The objective of this trial is the global risk-benefit assessment of Cerebrolysin as compared to Placebo in patients with genetically proven CADASIL. In addition, a traditional approach will be taken based on an evaluation of the separate risk and benefit domains in comparison with placebo.

Safety data area collected throughout the study (adverse events, vital signs and laboratory tests) and thereafter in case of ongoing serious adverse events (SAEs) at study endpoint.

Optional secondary parameters include analyses of biomarkers (samples of blood, hair, urine, and saliva).

Inclusion Criteria:

1. Patients of ≥18 years of age, all genders
2. Diagnosis of CADASIL based on clinical symptoms, MRI, and genetic analysis
3. MoCA >11
4. Adequate visual, auditory, and language skills (no language interpreter required) to follow study procedures
5. Patient is not of childbearing potential (i.e. women are post-menopausal for two years, surgically sterile, or using adequate method of contraception)
6. Patient participates voluntarily and gave written informed consent

Exclusion Criteria:

1. Any significant neurological disease/conditions other than CADASIL

2. Focal lesions that may be responsible for the cognitive status of the patient (e.g.

   infectious disease, space-occupying lesion, normal pressure hydrocephalus)

3. Any other diseases/conditions that may affect compliance with the protocol, such as:

   1. severe psychiatric disorders within the last three months
   2. delusional symptoms
   3. history of schizophrenia, schizoaffective disorder, bipolar affective disorder
   4. major depressive disorder newly identified within eight weeks before screening
   5. history of alcohol or substance abuse or dependence within the past two years

4. Any circumstances that -in the investigator's opinion- may result in the patient's non-compliance with study procedures, e.g. fragile or thin veins that prevent many i.v. infusions

5. Any other disease/conditions that may affect the safety assessment, such as:

   1. history of systemic cancer within the past two years
   2. history of myocardial infarction in the past year or unstable or severe cardiovascular disease (including uncontrolled hypertension and/or history of unstable hypertension not compensated by antihypertensive therapy)
   3. any clinically significant laboratory abnormalities at screening
   4. uncontrolled insulin-requiring diabetes or non-insulin dependent diabetes mellitus (HbA1c >87 mmol/mol)

6. Use of concomitant medication with neuroprotective/neurotrophic/nootropic effects (e.g. ginkgo biloba, erythropoietin, citicoline, amantadine, piracetam)

7. Any condition that would represent a contraindication for Cerebrolysin administration:

   1. hypersensitivity to one of the components of the drug
   2. epilepsy
   3. severe renal impairment (estimated Glomerular Filtration Rate [eGFR] <30 ml/min/1.73 m2 as assessed at local laboratory within one month before screening)