ABSTRACT
BACKGROUND: Disease modifying therapies (DMTs) may be most beneficial in early disease, when progression is slow and changes small, with clinical relevance difficult to interpret. OBJECTIVES: Time component tests (TCTs) translate differences between treatments from mean change, vertical distance between longitudinal trajectories, into intuitively understood time saved, horizontal distance between trajectories, which can be readily combined across endpoints in a global TCT (gTCT). DESIGN: The value of composites, time savings estimates, and combination scores to optimize measurement and interpretation of DMTs are demonstrated, along with construction details and simulation studies. SETTING: TCT methods were applied to a randomized phase II clinical trial. PARTICIPANTS: Patients with early Alzheimer's disease (N=332). INTERVENTION: Three treatment groups with AFFITOPE® AD02 and two control groups with aluminum oxyhydroxide, AD04. MEASUREMENTS: The co-primary efficacy outcomes were an adapted ADAS-Cog (aADAS) and adapted ADCS-ADL (aADL), which were optimized composite scales specific to cognitive and functional domains. A composite based on these two scores was the study's prespecified primary outcome. The CDR-sb and standard non-adapted ADCS-ADL and ADAS-Cog scales were prespecified secondary outcomes. RESULTS: The AD04 2 mg group showed some statistically significant effects compared with other study arms. It is unclear whether the observed 3.8-point difference on the composite is clinically meaningful. TCT results show a time savings of 11 months in an 18-month study with AD04 2 mg. CONCLUSION: The relevance of 11 months saved is more universally understood than a mean difference of 3.8 points in the composite outcome. These results suggest that a combination of a composite approach and a time savings interpretation offers a powerful approach for detecting and interpreting disease modifying effects.
Subject(s)
Alzheimer Disease , Disease Progression , Humans , Alzheimer Disease/drug therapy , Aged , Female , Time Factors , Male , Decision MakingABSTRACT
The LipiDiDiet randomized clinical trial is evaluating the long term effects of a multinutrient intervention (Fortasyn Connect) compared with control in participants with prodromal AD. In this post-hoc analysis we used the Alzheimer's Disease Composite Score (ADCOMS) as a measure of cognition and global function, together with a global statistical test (GST) and Bayesian hierarchical modelling (BHM) to evaluate the totality of evidence for an effect of the intervention over 36 months. The analysis includes 67 participants (39 active, 28 control) with change from baseline data after 36 months intervention. All outcome measures showed a statistically significant effect for the intervention: ADCOMS (P =0.045), GST (P <0.001), and BHM (P =0.008 based on 3 outcomes and P <0.001 including all primary and secondary quantitative clinical outcomes). Fortasyn Connect was associated with significantly less clinical decline over 36 months, suggesting the long-lasting beneficial effects of the multinutrient in prodromal AD.
Subject(s)
Alzheimer Disease , Humans , Bayes Theorem , Outcome Assessment, Health Care , CognitionABSTRACT
In Alzheimer's disease (AD) clinical trials, disease-modifying therapies are expected to slow the rate of disease progression. Treatment effects are evaluated using a validated clinical scale as the difference between treatment and placebo in mean change from baseline to endpoint. Understanding the clinical relevance of this metric is not necessarily intuitive. Expressing active treatment-placebo difference as a time metric (i.e., months saved with treatment) has potential to provide a metric that is more easily and consistently interpreted. Using data from the TRAILBLAZER-ALZ study, time component tests (TCTs) were employed to determine the time saved with donanemab (an amyloid lowering drug) treatment. At study endpoint (Week 76), disease progression was delayed by 5.3 months and 5.2 months as measured by the Integrated Alzheimer's Disease Rating Scale (iADRS) and the Clinical Dementia Rating Sum of Boxes (CDR-SB), respectively.
