Multicenter, randomized, double-blind, parallel-group clinical trial to evaluate the efficacy and safety of Safinamide versus Rasagiline in fatigue associated with Parkinson's Disease.

Prior treatment

• Treatment with Selegiline, Rasagiline, Safinamide (or any other MAO-B inhibitor) for at least 2 months prior to study inclusion.
• Current diagnosis of substance abuse or history of alcohol or drug abuse in the 3 months prior to the initial visit.

Other illness

• Current clinically significant or unstable medical illness (gastrointestinal, renal, hepatic, endocrine, pulmonary, cardiovascular, neoplastic, sleep disorders) that would preclude study participation or contribute to fatigue (such as anemia, active neoplasm, or hypothyroidism), as judged by the clinical judgment of the investigator.
• Hypersensitivity or intolerance to Rasagiline, Safinamide or any of their excipients.
• History of Deep Brain Stimulation.
• Active major psychiatric illness or with antipsychotic treatment: major hallucinations, with a score ≥3 on item 2 (thought disorder) of the MDS-UPDRS Section 1, severe Impulse Control disorder, major depression according to DSM (Diagnostic and Statistical Manual) and score ≥3 on item 3 of the MDS-UPDRS Section 1.

Lab values

• Any significant alteration in the anamnesis, examination, vital signs or laboratory tests that, in the investigator's opinion, contraindicate participation in the study.

Other

• A score of less than 23 on the MoCA global cognitive rating scale (Dalrymple-Alford, 1995).
• Severe motor complications (moderate-severe motor fluctuations defined as a score >1 on MDS UPDRS Part IV item 42; or disabling dyskinesias defined as a score >1 on MDS UPDRS Part IV item 36).
• Pregnancy, gestational desires, refusal to use adequate contraception, or breastfeeding.
• Insufficient level of Spanish or local language, illiteracy, sensory disturbances (vision, hearing), legal disability or any other mental, physical or social situation that prevents giving the informed consent form or adequately completing the evaluations.
• History or impression, at the investigator's discretion, of low therapeutic compliance.
• Patients with diagnostic criteria for Apathy with a score ≥3 on item 4 of the MDS-UPDRS Section 1.

• Subjects of both sexes aged between 50-80 years.
• Diagnosis of Parkinson´s Disease based on MDS criteria (Postuma, 2015) (45) with at least three years of Parkinson´s Disease duration, based on medical history and neurological examination.
• Neuroimaging compatible with Parkinson´s Disease.
• Hoehn and Yahr (H&Y) stage I-IV (included) during the 'ON' phase (Hohen, 1967).
• Presence of fatigue since at least one month prior to the initial visit defined by a mean Parkinson's Fatigue Scale (PFS) fatigue score ≥ 8 ((Brown et al. 2005; Stocchi et al. 2014; Niimi et al. 2019).
• Treatment with levodopa (alone or with other antiparkinsonian medications) at a stable dose for at least 4 weeks prior to the screening visit.
• Subjects who can give written consent to participate in the study.