Will CMS Find Aducanumab Reasonable and Necessary for Alzheimer Disease After FDA Approval?

Engaging Medicare Beneficiaries in Coverage Choices

This Viewpoint discusses the recently announced monthly Medicare Part B premium hike and the limited role beneficiaries play in decisions about their coverage, and proposes ways to engage Medicare beneficiaries in program decisions.

Impacts of FDA approval and Medicare restriction on antiamyloid therapies for Alzheimer's disease: patient outcomes, healthcare costs, and drug development

In 2021, the US Food and Drug Administration (FDA) granted approval to aducanumab, an antiamyloid antibody for early-stage Alzheimer's disease, despite a lack of clear clinical evidence demonstrating the drug's cognitive benefits. The manufacturer initially priced the drug at a staggering $56,000 per year, a price that was later reduced to $28,200. Unfortunately, these costs do not include the additional expenses associated with monitoring the treatment. However, the Centers for Medicare and Medicaid Services (CMS) recently announced that they will only cover individuals enrolled in clinical trials and will limit coverage of future antiamyloid antibodies. This discrepancy between the FDA and CMS positions has caused confusion and concerns for patients who could potentially benefit from antiamyloid therapy. It is important to acknowledge the clinical and economic uncertainties surrounding aducanumab and its potential impacts on future antiamyloid drug development and approval processes. The FDA's approval, despite limited clinical evidence, raises questions about the integrity and rigor of the approval process. The drug's high cost also raises accessibility concerns, especially for those without insurance or sufficient financial resources. Given the CMS's limited coverage policy, it's critical to evaluate the long-term implications of this decision on future antiamyloid drug development. Without adequate support and coverage from insurance providers, the development and approval of future Alzheimer's treatments may be hindered. In summary, the approval and pricing of aducanumab, coupled with the CMS's limited coverage policy, has created a confusing and concerning landscape for Alzheimer's patients. It's important that stakeholders, including patients, clinicians, insurers, and regulatory bodies, work together to address these challenges and ensure that individuals with Alzheimer's have access to effective, affordable treatments.

Neuroinflammation represents a common theme amongst genetic and environmental risk factors for Alzheimer and Parkinson diseases

Multifactorial diseases are characterized by inter-individual variation in etiology, age of onset, and penetrance. These diseases tend to be relatively common and arise from the combined action of genetic and environmental factors; however, parsing the convoluted mechanisms underlying these gene-by-environment interactions presents a significant challenge to their study and management. For neurodegenerative disorders, resolving this challenge is imperative, given the enormous health and societal burdens they impose. The mechanisms by which genetic and environmental effects may act in concert to destabilize homeostasis and elevate risk has become a major research focus in the study of common disease. Emphasis is further being placed on determining the extent to which a unifying biological principle may account for the progressively diminishing capacity of a system to buffer disease phenotypes, as risk for disease increases. Data emerging from studies of common, neurodegenerative diseases are providing insights to pragmatically connect mechanisms of genetic and environmental risk that previously seemed disparate. In this review, we discuss evidence positing inflammation as a unifying biological principle of homeostatic destabilization affecting the risk, onset, and progression of neurodegenerative diseases. Specifically, we discuss how genetic variation associated with Alzheimer disease and Parkinson disease may contribute to pro-inflammatory responses, how such underlying predisposition may be exacerbated by environmental insults, and how this common theme is being leveraged in the ongoing search for effective therapeutic interventions.

Resveratrol ameliorates learning and memory impairments induced by bilateral hippocampal injection of streptozotocin in mice

Resveratrol (RES) is a polyphenol with diverse beneficial pharmacological activities, and our previous results have demonstrated its neuroprotective potential. The purpose of this study was to investigate the therapeutic effect of RES in Alzheimer's disease (AD)-like behavioral dysfunction induced by streptozotocin (STZ) and explore it's potential mechanism of action. STZ was microinjected bilaterally into the dorsal hippocampus of C57BL/6J mice at a dose of 3 mg/kg, and RES was administered intragastrically at a dose of 25 mg/kg for 5 weeks. Neurobehavioral performance was observed, and serum concentrations of insulin and Nesfatin-1 were measured. Moreover, the protein expression of amyloid beta 1-42 (Aβ_1-42), Tau, phosphorylated Tau (p-Tau) (Ser396), synaptic ras GTPase activation protein (SynGAP), postsynaptic density protein 95 (PSD95), synapsin-1, synaptogomin-1, and key molecules of the Wnt/β-catenin signaling pathway in the hippocampus and prefrontal cortex (PFC) were assessed. Finally, pathological damage to hippocampal tissue was examined by Nissl and immunofluorescence staining. The results showed that compared with the controls, bilateral hippocampal microinjections of STZ induced task-specific learning and memory impairments, as indicated by the disadvantaged performances in the novel object recognition test (NOR) and Morris water maze (MWM), but not the contextual fear conditioning test (CFC). Treatment with RES could improve these behavioral disadvantages. The serum concentrations of insulin and Nesfatin-1 in the model group were remarkably higher than those of the control group. In addition, protein expression of Aβ_1-42, Tau, and p-Tau (Ser396) was increased but expression of SynGAP, PSD95, brain-derived neurotrophic factor (BDNF), and p-GSK-3β/GSK-3β were decreased in the hippocampus. Although the protein expression of BDNF and SynGAP was also markedly decreased in the PFC of the model mice, there was no significant difference among groups in the protein expression of PSD95, BDNF, synapsin-1, synaptogomin-1, and p-GSK-3β/GSK-3β. RES (25 mg/kg) reversed the enhanced insulin level, the abnormal protein expression of Aβ_1-42, Tau, and p-Tau (Ser396) in the hippocampus and PFC, and the hippocampal protein expression of SynGAP, PSD95 and BDNF. In addition, RES reversed the STZ-induced decrease in the number of Nissl bodies and the increase in fluorescence intensity of IBA1 in the hippocampal CA1 region. These findings indicate that RES could ameliorate STZ-induced AD-like neuropathological injuries, the mechanism of which could be partly related to its regulation of BDNF expression and synaptic plasticity-associated proteins in the hippocampus.

Cost-effectiveness of Aducanumab and Donanemab for Early Alzheimer Disease in the US

Importance

Several anti-amyloid monoclonal antibodies have been developed for slowing the progression of Alzheimer disease (AD). Among the furthest developed are aducanumab, which received accelerated approval from the US Food and Drug Administration in 2021, and donanemab, which is currently undergoing phase 3 trials. The cost-effectiveness of these treatments has not been established.

Objectives

To estimate the cost-effectiveness of aducanumab and donanemab relative to standard care for early AD in the US.

Design, Setting, and Participants

A decision analytic model was used to estimate the lifetime health and economic outcomes of adults with early AD, from US healthcare sector and societal perspectives. Simulated patients had a mean (SD) age of 75.2 (5.5) years; 65% had mild cognitive impairment and 35% had mild dementia. Analyses were conducted from April 6, 2021, to January 20, 2022.

Interventions

Standard care, aducanumab (selected inputs including disease progression hazard ratio [HR] of 0.89 [95% CI, 0.63-1.15], annual price of $28 000, and twice-yearly monitoring with magnetic resonance imaging [MRI] of the brain), or donanemab (selected inputs including disease progression HR of 0.68 [95% CI, 0.44-0.99], annual price of $28 000, and twice-yearly monitoring with MRI of the brain and amyloid positron emission tomography [PET] monitoring). Donanemab was switched to placebo after substantial amyloid reduction on PET imaging, which occurred in 27% of patients at 6 months and 55% of patients at 12 months.

Main Outcomes and Measures

Quality-adjusted life-years (QALYs); costs, in 2020 US dollars; incremental cost-effectiveness ratios (ICERs); and value-based prices, defined as the maximum price at which a treatment would be cost-effective given a cost-effectiveness threshold of ICER of $150 000/QALY.

Results

Lifetime QALYs increased by 0.133 with aducanumab and 0.408 with donanemab. Total health care sector and societal costs increased by $130 100 and $127 800, respectively, with aducanumab and by $78 700 and $71 600, respectively, with donanemab, driven largely by drug costs ($119 000 for aducanumab and $44 600 for donanemab). Health care sector and societal ICERs relative to standard care were $981 000/QALY and $964 000/QALY, respectively, for aducanumab and $193 000/QALY and $176 000/QALY, respectively, for donanemab. In sensitivity analysis, aducanumab's value-based price remained less than $50 000/y, even when assuming a 90% reduction in disease progression. Donanemab's value-based price surpassed $50 000/y once its efficacy exceeded 50%.

Conclusions and Relevance

These findings suggest that at current expected prices, neither aducanumab nor donanemab would be cost-effective for early AD in the US. Donanemab's dosing scheme, in which patients suspend treatment on achieving substantial amyloid reductions, may provide a rubric by which sufficiently effective anti-amyloid antibody treatments could be cost-effective even when priced comparably to other biologics.

The value of anticancer drugs - a regulatory view

The high prices of new anticancer drugs and the marginal added benefit perceived by some stakeholders have fuelled a debate on the value of anticancer drugs in the European Union, even though an agreed definition of what constitutes a drug's value does not exist. In this Perspective, we discuss the value of drugs from different viewpoints and objectives of decision makers: for regulators, assessment of the benefit-risk balance of a drug is a cornerstone for approval; payers rely on cost-effectiveness analyses carried out by health technology assessment agencies for reimbursement decisions; for patients, treatment choices are based on personal preferences and attitudes to risk; and clinicians can use several scales (such as the ESMO Magnitude of Clinical Benefit Scale (ESMO-MCBS)) that have been developed as an attempt to measure value objectively. Although a unique definition that fully captures the concept of value is unlikely to emerge, herein we discuss the importance of understanding different perspectives, and how regulators can help to inform different decision makers.

Exosomes derived from bone-marrow mesenchymal stem cells alleviate cognitive decline in AD-like mice by improving BDNF-related neuropathology

Background

Alzheimer's disease (AD) is a neurodegenerative disease characterized by a progressive decline in cognitive ability. Exosomes derived from bone-marrow mesenchymal stem cells (BMSC-exos) are extracellular vesicles that can execute the function of bone-marrow mesenchymal stem cells (BMSCs). Given the versatile therapeutic potential of BMSC and BMSC-exos, especially their neuroprotective effect, the aim of this study was to investigate the potential effect of BMSC-exos on AD-like behavioral dysfunction in mice and explore the possible molecular mechanism.

Methods

BMSC-exos were extracted from the supernatant of cultured mouse BMSCs, which were isolated from the femur and tibia of adult C57BL/6 mice, purified and sorted via flow cytometry, and cultured in vitro. BMSC-exos were identified via transmission electron microscopy, and typical marker proteins of exosomes were also detected via Western blot. A sporadic AD mouse model was established by intracerebroventricular injection of streptozotocin (STZ). Six weeks later, BMSC-exos were administered via lateral ventricle injection or caudal vein injection lasting five consecutive days, and the control mice were intracerebroventricularly administered an equal volume of solvent. Behavioral performance was observed via the open field test (OFT), elevated plus maze test (EPM), novel object recognition test (NOR), Y maze test (Y-maze), and tail suspension test (TST). The mRNA and protein expression levels of IL-1β, IL-6, and TNF-α in the hippocampus were measured via quantitative polymerase chain reaction (qPCR) and Western blot, respectively. Moreover, the protein expression of Aβ_1-42, BACE, IL-1β, IL-6, TNF-α, GFAP, p-Tau (Ser396), Tau5, synaptotagmin-1 (Syt-1), synapsin-1, and brain-derived neurotrophic factor (BDNF) in the hippocampus was detected using Western blot, and the expression of GFAP, IBA1, Aβ₁₋₄₂ and DCX in the hippocampus was measured via immunofluorescence staining.

Results

Lateral ventricle administration, but not caudal vein injection of BMSC-exos improved AD-like behaviors in the STZ-injected mouse model, as indicated by the increased number of rearing, increased frequency to the central area, and increased duration and distance traveled in the central area in the OFT, and improved preference index of the novel object in the NOR. Moreover, the hyperactivation of microglia and astrocytes in the hippocampus of the model mice was inhibited after treatment with BMSC-exos via lateral ventricle administration, accompanied by the reduced expression of IL-1β, IL-6, TNF-α, Aβ_1-42, and p-Tau and upregulated protein expression of synapse-related proteins and BDNF. Furthermore, the results of the Pearson test showed that the preference index of the novel object in the NOR was positively correlated with the hippocampal expression of BDNF, but negatively correlated with the expression of GFAP, IBA1, and IL-1β. Apart from a positive correlation between the hippocampal expression of BDNF and Syt-1, BDNF abundance was found to be negatively correlated with markers of glial activation and the expression of the inflammatory cytokines, Aβ_1-42, and p-Tau, which are characteristic neuropathological features of AD.

Conclusions

Lateral ventricle administration, but not caudal vein injection of BMSC-exos, can improve AD-like behavioral performance in STZ-injected mice, the mechanism of which might be involved in the regulation of glial activation and its associated neuroinflammation and BDNF-related neuropathological changes in the hippocampus.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-022-02393-2.

[Disease-modifying treatment approaches for Alzheimer's disease]

Die Alzheimer-Krankheit ist eine der großen Volkskrankheiten mit bisher allein symptomatischen Therapieoptionen. Neue Erkenntnisse zu einem Krankheitskontinuum mit einer sehr langen präklinischen und frühsymptomatischen Krankheitsphase sowie molekulare Therapiestrategien, die auf den Erkenntnissen zur molekularen Neurobiologie der Erkrankung fußen, eröffnen eine Vielzahl neuer therapeutischer Strategien. Im Jahr 2021 ist erstmals ein Antiamyloidantikörper in den USA als krankheitsmodifizierende Therapie bei Alzheimer-Krankheit zugelassen worden, was einen ersten, sehr kontrovers diskutierten Schritt hin zu einer molekularen, ursachenorientierten Therapie darstellt. Die Übersicht stellt die am weitesten entwickelten molekularen Therapiestrategien sowie die Auswirkungen der zugelassenen Antikörpertherapie für die Praxis vor. Die Besonderheiten einer Langzeittherapie mit i.v. Infusionen in einer besonders vulnerablen Patientenpopulation und einem speziellen Nebenwirkungsprofil wird für die Implementierung in die Praxis große Herausforderungen mit sich bringen und ein hohes Maß an Kooperation erfordern. Die Zukunft der Alzheimer-Therapie mit einem multimodalen Therapieansatz mit verschiedenen Substanzen wird diesen Trend wahrscheinlich noch verstärken.

Accelerated Approval of Aducanumab: Where Do We Stand Now?

Aducanumab was approved by the Food and Drug Administration (FDA) in June 2021 to treat Alzheimer disease (AD). Its path to approval has been highly scrutinized, with many experts arguing that the FDA's decision was premature. Accelerated approval was based on a surrogate end point, with evidence to support clinical effectiveness pending a postapproval trial by the drug company sponsor Biogen. As a result, the role of aducanumab in treating AD remains uncertain. A summary of key areas of controversy to guide informed decisions about use of this drug is provided, along with a timeline describing preapproval and postapproval events.