Eligibility Criteria:
Inclusion Criteria:
* written informed consent to participate in the study
* verified capacity to consent by a doctor not involved in the study
* mild Alzheimer's disease (NINCDS / ADRDA criteria and Mini-Mental State Examination (MMSE) 22-27)
* age (including) from 55 to 90 years
* subjects must be able to meet the requirements described in the study protocol
* outpatient living
* Informant lives with subject in the same household
* Rosen modified Hachinski ischemia score ≤4
* concerning only female patients: postmenopausal
* concerning only male patients: commitment to use a suitable contraceptive
* cerebral imaging study (CT or cMRI), which is consistent with a diagnosis of probable Alzheimer's disease (not older than 3 years)
Exclusion Criteria:
* other neurological and psychiatric diseases explaining cognitive deficits better than an AD diagnosis
* conspicuous MRI / CCT scan explaining the cognitive deficits better than an AD diagnosis
* severe physical, neurological or psychiatric disorders that interfere with the participation in the study
* history of malignant tumors except non- metastasizing basal cell carcinoma of the skin
* history of seizures
* dysphagia leading to the inability to swallow capsules
* untreated severe acute infections with clinical symptoms such as respiratory infections, pneumonia, bronchitis, acute diarrhea, influenza, untreated urinary tract infections
* in the family history, unexplained sudden cases of heart failure before the age of 50 years
* long QT syndrome in the family history
* evidence of QTc prolongation ≥480 ms at screening (Fridericia adjusted QT interval), of arrhythmias especially of severe uncontrolled ventricular arrhythmias or atrial fibrillation in ECG
* not sufficiently treated angina
* heart failure (NYHA III, IV)
* myocardial infarction
* known infection with HBV, HCV and / or HIV
* occurrence of venous thrombosis or embolism
* therapy with antidepressants begun in the last 12 weeks or dose modification of a pre-existing therapy with antidepressants
* antidiabetic treatment begun in the last 12 weeks or dose modification of pre-existing antidiabetic treatment
* long-term use of anti-inflammatory drugs except acetylsalicylic acid for cardiovascular prophylaxis
* current treatment or treatment within the past 12 weeks with HDAC inhibitors (eg valproate)
* taking medication that may increase the dose-dependent side effects myelosuppression or QTc interval prolongation.
These include, but are not limited to:
* Class Ia antiarrhythmic agents such as quinidine, procainamide, disopyramide
* Class III antiarrhythmic drugs such as amiodarone, sotalol, ibutilide
* Class Ic antiarrhythmics such as flecainide, propafenone
* penicillamine
* opioids such as methadone and pyrazolone derivatives such as metamizole and Propyphenazone
* doxorubicin, epirubicin
* macrolides and their analogues such as erythromycin, clarithromycin
* telithromycin
* oxazolidinones such as linezolid
* quinolones such as moxifloxacin, levofloxacin
* fluoxetine, maprotiline
* tricyclic and tetracyclic antidepressants
* chlorpromazine, pimozide, haloperidol, droperidol, ziprasidone and clozapine
* antiemetics
* azole like ketoconazole, fluconazole, voriconazole
* aminocholine such as primaquine
* pentamidine such as quinine, chloroquine
* diaminopyrimidine such as pyrimethamine
* salbutamol and formoterol methotrexate
* azathioprine, cyclosporine Interferon gamma 1b
* alemtuzumab, basiliximab, efalizumab, natalizumab
* sunitinib, nilotinib, lapatinib
* mitoxantrone, Hydroxycarbamide, mercaptopurine
* taking of prescription and non-prescription drugs for cognitive enhancement (except cholinesterase inhibitors and memantine at a stable dose for at least 3 months before baseline)
* therapy with anticoagulants except acetylsalicylic acid
* HbA1c in screening more than 10% above the upper limit of normal
* magnesium, sodium, calcium and potassium levels outside the normal range (at screening and baseline)
* existing anemia with Hb \<11 (at screening and baseline)
* existing thrombocytopenia; platelet ≤150.000 / ul, leukocytes ≤ 3.000 / ul, neutrophils absolutely ≤ 1.500 / ul (at screening and baseline)
* prothrombin or INR ≥ 1.5 above the laboratory limit of normal; PTT ≥ 1.5 x above the laboratory limit of normal (at screening and baseline)
* clinically relevant renal and / or hepatic impairment at screening and baseline (total bilirubin ≥ 1.5 x above the upper limit of the norm and / or GPT, AST ≥ 4x above the upper limit of the norm and / or creatinine ≥ 1.5x above the upper limit of the norm and / or creatinine clearance \<60 ml / min)
* hematuria\> 15 RBCs / mL at screening and baseline
* proteinuria at screening and baseline except in asymptomatic urinary tract infections
* participating in other clinical and therapeutic trials within the last 12 weeks
relevant only for dose confirmation:
* subjects with existing contraindications for performing an MRI if no MRI available from the period of 6 months prior to screening
* cardiac pacemaker
* metal objects in the body, which exclude a 1.5 or 3 T MRI
* claustrophobia