weighting three outcomes (ADCS-ADL, ADAS-Cog, CDR-Sb) into a single outcome. An analysis of relevant outcomes was performed adjusting for key baseline characteristics. Result Analysis of discontinuations suggested that the treatment differences and effect sizes estimated using the primary model MMRM are likely to be conservative and that lowering dropouts is likely to increase effect sizes. Effect sizes were consistent across outcomes (between 51% and 76%). The GST score showed slowing of progression at month 14 with statistically significant differences between all active treatments and placebo from month 9 onward. When the model was adjusted for key baseline characteristics, the analysis showed statistically significant differences against placebo of all treatment groups in most of the relevant outcomes. Conclusion Results of this analysis disprove the possible bias of dropout effect in the AMBAR trial. Effect sizes were consistent across outcomes and the Global Statistical Test showed an overall impact of the treatment on the disease. The analysis corrected for baseline factors supports and reinforces the findings that the PE-treated arms were superior to the placebo group.
2020 · 2020 Alzheimer's Association International Conference
Background: Diet and nutrition are important modifiable risk factors for Alzheimer’s disease (AD). For the last two decades, the LipiDiDiet consortium has been investigating the role of nutrients and their synergistic action on key AD pathological features. Based on preclinical results, 11 nutrients were selected which, when applied in this specific combination, gave the best results in rodent AD models: i.e. the omega-3 fatty acids DHA and EPA, phospholipids, vitamins B6, B12, folic acid, C and E, choline, selenium, and UMP. The LipiDiDiet trial1 is a 6-year, double-blind, parallel-group, multi-centre, randomised controlled clinical trial, designed to investigate effects of the specific multinutrient combination Fortasyn Connect on cognition and related measures in prodromal AD. Initial 24 month results showed significant benefit on clinical dementia rating-sum of boxes (CDR-SB) and hippocampal and ventricular volumes in the modified intention-to-treat population. Here we report previously specified primary and secondary outcomes over 36 months of intervention. Method: Prodromal AD participants (n=311) were randomised to receive either active product (125 mL drink containing Fortasyn Connect) or a calorie-matched placebo control once daily. Result: 162 participants completed the 36-month period. With increasing treatment duration, the benefit of the active group over the control group exceeded what had been observed for the first 24 months (Soininen et al., Lancet Neurology 2017). For the 5-item neuropsychological test battery (NTB) on cognition, a significant between-group difference was observed in estimated mean change from baseline over 36 months favouring active intervention (0.212 [95% CI 0.044 to 0.380]; p=0.014; 60% reduction in decline). In addition, significant benefits were found on CDR-SB, NTB memory, and hippocampal, ventricular, and whole brain volumes on MRI. Self-reported compliance to the study product was high and there was no indication of safety concern. Conclusion: We observed significantly slower decline in cognition including memory, CDR-SB measuring cognition and function, and brain structural measures. Importantly, prolonged intervention with this specific combination of nutrients resulted in a broader range of endpoints showing statistically significant differences. Sustainable benefits lasting for 3 or more years have not been reported before in prodromal AD.
2016 · J Prev Alzheimers Dis
Brown, Bruce · Hendrix, Suzanne
Background: Tramiprosate is an oral amyloid anti-aggregation agent that reduces amyloid oligomer toxicity in preclinical studies and was evaluated in two 78-week trials in North America and Western Europe that enrolled 2,025 patients with Mild to Moderate Alzheimer's Disease. The completed North American study did not achieve its efficacy objectives, but a pre-specified subgroup analysis suggested potential efficacy in apolipoprotein E4 (APOE4) carriers. To further explore this observation, we analyzed tramiprosate Phase 3 clinical data based on the number of APOE4 alleles. Objectives: To analyze tramiprosate efficacy, safety, and occurrence of vasogenic edema in the three APOE4 subgroups: homozygous, heterozygous and non-carriers. Design: Randomized, double-blind, placebo-controlled parallel-arm multi-center studies. Setting: Academic Alzheimer's disease and dementia centers, community-based dementia and memory clinics, and neuropsychiatric clinical research sites. Participants: Subjects included 2,025 patients, 50 years of age or older, with approximately 60% having APOE4 carrier status (10-15% homozygotes and 45-50% heterozygotes), and mild to moderate disease. All subjects were on stable symptomatic drugs. Intervention: Randomized subjects received placebo, 100 mg BID, or 150 mg BID of tramiprosate. Measurements: Co-primary outcomes in both studies were change from baseline in the ADAS-cog11 and CDR-SB assessment scales. Results: Highest efficacy was observed in APOE4/4 homozygotes receiving 150 mg BID of tramiprosate, showing statistically significant effects on ADAS-cog and positive trends on CDR-SB (respectively, 40-66% and 25-45% benefit compared to placebo). APOE4 heterozygotes showed intermediate efficacy, and non-carriers showed no benefit. In 426 patients with MRI scans, no cases of treatment-emergent vasogenic edema were observed. In the three subgroups, the most common adverse events were nausea, vomiting, and decreased weight. Conclusions: The "APOE4 Gene-Dose effect" is likely explained by the high prevalence of amyloid pathology in symptomatic APOE4 carriers. In APOE4/4 Alzheimer's disease patients, the high dose of tramiprosate showed favorable safety and clinically meaningful efficacy in addition to standard of care.
2012 · Alzheimer's & Dementia
Background: No well-established, validated endpoints exist that are sensitive to change in MCI populations in clinical trials. Our goal was to develop a tool based on standard clinical items that would demonstrate maximum responsiveness to progression and to treatment in an MCI population and would also perform well in a mild AD population (collectively referred to as Early AD). This analysis uses a novel approach by utilizing data from multiple studies to investigate responsiveness to progression and treatment effects rather than sensitivity to baseline deficits. Methods: This tool was built empirically with no a priori assumptions. A partial least squares (PLS) regression model used placebo data from 4 MCI studies over 12 months to select the combination of cognitive and functional items which is most sensitive to change over time, using items from a variety of well-established and validated scales. The PLS regression coefficients from the model were used to form a weighted composite score. The resulting composite score is comprised of ADAS-Cog, MMSE and CDR items. Performance of the composite score was assessed against the original scales in an MCI population, in enriched (CSF Aβ positive) MCI subgroups, with split sample validation, in the presence of a treatment effect and in a mild AD patient population combining data from 3 studies. Results: A composite clinical score was devised from 12 items from the ADAS-Cog, MMSE, and CDR-SB that assess both cognition and global function. This score demonstrates improved sensitivity to decline, as well as reduced heterogeneity, as compared with original scales, and is responsive to treatment effect in MCI, enriched MCI and mild AD populations. The composite score allows for substantial sample sizes reductions in non-enriched and enriched MCI populations for a 12-month study (see Figure). Conclusions: A new composite clinical score that utilizes relevant items from validated and well-established clinical tools provides a tool that can be used as a single clinical outcome in studies that target MCI, enriched MCI and mild AD populations. This tool will enable the use of substantially smaller sample sizes due to improved sensitivity to disease progression and treatment effects.
2008 · Alzheimer's & Dementia
Background: Tarenflurbil is a Selective Aβ42-Lowering Agent (SALA) that modulates γ-secretase activity to preferentially reduce production of Aβ42 in vivo and in vitro. Evidence for potential benefit of tarenflurbil 800 mg bid in subjects with mild AD was recently observed in a randomized, double-blind Phase 2 trial of up to 24 months of treatment. Methods: A target of 1600 subjects with mild AD (MMSE score 20–26) were to be randomized (1:1) to receive tarenflurbil 800 mg bid or placebo for 18 months. Randomization was stratified according to stable use/nonuse of acetylcholinesterase inhibitors (AChEIs) and/or memantine. The co-primary efficacy outcomes are the rate of change (slope) in ADAS-cog and the ADCS-ADL, with assessments conducted every 3 months. The secondary outcome is the CDR-sb, with additional exploratory outcomes including the NPI, Quality of Life-AD, and Caregiver Burden Inventory. ECGs are obtained every 3 months, with adverse events monitored throughout the study. Plasma samples are collected every 3 months for pharmacokinetic and exploratory biomarker analyses. Results: This trial enrolled 1684 subjects at 133 sites in the United States. The last patient visit occured in March 2008, with database lock occuring in June of 2008. At enrollment, 33% of subjects were using AChEIs alone (stable for ≥ 6 months), 6% of subjects were using memantine alone (stable for ≥ 3 months), 41% of subjects were using both AChE is and memantine and 19% of subjects were taking no AD therapy. A second Phase 3 trial of similar design, fully enrolled with 840 subjects, is ongoing in the US, Canada and Europe and is expected to be completed in the clinic in October of 2008. Conclusions: This Phase 3 protocol was developed based on Phase 2 trial results. It is powered to evaluate the efficacy of tarenflurbil with respect to the primary outcomes, and to examine its effect both as monotherapy and as add-on therapy with currently marketed AD medications.
2006 · Alzheimer's & Dementia
Background: MPC–7869 (R–flurbiprofen) is a Selective Aβ42–Lowering Agent (SALA). In a mouse model of AD (Tg2576), MPC–7869 lowers brain levels of Aβ42 and chronic dosing in this model reduces brain amyloid pathology and prevents defects in learning and memory. These data suggest a potential for MPC–7869 to have disease–modifying properties. Objective(s): This study evaluated the efficacy and safety of treatment with MPC–7869 for 12 months in subjects with mild–to–moderate AD, and includes data from a 1–year follow–on study. Methods: This was a placebo–controlled, double–blind, 1–year trial evaluating 400 mg BID and 800 mg BID of MPC–7869 in 207 patients with mild–to–moderate AD (MMSE 15–26, with an average MMSE score of 21). The mean age of the subjects at baseline was 75 years and 94% of subjects were on stable acetylcholinesterase inhibitor therapy. Primary outcomes included measures of cognition (ADAS–cog), activities of daily living (ADCS–ADL), and global function (CDR–sb). A population pharmacokinetic analysis was also performed. At the end of this study, over 80% of eligible patients were enrolled into a 1–year follow–on treatment study in which placebo patients were randomized into one of the two treatment groups and treated patients continued their stable dose. Treatment groups remained blinded to patient/investigator. Results: A prespecified interaction analysis revealed that mild and moderate AD patients responded differently to MPC–7869 (P= 0.03). In mild AD patients (MMSE 20–26) taking the 800–mg BID dose, statistically significant benefit was observed at 12 months in activities of daily living with a treatment effect size of d=0.44 (P= 0.033) and global function with a treatment effect size of d=0.42 (P= 0.042) with a positive trend observed in cognition. In addition, there was a significant plasma drug concentration to response relationship (ADCS–ADL, P= 0.037 and CDR–sb, P= 0.019). No benefit was observed in moderate AD patients. MPC–7869 was well tolerated and patients taking the 800–mg BID dose continued to show benefit in the 1–year follow–on study. Conclusions: MPC–7869 has an attractive therapeutic and safety profile in patients with mild AD. This study justifies larger–scale confirmatory trials of MPC–7869 as an amyloid–based intervention strategy for AD treatment.
2005 · Alzheimer's & Dementia
Background: Several epidemiological studies have suggested that longer-term use of NSAIDs may reduce the risk of developing Alzheimer's disease (AD). Although there were encouraging results from some earlier studies, more recent longer-term, larger, placebo-controlled clinical trials utilising drugs with an anti-inflammatory action have produced disappointing outcomes. Re-analysis of the epidemiological data has shown that the protective effect is limited to a subgroup of NSAIDs, including flurbiprofen, which have Aβ-42 lowering properties and which were not used in the previous longer-term placebo-controlled trials. Flurizan (MPC-7869 (R)-flurbiprofen) is a single enantiomer of flurbiprofen, which has been shown to lower brain levels of Aβ-42 in a mouse model of AD (Tg2576), with some evidence of an effect on learning and memory. There is little risk of gastric toxicity because of a lack of anti-COX activity, and the compound has been shown to be safe and well tolerated in healthy older volunteers (55-80yrs) at doses of up to 1600mg per day when administered for 21 days in a phase I study. It is therefore an exciting potential disease modifying treatment for AD. Objective(s): This presentation will provide efficacy and safety data from a clinical trial of Flurizan, which to our knowledge will be the first multi-centre, placebo-controlled, double-blind clinical study of a selective Aβ-42 lowering agent in patients with mild to moderate Alzheimer's disease. Methods: This is a one-year trial evaluating both 400mg BID and 800mg BID of (R)-flurbiprofen per day, in 210 patients (50% female) with mild to moderate AD (MMSE 15-26). It employed the ADAS-cog, ADCS-ADL, CDR-sb, CIBIC plus, NPI and MMSE as outcome measures. At baseline the mean age of the subjects was 75 years with an average MMSE score 21 and an average standard ADAS-cog score 23. Of the patients enrolled in the trial, 94 per cent were also taking stable doses of cholinesterase inhibitors. Concomitant treatment with memantine was not allowed. Conclusions: The study completes in March 2005, and the cognitive, functional, global and behavioural outcomes will be presented, together with the safety data.
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