Avoiding future controversies in the Alzheimer's disease space through understanding the aducanumab data and FDA review.

Key points of disagreement between the aducanumab FDA statistical review, which had primarily negative conclusions, and the clinical review, which had primarily positive conclusions, were investigated. Results from secondary endpoints in positive Study 302 were significant and these endpoints provided meaningful additional information. Findings indicate the statistical review of the aducanumab data was incorrect in a number of key areas. Greater placebo decline was not responsible for the significant results in Study 302. Correlations did exist between reduction in ß-amyloid and clinical outcomes. Missing data and functional unblinding did not likely bias results. In contrast, the clinical review went too far in saying the negative results in Study 301 did not detract from the positive results in Study 302, as all clinical data should be considered in the evaluation, and the clinical review accepted the company's explanation for divergence of the results between the studies although much of the divergence remained unexplained. Interestingly, both the statistical review and the clinical review considered the available efficacy evidence despite both studies being terminated early. Implications of these findings include that the divergence in results seen in the two phase 3 aducanumab studies can be expected in other studies with similar design and analysis. Therefore, further research is needed to determine if analysis methods other than MMRM and/or optimized outcomes will provide more consistent results across studies.

Survival analyses from the CENTAUR trial in amyotrophic lateral sclerosis: Evaluating the impact of treatment crossover on outcomes.

INTRODUCTION/AIMS: Trials incorporating placebo-to-active treatment crossover are encouraged in fatal conditions like amyotrophic lateral sclerosis (ALS) but may underestimate active treatment survival benefit. Here, we apply methods for modeling survival without crossover, including the rank-preserving structural failure time model (RPSFTM), to data from the CENTAUR trial of sodium phenylbutyrate and taurursodiol (PB and TURSO) in ALS incorporating both randomized placebo-controlled and open-label extension (OLE) phases. METHODS: Intent-to-treat (ITT) and RPSFTM survival analyses were performed with final data at a July 2020 cutoff date. Analyses of subgroups based on randomized treatment and OLE phase participation were also performed. RESULTS: Hazard ratios (95% confidence intervals) of death for PB and TURSO versus participants initially on placebo were 0.57 (0.35-0.92) on ITT analysis and 0.39 (0.17-0.88) in the primary on-treatment RPSFTM analysis (p = .023). Median ITT survival duration for PB and TURSO (25.8 mo) was 6.9 mo longer than placebo (18.9 mo) on ITT analysis and 10.6 mo longer than the median RPSFTM-adjusted survival duration for placebo (15.2 mo). Median survival duration was 18.8 mo longer in the PB and TURSO-randomized subgroup who continued into the OLE phase versus the placebo-randomized subgroup who did not continue into the OLE phase (p < .0001), although OLE phase selection bias may have potentially confounded these results. DISCUSSION: Similar to the prespecified ITT analysis, post hoc analyses adjusting for treatment crossover in CENTAUR showed a significant survival benefit for PB and TURSO. Such methods may provide clinical context for observed survival outcomes in future ALS crossover trials.

Effect of sodium phenylbutyrate/taurursodiol on tracheostomy/ventilation-free survival and hospitalisation in amyotrophic lateral sclerosis: long-term results from the CENTAUR trial.

BACKGROUND: Coformulated sodium phenylbutyrate/taurursodiol (PB/TURSO) was shown to prolong survival and slow functional decline in amyotrophic lateral sclerosis (ALS). OBJECTIVE: Determine whether PB/TURSO prolonged tracheostomy/ventilation-free survival and/or reduced first hospitalisation in participants with ALS in the CENTAUR trial. METHODS: Adults with El Escorial Definite ALS ≤18 months from symptom onset were randomised to PB/ TURSO or placebo for 6 months. Those completing randomised treatment could enrol in an open-label extension (OLE) phase and receive PB/TURSO for ≤30 months. Times to the following individual or combined key events were compared in the originally randomised treatment groups over a period spanning trial start through July 2020 (longest postrandomisation follow-up, 35 months): death, tracheostomy, permanent assisted ventilation (PAV) and first hospitalisation. RESULTS: Risk of any key event was 47% lower in those originally randomised to PB/TURSO (n=87) versus placebo (n=48, 71% of whom received delayed-start PB/TURSO in the OLE phase) (HR=0.53; 95% CI 0.35 to 0.81; p=0.003). Risks of death or tracheostomy/PAV (HR=0.51; 95% CI 0.32 to 0.84; p=0.007) and first hospitalisation (HR=0.56; 95% CI 0.34 to 0.95; p=0.03) were also decreased in those originally randomised to PB/TURSO. CONCLUSIONS: Early PB/TURSO prolonged tracheostomy/PAV-free survival and delayed first hospitalisation in ALS. TRIAL REGISTRATION NUMBER: NCT03127514; NCT03488524.

Long-term survival of participants in the CENTAUR trial of sodium phenylbutyrate-taurursodiol in amyotrophic lateral sclerosis.

An orally administered, fixed-dose coformulation of sodium phenylbutyrate-taurursodiol (PB-TURSO) significantly slowed functional decline in a randomized, placebo-controlled, phase 2 trial in ALS (CENTAUR). Herein we report results of a long-term survival analysis of participants in CENTAUR. In CENTAUR, adults with ALS were randomized 2:1 to PB-TURSO or placebo. Participants completing the 6-month (24-week) randomized phase were eligible to receive PB-TURSO in the open-label extension. An all-cause mortality analysis (35-month maximum follow-up post-randomization) incorporated all randomized participants. Participants and site investigators were blinded to treatment assignments through the duration of follow-up of this analysis. Vital status was obtained for 135 of 137 participants originally randomized in CENTAUR. Median overall survival was 25.0 months among participants originally randomized to PB-TURSO and 18.5 months among those originally randomized to placebo (hazard ratio, 0.56; 95% confidence interval, 0.34-0.92; P = .023). Initiation of PB-TURSO treatment at baseline resulted in a 6.5-month longer median survival as compared with placebo. Combined with results from CENTAUR, these results suggest that PB-TURSO has both functional and survival benefits in ALS.

Education Research: Online Alzheimer education for high school and college students: A randomized controlled trial.

OBJECTIVE: Alzheimer disease (AD) risk factors are present throughout the lifespan. This randomized controlled trial evaluated the effectiveness of various online education strategies concerning AD risk reduction and brain health in younger populations. METHOD: High school and college students were recruited via social media (Facebook and Instagram) to join AlzU.org, an evidence-based education portal, and were randomized to 1 of 4 courses: highly interactive webinar lessons narrated by actor Seth Rogen (celebrity webinar) or a physician (doctor webinar), minimally interactive video lessons with Seth Rogen (celebrity video), or minimally interactive video lessons (control). Surveys were administered at baseline and postcourse. The primary outcome was change in knowledge of AD risk reduction assessed by pre vs post lesson quiz scores. Secondary outcomes included change in awareness of AD research, hopefulness about AD, interest in pursuing health care, willingness to volunteer, and likelihood of recommending AlzU.org. RESULT: A total of 721 participants joined. A total of 281 (38.9%) completed the course. Among college students, quiz score improvements were greater in celebrity webinar and celebrity video vs doctor webinar and control. Among high school students, no differences were found in quiz scores. In both groups, celebrity webinar, celebrity video, and doctor webinar resulted in greater improvements in awareness that nutrition and exercise may reduce AD risk vs controls. Among college students, celebrity webinar and celebrity video group participants felt more hopeful about the future of AD and more likely to recommend AlzU.org vs doctor webinar and control participants. Among college students, celebrity webinar, celebrity video, and doctor webinar participants were more willing to volunteer for AD causes and pursue health care careers vs controls. CONCLUSION: Online education involving a celebrity may be an effective strategy for educating college students about AD risk reduction strategies. Further studies are warranted in high school students.

Effectiveness of online education for recruitment to an Alzheimer's disease prevention clinical trial.

INTRODUCTION: Low awareness of Alzheimer's disease (AD) clinical trials is a recruitment barrier. To assess whether online education may affect screening rates for AD prevention clinical trials, we conducted an initial prospective cohort study (n = 10,450) and subsequent randomized study (n = 351) using an online digital tool: AlzU.org. METHODS: A total of 10,450 participants were enrolled in an initial cohort study and asked to complete a six-lesson course on AlzU.org, as well as a baseline and 6-month follow-up questionnaire. Participants were stratified into three groups based on lesson completion at 6 months: group 1 (zero to one lesson completed), group 2 (two to four lessons), and group 3 (five or more lessons). For the subsequent randomized-controlled trial (RCT), 351 new participants were enrolled in a six-lesson course (n = 180) versus a time-neutral control (n = 171). Screening and enrollment in the Anti-Amyloid Treatment in Asymptomatic AD (A4) clinical trial were reported via the 6-month questionnaire and are the primary outcomes. RESULTS: Cohort: 3.9% of group 1, 5% of group 2, and 8.4% of group 3 screened for the A4 trial. Significant differences were found among the groups (P < 0.001). Post hoc analyses showed differences in A4 screening rates between groups 1 and 3 (P < 0.001) and groups 2 and 3 (P = 0.0194). There were no differences in enrollment among the three groups. RCT: 2.78% of the intervention group screened for A4 compared to 0% of controls (P = 0.0611). DISCUSSION: Online education via the AlzU.org digital tool may serve as an effective strategy to supplement clinical trial recruitment.