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A. Ruiz1,2, D. Sánchez1, A. Lafuente1, G. Ortega1,2, M. Buendía1, J. Papasey1, S.Y. Jimeno3, F.P. Badia4,
M.E. Palacio1,5, C. Abdelnour1,2, F. Ramírez-Toraño6,7, F. Maestú6,7, M.E. Sáez8, L. Tárraga1,2, P.C. Dagnelie9,10, M. Boada1,2


1. Research Center and Memory Clinic, Fundació ACE, Barcelona Alzheimer Treatment and Research Centre, Institut Català de Neurociències Aplicades, Universitat Internacional de Catalunya (UIC) – Barcelona, Spain; 2. Networking Research Center on Neurodegenerative Diseases (CIBERNED), Madrid, Spain; 3. Neurophysiology Unit, Hospital Quirón Dexeus, Barcelona, Spain; 4. Diagnosis Imaging Unit, Hospital Quirón Dexeus, Barcelona, Spain; 5. Clinical Pharmacy, Hospital Universitari de la Vall d’Hebron, Barcelona, Spain; 6. Department of Experimental Psychology, School of Psychology, Complutense University of Madrid, Madrid, Spain; 7. Laboratory of Cognitive and Computational Neuroscience, Center for Biomedical Technology (Technical University of Madrid and Complutense University of Madrid), Madrid, Spain; 8. Andalusian Bioinformatics Research Centre (CAEBi), Seville, Spain; 9. Department of Internal Medicine, Maastricht University, the Netherlands; 10. School for Cardiovascular Diseases (CARIM), Maastricht University, the Netherlands

Corresponding Author: Dr. Agustín Ruiz, Research Center and Memory Clinic, Fundació ACE, Barcelona Alzheimer Treatment and Research Centre, Institut Català de Neurociències Aplicades, Universitat Internacional de Catalunya (UIC) – Barcelona, Spain,,

J Prev Alz Dis 2022;
Published online April 22, 2022,



Background: There are currently no drug therapies modifying the natural history of patients suffering Alzheimer’s disease (AD). Most recent clinical trials in the field include only subjects in early stage of the disease, while patients with advanced AD are usually not represented.
Objectives: To evaluate the feasibility, safety and efficacy of systemic infusions of adenosine triphosphate (ATP) in patients with moderate to severe AD, and to select the minimum effective dose of infusion.
Design: A phase IIb, randomized, double-blind, placebo-controlled clinical trial investigates.
Participants: A total of 20 subjects with moderate or severe AD were included, 16 in the treatment group and 4 in the placebo group (4:1 randomization) at two dosage regimens, 6-hour or 24-hour infusions.
Results: The proof-of-concept study was successfully conducted, with no significant deviations from the study protocol and no serious adverse events reported. Regarding efficacy, only marginal differences were observed between ATP and placebo arms for H-MRS and MMSE variables.
Conclusions: Our study demonstrates that the use of ATP infusion as therapy is feasible and safe. Larger studies are however needed to assess the efficacy of ATP in moderate to severe AD.

Key words: Alzheimer’s disease, adenosine triphosphate, clinical trial.



Alzheimer’s disease (AD) is the leading cause of dementia worldwide, with an increasing prevalence that has significantly outnumbered the initial estimates for 21st century (1, 2). The development of effective therapies is hampered by a challenging early-stage diagnosis, a difficult differential diagnosis from other dementias, and by a restricted knowledge about pathological mechanisms of the disease beyond the characteristic amyloid and tau AD hallmarks. Despite that the hypothesis of the deposits of both proteins as the etiological basis of the pathological process is still a topic of intense debate (3, 4), this hypothesis has dominated most therapeutics approaches to AD with little success (5).
Genome Wide Association Studies (GWAS) are helping to elucidate the etiological basis of Alzheimer. In the last years, diverse regions have been isolated from the genome, some of them consistently replicated by independent groups (6–16). The information provided by these studies is being used to design new therapeutic strategies targeting the basic processes that lead to neurodegeneration. One of the novel AD susceptibility loci, ATP5H/KCTD2, is located on chromosome 17, and it is directly related to adenosine 5′-triphosphate (ATP) synthesis and the regulation of potassium channels (17). Synthesized in the mitochondria. the ATP molecule is a naturally occurring nucleotide which is present in every cell. It consists of a purine base (adenine), ribose, and three phosphate groups. The phosphates are held together by high energy phosphate bonds, which store energy released by other biochemical processes occurring within the cell, functioning as an “energy storage molecule”, releasing energy for bodily functions.
Thanks to anoxia tolerance models (18) hypoxia is known to directly activate various neuroprotection circuits in the CNS. These physiological mechanisms lead to the massive reduction of ATP consumption, the opening of ATP-dependent potassium channels (KATPs) and inhibition of synaptic depolarization preventing the opening of voltage-dependent sodium and calcium channels. In fact, several authors have proposed the alteration of mitochondrial and energy metabolism resulting in bioenergetic deficit as a key early mechanism leading to progressive neuronal death and clinical expression of dementia (19–22). Metabolic stress and production of reactive oxygen species (ROS) would shift the normal, processing of amyloid-β protein precursor, being the characteristic amyloid-β plaques and tau-containing neurofibrillary tangles the result rather than the cause of AD pathogenesis (23–25).
The ATP molecule has been in use for more than 70 years. As endovenous injection ATP has been used since the middle of the last century to diagnose some types of syncope and treat some arrhythmias (26). As infusion, It has been clinically tested in the palliative treatment of cancer and cachexia, with favourable effects on nutritional status and quality of life (QoL) of the patients in most of these studies (27–29).
This report presents the results of ECA4A, a pilot proof-of-concept phase IIb clinical trial aimed at investigating potential effects of systemic treatment with ATP in the brain metabolic profile of patients with moderate to severe AD, and to adjust the infusion (minimum effective dose) that promotes this metabolic change.



Study Design

ECA4A is a phase IIb, randomized, double-blind, placebo-controlled conducted at Fundació ACE (Barcelona, Spain) as single recruitment centre. ATP infusions and proton Magnetic Resonance Spectroscopy (H-MRS) explorations were performed at the Quirón-Dexeus hospital (Barcelona, Spain). The final study protocol, amendments, and informed consent documentation were reviewed and approved by the Institutional Review Boards of the Hospital Clinic (Barcelona, Spain). Monitoring was performed by the clinical trial unit of the Hospital Clinic (Barcelona, Spain). The study was conducted in compliance with the declaration of Helsinki and the International Conference on Harmonization Good Clinical Practice Guidelines. All participants or their legal representative provided written informed consent prior to screening.
The primary objectives of the study were to explore brain metabolic after ATP infusion by changes using proton magnetic resonance spectroscopy (H-MRS). Secondary objectives were to explore whether ATP improves the cognitive status of patients with severe to moderate AD, promotes changes in synaptic activity and to evaluate the rate of complications associated with ATP administration.
The design involved two infusions two weeks apart (intervention period) followed by a safety visit 3 months after the last infusion. A total of 20 subjects who met eligibility criteria were randomized in a ratio 4:1 to receive ATP (N=16) or placebo (N=4), receiving 6h or 24h continuous infusion (ratio 1:1), in two successive weeks. Subjects on the active arm received an infusion of 2.5g of disodic ATP (ATEPODIN, MEDIX S.A. laboratories) in 500 ml of a saline solution 0.9% sodium chloride. All sessions started at an infusion dose of 20μg/kg.min with increments of 10μg/kg.min every 30 minutes until a maximum dose of 50μ g/kg.min (MTD) was reached. Patients assigned to placebo group received physiological serum infusions.
The screening or selection visit (Vs) was performed 4 to 60 prior to the initialvisit (Vi), and involved granting of the informed consent, assignment of a selection number, review of inclusion and exclusion criteria as well as physical and neurological explorations (for details see below), Mini-Mental State Examination (MMSE), electrocardiogram (ECG), vital signs, biochemistry, hemogram and urine analysis (Table 1). Randomization was performed within 32 days from Vs. At the basal visit (Vi), selection criteria were reviewed, and vital signs, MMSE and California Computerized. Assessment Package (CalCAP) were assessed. At the two intervention visits (V1 and V2), H-MRS, CalCAP and electroencephalogram (EEG) examinations were performed within 1 hour interval before and after ATP/placebo infusions, an ECG was performed before infusion and vital signs were determined after infusion.; additionally, at V2 (pre-infusion), biochemistry, hemogram and urine analysis were performed. Finally, at the last visit (Vf) physical and neurological explorations, H-MRS, CalCAP, MMSE, ECG, vital signs, biochemistry, hemogram and urine analysis were performed. Adverse events (AEs) were monitored during and up to 24h after the infusion (V1 and V2).

Table 1. Clinical trial design: schedule of events

MMSE: Mini-Mental State Examination; CalCAP; California Computerized. Assessment Package; ECG: electrocardiogram; H-MRS: using proton magnetic resonance spectroscopy ; EEG: electroencephalogram; AE: adverse event.


Study population

No formal sample size calculation has been performed for this study since it is an exploratory pilot trial. The study population includes a total of 20 subjects with moderate or severe AD, 16 in the treatment group and 4 in the placebo group (4:1 randomization) at two dosage regimens, 6-hour or 24-hour infusions. Therefore, 8 patients received ATP 24h continuous infusion, 8 patients received ATP 6h continuous infusion, 2 patients received placebo 24h continuous infusion and 2 patients received placebo 6h continuous infusion.
Male and female patients with moderate to severe AD dementia were recruited. Our inclusion criteria were as follows: (1) age ranged between 55 and 85, (2) diagnosis of possible or probable AD according to NIA-AA 2011 criteria, (3) cognitive function in the range 5 (moderate AD)-6 (severe AD) according to the Global Deterioration Scale (GDS) and MMSE ranged 5 to 15, (4) the patient has a qualified caregiver to be available as a study partner, (5) both patient and caregiver wished to participate in the study, (6) patient did not have sensory deficits that prevent their evaluation, (7) patient received a conventional medication for stable AD, with no treatment changes at least 90 days prior to selection, (8) patient received a conventional stable medication for possible comorbidities with no treatment changes at least 90 days prior to selection. The exclusion criteria included (1) severe neurological disease concomitant to AD, (2) current or past psychiatric disorders with special emphasis on positive behavioural disorders associated with AD (aggression, agitation, delusions, hallucinations, anxiety), (3) current severe systemic disease that could prevent completion of the study, (4) history of ictus, (5) history of seizures and use of anticonvulsants, (6) history of acute myocardial infarction, angor pectoris, cardiac arrhythmias and other serious cardiovascular disorders such as heart failure congestive, aneurysms and valvulopathies, (7) history of Diabetes Mellitus and/or hypoglycaemia, (8) uncontrolled hypertension (systolic > 160 mmHg and/or diastolic > 95 mmHg), (9) systemic hypotension (PAS<86 mmHg) or bradycardia (<50 beats per minute), (10) history of bronchial asthma or lung diseases, (11) renal impairment, (12) liver failure, (13) respiratory failure, (14) blood donation in the last 90 days or anaemia (Hb<10g/dL), (15) non-stable use (<30 days prior to selection) of antidepressants, sedatives and hypnotics, (16) use of experimental drugs for AD in the last 60 days prior to selection, (17) women who are pregnant or in a fertile period, (18) inadequate venous access that prevents parenteral administration of infusions.
Although presence of small vessel disease (SVD) was not probable given the selection criteria, it was not specifically rule out, which is a limitation of the study. In this line, neuroimage studies for those subjects with available data (Supplementary table 1) did not show evidence of vascular pathology.

Primary efficacy endpoints

The primary efficacy endpoints were the differences between post and pre-infusion of H-MRS variables and CalCAP variables (hits, errors and speed) at V1 and V2. H-MRS variables included creatinine (Cr), N-acetylaspartate (NAA), choline (Ch) and myo-inositol (mI), as absolute area values and as creatinine ratios (NAA/Cr, Ch/Cr and mI/Cr).

Secondary efficacy endpoints

Secondary efficacy endpoints included:
• differences between V1 pre-infusion and final visit for H-MRS and CalCAP variables
• pre-post infusion changes of EEG variables at V1 and V2
• changes in cognitive status as determined by MMSE from screening or basal visits to final visit.

As changes in certain aspects such as mood or social performance are difficult to quantify, these characteristics were captured through consultation with caregivers by two experienced neurologists.

Safety endpoints

Safety endpoints were defined as the occurrence of adverse events (AEs) and serious AEs (SAEs). Additionally, vital signs, clinical chemistry, haematology, urine analysis, neurologic and physical examination, weight and ECG were monitored during the trial.

Statistical analyses

Three analysis populations were stablished for this study: the modified ITT (intention to treat) population (all randomized subjects who met the selection criteria, received study medication, had a baseline efficacy measurement and at least one corresponding post-baseline efficacy measurement), the PP (per protocol) population (all randomized subjects who met the inclusion criteria, received study medication, had a baseline efficacy measurement and at least one corresponding post-baseline efficacy measurement and did not present major violations of the protocol) and the Safety population (all randomized subjects who took at least one dose of the study medication). All analyses were performed on the modified ITT population. The primary efficacy endpoints were also analysed using the PP population (sensitivity analysis).
For primary efficacy endpoints, changes in H-MRN metabolite levels and CalCAP parameters before and after each treatment administration (V1post-V1pre and V2post-V2pre) were compared between treatment arms, irrespective of the drug/placebo dose (two-treatments arms) or taking length of infusion (6h or 24h) into account (four-treatment arms); average changes in the two interventions were also considered (MV1V2). For secondary efficacy endpoints and safety endpoints, changes between other timepoints were evaluated, taking as basal visit the screening visit (Vs), the initial visit (Vi) or the visit 1 pre-infusion depending on available data. The non-parametric Kruskal-Wallis or Mann-Whitney tests were used for analysing efficacy variables changes at each time point (between sample comparisons), whereas the Wilcoxon test for within sample comparisons were employed for analysing changes after the two interventions. Effects are provided as median and 25th and 75th percentiles (p25,p75). For categorical variables, the Fisher’s exact test was applied.



Efficacy endpoints

Of the 21 patients screened, 20 patients were randomized and 18 were included in the PP protocol (Figure 1). Of these 20 randomized subjects, 16 were assigned to the ATP group and 4 to the placebo group in two dose regimens (6h or 24h infusions). The median age was 71 years (range 55-82) and the male:female ratio was 4:16 (Table 2). Median MMSE at screening visit was 13 (range 5-15), most patients (75%) showing a GDS score of 5.

Figure 1. Clinical trial design: workflow

ATP: adenosine 5′-triphosphate; ITT: intention to treat; PP: per protocol.

Table 2. Baseline characteristics of study subjects (ITT & Safety populations)

GDS: Global Deterioration Scale; MMSE: Mini-Mental State Examination


Primary efficacy endpoints, H-MRS and CalCAP, were measured before and after each intervention (Supplementary Figures 1-9). ATP therapy induced a significant decrease of Cr at V1 (p=0.0496) and of average Ch change after the two infusions (p=0.046) (Table 3, Supplementary table 2) . For CalCAP parameters, ATP infusion was associated with an improvement of the number of hits after V1 treatment (p=0.0453) and with the average hit gain after the two visits (p=0.0327), whereas a trend for reduction of the number of errors was observed in the two-treatment arms analysis (Table 3, Supplementary table 3). None of the primary efficacy variables were significant when the length of infusion was also considered (Table 4, Supplementary tables 4-5). Additionally, within sample comparisons did not identify any significant differences between study parameters either in the two-treatment groups analysis or in the four-treatment groups analyses for any of the primary efficacy endpoints (Supplementary tables 6-9). Creatinine normalized NAA, Ch or mI gains did not differ between treated and untreated subjects in any of the analyses performed (Supplementary tables 2, 4, 6 and 8).

Table 3. Efficacy endpoints: two groups comparison

V1:Visit 1; V2: visit 2; MV1V2: average of V1 and V2; Vf: Final Visit; CalCAP: California Computerized. Assessment Package; H-MRS: using proton magnetic resonance spectroscopy; Cr: creatinine, NAA: N-acetylaspartate, Ch: choline, mI: myo-inositol (absolute values)


When changes of H-MRS and CalCAP parameters from baseline (V1preinfusion) to final visit (Vf) were considered (secondary efficacy endpoints), no significant associations were found, with the exception of mI levels in the four treatment between-groups analysis (p=0.0248, Table 4, Supplementary tables 10-13). However, the direction of the effect on mI values was related to the length of the infusion rather than to the administered treatment (ATP or placebo), decreasing in those individuals receiving a 6h infusion and increasing in those receiving a 24h infusion (Table 4). Additional secondary efficacy endpoints, EEG parameters gains at V1 and V2 and MMSE changes from Vs or Vi to Vf did not significantly differ between treatment arms (Supplementary tables 14-19, Supplementary figures 10-17).
Finally, caregivers reported an improvement in cognitive performance (i.e. better mood, increased attention, willingness to communicate with family and caregivers) for four patients receiving 6h infusions, three of them receiving ATP and one receiving placebo (Supplementary table 20).

Sensitivity analysis on PP population showed similar results (Supplementary tables B1-B18).

Table 4. Efficacy endpoints: four groups comparison

V1: Visit 1; V2: visit 2; MV1V2: average of V1 and V2; Vf: Final Visit; CalCAP: California Computerized. Assessment Package; H-MRS: using proton magnetic resonance spectroscopy; Cr: creatinine, NAA: N-acetylaspartate, Ch: choline, mI: myo-inositol (absolute values)


Safety endpoints

A total of ten adverse events were identified for seven of the study subjects, all but one receiving ATP, being this incidence not statistically significant between groups (Fisher’s exact test p-value=1) (Supplementary table 21). Half of these events were urinary tract infections, followed by dry mouth, dysphagia, chest discomfort, psychomotor hyperactivity and hot flush. All these events were considered mild and did not require any action except for one patient who received medication for urinary tract infection. Neurological and physical explorations performed during the trial did not identify any relevant alterations for any of the treatment groups. Additionally, statistical analysis of ECGs, vital signs, haematology and urinalysis did not suggest deleterious effects associated to ATP infusion (Supplementary tables 22-33, Supplementary figures 18-69). A trend towards weight gain for patients receiving ATP was observed (0.60 [-0.75;1.65] kg from Vs to Vf) in contrast with median weight loss observed for patients receiving placebo, ( -0.80[-2.10;0.80] kg from Vs to Vf), although this difference was not statistically significant (p=0.3034) (Supplementary tables 34-35, Supplementary figures 70-71).

Figure 2. Efficacy outcomes line plot

Cr: creatinine; NAA: N-acetylaspartate; Ch: choline; mI: myo-inositol.



This report presents the results of an exploratory trial for assessing the feasibility and safety of ATP infusion in subjects with severe to moderate AD. The intervention also aimed to obtain preliminary insights about brain metabolic effects boosted by ATP, exploring its potential for promoting a cognitive improvement in subjects with established dementia. Our results showed that ATP infusion for periods up to 24h is safe, not leading to unexpected adverse events or relevant alterations of vital signs, blood cell counts or plasma and urine metabolites. Regarding efficacy, this preliminary study is not powered enough for driving significant conclusions, although the results suggest a modification of Ch and Cr values after ATP therapy, more prominent in the group receiving 24h ATP infusions. Furthermore, the caregivers directly reported to the physicians monitoring this trial about an unexpected overt improvement in term of consciousness, speech and other daily-life activities in some subjects receiving the ATP infusions. However, because of the lack of additional scientific evidence, these observations must be considered anecdotical. Further studies increasing the sample size even increasing dose (additional periodic infusions) are necessary to demonstrate the potential effectiveness of these therapies in advanced stages of Alzheimer’s disease.
Recent genome scans have proposed a good number of genes and pathways, involved in AD aetiopathogenesis. One of this locus is the ATP5H/KCTD2 locus, described by our group in collaboration with the international consortium CHARGE (17). Moreover, a meta-analysis performed by the METASTROKE and International Genomics of Alzheimer’s Project (IGAP) consortia has demonstrated that AD and SVD, a condition tightly linked to reduced tissue oxygenation, share a large proportion of genetic susceptibility, being the ICT1/KCTD2/ATP5H locus the strongest signal associated with AD and SVD in the meta-analysis performed.[30]. In fact, hypoxia models have shown that a reduction on ATP levels results in the opening of ATP-dependent potassium channels (KATPs) and the inhibition of synaptic depolarization by preventing the opening of voltage-dependent sodium and calcium channels as a neuroprotection mechanism (18). It has been reported that β- amyloid seems to modulate potassium channels, and that the APP gene is overexpressed under conditions of hypoxia (31, 32). More recently, ATP5H (also known as ATP5PD, ATP synthase subunit D) was shown to be significantly decreased in male triple transgenic AD mice models (APP/PSEN1/TAU), restraining oxidative phosphorylation and ATP production (33). Results from proof of concept studies in AD mice models with the KATP agonist diazoxide suggest that the long-term supply of the agonist eliminates amyloid and tau-dependent pathologies in these animals (34). Moreover, the stimulation of KATP channels also decreased the memory disorders, improved bioenergy balance neurons and increased the brain flow of these mice. All these findings suggest that the activation of KATP channels could have a high therapeutic potential for Alzheimer’s disease.
Regarding safety, ATP is a molecule that has been in use for more than 70 years as a diagnostic and therapeutic drug for the management of cardiac bradyarrhythmias and in the palliative treatment of cancer and cachexia, in some cases administered in the home setting (26–28, 35, 36). Remarkably, most infusions were performed without AEs, and those events observed were moderate and transitory, disappearing within a few minutes after reducing the rate of infusion. Our results confirm the safety of ATP therapy, with only one non-serious AE reported in the treatment arm. Moreover, our results suggest a beneficial effect of ATP therapy on patient weight, an appealing observation that, if confirmed in additional studies, would be of relevance given the progressive weight loss observed at advanced stages of the disease (37, 38). Our study demonstrated that clinical trials in these patients are feasible and safe, despite patients in advances stages of disease are frequently excluded form clinical trials (39, 40), being doomed to the traditional mandatory care and deprived of the potential benefit of new study drugs.
Currently Alzheimer’s dementia has no effective drugs, and only symptomatic treatments based on acetylcholinesterase inhibitors and/or NMDA type glutamate receptor antagonists are available (41), More recently, a therapeutic intervention using plasma exchange with different replacement volumes of therapeutic albumin has been also proposed (42)). Most new therapies in development are targeting the toxic effect of β-amyloid and, more recently, the tau phosphorylated protein accumulation in affected brains. On the side, alteration of mitochondrial and energy metabolism has been a recurrent idea to explain the early events that take place in AD, driven by the downregulation of genes involved in oxidative phosphorylation (43–45). In fact, creatine supplementation has been proposed for targeting energy disbalance in neurological disorders, given that in tissues with large energy requirements such as brain, free Cr, phosphocreatine (PCr) and the creatine kinase (CK) enzyme catalysing this phosphoryl group transfer serve as a temporary energy buffer for ATP generation from ADP (46). Although a trend for a decrease of Cr values after ATP therapy was observed, and Cr values after ATP therapy, further research increasing power and analysing creatine parameters and associated enzymatic activities could help to elucidate the potential effect of ATP infusions in the Cr/PCr/CK system. Following this idea, we plan to incorporate additional central and peripheral biomarkers associated to the creatine physiology in future trials.
The clinical trial reported here is the first study in humans on the potential benefit of ATP infusions in the cognitive ability or quality of life of patients affected by AD. Most important limitations of this study are the small sample size and the short-term exposure of the patients to the proposed therapy. The clinical trial was conceived to check feasibility of the therapeutic intervention and to identify suitable doses of ATP infusion for AD patients. As mentioned earlier, this preliminary study is not powered enough for driving significant conclusions on efficacy. For this reason, well powered studies to evaluate the efficacy in AD patients are further warranted.
In conclusion, while our study failed to demonstrate a clear treatment effect of ATP infusion, our results evidence that the intervention is safe and feasible. Additional studies involving a larger number of study subjects and even a larger exposure to ATP for deriving significant conclusions about the potential of ATP therapy for moderate to severe AD for whom no treatment options nor clinical trials are currently available.


Acknowledgements: We would like to thank patients and controls who participated in this project. We are indebted to the Trinitat Port-Carbó legacy and her family for their support of Fundació ACE research programs. A. R. has received support from CIBERNED (Instituto de Salud Carlos III (ISCIII), the EU/EFPIA Innovative Medicines Initiative Joint Undertaking, ADAPTED Grant No. 115975, from EXIT project, EU Euronanomed3 Program JCT2017 Grant No. AC17/00100, from PREADAPT project. Joint Program for Neurodegenerative Diseases (JPND) Grant No. AC19/00097, and from grants PI13/02434, PI16/01861 BA19/00020, and PI19/01301. Acción Estratégica en Salud, integrated in the Spanish National RCDCI Plan and financed by Instituto de Salud Carlos III (ISCIII)- Subdirección General de Evaluación and the Fondo Europeo de Desarrollo Regional (FEDER – “Una manera de Hacer Europa”), by Fundación bancaria “La Caixa” and Grífols SA (GR@ACE project).

Funding: This work has been supported by the Dirección General the Farmacia. Instituto de Salud Carlos III (ISCIII). Ministerio de Innovacion Ciencia y Universidades. Gobierno España. Grant number EC11-358 and Fundació ACE.

Ethics approval and consent to participate: This clinical trial was conducted in compliance with the declaration of Helsinki. All participants (or their legal representative) provided written informed consent prior to screening. The final study protocol and informed consent documentation were reviewed and approved by the Ethics Committee from Hospital Clinic (Barcelona). The Study was registered at the EU Clinical Trials Register (EudraCT: 2013-004593-95) and approved by the Spanish Agency for Medicines and Medical Devices (AEMPS).

Availability of data and materials: The datasets used and/or analysed during the current study, as well as the two independent statistical analysis reports from the Medical Statistics Core Facility of IDIBAPS – Hospital Clínic Barcelona and the Andalusian Bioinformatics Research Centre (CAEBi), are available from the corresponding author on reasonable request.

Competing interests: The authors declare that they have no competing interests related to this manuscript. AR is member of the Scientific Advisory Board of Landsteiner Genmed and AMBAR program (Grifols). MES is member of the Scientific Advisory Board of Landsteiner Genmed.

Authors’ contributions: AR conceived this treatment. AR, LT, MBo, MEP, PCD designed the research program and the clinical trial. DS, AL, GO, MBu, JP, MEP, CA, SYJ, FPB, implemented the clinical trial, study. AR, MES, FRT, FM, PCD and MBo interpreted the CT results. MES and AR wrote the manuscript and all authors revised the text and contributed to the ms editing.

Trial registration: EudraCT: 2013-004593-95. Registered 13th February 2014,







1. Livingston, G.; Huntley, J.; Sommerlad, A.; Ames, D.; Ballard, C.; Banerjee, S.; Brayne, C.; Burns, A.; Cohen-Mansfield, J.; Cooper, C.; et al. Dementia prevention, intervention, and care: 2020 report of the Lancet Commission. Lancet 2020.
2. Prince, M.; Jackson, J. World Alzheimer Report 2009; 2009;
3. Treusch, S.; Hamamichi, S.; Goodman, J.L.; Matlack, K.E.S.; Chung, C.Y.; Baru, V.; Shulman, J.M.; Parrado, A.; Bevis, B.J.; Valastyan, J.S.; et al. Functional links between Aβ toxicity, endocytic trafficking, and Alzheimer’s disease risk factors in yeast. Science (80-. ). 2011, doi:10.1126/science.1213210.
4. Selkoe, D.J. Translating cell biology into therapeutic advances in Alzheimer’s disease. Nature 1999, 399, A23–A31, doi:10.1038/399a023.
5. Huang, Y.M.; Shen, J.; Zhao, H.L. Major Clinical Trials Failed the Amyloid Hypothesis of Alzheimer’s Disease. J. Am. Geriatr. Soc. 2019, doi:10.1111/jgs.15830.
6. Antúnez, C.; Boada, M.; González-Pérez, A.; Gayán, J.; Ramírez-Lorca, R.; Marín, J.; Hernández, I.; Moreno-Rey, C.; Morón, F.J.; López-Arrieta, J.; et al. The membrane-spanning 4-domains, subfamily A (MS4A) gene cluster contains a common variant associated with Alzheimer’s disease. Genome Med. 2011, 3, 33, doi:10.1186/gm249.
7. Harold, D.; Abraham, R.; Hollingworth, P.; Sims, R.; Gerrish, A.; Hamshere, M.L.; Pahwa, J.S.; Moskvina, V.; Dowzell, K.; Williams, A.; et al. Genome-wide association study identifies variants at CLU and PICALM associated with Alzheimer’s disease. Nat. Genet. 2009, doi:10.1038/ng.440.
8. Kunkle, B.W.; Grenier-Boley, B.; Sims, R.; Bis, J.C.; Damotte, V.; Naj, A.C.; Boland, A.; Vronskaya, M.; van der Lee, S.J.; Amlie-Wolf, A.; et al. Genetic meta-analysis of diagnosed Alzheimer’s disease identifies new risk loci and implicates Aβ, tau, immunity and lipid processing. Nat. Genet. 2019, 51, 414–430, doi:10.1038/s41588-019-0358-2.
9. Hollingworth, P.; Harold, D.; Sims, R.; Gerrish, A.; Lambert, J.C.; Carrasquillo, M.M.; Abraham, R.; Hamshere, M.L.; Pahwa, J.S.; Moskvina, V.; et al. Common variants at ABCA7, MS4A6A/MS4A4E, EPHA1, CD33 and CD2AP are associated with Alzheimer’s disease. Nat. Genet. 2011, doi:10.1038/ng.803.
10. Lambert, J.C.; Heath, S.; Even, G.; Campion, D.; Sleegers, K.; Hiltunen, M.; Combarros, O.; Zelenika, D.; Bullido, M.J.; Tavernier, B.; et al. Genome-wide association study identifies variants at CLU and CR1 associated with Alzheimer’s disease. Nat. Genet. 2009, doi:10.1038/ng.439.
11. Naj, A.C.; Jun, G.; Beecham, G.W.; Wang, L.S.; Vardarajan, B.N.; Buros, J.; Gallins, P.J.; Buxbaum, J.D.; Jarvik, G.P.; Crane, P.K.; et al. Common variants at MS4A4/MS4A6E, CD2AP, CD33 and EPHA1 are associated with late-onset Alzheimer’s disease. Nat. Genet. 2011, 43, 436–443, doi:10.1038/ng.801.
12. Seshadri, S.; Fitzpatrick, A.L.; Ikram, M.A.; DeStefano, A.L.; Gudnason, V.; Boada, M.; Bis, J.C.; Smith, A. V.; Carassquillo, M.M.; Lambert, J.C.; et al. Genome-wide analysis of genetic loci associated with Alzheimer disease. JAMA – J. Am. Med. Assoc. 2010, doi:10.1001/jama.2010.574.
13. Bellenguez, C.; Küçükali, F.; Jansen, I.; Andrade, V.; Moreno-grau, S. New insights on the genetic etiology of Alzheimer’s and related dementia. MedRxiv 2020.
14. Jansen, I.E.; Savage, J.E.; Watanabe, K.; Bryois, J.; Williams, D.M.; Steinberg, S.; Sealock, J.; Karlsson, I.K.; Hägg, S.; Athanasiu, L.; et al. Genome-wide meta-analysis identifies new loci and functional pathways influencing Alzheimer’s disease risk. Nat. Genet. 2019, doi:10.1038/s41588-018-0311-9.
15. Lambert, J.C.; Ibrahim-Verbaas, C.A.; Harold, D.; Naj, A.C.; Sims, R.; Bellenguez, C.; Jun, G.; DeStefano, A.L.; Bis, J.C.; Beecham, G.W.; et al. Meta-analysis of 74,046 individuals identifies 11 new susceptibility loci for Alzheimer’s disease. Nat. Genet. 2013, doi:10.1038/ng.2802.
16. Witoelar, A.; Rongve, A.; Almdahl, I.S.; Ulstein, I.D.; Engvig, A.; White, L.R.; Selbæk, G.; Stordal, E.; Andersen, F.; Brækhus, A.; et al. Meta-analysis of Alzheimer’s disease on 9,751 samples from Norway and IGAP study identifies four risk loci. Sci. Rep. 2018, doi:10.1038/s41598-018-36429-6.
17. Boada, M.; Antúnez, C.; Ramírez-Lorca, R.; Destefano, A.L.L.; González-Pérez, A.; Gayán, J.; López-Arrieta, J.; Ikram, M.A.A.; Hernández, I.; Marín, J.; et al. ATP5H/KCTD2 locus is associated with Alzheimer’s disease risk. Mol. Psychiatry 2014, 19, doi:10.1038/mp.2013.86.
18. Milton, S.L.; Prentice, H.M. Beyond anoxia: The physiology of metabolic downregulation and recovery in the anoxia-tolerant turtle. Comp. Biochem. Physiol. – A Mol. Integr. Physiol. 2007, 147, 277–290.
19. Davis, J.N.; Hunnicutt, E.J.; Chisholm, J.C. A mitochondrial bottleneck hypothesis of Alzheimer’s disease. Mol. Med. Today 1995, 1, 240–247.
20. Blass, J.P.; Sheu, R.K.F.; Gibson, G.E. Inherent abnormalities in energy metabolism in Alzheimer disease: Interaction with cerebrovascular compromise. In Proceedings of the Annals of the New York Academy of Sciences; New York Academy of Sciences, 2000; Vol. 903, pp. 204–221.
21. Erol, A. An integrated and unifying hypothesis for the metabolic basis of sporadic Alzheimer’s disease. J. Alzheimer’s Dis. 2008, 13, 241–253.
22. Demetrius, L.A.; Driver, J. Alzheimer’s as a metabolic disease. Biogerontology 2013, 14, 641–649.
23. Ebanks, B.; Ingram, T.L.; Chakrabarti, L. ATP synthase and Alzheimer’s disease: Putting a spin on the mitochondrial hypothesis. Aging (Albany. NY). 2020, 12, 16647–16662, doi:10.18632/aging.103867.
24. Kosenko, E.; Tikhonova, L.; Alilova, G.; Urios, A.; Montoliu, C. The Erythrocytic Hypothesis of Brain Energy Crisis in Sporadic Alzheimer Disease: Possible Consequences and Supporting Evidence. J. Clin. Med. 2020, 9, 206, doi:10.3390/jcm9010206.
25. Blonz, E.R. Alzheimer’s Disease as the Product of a Progressive Energy Deficiency Syndrome in the Central Nervous System: The Neuroenergetic Hypothesis. J. Alzheimer’s Dis. 2017, 60, 1223–1229, doi:10.3233/JAD-170549.
26. Pelleg, A.; Kutalek, S.P.; Flammang, D.; Benditt, D. ATPaceTM: injectable adenosine 5’-triphosphate : Diagnostic and therapeutic indications. Purinergic Signal. 2012.
27. Beijer, S.; Van Rossum, E.; Hupperets, P.S.; Spreeuwenberg, C.; Van Beuken, M. Den; Winkens, R.A.; Ars, L.; Van Den Borne, B.E.; De Graeff, A.; Dagnelie, P.C. Application of adenosine 5′-triphosphate (ATP) infusions in palliative home care: Design of a randomized clinical trial. BMC Public Health 2007, doi:10.1186/1471-2458-7-4.
28. Agteresch, H.J.; Dagnelie, P.C.; Van Der Gaast, A.; Stijnen, T.; Wilson, J.H.P. Randomized clinical trial of adenosine 5’-triphosphate in patients with advanced non-small-cell lung cancer. J. Natl. Cancer Inst. 2000, 92, 321–328, doi:10.1093/jnci/92.4.321.
29. Beijer, S.; Hupperets, P.S.; Van Den Borne, B.E.E.M.; Wijckmans, N.E.G.; Spreeuwenberg, C.; Van Den Brandt, P.A.; Dagnelie, P.C. Randomized clinical trial on the effects of adenosine 5’-triphosphate infusions on quality of life, functional status, and fatigue in preterminal cancer patients. J. Pain Symptom Manage. 2010, 40, 520–530, doi:10.1016/j.jpainsymman.2010.01.023.
30. Traylor, M.; Adib-Samii, P.; Harold, D.; AdibSamii, P.; Harold, D.; Dichgans, M.; Williams, J.; Lewis, C.M.; Markus, H.S.; Fornage, M.; et al. Shared genetic contribution to ischemic stroke and Alzheimer’s disease. Ann. Neurol. 2016, doi:10.1002/ana.24621.
31. Plant, L.D.; Webster, N.J.; Boyle, J.P.; Ramsden, M.; Freir, D.B.; Peers, C.; Pearson, H.A. Amyloid β peptide as a physiological modulator of neuronal ’A’-type K+ current. Neurobiol. Aging 2006, doi:10.1016/j.neurobiolaging.2005.09.038.
32. Tomimoto, H.; Wakita, H.; Akiguchi, I.; Nakamura, S.; Kimura, J. Temporal profiles of accumulation of amyloid β/A4 protein precursor in the gerbil after graded ischemic stress. J. Cereb. Blood Flow Metab. 1994, doi:10.1038/jcbfm.1994.70.
33. Yu, H.; Lin, X.; Wang, D.; Zhang, Z.; Guo, Y.; Ren, X.; Xu, B.; Yuan, J.; Liu, J.; Spencer, P.S.; et al. Mitochondrial molecular abnormalities revealed by proteomic analysis of hippocampal organelles of mice triple transgenic for alzheimer disease. Front. Mol. Neurosci. 2018, doi:10.3389/fnmol.2018.00074.
34. Liu, D.; Pitta, M.; Lee, J.H.; Ray, B.; Lahiri, D.K.; Furukawa, K.; Mughal, M.; Jiang, H.; Villarreal, J.; Cutler, R.G.; et al. The KATP channel activator diazoxide ameliorates amyloid-β and Tau pathologies and improves memory in the 3xTgAD mouse model of Alzheimer’s disease. J. Alzheimer’s Dis. 2010, doi:10.3233/JAD-2010-101017.
35. Agteresch, H.J.; Dagnelie, P.C.; Rietveld, T.; Van Den Berg, J.W.O.; Danser, A.H.J.; Wilson, J.H.P. Pharmacokinetics of intravenous ATP in cancer patients. Eur. J. Clin. Pharmacol. 2000, doi:10.1007/s002280050719.
36. Beijer, S.; Gielisse, E.A.R.; Hupperets, P.S.; Van Den Borne, B.E.E.M.; Van Den Beuken-Van Everdingen, M.; Nijziel, M.R.; Van Henten, A.M.J.; Dagnelie, P.C. Intravenous ATP infusions can be safely administered in the home setting: A study in pre-terminal cancer patients. Invest. New Drugs 2007, doi:10.1007/s10637-007-9076-1.
37. Albanese, E.; Taylor, C.; Siervo, M.; Stewart, R.; Prince, M.J.; Acosta, D. Dementia severity and weight loss: A comparison across eight cohorts. the 10/66 study. Alzheimer’s Dement. 2013, 9, 649–656, doi:10.1016/j.jalz.2012.11.014.
38. Tamura, B.K.; Masaki, K.H.; Blanchette, P. Weight loss in patients with Alzheimer’s disease. J. Nutr. Elder. 2007, 26, 21–38, doi:10.1300/J052v26n03_02.
39. Hanson, L.C.; Gilliam, R.; Tae Joon Lee Successful clinical trial research in nursing homes: The improving decision-making study. Clin. Trials 2010, 7, 735–743, doi:10.1177/1740774510380241.
40. Banzi, R.; Camaioni, P.; Tettamanti, M.; Bertele’, V.; Lucca, U. Older patients are still under-represented in clinical trials of Alzheimer’s disease. Alzheimers. Res. Ther. 2016, 8, 32, doi:10.1186/s13195-016-0201-2.
41. Hüll, M.; Berger, M.; Heneka, M. Disease-modifying therapies in Alzheimer’s disease: How far have we come? Drugs 2006, doi:10.2165/00003495-200666160-00004.
42. Boada, M.; López, O.; Núñez, L.; Szczepiorkowski, Z.M.; Torres, M.; Grifols, C.; Páez, A. Plasma exchange for Alzheimer’s disease Management by Albumin Replacement (AMBAR) trial: Study design and progress. Alzheimer’s Dement. (New York, N. Y.) 2019, 5, 61–69, doi:10.1016/J.TRCI.2019.01.001.
43. Terni, B.; Boada, J.; Portero-Otin, M.; Pamplona, R.; Ferrer, I. Mitochondrial ATP-synthase in the entorhinal cortex is a target of oxidative stress at stages I/II of alzheimer’s disease pathology. Brain Pathol. 2010, doi:10.1111/j.1750-3639.2009.00266.x.
44. Liang, W.S.; Reiman, E.M.; Valla, J.; Dunckley, T.; Beach, T.G.; Grover, A.; Niedzielko, T.L.; Schneider, L.E.; Mastroeni, D.; Caselli, R.; et al. Alzheimer’s disease is associated with reduced expression of energy metabolism genes in posterior cingulate neurons. Proc. Natl. Acad. Sci. U. S. A. 2008, doi:10.1073/pnas.0709259105.
45. Bell, S.M.; Barnes, K.; De Marco, M.; Shaw, P.J.; Ferraiuolo, L.; Blackburn, D.J.; Venneri, A.; Mortiboys, H. Mitochondrial dysfunction in Alzheimer’s disease: A biomarker of the future? Biomedicines 2021, 9, 1–26, doi:10.3390/biomedicines9010063.
46. Adhihetty, P.J.; Beal, M.F. Creatine and Its Potential Therapeutic Value for Targeting Cellular Energy Impairment in Neurodegenerative Diseases. Neuromolecular Med. 2008, 10, 275, doi:10.1007/S12017-008-8053-Y.